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This article explores the evolution of soda ash production methods, highlighting the shift towards more sustainable practices. It analyzes the environmental and economic challenges of traditional methods, including high energy consumption, pollution, and waste generation. The discussion progresses chronologically, examining obsolete natural methods and their gradual replacement by more efficient techniques like the Solvay Process. However, the production of calcium chloride (CaCl2) as a byproduct in the Solvay Process necessitates further advancements. The article explores promising alternatives such as modified Solvay methods utilizing external CO2 sources and exciting new frontiers like microbial-assisted production. Additionally, it delves into methods utilizing wastes like CaO (calcium oxide) and the potential of layered double hydroxides (LDHs) and cyclic CO2, even though these may generate hydrochloric acid (HCl) as a byproduct. The primary focus remains on the potential of innovative methods based on physical and biological processes to achieve enhanced efficiency, decreased environmental impact, and reduced energy and resource demands.

In the contemporary landscape of advanced manufacturing, there is an increasing demand for machining processes that excel in both quality and energy efficiency. One of the prime objectives is to excel in an era of machining practices that are environmentally conscious and economically sustainable. This research addresses this challenge by undertaking a comprehensive exploration of multi-objective optimization, specifically tailored to address the machining challenges presented by Titanium Grade 3 alloy. A robust Taguchi-Grey integrated approach was adopted with research aim to strike an optimum balance among specific cutting energy, tool wear, surface finish, and material removal rate. The impact of machining inputs i.e., feed rate, cutting speed, and depth of cut were analyzed. Best machining setting was identified using grey relational analysis. Feed rate was identified as the most influential member affecting grey relational grade having contribution ratio of 73.95%. Furthermore, surface plots and contour plots were developed for aid of machinists on job floor in selection of best cutting conditions. Harnessing the usefulness of response surface optimization, the machinability was further enhanced by 9% reduction in specific cutting energy and 7% improvement in tool wear. However, it is imperative to acknowledge the trade-offs as a result of MOO; surface roughness increases by 12%, potentially necessitating additional post-processing steps.

The traditional linear economic model, characterized by extraction, production, consumption, and waste disposal, has increasingly exposed its limitations, particularly in the depletion of natural resources and the acceleration of global warming, which are critical global issues. These challenges inherent in the linear economy have prompted a shift towards a circular economy. This study analyzes the opportunities and challenges for transitioning to a circular economy through green entrepreneurship among 29 environmentally friendly entrepreneurs in Togo, West Africa. The descriptive analysis of the results revealed that green entrepreneurs are mainly motivated by economic factors, such as job creation and business opportunities, which take precedence over environmental motivations. However, they face significant challenges, including a lack of access to appropriate financing and complex administrative procedures that affect their growth. It is essential to develop themselves, provide specific support by alleviating bureaucratic obstacles to access to finance, and meet economic and environmental goals from green entrepreneurship. In addition, it's important to advocate for pro-environmental behavior among the general public and to support research and development to increase understanding of the advantages of promoting environmentally friendly entrepreneurship for sustainable development while combating climate change. Mainstreaming gender into circular economy policies design and implementation for sustainable development is crucial due to the low representativeness of women in green entrepreneurship. These measures will strengthen Togo's economic resilience while enabling the transition to a circular economy, thus aligning financial objectives with environmental preservation in pursuing green entrepreneurship.

This research investigates the intricate relationships between Environmental Management Control Systems (EMCS), Blockchain Adoption (BCHA), Cleaner Production (CLPR), Product Efficiency (PROD), Environmental Reputation (ENRE), and Environmental Performance (ENPE) within organizational contexts in Indonesia. The study aims to shed light on the role of technology adoption, sustainability practices, and reputation management in shaping environmental outcomes. Methodologically, the research employs a quantitative approach, utilizing survey data from diverse organizations. Structural equation modeling (SEM) analyzes the data and tests the hypothesized relationships. The findings reveal significant positive relationships between EMCS and BCHA, EMCS and CLPR, EMCS and PROD, BCHA and CLPR, BCHA and PROD, and BCHA and ENRE. Cleaner Production demonstrates a substantial positive impact on both ENRE and ENPE. Product Efficiency influences ENRE positively. However, the direct influence of PROD on ENPE is found to be inconclusive. The study contributes to understanding sustainability dynamics by highlighting the pivotal roles of EMCS, BCHA, CLPR, and PROD in driving environmental reputation and performance within organizations. Furthermore, it underscores the significance of aligning perceived reputation with tangible environmental commitment. Limitations include potential data constraints and the challenge of establishing causality due to the study's correlational nature. Future research is encouraged to explore diverse contexts, conduct in-depth case studies, and investigate moderating variables. This research offers novel insights into the complex interplay between technology adoption, sustainability practices, reputation management, and environmental outcomes, providing valuable guidance for organizations striving to navigate the sustainability landscape in an era of heightened environmental awareness.

