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The sustainable management of residual waste streams generated from the pulp and paper industry (PPI) has garnered increasing concerns due to the energy crisis and the pressing environmental threats posed by substantial effluent discharges. Using renewable lignocellulosic waste for resource generation presents a revolutionary approach to achieve environmental sustainability. Integrating the PPI with biorefinery processes allows for diversification beyond paper production and facilitates resource recovery. This review critically evaluates the valorization of waste streams from the PPI, with a pronounced emphasis on expanding into bioenergy and biofuels production, while also fostering the development of innovative biomaterials, such as biochar and activated carbon for applications with high added-value, such as environmental remediation and supercapacitors development, thus ensuring long-term sustainability. The review also emphasizes the significance of adopting a circular economy and its role in achieving environmental sustainability, with a particular emphasis on thermochemical technologies, which hold promise for resource recovery from wastewater. Furthermore, the review identifies critical bottlenecks in the path of waste stream valorization and engages in a forward-looking discussion on future prospects within the PPI. [Display omitted] • Black liquor contains major inhibitors e.g., furfural, 5-hydroxymethylfurfural. • Black liquor is used as a low-cost sugar, to produce e.g., bioethanol, biobutanol. • Paper mill wastewater used e.g., graphene sheet development, biochar, carbon fuel cell. • Porous carbon by black liquor showed capacitances for supercapacitor electrode. • Integrated biorefineries can achieve sustainability by Kraft pulp conversion. [ABSTRACT FROM AUTHOR]

Synergy in the co-processing of lignocellulosic wastes and municipal biowaste (MB) can unlock their potential for biobutanol production. This study assessed the potential for biobutanol production through the co-processing of lignocellulosic waste and MB. Specifically, it compared the co-processing of paper waste with MB to that of garden waste and MB. Ethanol organosolv pretreatment served as a dual-function process for both pretreatment and detoxification purposes. Initial fermentation of hydrolysates from untreated paper waste using Clostridium acetobutylicum produced 0.9 g/L of acetone and ethanol but no detectable butanol. Organosolv pretreatment led to a significant increase in acetone and ethanol production but did not yield butanol. Co-processing paper waste with MB using organosolv pretreatment resulted in the production of 2.8–3.2 g/L butanol, along with increased acetone and ethanol production. Furthermore, co-processing a 1:1 (w/w) mixture of paper waste and MB under mild and severe pretreatment conditions produced 45.5 g and 43.4 g butanol, respectively, compared to 34.8 g and 14.4 g butanol when processing these waste streams separately. The study also explored the positive impact of co-processing garden waste with MB, a distinct lignocellulosic source, enhancing acetone-butanol-ethanol (ABE) yield by 27–40%. These findings highlight the potential of synergistic waste co-processing for achieving a more suitable balance of nutrients to enhance biobutanol and ABE production from biowastes. Additionally, the simultaneous treatment of lignocellulosic waste and municipal biowaste offers a simplified approach to waste processing, contributing to advancements in sustainable biomass utilization and bioenergy production. [Display omitted] • The fermentation of the paper-derived hydrolysates led to acetone but not butanol. • Co-processing with municipal biowaste led to butanol production from paper waste. • The synergy of co-processing and organosolv pretreatment led to higher ABE yields. • The pretreatment positively affected the starch release and cellulose hydrolysis. • Ethanol is a byproduct used as a pretreatment agent to help process circularity. [ABSTRACT FROM AUTHOR]

[Display omitted] • The alcohol yields achieved were 41.3 wt% and 48.5 wt% from the corrugated box and A4 paper. • Cellulose exhibited the conversion rate of 100 %, with alcohol substances achieving a yield of 71.2 wt% and a selectivity of 89.4 % within 6 h. • The mechanism of cellulose hydrolysis and the catalytic effect of CuMgAlO x were explored. • Multiple techniques were utilized to analyze the alcoholysis pathways and mechanisms of cellulose in waste paper. In an effort to valorize under-exploited cellulose sources like waste paper for sustainable energy production, this study investigates a catalytic process to convert these materials into low-carbon alcohols. We explored the conversion efficiency of various cellulose materials, including corrugated box, A4 paper, and pure cellulose, under the influence of a CuMgAlO x catalyst. Our findings indicate that at 360 °C for 6 h, the conversion rates were substantial, yielding 70.1 % for corrugated box, 85.2 % for A4 paper, and 100 % for cellulose. The respective alcohol selectivities achieved were 54.7 %, 83.0 %, and 89.4 %, with alcohol yields of 41.3 wt%, 48.5 wt%, and 71.2 wt%. Notably, the absence of the catalyst led predominantly to the production of sugars and lipids, whereas the catalytic conditions facilitated the formation of alcohols. The study also examined the effects of temperature and reaction time on cellulose conversion. It was found that a complete conversion was possible at 320 °C within 1 h, with extended temperature and time improving the alcohol yield. The development of a kinetic model for the cellulose conversion process has allowed for accurate predictions of the transformations under varied conditions, which offers a strategic framework for reaction optimization. Furthermore, the role of the CuMgAlO x catalyst was elucidated through the examination of model compounds, demonstrating its capability in converting cellulose intermediates such as sugars, lipids, and ketones into alcohols. This research highlights a potent strategy for the production of high-value, eco-friendly green fuels from readily available paper products and cellulose biomass, marking a significant advancement in chemical engineering and sustainable energy resources. [ABSTRACT FROM AUTHOR]

[Display omitted] • Office paper waste is processed using physiochemical and enzymatic hydrolysis. • The yeast is isolated from rotten banana for the fermentation process. • Box-Behnken analysis was used to determine optimal conditions for key variables. • A blended membrane was applied for the purification process. • Amicon cell and polymeric membrane dehydrate ethanol–water combinations. One potential replacement for fossil fuels is the generation of biofuel from biomass feedstock. To reach the global sustainability goals, it is also necessary to address a number of issues, such as reducing environmental pollution, climate change, and carbon emissions. This work was aimed to convert the office paper waste as biomass feedstock into bioethanol through a sustainable pathway. The office paper waste was hydrolyzed via physiochemical and enzymatic hydrolysis, the liberated glucose was estimated at 15.72 g/L using the optimum conditions of 15 % HCl and 6 % office paper waste followed by enzymatic hydrolysis. The yeast isolate B2 that was applied for the fermentation process was isolated from rotten banana, identified as Hanseniaspora uvarum (STDF-B2) and submitted to GenBank with accession number (OP800106). The Box-Behnken design was applied to estimate the optimal conditions for the three most significant variables depending on the one variable at a time results. A blended membrane of sulphonated polyvinyl chloride with poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (SPVC-PAMPS) was applied for the purification of both standard ethanol and produced bioethanol via pervaporation technique (PV). The morphology, chemical composition, mechanical properties and permeability of the membrane were all analyzed in various ways. Following purification using a membrane-integrated amicon cell, the total permeate flows of the laboratory-prepared ethanol and generated bioethanol were 289.54 and 253.06 (g/m2 h), respectively. [ABSTRACT FROM AUTHOR]

Paper-based analytical devices (PADs) enable the affordable, easy, rapid, and reliable detection of a range of analytes at the point-of-care. Cellulose is a versatile substrate for antibody attachment. However, how immunoreagents are immobilized onto cellulose plays an important role in assay performance. To provide an overview of the different antibody immobilization strategies used for developing PADs, we here critically review the existing literature from the last decade (2013–2023). First, we introduce cellulose as a substrate and summarize the different fabrication techniques for developing PADs. Thereafter, we delve into how antibodies are immobilized onto cellulose passively, covalently, or by affinity linkage. Affinity-based immobilization is further explored in a case study focused on using recombinant bifunctional proteins with cellulose-binding modules to anchor immunoreagents to cellulose. The final section discusses the validation and sustainable development of PADs addressing the existing and future challenges associated with developing such devices. [Display omitted] • Strategies for antibody immobilization onto cellulose substrates are reviewed. • Immobilizing antibodies in a site-selective manner improves analytical performance. • Cellulose requires modification before antibodies can be covalently attached to it. • Cellulose-binding modules facilitate antibody attachment onto unmodified cellulose. • Future challenges of developing sustainable paper-based immunoassays are discussed. [ABSTRACT FROM AUTHOR]

The landfilling of paper mill sludge (PMS) has been restricted or even banned in many countries due to the raised concern about greenhouse gas (GHG) emissions and contamination of the soil and water, calling for a sustainable PMS management approach. The potential valorization of PMS to nanomaterials combined with traditional biorefinery was examined in this work. Three types of PMS-derived cellulose nanofibrils (CNFs) were prepared and evaluated: enzymatically assisted CNF (AU: with in-house produced enzyme and CT: with commercial enzyme), mechanically pretreated CNF (BT), and chemically pretreated CNF by TEMPO oxidation (TEMPO). It was found that enzyme-assisted mechanical fibrillation-derived CNFs had a comparable average diameter (27.9 nm for AU and 22.7 nm for CT) with that produced from mechanical pretreatment (26.5 nm for BT) and TEMPO oxidation pretreatment (20.0 nm for TEMPO), and they showed the best drainage properties among the three types of CNF. The CNFs resulting from enzymatic pretreatment reduced 15% of energy consumption compared to the mechanical method and had better thermostability than TEMPO oxidation method. In addition, the on-site produced enzyme showed similar performance to the commercial enzymes towards the CNF properties. These findings provide new insights into a promising integrated strategy in engineering CNF from PMS with on-site enzyme production as a novel and sustainable approach for PMS management and valorization. [Display omitted] • A novel and integrated biorefinery strategy was developed for enzyme hydrolysis-assisted CNF fabrication. • The in-house enzyme was comparable to the commercial enzyme in CNF preparation. • The CNF prepared by enzyme was compared with that using mechanical and chemical pretreatment. • The enzyme-hydrolysis-assisted CNF had the best drainage property. [ABSTRACT FROM AUTHOR]

