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Abstract Biochar, a carbon-rich material produced from biomass waste through thermal conversion, holds great environmental promise. This article offers a comprehensive overview of the various feedstocks used in biochar production, the different types of thermal degradation processes, biochar characterization, properties, modifications to engineered materials, and their applications in the environment. The quality of biochar, including surface area, pore size and volume, and functional group formation, is significantly influenced by the specific conditions under which thermal conversion takes place. Each of the diverse processes employed to produce biochar yields a distinct set of properties in the final product. In recent years, biochar has gained widespread recognition and utilization in diverse fields such as wastewater treatment, carbon sequestration, reduction of greenhouse gas emissions, biogas production, catalysis in biofuel industries, construction, and soil enhancement. In summary, biochar is a promising environmental mitigation tool to achieve a sustainable environment. In addition to its benefits, the application of biochar presents several challenges, including the selection of feedstocks, methods of biochar production, modifications to biochar, the properties of biochar, and the specific applications of biochar. The current review summarizes factors that could lead to significant advancements in future applications. Graphical Abstract

Natural gas, coal, and oil account for over 84 % of the world’s energy demand. Greenhouse gases, including carbon dioxide, methane, and oxides of nitrogen and sulphur, are released during the combustion of fossil fuels, leading to substantial climate changes and environmental damage. Therefore, harnessing energy from alternative sustainable resources without the emission of harmful waste products is vital for the ecosystem’s health. By 2050, global food waste production will reach 3.4 billion metric tons. Although widely recognized as a substantial energy resource, its value is underutilized throughout sub-Saharan Africa (SSA). Therefore, understanding and exploiting the potential value of food waste as a biofuel can result in net-zero emissions, reducing significant environmental pollution while conserving natural resources. Furthermore, this paper reviews how effective management of food waste will have the potential to contribute to the development of waste-to-energy resources in SSA countries, as well as help improve global ecosystems.

Aflatoxin is one of the most toxic biotoxins found in contaminated agricultural products. It has strong mutagenicity, carcinogenesis and teratogenicity to humans and animals. In this study, instant catapult steam explosion combined with ammonia water was examined for its potential to degrade aflatoxin B1 in peanut cake in order to improve its utilization as a toxic-free animal feed. Incubation of AFB1-containing peanut cake followed by processing with Instant Catapult Steam Explosion (ICSE) led to approximately 79.03 % degradation of AFB1, while the degradation of AFB1 was up to 91.48 % under the treatment of ICSE combined with 4 % NH₃·H₂O at 1.2 MPa in 200 s of process time. After treatment, nutrients in peanut cake were not significantly changed. The toxicity of AFB1 degradation products was evaluated and the results showed that the toxicity of these products were found to be substantially less than that possessed by AFB1. A low chemical pollution, efficient and toxic-free technology system of AFB1 degradation was established, which detoxify aflatoxin-contaminated biomass for sustainable and safe utilization of agricultural biomass as animal feed.

The search of sustainable route for biofuel production from renewable biomass have garnered wide interest to seek for various routes without compromising the environment. Co-pyrolysis emerges as a promising thermochemical route that can improve the pyrolysis output from simultaneously processing more than two feedstocks in an inert atmosphere. This paper focuses on the kinetic modeling and neuro-evolution optimization in the application of catalytic co-pyrolysis of microalgae and plastic waste using HZSM-5 supported on limestone (HZSM-5/LS), in which co-pyrolysis of binary mixture of microalgae and plastic wastes (i.e. High-Density Polyethylene and Low-Density Polyethylene) was investigated over different heating rates. The results have shown a positive synergistic effect between the microalgae and polyethylene in which the apparent activation energies values have reduced significantly (∼20 kJ/mol) compared to that obtained by pyrolysis of individual microalgae component. The kinetic models reflect that the mixture of microalgae and Low-Density Polyethylene for use as co-pyrolysis feedstock requires activation energy that is 23% and 13% lower compared to that required by pure microalgae and the mixture of microalgae and High-Density Polyethylene, respectively. The Progressive Depth Swarm-Evolution (PDSE) was used for neural architecture search, which subsequently provided optimal reaction condition at 873 K can achieve 99.6 % of degradation rate using a tri-combination of LDPE (0.13 %) + HDPE (0.77 %) + MA (0.11 %) in the presence of HZSM-5/LS catalyst.