Insect resistant genetically modified Bt cotton (containing a gene of Bacillus thuringiensis) has substantial potentiality of mounting cotton productivity. This study unveils an early insight on the economic viability of Bt cotton in Bangladesh. A total of 248 traditional cotton farmers and 8 Bt cotton experimental fields were surveyed in April 2022 for achieving the objectives. The data were analysed using descriptive statistics. Findings showed that the cost of Bt cotton production was slightly higher than that of conventional cotton. However, Bt cotton yielded a productivity increase of 0.81 t/ha. The cultivation of Bt cotton resulted in a higher net return (USD 2436/ha) compared to conventional cotton (USD 1624/ha). The results further indicated that the use of insecticides and pesticides in Bt cotton was significantly lower compared to traditional cotton, thereby contributing to the preservation of the natural environment. Overall, cultivation of Bt cotton is economically viable and may generate environmental benefits. Steps are warranted to disseminate and expand its cultivation.

A salient perspective to the global net zero emission aspiration that has yet received sparse attention is the unabating conventional energy reserves to production ratio. Considering the both the energy and energy-related emission profiles of the United States, this study considers the outlook of the country's carbon neutral 2050 with reference to the coal, natural gas, and oil energy reserves to production ratios for the period 1970 to 2040. The investigation implied a number of relevant results after employing the Markov switching, cointegration, and causality approaches. The result revealed that both oil and natural gas reserves to production ratio on global scale exert a significantly and positive influence on emission of carbon dioxide in the USA while coal has negative significant effect on carbon dioxide (CO2) emission in two different regimes. From the Wavelet coherence, both in phase and anti-phase relationship, CO2 and oil reserves-production ratio display strong interdependence while a mixed result in the short run (in phase) and medium run (anti phase) is established for CO2 and coal reserves-production ratio. In both short and medium run, natural gas reserves-production ratio leads CO2, and the reverse is also true. Additionally, from the frequency domain causality result, we found causality from oil reserves-production ratio to CO2 while there is bidirectional causality between CO2 and gas reserves-production ratio. The relevance of this study is that it offers insight into the seriousness of the carbon global goal amidst the dimension of energy reserves and production.

Circulation of Sb in an Sn refining system strongly affects the production process. In this study, an innovative multi-stage vacuum separation process was developed and successfully applied on an industrial scale. Our results indicate that Sn–Sb alloys can be completely separated by vacuum evaporation. In this study, we used single-factor experiments to investigate the effects of distillation temperature and time on several factors, such as the Sn content in the residue, Sb content in the volatile matter, separation rate, and direct recovery rate of Sb from high-Sb crude Sn. The purity of the obtained Sn and Sb products was above 99%, and the recovery rate of the metal was above 99% under the optimal distillation conditions of 1673 K and 150 min. In addition, we suggest that Sn volatilization occurs due to the presence of SbSn intermetallic compounds. A two-stage vacuum-separation process for high-Sb crude Sn was developed for industrial production. Continuous production data showed that the direct yields of Sn and Sb were 72.99% and 71.15%, respectively. The total power consumption of this process was as low as 1086 kWh/t, which is better than the corresponding parameters of other treatment processes.

Cleaner Production, as an environmental strategy, is integrated into processes, products, and services to increase efficiency and reduce risks to people and the environment. However, Cleaner Production management in water treatment services does not receive much public attention. To address this need, a scientometric analysis of the integration of Cleaner Production in water treatment was developed to investigate the efficacy and limitations of various Cleaner Production strategies applied in water treatment. A search was carried out in the Scopus database using the keywords ``Cleaner production,'' ``Wastewater treatment,'' and ``Drinking water treatment'' between January 1, 2002, and October 31, 2022. Through the scientometric analysis, it was possible to identify that Cleaner Production has been little applied in drinking water treatment. The reason for this was a systematic review of the application of Cleaner Production in drinking water treatment. The data and information obtained were filtered following the guidelines of the Preferred Reporting Declaration of elements for systematic reviews and meta-analyses (PRISMA). The PICO method was used to structure the important components of the research questions. The results of this review showed that there is currently little application of Cleaner Production in drinking water systems. This article concludes that Cleaner Production is a strategy that contributes to reducing the environmental impact generated by the different activities of treatment and distribution of drinking water. However, it is necessary to carry out research that promotes the dissemination and knowledge of the different Cleaner Production strategies, as well as highlighting the social, environmental, and economic benefits that their application could generate. Future research should aim at the application of Cleaner Production strategies such as water recycling and Good Housekeeping. Technological progress in purification processes can offer promising results for saving water, energy, waste reduction, and gaseous emissions.