Paper mills are among the most polluting industries, responsible for many organic and inorganic compounds emissions. The fibres electro-kinetic features strongly affect the ability to retain fillers since the fillers–fibres interactions are charge induced. The control and the prediction of these parameters would represent a precious aid for process management, allowing the fillers retention enhancement, a lower environmental impact and the paper sheet properties streamlining. The work presented deals with the implementation and training of four artificial neural networks (ANNs) for the prediction of the main electrochemical and physical features of cellulose pulp and paper. First, two ANNs predict the electrochemical parameters. Following, they were applied to predict the paper sheet properties and fillers retention. The neural models implemented showed outstanding prediction performance, with R2 in the order of 0.999 and a low mean error. The results demonstrate how Artificial Neural Networks may be a valuable instrument for paper mill pollutant reduction. However, they suggest a more inclusive investigation for a better fibres behaviour representation. • Main process parameters of an industrial papermaking process were identified. • Experimental datasets were achieved during industrial production. • Artificial Neural Networks were trained for process parameters prediction. • Accurate predictions of papermaking process were obtained. [ABSTRACT FROM AUTHOR]

• RCF wastes brick achieves 24% lower thermal properties than the control brick. • RCF wastes brick requires 10% lower firing temperature than the control brick. • Utilizing as-received waste materials requires zero grinding energy, benefiting manufacturers and cutting emissions. • Lower firing temperature saved $158,460 by cutting 417 tonnes of CO 2. Building materials drive the global economy, yet face severe environmental hurdles: resource depletion, greenhouse gas emissions, and waste generation. In order to mitigate the impact from these challenges, authorities seek sustainable and eco-friendly alternatives as an urgent need. This study focuses on the utilization of as-received rejected contaminated fines (RCF) obtained from the yellow bins' waste (paper) recycling process, in brick production. Diverse tests assessed the brick performance, including compressive strength, absorption rate, thermal conductivity, 3D CT scanning for morphological analysis, and durability analysis. Additionally, a leachate analysis was performed to evaluate the environmental implications. Economic benefits, particularly the reduction of CO 2 emissions, were also evaluated. The findings confirmed that as-received waste can be utilized for fired clay brick production without the need for pulverization. The novel brick product made with as-received RCF waste exhibited superior thermal characteristics (up to a 31.25 % reduction compared to control bricks) while meeting the essential compliance requirements outlined by national standards. Moreover, each firing cycle led to a potential value of up to USD 158,460 through a reduction of 417 tonnes of CO 2 , resulting from a 9.5 % reduction in firing temperature (1000 °C). The results from this study offer valuable insights into the potential of using RCF waste as a sustainable alternative in the brick manufacturing industry. This alternative could address the soaring demand in the current market, resolve the escalating solid waste crisis, and mitigate clay shortages, while providing a sustainable solution for the brick industry. [ABSTRACT FROM AUTHOR]

This comprehensive review explores recent advancements in the manufacturing of cellulose nanofiber (CNF)-based cellulose nanopaper (CNP). The analysis delves into customizing CNPs through nanofiber manufacturing, mechanical refining, and chemical treatments. The report underscores the growing interest in CNPs derived from CNF due to their exceptional properties and eco-friendly attributes. CNP strength significantly enhanced through mechanical refining encompassing cellulose nanofibrillation were breaking down of cellulose into nanofibers takes place. Conversely, dense CNF network formed through filtration and casting method. Chemical treatments such as dispersion, functionalization, and coating methods followed by drying and consolidation introduce custom functionalities for diverse applications. These applications span packaging, electronics, energy harvesting, EMI shielding, optoelectronics, nanogenerators, transparent conducting films, water treatment, bioelectronics, and neuromorphic computing. The study conducts an in-depth investigation to assess CNP's effects on promoting sustainability and minimizing environmental waste, making a significant contribution to the circular economy. This investigation underscores the pursuit of innovation and aligns with the principles of progressing toward a more environmentally sustainable future. [Display omitted] • Explores CNF production, refining and chemical treatments for CNP customization. • Remarkable properties of CNP draw academic and industrial interest. • CNP applied in packaging, electronics, energy, and environmental science. • Investigates role of CNP in circular economy. • Emphasizes CNPs as eco-friendly, fostering innovation and sustainability. [ABSTRACT FROM AUTHOR]

Separators are indispensable components in lithium-ion batteries (LIBs), providing efficient pathways for lithium ions to travel and isolating the positive and negative electrodes to avoid short circuits. However, traditional polyolefin-based separators exhibit inferior electrolyte affinities, limited porosities, and low thermal stabilities. In this study, a novel method was developed to prepare chitosan micro/nanofiber membranes as LIB separators using natural materials. The pore sizes of the chitosan micro/nanofibers separators were modulated by changing the diameters of the chitosan fibers. The results demonstrated that the chitosan nanofiber separators (CSNFs) had superior electrolyte uptake (281 %), excellent thermal dimensional stability, and electrochemical performance in LiFePO 4 /Li half-cell, as indicated by the higher discharge capacity after 100 cycles, and higher rate capacity than commercial Celgard2325 separator. This study paves the way for the fabrication of eco-efficient and environment-friendly separators for high-performance LIBs. [Display omitted] [ABSTRACT FROM AUTHOR]

Sustainable hydrophobic coatings on paper have become increasingly important due to the high demand for environmentally friendly materials. In this study, a novel sustainable hydrophobic coating was developed by combining natural rubber latex (NRL) and butyl stearate (BS). The NRL acts as binder and hydrophobic agent, while the butyl stearate improves the hydrophobicity of the coating. Different coating formulations containing 0–50 wt% BS were applied to the paper using a simple bar-coating method at a constant thickness, and the hydrophobic properties were evaluated by using contact angle, Cobb and water vapour transmission rate (WVTR) measurements. The lowest WVTR value was 3.428 g/cm2. Day, obtained when NRL coated, and WVTR of 4.405 g/cm2.day was obtained with an addition of 50 wt% BS, lower than the uncoated paper (5.485 g/cm2.day). All the formulations promoted a remarkable decrease in water absorption (Cobb30 values decreased from 128 g/m2 to 0.8 g/m2, and Cobb60 values decreased from 134.4 g/m2 to 0.7 g/m2). Results showed that the coating effectively reduced the surface energy of the paper, resulting in a high contact angle of 90.6° and increased hydrophobicity. Furthermore, the NRL and butyl stearate coating demonstrated good mechanical properties, suggesting its potential as a sustainable and effective alternative to synthetic hydrophobic coatings. Overall, this study presents a promising approach for the development of sustainable hydrophobic coatings on paper, which can have significant environmental and economic benefits. [Display omitted] • Water resistant paper based on natural rubber latex and butyl stearate hydrophobic coating for packaging. • Butyl stearate addition improved the hydrophobicity of the NRL coating formulation. • Coating formulation potential as a sustainable and effective alternative to synthetic hydrophobic coatings. • NRL/BS coating technology may be a desirable choice for eco-friendly paper. [ABSTRACT FROM AUTHOR]

One of the biggest challenges to the sustainable manufacture of liquid ammonia and the prevention of worldwide water contamination is the development of effective electrocatalysts for the electrochemical reduction of nitrate (NO 3 −) to NH 3 with high stability. Herein, a highly active and serviceable electrocatalyst is synthesized by pyrolysis, composed of nanostructure nickel phosphide (Ni 2 P) embedded in nitrogen phosphide doped carbon (NPC) followed by deposition on carbon paper (CP) to improve the electrocatalytic nitrate reduction. Various characterization techniques investigate the crystallinity, morphology, and chemical components of the Ni 2 P-NPC/CP nanoparticles. The results support the formation of nanostructure Ni 2 P and strong synergistic interactions between Ni 2 P and NPC, which resulted in substantial active sites and high electrical conductivity. Excellent performance of Ni 2 P-NPC/CP nanoparticles is achieved for electrocatalytic NO 3 − reduction with an NH 4 + yield rate of 2.468 mg h−1 mg cat. −1 and Faradaic efficiency (FE) of 84.6% at −1.2 V vs. RHE. Additionally, Ni 2 P-NPC/CP nanoparticles exhibit exceptional robustness and endurance. Studies using isotope labeling have been carried out, and the results show that nitrate reduction produces ammonia. Ni 2 P-based electrocatalysts can effectively treat nitrate wastewater to recover ammonia and facilitate its use in diverse industrial applications. • Ni 2 P-NPC/CP offers a highly active and durable electrocatalyst for the conversion of nitrate to ammonia. • Ni 2 P-NPC/CP achieved NH 4 + yield rate of 2.468 mmol h−1 mgcat−1 and Faradaic efficiency of 84.6% at −1.2 V. • The unique Ni 2 P-NPC/CP ensures robustness and practical options for continuous nitrate reduction processes. • Ni 2 P-NPC/CP offers a carbon-free energy solution through the selective conversion of nitrate to NH 3. [ABSTRACT FROM AUTHOR]

Pulp mill excess sludge (PMES) is an industrial biomass waste containing high moisture, many organic compounds, and highly concentrated adsorbed organic halides (AOX). The safe disposal and recycling of PMES using an environmentally friendly and sustainable treatment represents a major challenge. In this study, alkali-oxygen cooking was used to recover cellulose nanocrystals (CNC) from PMES while removing AOX in a one-pot process. Single-parameter experiments showed that more than 95% of AOX was effectively removed, meeting sewage emission standards, and greater than 70% of cellulose was recovered as CNC. A response surface experimental design was then applied to determine the optimal reaction conditions. A temperature of 200 °C, alkali dosage of 35 wt%, and reaction time of 5 h resulted in an AOX removal rate of 96.57% and CNC recovery rate of 73.78%. The results of this study not only demonstrate an environmentally friendly, sustainable strategy for the treatment and recycling of PMES into CNC, And the alkali-oxygen cooking process can be applied other cellulose-rich industrial wastes to recover value-added products. [ABSTRACT FROM AUTHOR]