Increasing studies of plastisphere have raised public concern about microplastics (MPs) as vectors for pathogens, especially in aquatic environments. However, the extent to which pathogens affect human health through MPs remains unclear, as controversies persist regarding the distinct pathogen colonization on MPs as well as the transmission routes and infection probability of MP-associated pathogens from water to humans. In this review, we critically discuss whether and how pathogens approach humans via MPs, shedding light on the potential health risks involved. Drawing on cutting-edge multidisciplinary research, we show that some MPs may facilitate the growth and long-range transmission of specific pathogens in aquatic environments, ultimately increasing the risk of infection in humans. We identify MP- and pathogen-rich settings, such as wastewater treatment plants, aquaculture farms, and swimming pools, as possible sites for human exposure to MP-associated pathogens. This review emphasizes the need for further research and targeted interventions to better understand and mitigate the potential health risks associated with MP-mediated pathogen transmission.

Sustainable socio-economic development largely depends on the sustainability of the energy supply from economic, environmental, and public health perspectives. Fossil fuel combustion only meets the first element of this equation and is hence rendered unsustainable. Biofuels are advantageous from a public health perspective, but their environmental and economic sustainability might be questioned considering the conflicts surrounding their feedstocks, including land use change and fuel vs. food conflict. Therefore, it is imperative to put more effort into addressing the downsides of biofuel production using advanced technologies, such as nanotechnology. In light of that, this review strives to scrutinize the latest developments in the application of nanotechnology in producing biodiesel, a promising alternative to fossil diesel with proven environmental and health benefits. The main focus is placed on nanotechnology applications in the feedstock production stage. First, the latest findings concerning the application of nanomaterials as nanofertilizers and nanopesticides to improve the performance of oil crops are presented and critically discussed. Then, the most promising results reported recently on applying nanotechnology to boost biomass and oil production by microalgae and facilitating microalgae harvesting are reviewed and mechanistically explained. Finally, the promises held by nanomaterials to enhance animal fat production in livestock, poultry, and aquaculture systems are elaborated. Despite the favorable features of using nanotechnology in biodiesel feedstock production, the presence of nanoparticles in living systems is also associated with important health and environmental challenges, which are critically covered and discussed in this work.

According to the World Health Organization, women's breast cancer is among the most common cancers with 7.8 million diagnosed cases during 2016–2020 and encompasses 15 % of all female cancer-related mortalities. These mortality events from triple-negative breast cancer are a significant health issue worldwide calling for a continuous search of bioactive compounds for better cancer treatments. Historically, plants are important sources for identifying such new bioactive chemicals for treatments. Here we use high-throughput screening and mass spectrometry analyses of extracts from 100 plant species collected in Chinese ancient forests to detect novel bioactive breast cancer phytochemicals. First, to study the effects on viability of the plant extracts, we used a MTT and CCK-8 cytotoxicity assay employing triple-negative breast cancer (TNBC) MDA-MB-231 and normal epithelial MCF-10A cell lines and cell cycle arrest to estimate apoptosis using flow cytometry for the most potent three speices. Based on these analyses, the final most potent extracts were from the Amur honeysuckle (Lonicera maackii) wood/root bark and Nigaki (Picrasma quassioides) wood/root bark. Then, 5 × 106 MDA-MB-231 cells were injected subcutaneously into the right hind leg of nude mice and a tumour was allowed to grow before treatment for seven days. Subsequently, the four exposed groups received gavage extracts from Amur honeysuckle and Nigaki (Amur honeysuckle wood distilled water, Amur honeysuckle root bark ethanol, Nigaki wood ethanol or Nigaki root bark distilled water/ethanol (1:1) extracts) in phosphate-buffered saline (PBS), while the control group received only PBS. The tumour weight of treated nude mice was reduced significantly by 60.5 % within 2 weeks, while on average killing 70 % of the MDA-MB-231 breast cancer cells after 48 h treatment (MTT test). In addition, screening of target genes using the Swiss Target Prediction, STITCH, STRING and NCBI-gene database showed that the four plant extracts possess desirable activity towards several known breast cancer genes. This reflects that the extracts may kill MBD-MB-231 breast cancer cells. This is the first screening of plant extracts with high efficiency in 2 decades, showing promising results for future development of novel cancer treatments.