This paper delves into the pivotal role of cleaner production in the pursuit of global water security. Leveraging Biblioshiny, a robust bibliometric analysis tool based on R-Software, the paper examined Scopus data, following PICO protocols and PRISM guidelines. The study's findings underscore the potential of cleaner production strategies on wastewater to underpin water security. To this end, the study proffers three policy interventions: an ''Industrial Cleaner Production Policy,'' a ''Water Eutrophication Prevention Policy,'' and an ''Environmental Sustainability Club Policy.'' These policies collectively constitute a comprehensive framework for ushering in an era of water security anchored in cleaner production principles. In conclusion, the study calls for the seamless integration of cleaner production into global discourse on water security, particularly within the United Nations framework, and its incorporation into various policy documents. This approach ensures cleaner production's central role as a multifaceted intervention tool, enhancing global commitment to water security.

Metal vanadium smelting produces roasting-acid leaching tailings containing approximately 1% vanadium residue, making it challenging to store and recycle these waste tailings in an environmentally friendly manner. To address this issue, a clean method called ultrasonic-enhanced oxalic acid complexation was proposed in this study for efficient removal of residual vanadium. Under the optimal conditions, the removal rate of vanadium and the decomposition rate of oxalic acid reached 86.88% and 23.6%. An in-depth analysis on the experimental results in combination with thermodynamics found a virtuous cycle chain induced by ultrasonic cavitation. Ultrasonic waves facilitated the decomposition of oxalic acid, producing more CO2 to supplement the limited cavitation bubble nucleuses. Consequently, the cavitation effect was strengthened, leading to an increased yield of OH radicals. This resulted in a continuous improvement in the oxidation environment. Furthermore, the enhanced virtuous cycle generated by ultrasonic cavitation produced powerful microjets that facilitated the stripping and dispersion of mineral particles. Overall, the oxalic acid-ultrasonic leaching technique offers a clean and efficient technology for separating vanadium.

We question the prevailing assumption that energy efficiency measures are always the more cost-effective measures for improving resource efficiency in manufacturing companies. We do this by analyzing data about potential reductions in energy, water, and raw material use in 58 companies. The data were collected by United Nations Industrial Development Organization country teams that implemented a Transfer of Environmentally Sound Technology project in three North African countries (Algeria, Morocco, and Tunisia). Our analysis of approximately 650 measures finds that there are equally attractive measures across all three resources in terms of their payback periods and use reductions. We also find both significant similarities and differences in payback periods and reductions in resource use across manufacturing sectors and countries. Based on our findings, we recommend that those who undertake energy audits and cleaner production assessments investigate in their work the potential savings and use reductions for water and raw material measures in addition to those for energy.

Mortar is subjected to high temperatures during fire attacks or when it is near heat-radiating equipment like furnaces and reactors. The physical and microstructure of mortar were considerably altered by high temperatures. In this investigation, the effects of elevated temperatures on the flexural and compressive strengths of wood ash (WA) cement mortar modified with green-synthesised Nano titanium oxide (NT) were examined. In order to produce mortar samples, the cement was replaced with 10% WA, and 1–3% NT by weight of binder were added at constant water-binder ratio. The specimens were heated to 105, 200, 400, 600, and 800 °C with an incremental rate of 10 °C per min in the electric furnace for a sustained period of 2 h to measure their strengths. The machine learning algorithm of artificial neural networks with Levenberg-Marquardt backpropagation training techniques of different network architectures was engaged to predict the compressive strength of WA-cement-NT-based mortar produced. The findings showed that higher temperatures reduced compressive strength after 400 °C and flexural strength after 200 °C. The mortar specimen with a 3% NT addition showed the highest residual compressive strength increase, ranging from 18.75 to 27.38%. Compared to compressive strength, flexural strength is more severely affected by high temperatures. The backpropagation training algorithm revealed that each hidden layer displayed its unique strong prediction. However, Levenberg-Marquardt backpropagation training technique of 7–10-10-1 network structures yielded the best performance metrics for training, validation, and testing compared to 7-10-10-10 and 7-10-1 network architectures.