Production systems are being restructured to close production cycles via implementing circular economy (CE) practices. The planted tree industry in Brazil has shown potential for applying CE practices due to its efficient use of resources and inclination towards environmental innovation. However, some gaps and difficulties have been observed in several industrial segments so that the logic of the circular production system is put into practice more effectively and intensely. In this context, the aim was to investigate the use and impacts of CE practices in the Brazilian planted tree industry by sector of operation and scale of enterprises based on the ReSOLVE framework. Data were collected from 34 companies that answered a questionnaire, corresponding to 47.2% of Brazilian planted tree industry companies. Data analysis involved univariate and multivariate statistical techniques, considering the grouping of companies by sector of activity (forest producer, pulp and paper, and timber processing) and scale (small, medium, and large). The results revealed that "pulp and paper" and medium- and large-scale companies had the most significant application of CE practices and reported more significant impacts. [Display omitted] • Explores a segmented analysis of the circular economy by scale and sub-sector groups. • Scores of circular practices and their impacts are presented according to the groups. • The association between circular practices and impacts by group are analyzed. • Propositions to enable the adoption of circular practices are presented. [ABSTRACT FROM AUTHOR]

Cellulosic paper has combined characteristics of renewability, biodegradability, flexibility, and recyclability. Based on disassembly-initiated fiber processing, the conversion of regular paper into a multifunctional wet-strength product was explored. In this concept, disassembly generates cellulosic additives for surface engineering. Encouragingly, the use of the aqueous solvent system containing mixed metal salts allows controllable fiber disassembly and formation of room-temperature-stable cellulosic solutions, leading to wet and dry strengthening of paper following cellulose regeneration. In-situ generation of cellulosic film-forming additives led to the increase of dry and wet strengths by more than 8 and 35 times respectively, in the case of a typical grade of quantitative filter paper. The engineered paper shows flame-retardant, antibacterial, and liquid-barrier features. The combination of functional properties of cellulosic paper can shed light on diversified applications, e.g., replacement of difficult-to-degrade synthetic plastics. [Display omitted] [ABSTRACT FROM AUTHOR]

Climate change and energy crises are twin challenges that require collective wisdom and polygeneration energy systems for sustainable development. Hydrogen is an abundant element in the universe that can shape the future of energy transmission and storage from electrons to molecules. This paper presents utilization of a solar PV assisted hydrogen and electricity production and storage system for a university transportation fleet of 43 student transit buses to reduce annual 9842 liter fuel consumption and 26.52 Mt CO 2 emissions. The system is designed, modeled, and simulated using TRNSYS® energy simulation software and optimized in TrnOpt linked to GenOpt for dynamic weather conditions of Gujrat (Pakistan), Fargo (USA), London (UK). As a model, the results of a 27kW p PV system are presented that assists an alkaline electrolyzer generating 12696 m3 hydrogen, 6348 m3 oxygen, 16848 KWh electricity exported to national grid and 11.56 GJ thermal energy annually. The proposed system generates energy vectors including hydrogen, electricity, heat, and oxygen with optimal performance during intermittent weathers. In this paper, a business model canvas is developed for solar PV assisted hydrogen production and storage system. These outputs can be accredited to the hydrogen as an energy alternative for green and sustainable future for transportation sector. [Display omitted] • A paradigm energy shift from electron to molecules for a sustainable future. • A Solar assisted polygeneration system is dynamically simulated and optimized in TRNSYS for various climate conditions. • Proposed 27kWp system effectively produces 12696 m³ hydrogen, 6348 m³ oxygen, and exports 16848 kWh electricity to grid. • The system cuts annual fuel consumption by 9842 liters for university fleet, reducing CO 2 emissions by 26.52 Mt annually. • Developed a business model for the sustainable application of solar PV-assisted hydrogen production in transportation. [ABSTRACT FROM AUTHOR]

Over the past decade, the number of member states in the United Nations Committee on the Peaceful Uses of Outer Space (UNCOPUOS) has risen by 40%. The UNCOPUOS continues to be one of the largest committees in the United Nations, with recent additions representing many emerging space nations including the Dominican Republic, Rwanda, Angola, Guatemala, and Bangladesh, among many others. This paper addresses the role of emerging space nations in updating and refining current policies and norms of behavior related to the long-term sustainability of the space environment. The paper provides examples of the recent implementation of long-term space sustainability design and operational guidelines in the national space strategies of several emerging space nations, highlighting the importance nations give to the development of legal mechanisms to regulate the peaceful use of the space environment. Examples of both national and regional initiatives are presented including Thailand's 2021 Draft National Space Act, aimed at creating a national legal regime and establishing a governmental agency dedicated to developing space policies for the registration of objects launched into outer space and space debris mitigation measures, and the National Space Law Initiative (NSLI) study group consisting of Australia, Indonesia, India, Japan, Malaysia, the Philippines, the Republic of Korea, Thailand, and Vietnam to create a framework that aims to promote information sharing and mutual learning in relation to the participants' respective national regulatory frameworks for long-term space sustainability. More recently, new initiatives have been developed that celebrate the efforts of satellite mission operators with the aim to reduce the likelihood of space debris and collisions among space objects. The Space Sustainability Rating (SSR) was created by the World Economic Forum, the European Space Agency, the University of Texas at Austin, BryceTech, and the Massachusetts Institute of Technology, and is now hosted by the EPFL Space Centre. The SSR is a rating system to assess and recognize missions that are designed to be compatible with sustainable and responsible operations, reducing the potential harm to the orbital environment and the impact on other operators. The SSR comprises six modules aimed at assessing missions for their compatibility with sustainable and responsible operations. This paper specifically focuses on evaluating the Detection, Identification and Tracking (DIT) scores for satellite missions launched by emerging space nations. The DIT module of the SSR serves as a standardized measure for assessing space sustainability. The paper adopts an exploratory multi-case study approach. Through this focused study, the paper identifies barriers and unique challenges emerging space nations face, including experiences of operator organizations, launch options, financial constraints, technical options available, and other relevant factors. • Paper title: Role of Emerging Nations in Ensuring Long-term Space Sustainability. • UNCOPUOS membership rises 40%, highlighting emerging nations in space policy. • Emerging space nations prioritize guidelines for peaceful and sustainable space use. • SSR serves as an effective tool for evaluating space sustainability metrics. • Case study on THEOS, CBERS, and SumbandilaSat reveals barriers for new players. [ABSTRACT FROM AUTHOR]

This study describes the development of electrochemical paper-based analytical devices (ePADs) using carbon-based paste combining silicone glue and graphite powder. The ePADs were manufactured using the screen-printing technique, which consisted of depositing the conductive ink on a screencast on the paper surface. In addition, an alternative electrical connector was designed and 3D-printed to make the detection method cheaper, portable and reproducible. The morphological, structural, and electrochemical properties of the conductive material developed were investigated through scanning electron microscopy (SEM), Raman spectroscopy, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) measurements. The ePADs combined with the alternative connector revealed high repeatability, reproducibility, and stable responses considering a well-known redox probe ([Fe(CN) 6 ]4-/3-). In addition, the proposed ePAD provided a linear response for standard solutions of ascorbic acid (AA) in the concentration range between 0.1 and 2.0 mmol L−1. The achieved limit of detection was 4.0 μmol L−1. As proof of applicability, the ePADs were evaluated for AA analysis in synthetic biofluids (blood plasma and urine), vitamin C tablets, and food (gelatine and orange juice) samples. The analytical parameters of the proposed device were compared with other reports in the literature and exhibited similar or even superior performance, highlighting its feasibility for sensing applications. [Display omitted] • A carbon-based ink prepared by mixing graphite powder and silicone glue was used to develop screen-printed electrodes on paper. • An inexpensive 3D printed holder ensured simple assembling and suitable reproducibility. • Paper-based sensors revealed great stability and analytical performance. • Ascorbic acid was successfully determined in different samples. [ABSTRACT FROM AUTHOR]

This review paper explores into the extensive realm of alkaline water electrolysis (AWE), a transformative technology for hydrogen production, offering profound insights and future prospects for sustainable growth. It embarks on this journey by explaining the fundamental principles, the application of Faraday's laws, electrolyzer design, and the intricate electrochemical processes transpiring at the cathode and anode. Subsequently, it investigates electrode materials, catalysts, membrane material and their recent developments, unveiling essential aspects of material selection and performance enhancement. The exploration extends to the domain of alkaline electrolyte solutions, where it provides a comprehensive overview of common electrolytes, the impact of concentration on system performance, and pioneering research on alternative electrolytes. Shifting focus towards large-scale systems and industrial applications, the paper unravels the economic feasibility, considerations regarding costs, and the transformative influence of alkaline water electrolysis on diverse industries. The final segment is dedicated to emerging trends and future directions. It casts light on recent breakthroughs and the potential for commercialization, presenting a vivid image of the evolving role of this technology in the sustainable energy landscape. The conclusive segment, this review offers a recapitulation of the key discoveries and insights presented throughout the paper, while delivering a critical evaluation of the present state of alkaline water electrolysis. It emphasizes the potential of the technology while recognizing critical research areas such as electrode materials, safety standards, scaling efficiency, flexible operation, and surface modification techniques. In the rapidly changing energy scenario, this paper stands as a testament to the dynamic nature of alkaline water electrolysis and its pivotal role in a sustainable energy future. • Identifying different alkaline water electrolysis (AWE) cell efficiencies and transport resistances. • Insights into recent development in electrodes, catalysts, and separator membranes materials. • Recognizing recently examined alkaline electrolytes. • Recent and emerging trends in AWE including the use of electromagnetic field and pulsating potential. • Perspectives of scaling up AWE and its industrial commercial applications. [ABSTRACT FROM AUTHOR]