Natural radioactive substances that are produced because of industrial processes pose a risk to both the environment and people. An extensive analysis of the radiological properties of industrial byproducts was undertaken in this work, and the risks for both indoor and outdoor environments were assessed based on activity concentrations. The machine learning technique of artificial neural networks was used with various training algorithms to predict the internal and external hazards from these industrial byproducts. The findings demonstrated that, with the exception of incinerated sewage sludge ash, metakaolin, marble powder, nickel slag, pyrite ash, silica fume, steel slag, and glass waste powder, every industrial byproduct examined poses potential indoor and outdoor dangers. All backpropagation training algorithms that were used showed high prediction, according to the neural networks. However, when compared to the Bayesian Regularization and Scaled Conjugate Gradient backpropagation training algorithms, the Levenberg-Marquardt backpropagation technique had the best performance indicators for training, validation, and testing. The results can provide reference information for developing a framework for monitoring hazards and their accompanying precise management.

The present study aims to assess the prospects for cleaner production (CP) and sustainable development (SD) of informally operated small manufacturing enterprises, which are frequently blamed for uncontrolled waste disposal and causing pollution to the environment. The economic efficiency level of these firms has been explored to this end, and the metallic pollution loads in the surrounding environment have been scientifically analyzed to investigate the nexus between these two. DEA (Data Envelopment Analysis)-Tobit analysis has been employed, and a pollution load index (PLI) of heavy metal pollution comprising two environmental compartments (soil and water) has been constructed based on the concentration level of metalloid pollutants in the samples collected from the surrounding areas of the studied informal firms in Bangladesh. The study disproves CP practice in majority of the informal firms in Bangladesh by observing a positive relationship between firm-level efficiency and pollution load sourced from their production activities. Afterwards, this study estimates the eco-efficiency level of firms by considering pollution load as an undesirable output and minimizing its impact in an input-oriented DEA model. Applying the eco-efficiency scores in censored Tobit regression analysis, the outcome endorses the prospect of CP for informally operated enterprises in Bangladesh. However, the CP prospect can only materialize if and only if firms are provided with adequate technical, financial, and strategic support for achieving eco-efficiency in their production. The informal and marginal nature of the studied firms restricts them from getting access to the facilities and support services needed for implementing CP and moving towards sustainable manufacturing. Therefore, this study recommends green practices in informal manufacturing and limiting the informal firms by bringing them gradually under the coverage of formalization, which is in line with the achievement of the targets mentioned in Sustainable Development Goal 8.

Industrial development has resulted in economic progress and the well-being of the society. At the same time, the impact of the industrial complex has disrupted the environment and resulted in climate change related impacts. The purpose of this study was to carry out an exploratory diagnosis and propose a technological change and sustainable industrial development index at the international level. Therefore, a network study was conducted to identify the main nodes and thematic clusters associated with cleaner production. A patent analysis was applied to technologies related three selected/relevant areas of cleaner production, i.e. carbon footprint, wastewater treatment, and renewable energy. Additionally, based on factor analysis, an index including different indicators related to scientific, technological, economic, environmental, and social issues was developed and proposed in this study., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Nowadays, for soil stabilisation and cleaner production of geo-composites, the possibility of utilizing waste rubber is in vogue. The present paper deals with experimentally investigating the mechanical and micro-structural characteristics of weak Indian clayey soil partially substituted with lime (0-3.5%) and waste rubber tyre powder (0-15%). It was observed that, with increasing lime and rubber powder content, the plasticity index of the soil decreases. The shear strength and compaction testing results reveal that adding lime and rubber tyre powder (RTP) enhances the geotechnical performance of clayey soil up to an optimum dosage value. Also, the tri-axial shear testing was performed to obtain stress-strain curves for all considered soil mixes. For modified clayey soil containing 3% lime and 12.5% rubber powder, the cohesion values and bearing capacities improved phenomenally by 36.1% and 88.6% respectively, when compared to clayey soil. Further for this mix, SEM analysis reveals a compacted microstructure which improves dry-density and California's bearing ratio among all modified mixes. The novel co-relations upon regression analysis are found able to predict plasticity index, dry density, bearing capacity and shear strength with higher confidence levels. Overall, the cost-benefit analysis worked out to obtain the optimum cost of construction of footings and flexible pavement shows cost deductions up to 19% and 39% respectively while utilizing modified clay soil mixes containing 3% lime and 12.5% rubber powder in subgrade, ultimately making production stronger, cheaper and environment friendly., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The current study presents a novel method to prepare high-purity V2O5 from Na3VO4 solution. This process characterizes Na3VO4 calcification separation, Ca10V6O25 ammoniation and solubilization, NH4VO3 crystallization, and vanadium precipitation, which achieves elemental V migration from the Na3VO4–Ca10V6O25–NH4VO3–V2O5 phase, finally obtaining high-purity V2O5. The influencing factors of the preparation process were investigated, and the results showed that vanadium was released from Na3VO4 solution to synthesize Ca10V6O25 in the first stage under the most suitable conditions (Ca/V molar ratio of 1.8, and a concentration of NaOH less than 160 g/L). In the second stage, the leaching efficiency of vanadium reached 95% at optimal conditions (NH4+/V molar ratio was 1.2, reaction temperature and time were 90 °C and 30 min, respectively). In the third stage, NH4VO3 yield and crystal size reached maximum values under optimal conditions (feed rate, crystallization temperature, and the power factor of the circulating pump were 6 m3/h, 30 °C, and 80% respectively). Finally, high-purity V2O5 was prepared via a series of large particle NH4VO3 post-treatments. In addition, the ICP analysis confirmed that the purity of the generated V2O5 was more than 99.5%.