Utilization of agricultural and food wastes for biohydrogen generation is a hot research topic. In this paper, biohydrogen generation potentials from wheat, maize, barley, rice and potato production, consumption, associated losses, and household food waste generation in Turkey is estimated till 2030 using novel semi-empirical holistic models based on different scenarios. It was estimated that up to 90 thousand tonnes of biohydrogen could be produced from household food wastes in Turkey in 2030. This amount of biohydrogen would be worth 1.5 billon US$ and generate nearly 0.8 billion US$ of net return. In addition, this study clearly shows that there is a great potential for economic gain from agricultural and food waste based biohydrogen generation in Turkey. In conclusion, the methodology developed in this study could be used by researchers around the world to estimate local and national level biohydrogen generation potentials from agricultural and food wastes. [Display omitted] • This paper examines biohydrogen potentials from agricultural and food wastes. • Holistic per capita models for estimating annual biohydrogen production potentials. • Annual production and sale costs are estimated. • Annual net returns from biohydrogen generation are calculated. • The results highlight recommendations for future research directions. [ABSTRACT FROM AUTHOR]

COVID-19 has represented a watershed in people's lifestyle. One important consequence has been the change in how people buy groceries online/offline that represent the most frequent shopping-related trip any household performs. Since this has substantially different transport and environmental implications, it is crucial to investigate what are the COVID-19-induced variations. This paper estimates both travel and environmental impacts grocery channel choice implies by comparing, in a diachronic fashion, the pre and during COVID-19 situation in Norway, considering alternative scenarios describing different service configurations for each channel considered. Stated preferences are used to estimate market shares for grocery purchase distinguishing between different channels: in-store, home delivery and click&pick. The robust comparative analysis between the two time periods is guaranteed by the use of the same methodological approach in the same geographical context. Results show that total emissions are lower during the pandemic and adopting a free delivery strategy not only increases home delivery market shares but also produces the lowest level of CO2 emissions regardless of COVID-19. The results obtained are particularly relevant in the "new normal" the world is experiencing both from a public policymaking perspective, when promoting transport-related interventions to curb emissions, and from a private standpoint, when customising market strategies to increase sales and profits. • COVID-19 has represented a watershed in people's lifestyle. • Investigating changes in how people buy groceries online/offline is important. • Stated preferences are used to estimate grocery market shares for different channels. • The paper estimates travel and environmental impacts pre and during COVID-19 via scenario analysis. • Results are particularly relevant for both the public and private sector in the "new normal" conditions. [ABSTRACT FROM AUTHOR]

In the quest for a sustainable future, the bio-economy and biorefineries have emerged as pivotal agents of transformation. This review paper offers an accessible and comprehensive exploration of the multifaceted bio-economy landscape. Environmental concerns, resource scarcity, and the demand for renewable and bio-based products are the key drivers shaping this sustainable paradigm. Agriculture and agro-industry play an indispensable role, acting as the primary suppliers of the essential feedstock for biorefineries. They not only fuel the bio-economy but also foster sustainable farming practices and rural development, forming a mutually beneficial relationship. Biorefineries, the workhorses of the bio-economy, optimize resource usage, minimize waste, and produce a diverse range of bio-based products. Innovative biorefinery techniques are at the forefront, revolutionizing efficiency and expanding the array of feedstock's, thereby creating higher value-added derivatives. These value-added products, spanning biofuels, bio-plastics, and more, drive the market towards a greener and circular economy. The bio-economy's commitment to sustainability is evident through waste reduction and the promotion of circular economy principles. Policy, regulation, and market developments shape the bio-economy by promoting bio-based industries while favouring eco-friendly alternatives, creating a competitive and healthy ecosystem. While the bio-economy shows promise, it faces challenges. Optimizing conversion efficiency, discovering new feedstocks, and solving biorefinery environmental issues need technological breakthroughs and research. In summary, the bio-economy and biorefineries orchestrate a sustainable symphony, driven by environmental consciousness, rooted in agriculture, refined by innovative techniques, and harmonized by the production of bio-based products. The stage is set for a greener, more sustainable future. Bio-economy and biorefineries have become crucial drivers of transformation in the pursuit of a sustainable future. The review paper provides a thorough and easily understandable examination of the diverse bio-economy landscape. Environmental concerns, limited resources, and the need for biodegradable and renewable products are some of the main things that are shaping the sustainable paradigm. Agriculture and the agro-industry play a big role in this because they provide biorefineries with the feedstock they need. The bio-economy is not only fuelled by them, but they also contribute to sustainable farming practices and rural development, creating a mutually beneficial relationship. Biorefineries are the backbone of the bio-economy as they effectively utilize resources, minimize waste, and generate a wide array of bio-based products. At the forefront of innovation, biorefinery techniques are revolutionizing efficiency and expanding the range of feedstock's available. This, in turn, leads to the creation of higher-value derivatives and value-added products, such as biofuels and bioplastics, promoting a greener and more circular economy. The commitment of the bio-economy to sustainability is demonstrated through its efforts to reduce waste and promote the principles of a circular economy. Policy, regulation, and market developments impact the bio-economy by working together to support bio-based industries and encourage the use of eco-friendly alternatives. As a result, a competitive and healthy ecosystem is created. Although the bio-economy holds promise, it also encounters various challenges. Technological breakthroughs and research are necessary for optimizing conversion efficiency, discovering new feedstock's, and solving biorefinery environmental issues. In essence, a commitment to the environment guides how the bio-economy and biorefineries collaborate in a sustainable manner by utilizing innovative methods to refine and produce bio-based products. This harmonious process creates a symphony of sustainability, paving the way for the dream of a greener, more sustainable future. [ABSTRACT FROM AUTHOR]

Biodiversity markets offer considerable promise but are accompanied by controversies. Here, we map the utilization of native species (NS) from Brazil's biodiversity across eleven industrial sectors: foodstuffs, beverages, textiles, clothing, leather, wood, pulp and paper, biofuels, pharmochemicals, rubber and furniture. We show that there exists a diverse range of NS use in industrial products (48%) and activities (73%). These economic activities represent potential annual exports of approximately USD $50 billion. However, we found that only 1% of the potential business, USD $500 million of annual exports, is consolidated and can be traced to such products. We show that biodiversity markets and larger annual revenues locate in municipalities away from places in which biodiversity products originate. Therefore, the biodiversity business in Brazil remains largely untapped. This prompts a critical examination of the role of biodiversity within the Brazilian industry and its alignment with the Brazilian Biodiversity Law and the Nagoya Protocol. Our study is a pioneering effort that provides strategic recommendations. We suggest that the responsibility for sustainable NS utilization predominantly falls on sectors dominated by major corporations, most notably pharmochemicals and biofuels. These industry sectors possess the potential to lead the transition towards responsible and sustainable biodiversity practices within Brazil. [ABSTRACT FROM AUTHOR]

Biorenewable hydrogen is requisite to replace non-renewable hydrogen. Decarbonization is assured. Hydrogen demand is severely rising due to mitigating climate change and reducing fossil fuel dependency. Green Hydrogen from agro waste proposition makes bio-circular economy upcycling. The main objective of this study is to reinforce the hope of renewable, sustainable H 2 production from agro-waste. Initially, this paper shows the demand for green hydrogen, the sustainable availability of agro waste, and their capability to produce H 2. Insights into the gasification of agro waste about cellulose, hemicellulose, and lignin with conventional gasification. The effect of catalyst and supercritical gasification and their challenges is discussed. Most uniquely, other reviews highlight various aspirations behind agro-waste gasification to attain a strong business model, such as co-production, co-gasification, and CO 2 reforming with H2 yield. This review exhibits some main insight into various aspects of agro-waste gasification. H 2 from agrowaste gasification has high energy content (122 kJ/g) and high energy conversion efficiency in the range of 55–58 %, in addition to gaining the economic penalties of 2.2–2.5 net points for decarbonization. Agro waste is composed of lignocellulosic material that is relatively richer in hydrogen than fossil fuel resources. In SCWG, water is one of the natural solvents, which means feedstock effectively dissolves with water solvents. Intermittent density, low viscosity, and surface tension are nearly zero values due to SCW having no specific phase boundary, which enhances the gasification and substantially reduces tar formation during SCWG. Catalyst utilization enhances H 2 production. The present study comprehensively exhibits the role of catalyst and their supporter and promoter. Ni-based catalysts are mostly suggested for H2 production but fall into reusability issues. The main reason behind this is that Ni is inefficient in removing HCl, H 2 S, and total trace elements during gasification. Recently, low-cost and waste-to-wealth transformation aspects of biochar-based catalysts have gained attention. Renewable-assisted gasification significantly improves the energy and exergy of the system and suppresses the important concern of energy consumption during gasification. Renewable assisted and various aspiration incorporation into gasification is solidly recommended for future implementation based on energy, economic, and environmental benefits from them. Plastic and biomass are richer in hydrocarbon and oxygen, respectively; this synergistic effect has the potential to enhance the H 2 yield. From this study, PP plastic is mostly preferred for co-gasification with biomass. Compared to 100 wt% of biomass, the introduction of plastic slightly increased the coke formation, but the H 2 yield was improved. When the plastic mixture of 10 wt% increases coke deposition, however, significant coke deposition is not reported when 20 wt% of plastic concentration is not reported. Carbon capture via CO 2 inert gas supply enhances the H 2 yield, provides a route to carbon trade, and substantially contributes to GHG pollution mitigation. Agro-waste gasification is produced by a product that has the potential to be used in a wide range of applications due to its unique properties, such as large specific surface area, porosity, functional groups, high reliability, and minimum cost. Hopefully, this review will be an optic to the most appropriate green hydrogen production path for sustainable clean energy production and effective agro-waste management. • This review acts as an optic to the most appropriate green hydrogen production path. • Hydrogen separation, purification, and storage need more care. • Carbon dioxide reformation aids a carbon trading system and reduces environmental effect. • These research provide direction for energy nexuses that may be derived from agricultural waste. [ABSTRACT FROM AUTHOR]

• AI improves infectious waste management. • Ensemble model exceeds 97.81% accuracy. • Reinforcement learning optimizes classification. • Geometric augmentation boosts model robustness. • Study addresses urgent urban waste challenges. This research paper focuses on effective infectious municipal waste management in urban settings, highlighting a dearth of dedicated research in this domain. Unlike general or specific waste types, infectious waste poses distinct health and environmental risks. Leveraging advanced artificial intelligence techniques, we prioritize infectious waste categorization and optimization, integrating metaheuristics into optimization methods to create a robust dual-ensemble framework. Our model, the "Enhanced Artificial Intelligence for Infectious Municipal Waste Classification System," combines ensemble image segmentation methods and diverse convolutional neural network models. Innovative geometric image augmentation enhances model robustness, diversifies training data, and improves accuracy across waste types. A pivotal aspect is the integration of a reinforcement learning-differential evolution algorithm as a decision fusion strategy, optimizing classification by harmonizing outputs from ensemble methods and convolutional neural network models. Computational results, using a newly collected dataset, demonstrate our model's accuracy exceeding 96.54% while using the existing solid waste dataset we achieve the accuracy of 97.81%, outperforming advanced approaches by margins ranging from 2.02% to 8.80%. This research significantly advances sustainable waste management, showcasing artificial intelligence's transformative potential in addressing intricate waste challenges. It establishes a foundational framework prioritizing efficiency, effectiveness, and sustainability for future waste management solutions. Acknowledging the importance of diverse datasets, customization for urban contexts, and practical integration into existing infrastructures, our work contributes to the broader discourse on the role of artificial intelligence in evolving waste management practices. [ABSTRACT FROM AUTHOR]

• Adoption of sustainable investing exchange-traded funds is shaped by various factors. • Insurance companies and pension funds with positive effects. • Also supporting impact of stock markets, new technologies and financial development. • Lesser importance of the financial motives. • In case of mutual funds and institutional variables results are mixed. Despite the growing interest in various topics related to sustainable (ESG) investing, some issues remain understudied, such as the determinants of their utilization at the macro level. This paper contributes to the state of knowledge two-directionally. First, it shows the development of sustainable investing exchange-traded funds (ETFs) in European countries. Second, it traces the significant determinants of adopting sustainable investing/ESG ETFs in Europe. More specifically, we aim to determine which financial, technological, social or institutional factors have the most significant impact on the growth of levels and over-time dynamics of the sustainable investing ETFs. The empirical sample covers five European economies: France, Germany, Italy, Switzerland, and the United Kingdom and the period of the analysis is 2006–2020. Adopting panel regression analysis, we investigate twenty different variables that potentially impact the development of sustainable investing ETFs across examined countries. Our results confirm the positive effects of the development of insurance companies and pension funds for the assets of the ESG ETFs. Also, factors such as stock markets development, ICT adoption, financial access and literacy, and the prevalence of tertiary-level education demonstrate a positive impact on ESG ETFs. The role of the financial performance and tax levels resulted in being neutral, thus indicating the lesser importance of the financial motives in relation to the other factors. The results were mixed in the case of the mutual funds and institutional variables. [ABSTRACT FROM AUTHOR]

World is presently facing major challenges in energy industry to reduce or replace greenhouse gases (CO 2 , CH 4 , NO x etc.) emissions to net zero in the coming decades while decreasing the reliance on traditional fossil fuels. In the current scenario, hydrogen (H 2) appears to be an excellent alternative energy source to meet the criteria. Storage of H 2 over a long period of time in large quantities poses a significant challenge for its widespread uses. In order to overcome this issue, the idea of using large-scale depleted underground hydrocarbon reservoirs, salt caverns, underground aquifers, etc. is considered to be a suitable option for underground hydrogen storage. However, underground storage of H 2 for a longer time period comes up with a potentially high microbial activity where H 2 can be utilized in the microbial metabolism and converted into undesirable gases like CH 4 and H 2 S which in turn, damage the porous medium due to clogging, acid formation, and corrosion activity. This review paper explores the various scientific challenges during large-scale H 2 storage in porous medium to facilitate the global H 2 economy. Moreover, a detailed description of the effect of subsurface environment conditions such as pressure, temperature, pH, and salinity on microbes is included in this study. In addition to this, steps to counter microbial activity in stored H 2 monitoring and mitigation approaches are also discussed in this article. • Underground hydrogen storage and its mechanism are discussed. • Effect of microorganisms on stored hydrogen and porous media properties comprehensively reviewed. • The impact of microbial activity on subsurface storage environment conditions. • Monitoring and mitigation strategies to counter microbial activities comprehensively reviewed. • Latest treatment proposition of microbial activities and role of biocides in underground hydrogen storage discussed. [ABSTRACT FROM AUTHOR]

Transportation is an economic sector that contributes significantly to global warming due to its high consumption of fossil fuels, and sustainably produced hydrogen is a major contender for an alternative clean energy source. Public transit is vital for environmental sustainability via reducing individual vehicle usage and traffic congestion, and the prospect of powering buses using hydrogen fuel has been extensively studied lately. This paper seeks to comprehensively review the current status of research on hydrogen-powered buses considering triple bottom line sustainability perspectives. A brief technical overview of prospective environmentally benign hydrogen production processes has been presented. Technological, economic, and environmental findings and research trends seen in recent analyses on hydrogen-powered buses have been summarized, along with the status quo of global hydrogen refuelling stations. Identified focal points for future studies include performance enhancements, refuelling infrastructure propagation, and policy formulation. The conclusions derived from this review will benefit the accelerated deployment of hydrogen-fuelled public transit fleets. • Environmentally benign hydrogen production is reviewed techno-economically. • The prospects of using hydrogen for public bus transport are discussed thoroughly. • Blue and green hydrogen production are likely to coexist in the hydrogen economy. • Costs and energy consumption of hydrogen-powered buses need improvement. • Refuelling facility deployment and public awareness of safety should be enhanced. [ABSTRACT FROM AUTHOR]

This paper contributes to the growing debate about the role of board-level sustainability committees, focusing on whether they leverage sustainability expertise for impactful environmental initiatives or purely serve as symbolic actions aimed at greenwashing. Using a large set of firms from 35 countries over the 2010–2017 period, we find that the presence of a sustainability committee is positively associated with higher-quality GHG emissions disclosure. This finding is robust to endogeneity and sample selection bias concerns. The sustainability committee effect is more pronounced when external environmental institutions are too weak to properly monitor corporate environmental disclosure. Our findings suggest that sustainability committees are not a symbolic management tool, but play a crucial role in enhancing corporate environmental disclosure. [ABSTRACT FROM AUTHOR]

Water removal during paper manufacturing is of primary importance to production rate and cost efficiency for the pulp and paper industry. It is crucial to develop methods to reduce energy consumption by increasing the percent solids in the paper web entering the dryers from the presses. This research aimed to develop a fundamental understanding of the effect of bio-chemo-mechanical pretreatments on a bleached softwood fiber matrix and evaluate the impact on the percent solids of the paper web after pressing. Experiments included enzymatic, refining, and cationic polymer pretreatments on the bleached softwood pulps, followed by laboratory papermaking and determining the equilibrium moisture content (EMC) after pressing and the pulp and paper properties. The combined effect of mild refining, controlled enzymatic pretreatments, and cationic strength aids proved to enhance the water removal during wet pressing (up to 35 % reduction) and increase paper strength (up to 60 % increase). The results of increased solids after pressing were used to calculate the potential reduction in drying energy during paper manufacturing. Energy savings of around 10 % for paper drying could be achieved through fiber matrix modification by bio-chemo-mechanical pretreatment. Enzymatic pretreatments have previously been conventionally applied before refining as an energy-saving method. However, this research shows that synergistic actions of enzymes added after refining modify the fibers and create the optimal conditions for enhancement in drainage, press dewatering, and paper properties. [Display omitted] • Enzyme-assisted fiber modifications improve press dewatering and paper strength. • Enzyme blends can enhance fiber cell wall flexibility and fibrillation. • Synergistically, enzymes increased ∼35% press dewatering and ∼60% tensile strength. • Enzymes, mild refining, and cationic biopolymers enhance paper process efficiency. • This research introduces alternative methods for decarbonizing the paper industry. [ABSTRACT FROM AUTHOR]