Climate change is a challenge that endangers societal TBL elements' stability. The countries' economies focus on planning for reducing carbon emissions ‘CE’ and replacing them with low CE energy. This objective needs accurate prediction for CE till 2030 via recording the most significant variables related to CE causes. The variables (Liq) are divided into two types tacking in phase I through two steps. The first step classifying the government policies that tackling by the backcasting approach to ranking them. The second step classifies the nature of the energy source which produces CE in Mega ton by SVM. The second phase is fed by phase I outputs to generate a series of prediction values by the LSTM, which is supported by the grey recruitment technique GRPT (1,1) to reduce the forecasting errors. The proposed conceptual framework named (Green Eco-Safety Monitoring; GESM), which considered a methodology gathering the backcasting, SVM, and LSTM provided by GRPT (1,1) in phase II. The paper tracks 21 governorates' CE. Proactive monitoring helps take corrective actions, enhancing the reduction in errors gap to less than 2.4%. The paper reveals that the industrial sector extracting CE at (38.67%) to 2020 with hopeful reduction of 1.72% annually if the government's interested in supporting carbon sinks, which drastically decreased to 1% by 2020 and to 0.72% annually by 2030.

Introduction: Disposable instruments in healthcare have led to a significant increase of medical waste. The aim of this study is to validate the recycling of disposable Zamak laryngoscope blades into new medical components by using a new ‘all-in-one’ affordable reprocessing setup as alternative for die-casting. Methods: A n “all-in-one” casting set-up was designed and built. Laryngoscope blades, recovered from two hospitals, were disinfected, melted and cast into dog-bones and into new instrument parts. The quality of the cast material was evaluated using X-ray fluorescence spectrometry. The mechanical properties were obtained by assessing the Ultimate Tensile Strength (UTS) and tensile tests. Results: A recovery of 93 % Zamak was obtained using a melting temperature of 420 °C for 3 h. The XRF Spectro data showed higher Zinc and silicon concentrations when compared with Virgin Zamak. The dog-bones tests resulted in an average UTS, Yield Strength (YS) and Young's Modulus (YM) of 236 ± 61 (MPa), 70 ± 43 and 9 ± 3, respectively, representing 82 %, 103 % and 64 % of the UTS, YS and YM of standard Zamak. Functional instrument parts with extensions and inner chambers were cast with a maximal shrinkage percentage of 1 ± 1 %. Discussion: This study demonstrates that the created “all-in-one” reprocessing method can process contaminated disposable Zamak laryngoscope blades into new raw base material and new instrument parts. Although material and surface properties can deteriorate, reprocessed Zamak still has sufficient mechanical properties and can be used to cast complex parts with sufficient dimensional tolerances and minimal shrinkage. Conclusion: A micro reprocessing method was designed and used to turn disposed laryngoscope blades into new basis material and semi-finished components. Follow up studies are needed to scale and optimize this process towards a functional alternative for die casting. It should be further investigated how this process can contribute to further medical waste reduction and a circular healthcare economy.

The alignment of social, economic and environmental aspects within Sustainable Development Goals is of paramount importance in the oil industry. However, current methods used to conduct project analysis fail to consider these aspects in light of company's sustainability policies. In this article, a technique for a Preliminary Sustainability Analysis of the Enterprise-PSAE is proposed. The method developed uses a participatory action research methodology, based on successive case studies applied to real projects of a large oil company in Brazil. The PSAE makes it possible to identify “Actions for Sustainability-AS's” and evaluate their impacts on the three pillars of sustainability (economic, environmental, and social). When considering the “materiality test” and the “monetary aggregation” for measuring the impact of “AS's” on the sustainability pillars, PSAE contributes deeply to improving the assessment of sustainability indexes. Thus, the PSAE inhibits subjectivity in these assessments and aligns the project with the company's sustainability report. PSAE was applied to oil facilities projects, enabling a comprehensive vision of the pillars of sustainability. Moreover, PSAE presents good usability and compatibility with the project environment, in addition to offering relevant information to guide the decision making process of engineering managers in the direction of the company's sustainability policy.