The sustainable application of an up-flow anaerobic baffled reactor (UABR) to treat real paper and cardboard industrial effluent (PCIE) containing bronopol (2-bromo-2-nitropropan-1, 3-diol) was investigated. At a hydraulic retention time (HRT) of 11.7 h and a bronopol concentration of 7.0 mg L−1, the removal efficiencies of total chemical oxygen demand (COD total), COD soluble , COD particulate , total suspended solids (TSS), volatile suspended solids (VSS), carbohydrates, and proteins were 55.3 ± 5.2%, 26.8 ± 2.3%, 94.4 ± 4.6%, 89.4 ± 2.6%, 84.5 ± 3.2%, 72.1 ± 1.8%, and 22.4 ± 1.8%, respectively. The conversion of complex organics (e.g., carbohydrates and proteins) into bio-methane (CH 4) was assisted via enzyme activities of, in U (100 mL)−1, α-amylase (224–270), α-xylanase (171–188), carboxymethyl cellulase (CM-cellulase) (146–187), polygalacturonase (56–126), and protease (67,000–75300). The acidogenic condition was dominant at a short HRT of 2.9 h, where methane yield dropped by 32.5%. Under this condition, the growth of methanogenic bacteria could be inhibited by volatile fatty acids (VFA) accumulation. The analysis of Fourier-transform infrared (FTIR) spectra detected peaks relevant to methylene and nitro groups in the sludge samples, suggesting that entrapment/adsorption by the sludge bed could be a major mechanism for removing bronopol. The economic feasibility of UABR, as proposed to receive 100 m3 d−1 of PCIE, showed a payback period (profits from environmental benefits, biogas recovery, and carbon credit) of 7.6 yr. The study outcomes showed a high connection to the environmental-, economic-, and social-related sustainable development goals (SDGs). [Display omitted] • First study on biogas recovery from real paper and cardboard industry effluents (PCIE). • Up-flow anaerobic baffled reactor showed 55.3% COD removal and 191 mL CH 4 (g COD removed)−1. • The acidogenic condition was dominant at a short HRT of 2.9 h. • Sustainable application of UABR was evaluated via cost benefits analysis. • Payback period from pollutant removal, biogas recovery, and carbon credit was 7.6 yr. [ABSTRACT FROM AUTHOR]

• A methodology that defines and ranks KPIs encompassing the entire FSC. • A KPIs co-creation process involving experts and FSC stakeholders. • A new criteria (SMART +) that incorporates the digitization capability of KPIs. • An index that assesses the readiness of FSCs to implement FLW prevention strategies. The impact of food loss and waste (FLW) generation on food supply chains' (FSC) sustainability represents a challenge embodied in the Sustainable Development Goal (SDG) 12.3. This problem requires a methodology to measure such an impact in a rigorous, holistic, and standardized way that can be applied to any FSC. This paper aims to develop and validate a single index to assess the readiness of FSCs to implement FLW prevention strategies and measure their impact: the so-called FOODRUS index. The co-creation methodology followed incorporates experts and FSC stakeholders feedback. The index has been validated in 3 FSCs: The Slovak pilot scored 74.35%, the Spanish pilot reached 68.79%, and the Danish pilot was rated 61.14%. Its calculation, eased by the FOODRUS index self-assessment tool (described in the Appendix), allows quick diagnosis of the FSC capability to implement FLW prevention strategies considering both the knowledge provided by experts and the experience of the FSC stakeholders that participated in its co-creation process. In this way the FSC can assess its FLW prevention performance at a strategic and management level, with the aim of improving its sustainability impact. [ABSTRACT FROM AUTHOR]

Business-as-usual (BAU) cement production is associated with a linear model that contributes significantly to global warming and is dependent on volatile energy markets. A novel circular model is proposed, by adding three power-to-gas system components to current production systems: a calcium-looping (CaL) CO 2 capture unit; water electrolysis for hydrogen and oxygen generation; and a methanation unit for synthetic natural gas (SNG) production. The paper presents the first analysis of the combined industrial-scale operation of these components in a closed loop, where the SNG fuels the cement kiln and the CaL unit, while the O 2 produced feeds it. The circular, hybrid, and BAU models are compared in three feasibility scenarios. It is concluded that the circular model outperforms the other alternatives environmentally, opening a potential pathway for the cement industry to achieve near net-zero CO 2 emissions, reduce energy dependence and improve economic efficiency. [Display omitted] • Innovative circular model proposed for carbon-neutral cement production. • Novel integration of CaL CO 2 capture, water electrolysis and methanation units. • Comparative techno-economic and environmental analysis conducted. • Circular model outperformed current and hybrid models. • Near net-zero CO 2 emissions and increased energy independence achieved. [ABSTRACT FROM AUTHOR]

The increasing concern about environmental degradation and an energy crisis due to geopolitical conflicts, economic sanctions, and worsened energy security has prompted energy researchers to find environmentally friendly and renewable sources as an alternative to fossil fuel sources. Hydrogen is one of the most suitable replacements for fossil fuels due to its good thermal properties, wide applicability, multiple sources, and being carbon-free. Hydrogen can be produced sustainably from different biomass sources through biological and thermochemical pathways. This manuscript aims to present a comprehensive analysis of current approaches for producing hydrogen from biomass sources, elucidating recent advancements in this domain. The manuscript outlines the benefits and drawbacks of different approaches. Furthermore, a thorough bibliometric analysis using VOSviewer software was carried out for the years 2000–2023, covering 1840 relevant references. The incorporation of an extensive bibliometric analysis enhances the scholarly depth of the research. Through the mapping of historical and contemporary research emphases, significant contributors, and emerging trends, the paper provides a precise visual depiction of the research landscape. This not only contributes to a nuanced comprehension of the field's present condition but also functions as a valuable instrument for researchers in strategizing future studies. [Display omitted] • Biological and Thermochemical Pathways for H 2 production were reviewed and summarized. • Advantages and disadvantages of the common methods were clarified. • Bibliometric study unveils H 2 production from sustainable resources literature trends, research status, and future potential. [ABSTRACT FROM AUTHOR]

Airport ground accessibility is an important and integral part of airport planning, which significantly impacts airport attractiveness and its environmental sustainability. In this paper, we propose the combined use of road micro-simulation with meso-scope discrete choice modeling to support the evaluation of airport access interventions. The proposed integrated framework allows us to appraise mode choice and infrastructural interventions simultaneously to accurately assess the performance of airport access road networks in accommodating larger traffic. We validate and demonstrate the benefits of the proposed approach by applying it to a real-world case study based on the Milan–Bergamo Airport (BGY), in which (i) we conduct an ex-post counterfactual analysis to assess the impact of the interventions undertaken to mitigate the large growth (54.6%) in the years 2013–2019, and (ii) evaluate future scenarios up to 2030 considering the additional expected growth and introduction of direct rail services. Results indicate that BGY's ground access interventions have contributed to effectively accommodating traffic growth by significantly mitigating road congestion and associated pollutant emissions. Results also inform on the need and effectiveness of additional interventions to meet the substantial expected future growth. • Airport ground accessibility is an important and integral part of airport planning. • Road micro-simulation with meso-scope discrete choice modeling are propounded. • The hybrid framework appraises mode choice and infrastructural interventions. • This accurately assesses the performance of airport access road networks. • The approach is validated via a case study of the Milan–Bergamo airport. [ABSTRACT FROM AUTHOR]

• Directions for future research of sustainable use of biosolids as a N source. • Global biosolids regulations and common biosolids treatment methods are discussed. • Higher total N content in HDB and reduced N availability from CB are reported. • Key factors in biosolids treatment affecting biosolids properties are identified. • Existing models of soil N dynamics after biosolids application are summarized. Application of biosolids to agricultural land has gained increasing attention due to their rich nutrient content. There are a variety of treatment processes for converting sewage sludge to biosolids. Different treatment processes can change the physicochemical properties of the raw sewage sludge and affect the dynamics of nutrient release in biosolids-amended soils. This paper reviews heat drying, alkaline treatment, and composting as biosolids treatment processes and discusses the effects of these treatments on biosolid nitrogen (N) content and availability. Most N in the biosolids remain in organic forms, regardless of biosolids treatment type but considerable variation exists in the mean values of total N and mineralizable N across different types of biosolids. The highest mean total N content was recorded in heat-dried biosolids (HDB) (4.92%), followed by composted biosolids (CB) (2.25%) and alkaline-treated biosolids (ATB) (2.14%). The mean mineralizable N value was similar between HDB and ATB, with a broader range of mineralizable N in ATB. The lowest N availability was observed in CB. Although many models have been extensively studied for predicting potential N mineralization in soils amended with organic amendments, limited research has attempted to model soil N mineralization following biosolids application. With biosolids being a popular, economical, and eco-friendly alternative to chemical N-fertilizers, understanding biosolids treatment effects on biosolids properties is important for developing a sound biosolids management system. Moreover, modeling N mineralization in biosolids-amended soils is essential for the adoption of sustainable farming practices that maximize the agronomic value of all types of biosolids. [ABSTRACT FROM AUTHOR]

A range of existing and newly developed hydrogen standards, certification and labelling (SCL) schemes aim to promote the role of 'renewable', 'clean' or 'green' hydrogen in decarbonising energy transitions. This paper analyses a sample of these SCLs to assess their role in the scaling up of renewable hydrogen and its derivatives. To analyse these hydrogen SCLs, we embellish a novel conceptual framework that brings together Sustainability, Systems Thinking, and Governance (SSG) literatures. The results reveal noteworthy scheme differences in motivation, approach, criteria, and governance; highlighting the complex, interconnected, and dynamic reality within which energy systems are embedded. We consider whether the sustainable utilisation of renewable hydrogen is well-served by the proliferation of SCLs and recommend an SSG-informed approach. An SSG approach will better promote collaboration towards an authoritative, global, multistakeholder, compromise on hydrogen certification that balances economic considerations with social, and environmental dimensions. [Display omitted] • There is a proliferation of hydrogen standards, certification and labelling (SCL) schemes. • We analyse a sample of SCLs to investigate their role in scaling green hydrogen. • We employ a Sustainability, Systems Thinking, and Governance (SSG) approach. • We recommend an SSG lens to help craft a global multistakeholder initiative. [ABSTRACT FROM AUTHOR]

Saccharomyces cerevisiae is one of the prominent strains in the brewing and bioethanol industries and has been used for many industrial purposes for ages. Though the organism is an outstanding ethanol producer, the major limiting factor is the stress the organism undergoes during fermentation. One of the significant stresses is the ethanol stress, created by ethanol accumulation in the medium. The ethanol starts to interact with the yeast cell membrane; further, as ethanol concentration increases, it affects a lot of cell organelles. Thereby, cellular activities get disrupted, causing cell death and hence reducing ethanol production. The organism has developed many strategies to overcome this stress by activating the stress response pathway, which regulates many genes involved in modifying the cell membrane cell wall, renaturation of proteins, and altering the metabolism. However, with higher ethanol concentrations, the yeast cells will be unable to tolerate, leading to cell death. Hence, to minimize cell death at higher ethanol concentrations, there is a need to understand the effect of ethanol and its response by the organism; this helps improve the ethanol tolerance of the organism and, thereby, ethanol production. Although many research works are carried out to understand the vital aspect of the tolerance and are reported, very few review papers cover all these points. Hence, this review is designed to include information on all the elements of ethanol tolerance, i.e., ethanol tolerance of different strains of S. cerevisiae , the effect of ethanol on the yeast cells, the mechanism used to tolerate the ethanol, and various techniques developed to improve the ethanol tolerance of the yeast cells. [Display omitted] • Saccharomyces cerevisiae: key in brewing, bioethanol; historic importance; widespread applications. • Detailed exploration of ethanol's harmful effects on yeast, disrupting cellular activities and reducing ethanol production. • Explore ethanol stress adaptations, emphasizing stress response pathway's role in cell component modification. • Addressing the challenge of ethanol tolerance, emphasizing the importance of minimizing cell death for enhanced production. [ABSTRACT FROM AUTHOR]

Carbonaceous catalysts obtained from agricultural residue could have potential in the production of biofuels such as biodiesel. This review paper discusses the preparation conditions (temperature, heating rate, hold time, inert gas flow rate, etc play key roles in development of textural characteristics of the catalysts) and functionalization methods of biochar and activated carbon derived from agricultural residues and their application to produce biodiesel. Research works reported in achieving maximum yield of biodiesel in terms of variable precursors, alcohol-to-oil ratio, reaction time and temperatures have been profoundly tabulated. Effect of textural properties of the biochar and activated carbon (such as surface area, total pore volume, average pore size, and functional group attached with the catalyst) on the biodiesel yield are examined. Studies on Regeneration and reusing of the spent catalysts are carefully inspected. The economic evaluation studies for the biochar and activated carbon and the applications of these for biodiesel production are scrutinized. Finally, the strategies to increase biomass and catalyst productivity, future prospect and research directions to enhance biofuel/biodiesel production and for the development of biochar and activated carbon from agricultural residues for sustainable biodiesel production is suggested. [Display omitted] • Preparation methods of biochar & activated carbon (AC) from AR examined. • Reaction conditions and mechanisms for biodiesel synthesis discussed. • Biodiesel yield correlated with surface area, pore volume & pore size of catalysts. • Regeneration & recycling of biochar & AC catalysts discussed for biodiesel yield. • Economic studies for biochar & AC production & application for biodiesel covered. [ABSTRACT FROM AUTHOR]

Indirect evaporative cooling is a technology that can be used sustainably to replace traditional cooling systems using thermodynamic compression cycles, especially in tropical countries like Brazil, which have many regions with hot climates and low relative humidity. These meteorological aspects favor the simultaneous transfer of heat and mass, allowing the thermal cooling effect characteristic of evaporative cooling processes. Thus, this paper investigates the performance of a sustainable air cooling system by combining the psychrometric effects of warm, dry air with the flow features inside a cyclone covered by a layer of a fabric moistened with water. Fluid dynamic simulations previously indicated temperature decreases of up to 12.2 K between the feed and overflow streams of the cyclone. In addition, temperature contours showed that the fluid dynamics of the cyclone provide instantaneous thermal exchange between the walls and the internal fluid. These results directed the study to execute an experimental design using the response surface methodology to evaluate the influence of some variables in the process. The decrease in air stream temperature ranged from 3.9 to 13.1 K, with relative humidity and ambient temperature being the most significant variables. The results also indicated that water consumption to maintain the fabric wet is relatively low since 16·10-3 kg of liquid is required to cool 1 m³ of air flowing through the cyclone. [Display omitted] • High inlet temperature and low relative humidity provided maximum thermal gradients. • Within 0.75 s, in average, the system provided a thermal reduction of up to 13 K. • The thermal efficiency of the wet-bulb for the new system varied from 54.8 to 67.8 %. • Dimensionless numbers for psychrometric cooling system showed a linear behavior. [ABSTRACT FROM AUTHOR]

Energy efficiency can help facing the climate crises. Yet the energy intensity has decreased more slowly than required to achieve climate goals. Based on this premise, we build an agent-based model to study the effects of different energy efficiency policies. Policies analysed range from indirect policies – taxes, incentives, and subsidies – to direct technological policies, where a public research laboratory invests in R&D to establish a new technological energy efficiency paradigm. Results reveal that, although most of the policies effectively reduce energy intensity, the research lab is the most efficient in promoting energy efficiency without negative impacts on macroeconomic and public finance conditions. However, the success of this policy requires a long-term commitment, highlighting the importance of complementing this strategy with more "ready to use" measures. The findings also indicate that most policies do not induce significant macroeconomic rebound effects. Concerns about macroeconomic rebound effects may likely be overstated. • Improvements in energy efficiency help face the ongoing climate and energy crises. • Yet, energy intensity has declined more slowly than needed to meet climate goals. • The paper builds an agent-based model to study different energy efficiency policies. • Indirect policies work but are outperformed by direct technological policies. • The macroeconomic rebound effect induced by most of the policies is rather small. [ABSTRACT FROM AUTHOR]

• We explore the impact of the COVID-19 pandemic on cyclists' reactions to weather. • During COVID-19, cyclists in transit-oriented cities reacted stronger to weather. • In student cities, the weather elasticity did not change during pandemic. • Results of 2.2 million hourly bicycle count observations from 69 counting stations. Cycling can only unfold its full potential for environmental sustainability, livable cities, and health if people cycle under most seasonal and weather conditions. During the COVID-19 pandemic, many people preferred cycling over public transit, in order to avoid infection. This change may also have affected the weather–cycling association: the pandemic mainly attracted new, fair-weather cyclists; and it may have encouraged cyclists to continue cycling, even under less favorable conditions. In this paper, we explore how the COVID-19 pandemic affected the association between weather and cycling. We analyze data from bicycle counting stations in Germany, combined with city- and hour-specific weather information and a continuous measure of pandemic intensity. The data set contains more than 2.2 million hourly bicycle count observations from 69 counting stations, covering the years 2017–2021. Results from the most transit-oriented cities in the sample, Berlin and Munich suggest that the cycling volume was more dependent on weather conditions at times of high pandemic intensity. This suggests that the pandemic put new people in the saddle, but these additional cyclists were largely fair-weather cyclists who only cycled when the weather was sufficiently nice. For policy, this could set two targets. First, encourage the new pandemic-cyclists to stay on the bike and, second, support them in transitioning into year-round cyclists eventually. [ABSTRACT FROM AUTHOR]

• A direct evaporative cooler (DEC) integrates with split air conditioner (SAC). • DECSAC significantly improves C O P by 10.54 %−70.14 %. • Total cost rate (T C R) of DECSAC reduces by 5.07 %−25.36 %. • Water consumption for 1 kWh energy saving varies between 5.5 – 9.8 L. • Simple payback period lies between 1.21 to 2.99 years with maximum I R R being 59 %. As concerns regarding energy consumption and environmental impact continue to grow, the need for efficient and sustainable cooling technologies becomes increasingly significant. Among various alternatives, direct evaporative cooling (DEC) has emerged as a promising solution due to its energy-efficient operation and low environmental footprint. This paper aims to provide a comprehensive thermo-economic assessment of a 5.25 kW capacity split air conditioner (SAC) integrated with direct evaporative cooling, focusing on evaluating its performance, energy consumption, coefficient of performance (C O P) , and economic viability. A numerical model is developed to determine the reduction in the condenser inlet air temperature due to direct evaporative cooling. The ambient temperature (30–45 ⁰C), relative humidity (20–80 %), and evaporator temperature (3–12 ⁰C) are taken as the design variables. Box–Behnken design (BBD) technique of response surface methodology is applied for multi-objective optimization. The C O P , total cost rate (T C R) , and total exergy destruction ( E ˙ D , t ) are set as the objective functions. Cooling capacity, life period, operation time, interest rate, maintenance factor, and electricity cost are taken as constants. The thermoeconomic optimization evolved maximized C O P enhancement of 68.94 %, and reduction in TCR and E D , t by 26.12 % and 57.23 %, respectively. The water consumption to energy saving ratio varies from 5.5 to 9.8 L/kWh for different months of the cooling season. The thermoeconomic performance and sustainability of DECSAC is observed to significantly improve compared to conventional SAC specifically in hot-dry climates. The simple payback of the proposed system ranges between 1.21 to 2.99 years depending upon the operating conditions. [ABSTRACT FROM AUTHOR]