The research focuses on implementation of cleaner production techniques and sustainable practices to reduce the environmental footprint in 07 tanneries of Pakistan through the project titled, International Labour and Environmental Standards (ILES) in SEMs of Pakistan by WWF-Pakistan. The baseline data of the industries were collected, and each industrial unit was surveyed for 05 days to cover all the major areas of resource and energy consumption, chemical conservation, reduction in CO2 emission and economic feasibility including payback period and profit. Collected data were analyzed and suitable technological solutions were proposed for the opportunities. After a specific time, post-performance analysis was carried out to ensure the on-ground implementation and to develop strong business cases. Gaps were shared with the examined industries for their internal use and continuous improvements for further reduction in their environmental footprint. It was concluded that by working on the suggested interventions 07 industries, on average, conserved 71,131 m3 water per year, 1643.166 m3 per year compressed air was saved, and 333,791 kW energy was conserved on a yearly basis. Steam management helped industries to save 136,398 kg of steam on a daily basis, and the overall CO2 reduction was 300,842 kg/year. The graphical abstract below indicates the resources conserved by the industries that ultimately save the cost and reduce CO2 emission.Resource Conservation and GHG Reduction by 07 Tanneries.

Wastes and by-products of the food industry are often overlooked and utilized or underutilized. Of late, the emphasis is being given to recover, recycle, and recondition waste, promoting sustainable food processing. In this research, grape pomace and broken wheat which are otherwise sent for animal feed were collected from industries and were used as key ingredients of a 3D printing material supply for the production of functional cookies. The administration of grape pomace augmented the nutritional value and antioxidant properties of the cookies. Printing using a nozzle diameter of 1.28 mm, extruder motor speed of 600 rpm, and print speed of 400 mm/min gave the optimal printability for the in-house developed extrusion-based food 3D printer CARK. The printed constructs were post-processed at 130 °C for 12 min and the 6% grape pomace formulation received the highest preference during sensory evaluation. Interestingly, the developed product was rich in proteins and dietary fiber. This approach highlights the potential for value addition of industrial waste streams with good consumer preference. Accordingly, the unmatched levels of customization that additive manufacturing offers can be well complemented with personalizing foods in terms of nutritional content, whilst providing scope for cleaner production practices and improved recovery of resources from food processing wastes.

The need for sustainable development has been reflected in the adoption of cleaner production initiatives in the last years. However, the literature indicates that more research is still necessary to engage industries in adopting alternatives to reduce environmental impact. In that regard, we investigated a way to reduce the environmental impact in the metal-mechanical industry, caused by the conventional salt bath nitriding process. This technique commonly uses cyanides and cyanates salts as a nitrogen source for the formation of nitrides coating to improve the metal surface properties, especially to achieve high hardness. Thereby, this paper sets out an approach, as an alternative to obtain a nitride layer, formed by non-toxic salts: potassium nitrate additivated with a new condition of antioxidative salt, potassium chloride, which improves the nitriding efficiency and surface finish of carbon steel 0.2% C. The results indicated the formation of a white layer of 8 μm thickness and a diffusion zone around 200 μm, after 3 h of nitriding. There was an increase in hardness, from 198 HV on the substrate to 702 HV on the nitrided surface. Consequently, one can conclude that the use of non-toxic salts is an efficient alternative to improve the surface properties in low carbon steel with the advantage of applying green engineering approaches, feasible technologically to the decrease in the amount of pollution.

Palm oil processing generates enormous amount of wastewater, the palm oil mill effluent (POME), containing various recalcitrant pollutants. The biological processes commonly employed to treat POME often fail to achieve treatment levels required for safe disposal or recycling of the effluent, prompting the need to develop polishing technologies. In this work, we investigated the possibility of polishing biologically-treated POME using palm kernel shell activated carbon (PKSAC) derived from a solid waste generated during palm oil processing. The rationale is to provide impetus towards adopting cleaner production in the palm oil industry through recycling both wastewater and solid wastes generated from palm oil processing. The PKSAC was impregnated with iron oxide to produce a magnetic adsorbent that could be easily separated after the treatment. The adsorbent was characterized using BET, SEM/EDX, FTIR and VSM analyses. The adsorbent exhibited high specific surface area (611.85 ​m2/g), excellent magnetic property (15.16 emu/g) and various surface functional groups. Batch adsorption experiments were conducted to investigate the suitability of the adsorbent to polish biologically-treated POME. To investigate the effect of operational parameters (initial pH, adsorbent dosage and contact time) on the adsorption, response surface methodology using Box-Behnken Design was employed. Under the optimum condition (initial pH ​= ​3.5, adsorbent dosage ​= ​9.9 ​g/L and contact time ​= ​3.4 ​h), 99.7% of the initial color and 85.0% of the initial COD were removed. The initial pH and adsorbent dosage are the most significant parameters affecting the adsorption. The adsorbent maintained excellent adsorption performance over 4 cycles, with the removal efficiency reducing by less than 2% after the 4th cycle. This study has shown that palm kernel shell can be used as an effective adsorbent for POME polishing, indicating a potential for wastes recycling within the palm oil industry. The use of palm kernel shell to treat POME, which could be subsequently recycled, represents a significant step towards enhancing the sustainability of palm oil industry.