Aotearoa New Zealand's emerging New Space economy provides an opportunity for key actors to focus on space and sustainability issues beyond space debris. The conflict between competing definitions and paradigms of sustainability highlights the importance of diverse values, assumptions, and drivers of change that shape the normative understanding of space sustainability issues. This paper recognises that Indigenous knowledges and practices are in parallel with systems-thinking and transdisciplinary approaches to space and sustainability. The aim of this paper is to describe how current actions can have long term impacts on using and accessing space commercially, scientifically, and culturally. • Space sustainability requires a transdisciplinary approach to explore the definitions and values at various scales. • Space sustainability in New Zealand involves addressing issues beyond space debris. • Space sustainability requires addressing businesses in New Zealand, where sustainability frameworks are poorly implemented. • Space sustainability requires policy interventions beyond compliance with environmental legislation. [ABSTRACT FROM AUTHOR]

This study provides an in-depth analysis of the potential role of hydrogen (H 2) in the Belgian transport sector in the context of sustainable and environmentally friendly growth. This paper starts by examining the energy-climate roadmap and the emission mitigation programme defined by the Belgian federal government in the context of environmental sustainability. Then, the Belgian situation is critically evaluated in light of the needs for H 2 fuel in the transport sector, as well as issues about a roadmap on environmental considerations for a sustainable future, while preserving the country's economic stakes. There are several key advances in this direction, especially as H 2 is seen as one of the best viable options for sustained development, unlike other possibilities. This paper also highlights some limitations that make it difficult to accelerate the transition to a sustainable H 2 energy future. Although there are many interests in favour of an advanced and non-polluting transport system, there are differing views on the approach to be taken in political decision-making at national level. Therefore, this study will help public authorities to better integrate environmental and sustainability issues in the context of a transition to a comprehensive hydrogen economy in the current transport sector. • An in-depth analysis of hydrogen's role in the Belgian transport sector is presented. • Considerations of sustainable and environmentally friendly growth are addressed. • It highlights the constraints and barriers to the full development of H 2 in Belgium. • There is no unified national public policy for hydrogen development. • Policies should prioritise R&D, training and social empowerment of hydrogen energy. [ABSTRACT FROM AUTHOR]

The pressure on reducing greenhouse gas emissions has increased since the focus on climate change mitigation has grown. As the human development index is directly related to per capita energy consumption, sustainable energy production with reduced carbon footprint is the essential pathway for cleaner environment. Over numerous existing biological processes, hydrogen production via photo fermentation and photolysis of water is considered a more sustainable and economical method of hydrogen production. While both biological modes suffer from certain limitations, such as low yields and low production rates, practical implementation is still a long way off due to these limitations. The unique properties of nanomaterials (NMs) can help increase the efficiency of the biomass to biohydrogen process in significant ways. Applications of organic and inorganic nanoparticles in photocatalytic and photo fermentative hydrogen production is discussed in this paper. This review reports a wide range of applications of nanomaterials including the details of photo fermentative microorganisms and their mechanism of action. The maximum photo fermentative bio-H 2 production was reported in the presence of SiC–Fe 3 O 4 (3.02 mol H 2 /mol acetate), Ni (41 mol H 2 /mol sugar), graphite-C 3 N 4 (64.2 mol H 2 /mol sugar) whereas photocatalytic bio-H 2 yield was highest when Pd–Ni/CdS (54 mmol/g.h), Ni-MO/g-C 3 N 4 (1785 mmol/g.h) and CuO/TiO 2 (20.3 mmol/g.h) nanoparticles were employed. To design photocatalytic systems for practical and scalable use, the future research should be focused on deeper theoretical knowledge of mechanisms of light harvesting, ± charge separation and transport, surface biochemical reactions, semiconductor–liquid interactions, and reactor dynamics. [Display omitted] • Recent developments for improving water photolysis and photo-fermentation are reviewed. • Applications of organic and inorganic nanoparticles in hydrogen production are discussed. • The working principle and mechanism of hydrogen production are discussed. • The influence of key operating factors are presented. • Scope for future research was presented. [ABSTRACT FROM AUTHOR]

This paper explores the use of Solar Chimney Power Plants (SCPPs) for the production of green hydrogen as a means to store excess electrical energy generated from renewable energy resources (RESs). The proposed structure produces electrical energy and distilled water by heating the air under the SCPP. The electrolyzer is integrated into the seawater pool and installed at the solar chimney's base. The weather conditions at the proposed location of the SCPP including solar radiation, temperature, humidity, and wind speed, are analyzed to assess their impact on the performance of the SCPP. The potential applications and economic feasibility of the SCPP are discussed, considering its contribution to renewable energy generation and the benefits of hydrogen as a clean energy carrier. The results show that solar radiation levels and favorable temperature profiles play an important role in the performance of the SCPP. The SCPP could produce 380,263 kW h of electrical energy and 139,443 tons of distilled water annually. The results also showed that the SCPP could produce 13,000 kg of green hydrogen and 173,224 kg of oxygen annually. The revenue generated from the production of H 2 and O 2 has improved the levelized cost of energy (LCOE) for the SCPP to 0.51 $/kWh and made it compete with other energy production facilities. Monthly variations in electrical energy, H 2 , O 2 , and distilled water production, highlight the dependence of hydrogen production on solar intensity and temperature. Overall, the research demonstrates the potential of SCPPs and hydrogen production as a sustainable and efficient solution for storing and utilizing excess renewable energy. [Display omitted] • Solar-electrolysis system combing solar chimney & electrolysis station is proposed. • The system produces green hydrogen, oxygen, desalinated water, and electricity. • The solar-electrolysis system was modeled using MATLAB mathematical modeling. • The system produced 380 MW h, 13 ton H 2 , 173.3 ton O 2 , and 139,443 ton water per year. [ABSTRACT FROM AUTHOR]

The development of sustainable energy sources has become a major challenge for society. Green hydrogen, produced through the electrolysis of water using renewable energy sources, offers a potential solution to reducing our dependence on fossil fuels. The paper examines the integration of green hydrogen into various sectors, such as transportation, industry, power generation, and heating, highlighting its potential to decarbonize traditionally carbon-intensive areas. Furthermore, it analyses the strategies and policies employed by the European Union, Australia, Japan, the United States, and Canada to drive the development and adoption of green hydrogen technologies. The challenges and barriers that need to be addressed to fully realize the potential of green hydrogen, such as technological limitations, infrastructure development, costs and economic feasibility, regulatory and policy frameworks, and public perception and acceptance, have been investigated. Recommendations for overcoming these challenges and accelerating the adoption of green hydrogen technologies are provided, and the importance of research and development in this sector is emphasized. • Green hydrogen offers a sustainable solution to reduce fossil fuel dependency, decarbonizing key sectors. • Analyzed policies from the EU, Australia, Japan, the US, and Canada to foster green hydrogen technologies. • Discussing challenges: green hydrogen potential, tech limits, infrastructure, costs, regs, and public views. • Emphasized the importance of R&D and offers accelerating the adoption of green hydrogen technologies. [ABSTRACT FROM AUTHOR]

Mobility as a service (MaaS) is an emerging framework that integrates multiple transport services into a single and intuitive platform. This paper contrasts the urban passenger transport markets in developed versus developing economies to understand the challenges of integrating mobility services using the MaaS framework, with a focus on decarbonization and sustainability as societal goals. In addition, we conducted a Life Cycle Assessment of carbon emissions and energy requirements of travel alternatives in the city of Santiago, Chile, to shed light on the effects of multimodality as an environmental tool. A summary of findings follows. Data sharing and open data are new in developing countries, and thus more investment in data infrastructure is required so that MaaS can leverage digital technology and network optimization. If the scalability of MaaS is an open question in developed countries, it is more so in developing countries, owning to institutional and financial constraints that are present in the latter. The lack of public subsidies to support formal public transport is a key limitation for the implementation of MaaS schemes and multimodal frameworks in the developing world. Regarding formality, in countries with an informal public transport sector, a potential implementation of MaaS will be spatially constrained to those locations where public transport operates formally and frequently (BRT and rail lines), limiting its spatial coverage and posing social equity issues. In countries with scarce or no public funds available for the transport sector, MaaS could be used as a catalyst for a broad environmental and equity-seeking transport pricing reform which requires a direct involvement of public sector in both regulation and financial backing. We conclude that the formalization and general improvement of the public transport sector, the regulation of shared-mobility platforms including the formalization of the work of drivers, and the setting of proper pricing and subsidization instruments in the direction of internalizing the social costs of motorized traffic, are all prerequisites for any MaaS system that aims to improve economic efficiency, social equity, and sustainability. • Assess MaaS as a framework for decarbonization in developing world. • Discuss governance and equity issues in implementing MaaS. • Identify carbon policy for different cities to achieve sustainability. • Conduct a life cycle assessment to inform carbon strategies. • Scalability is a key challenge in both developing and developed worlds. [ABSTRACT FROM AUTHOR]

This study examined the threshold effect of debt on economic growth in Nigeria, with a view to investigating debt sustainability levels in the country. The analysis included yearly data from 1981 to 2021. To achieve its objectives, the study used two-regime threshold ARDL regression approaches. Findings reveal that the optimal thresholds for total debt as a ratio of GDP (TDB/GDP), GNI (TDB/GNI), total revenue (TDB/REV), and exports of goods and services (TDB/EXP) are 46.1%, 54.5%, 355.3%, and 24.9%, respectively. Findings also indicate that debt ratios below the threshold levels have a significant positive impact on economic growth. This is true for all the debt ratios, except debt-to-export ratio. However, debt ratios above the threshold levels have a negative and significant effect on Nigeria's economic growth. Furthermore, findings reveal that only the level of domestic debt is sustainable over the long and short run, whereas external debt and total debt are only sustainable over the long run. When expressed as ratios of GDP and GNI, evidence indicates that Nigeria's debt is not sustainable by all the five measures of debt adopted in the study, both in the short run and in the long run while total debt to revenue ratio is only sustainable only in the long run. The paper adequately explores the implications of these findings and offers relevant policy recommendations. [ABSTRACT FROM AUTHOR]