The aim of this study was to encourage cleaner production processes by investigating the economic feasibility of using LN2 as a cutting fluid in the turning of quenched and tempered AISI D6 tool steel using solid PCBN inserts. For this purpose, an LN2 supply system was developed to deliver liquid nitrogen to the tool rake and flank faces. In order to measure the LN2 mass flow rate, a system based on load cells was set up. Three different LN2 flow rates (79, 51 and 21 ​L/h) were investigated. For comparison, turning tests under dry and wet conditions using a mineral-based emulsion were also performed. Nose wear (VBC) was monitored and used as one of the input parameters for an economic analysis, which was performed based on a previous study. It was concluded that the LN2 delivery system and the method used for the LN2 flow rate measurement were effective in supplying liquid nitrogen to the cutting zone in a controlled way, and liquid nitrogen at the highest flow rates provided longer cutting tool life than dry and wet conditions. Furthermore, the use of an emulsion did not increase the cutting tool life in comparison with the dry condition and machining assisted by LN2 at the lowest flow rate presented no statistical difference as compared to the wet condition in terms of production cost. Thus, based on this case study, liquid nitrogen can be considered as a sustainable alternative to the use of mineral-based emulsions, without incurring economic losses.

Olive mill wastewaters (OMWWs) are a significant source of environmental pollution, especially in important olive oil producing countries such as Spain, Greece, Syria, Jordan and other countries in the Mediterranean. Due to cost issue no treatments plants are currently available at the mills; therefore, OMWW is normally discharged into the environment causing serious environmental problems such as: coloring and pollution of surface and ground waters, soil surface, and foul odors problems. Approximately 209,000 tons of olives have been processed in Jordan in 2017, which generated 175,000 m3 of OMWWs. They generated rougly 3,069 tons of BOD5, 7,956 tons of COD, 149 tons of residual olive oil, 2.07 tons of phenols, 3,753 ton total suspended solids and 4.2 ton of phosphorous. The OMWW is rich in organic matter expressed as BOD5 and COD with COD/BOD5 of 2.6 indicated that OMWWs is not suitable for biological treatment and therefore must be treated before discharge to the environment or sewer system. Cleaner production options and proper environmental waste management systems at the mills are needed to reduce their environmental impact. This may include the adoption of the two-phase mills to reduce water use to less than half the quantities used in traditional and three phases mills.

The contradiction between the rapid textile expansion and intensive energy consumption, highly environmental pollution calls for the adoption of cleaner production (CP). However, current evaluation system mainly targeted on CP at production stage, guidance and support on the life cycle assessment is still in its infancy. Meanwhile few studies brought the combination of water conservation and carbon reduction into considerations. This study compared the existing CP evaluation systems including guidelines for the whole industry, standards for textile industry and indicators for the dyeing and finishing sector by quantifying the differences of indicator score compositions. Comparisons analysis from six aspects suggested that all the evaluation systems had relevant indicators regarding "pollutant emissions". "Management", "process equipment and techniques" and "resource and energy consumption" have also been well concerned while "product characteristic" seemed to be overlooked at current stage. From the perspective of whole life cycle, the key of textile processing is the "printing and dyeing" (44.23 %) followed by "fabric manufacturing"(28.85 %) and setting (15.38 %). With regards to the environmental impacts, resources depletion gained the highest attention since their indicator scores reached up to 25.71 %, 18.47 % and 20.62 % for EMAS, ERG 2018 and HJ-1852006. Cleaner production awareness and social impact also played significant roles in ISO 14031:2021 and WMG. Subsequently, a set of new comprehensive CP evaluation indicator system was established, including 3 scopes and 7 goals. The newly-built indicator system incorporated with life cycle perspectives gave a powerful tool to measure the CP level in textile industry and of CP will benefit from water reuse and energy utilization with high efficiency., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Individual nanoparticle application has been documented to promote plant production; however, whether co-application of two nanoparticles (NPs) is more sustainable and significantly promotes plant production is unclear. Herein, foliar co-applications of two NPs or their conventional fertilizer forms on the growth, micronutrient (copper and zinc) enrichment, primary productivity, and essential oil (EO) production in a medicinal annual, dragonhead (Dracocephalum moldavica L.), were investigated. Treatments included 1:1 ratio of zinc oxide nanoparticles (ZnONPs):copper oxide nanoparticles (CuONPs) (40-400 mg/L), and compared with individual NPs, individual zinc suspension (ZnS) and chelated copper (chelated-Cu), and their combination, at equivalent concentrations. Results showed that the highest bioenrichment of Zn and Cu was observed with 80-160 mg/L ZnS+chelated-Cu, 400 mg/L ZnONPs+CuONPs, or ionic combination treatments. A dose-dependent increase in hydrogen peroxide and malondialdehyde was observed with co-treatment of NPs or ions, and oxidative stress responses were higher with NPs or ions co-treatment than individual treatment. With 160 mg/L ZnONPs+CuONPs treatment, total chlorophyll, aboveground biomass, and essential oil production increased significantly compared to control, 160 mg/L CuONPs, and 160 mg/L ZnONPs (227, 157 and 823 %; 58, 79, and 51 %; and 46, 80, and 3 %, respectively). Flavonoid and anthocyanin content also increased significantly (58 and 50 %, respectively) with ZnONPs+CuONPs compared to ZnS+chelated-Cu and were higher than ZnONPs or CuONPs alone by 10 and 25 %, and 37 and 36 %, respectively. More importantly, EO production and quality improved with 160 mg/L ZnONPs+CuONPs treatment compared to control. Taken together, our findings showed that foliar co-treatment of 160 mg/L ZnONPs+CuONPs could significantly improve primary productivity, aboveground biomass, and EO quality and yield in dragonhead grown in semi-arid field conditions; and thus, 160 mg/L ZnONPs+CuONPs is recommended as an optimal foliar co-treatment strategy for promoting sustainable plant production in semi-arid regions where soil nutrients and water are limiting factors inhibiting crop yield., Competing Interests: Declaration of competing interest The authors have no conflicts of interest to declare., (Copyright © 2023. Published by Elsevier B.V.)

As energy crisis is recognized as an increasingly serious concern, the topic on biohydrogen (bioH 2 ) production, which is renewable and eco-friendly, appears to be a highly-demanding subject. Although bioH 2 production technologies are still at the developmental stage, there are many reported works available on lab- and pilot-scale systems with a promising future. This paper presents various potential methods of bioH 2 production using biomass resources and comparatively assesses them for environmental impacts with a special emphasis on the specific biological processes. The environmental impact factors are then normalized with the feature scaling and normalization methods to evaluate the environmental sustainability dimensions of each bioH 2 production method. The results reveals that the photofermentation (PF) process is more environmentally sustainable than the other investigated biological and thermochemical processes, in terms of emissions, water-fossil-mineral uses, and health issues. The global warming potential (GWP) and acidification potential (AP) for the PF process are then found to be 1.88 kg-CO 2 eq. and 3.61 g-SO 2 eq., which become the lowest among all processes, including renewable energy-based H 2 production processes. However, the dark fermentation-microbial electrolysis cell (DF-MEC) hybrid process is considered the most environmentally harmful technique, with the highest GWP value of 14.6 kg-CO 2 eq. due to their superior electricity and heat requirements. The water conception potential (WCP) of 84.5 m 3 and water scarcity footprint (WSF) of 3632.9 m 3 for the DF-MEC process is also the highest compared to all other processes due to the huge amount of wastewater formation potential of the system. Finally, the overall rankings confirm that biological processes are primarily promising candidates to produce bioH 2 from an environmentally friendly point of view., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2023. Published by Elsevier B.V. All rights reserved.)

Since the birth of cyanidation, it has been dominant in the gold extraction industry. Recently, with the increasing awareness of environmental hazards and potential risks posed by the severe toxicity of cyanide, attempts to seek alternative lixiviants have arisen. Over the past three decades, a significant amount of literature has examined alternative lixiviants to cyanide for recovering gold, while few industrial applications have been reported due to various obstacles, such as toxicity, excessive consumption, or low leaching efficiency. These obstacles are progressively overcome in multiple ways, including process improvement, system optimization, use of co-intensifying systems, and development of additives. In this paper, related studies about alternative lixiviants and methods such as cyanide, thiosulfate, thiourea, thiocyanate, polysulfides, halides, and microbial leaching are summarized. The history, fundamentals, advancements, and challenges of alternative lixiviants are fully concluded to provide a reference for cleaner gold production. In addition, the comprehensive performance of lixiviants was evaluated according to a novel evaluation criterion proposed in terms of economy, efficiency, and environment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)