Abstract To support and move toward a sustainable bioeconomy, the production of polyhydroxyalkanoates (PHAs) using renewable biomass has acquired more attention. However, expensive biomass pretreatment and low yield of PHAs pose significant disadvantages in its large‐scale production. To overcome such limitations, the most recent advances in metabolic engineering strategies used to develop high‐performance strains that are leading to a new manufacturing concept converting biomass to PHAs with co‐products such as amino acids, proteins, biohydrogen, biosurfactants, and various fine chemicals are critically summarized. This review article presents a comprehensive roadmap that highlights the integrated biorefinery strategies, lifecycle analysis, and techno‐economic assessment for sustainable and economic PHAs production. Finally, current and future challenges that must be addressed to transfer this technology to real‐world applications are reviewed.

Sea cucumbers have high economic value, and in most forms of trade, their body wall is typically the only part that is harvested and sold. The organs of the sea cucumber, collectively known as the viscera, are frequently discarded, contributing to land and water pollution. However, discarded sea cucumber viscera contain various nutrients that can be used in many applications. Therefore, this review highlights the biological and economic aspects of sea cucumbers, followed by a critical discussion of the nutritional value of their internal organs and possible applications, including as functional feed additives in the aquaculture industry, sources of natural testosterone for application in sex reversal and production of monosex population, of neuroprotective agents against central nervous system disorders and of cosmetic ingredients, especially for skin whitening and anti-ageing products. The review further highlights the valorisation potential of viscera to maximize their economic potential, thus providing an enormous prospect for reusing sea cucumber waste, thereby reducing the negative impact of the sea cucumber fishery sector on the environment.

Wood-based panels, which contain wood raw materials along with urea-formaldehyde (UF) or phenol-formaldehyde (PF) resins, can increase the indoor air concentration of formaldehyde. Formaldehyde can stimulate the upper respiratory mucosa and cross-linking reaction with cell proteins and DNA, and this can result in degeneration and necrosis of respiratory cells and damaged cell proliferation. Formaldehyde can induce health hazards such as nasal cancer, leukemia, and destruction of the reproductive system. Acetaldehyde dehydrogenase 5 (ADH5) in the body cooperates with Fanconi anaemia complementation group D2 (FANCD2) to quickly metabolize formaldehyde into formate and maintain the balance of endogenous formaldehyde. However, when both ADH5 and FANCD2 proteins have defects or mutations, damaged DNA repair failure and cell proliferation induce a variety of health diseases. The damage has been found in the upper respiratory area, not on distal body tissues such as liver, kidney, and bone marrow. Meanwhile epidemiological survey has not shown a positive correlation between formaldehyde and health hazards. It is recommended that the use of wood formaldehyde-based products should be reduced, and pathogenesis genes and damage repair mechanism should be studied systematically and deeply to develop gene drugs to remove excess formaldehyde and activate the damage gene repair mechanism in the future.

As a traditional nourishing Chinese herbal medicine, Cornus officinalis Sieb. et Zucc. has a long history of application. At present, only the flesh of the fruit of Cornus officinalis is used as a medicine, which wastes a large quantity of ingredients in the nutlet. To improve the comprehensive utilization efficiency of the fruit’s nutlet, which could be used when there is a shortage of the plant’s fruit in the market, this study used Fourier transform-infrared spectroscopy (FT-IR), gas chromatography-mass spectrometry (GC-MS), thermogravimetric (TG) analysis, pyrolysis-gas chromatography-mass spectrometry (PY-GC-MS), and nuclear magnetic resonance (NMR) techniques to analyze the Cornus officinalis nutlet. The results showed that the active ingredients of Cornus officinalis nutlet have great medicinal value and could become a substitute for the fruit. After extracting the active ingredients, the residue can be used as a good biomass liquid fuel, providing reference for the future to replace fossil fuels. This study provides the scientific basis for the comprehensive utilization of high-quality resources for Cornus officinalis.

Microwave simulation is significant in identifying a reactor design allowing the biomass to be heated and processed evenly. This study integrated the radio frequency and transient heat transfer modules to simulate the microwave distribution and investigated the performance of microwave heating in the cavity. The simulation results were compared with the experimental findings using the finite element analysis software of COMSOL MULTIPHYSICS to predict the temperature profile and electric field of microwave in the biomass (empty fruit bunch pellets). The higher temperature distribution was observed at the bottom and centre section of the empty fruit bunch pellet bed in the reactor, showing the uniqueness of microwave heating. According to the simulation results, the temperature profile obtained through the specific cavity geometry and dielectric properties agreed with the experimental temperature profile. The simulated temperature profile demonstrated a logarithmic increase of 120 °C/min at the first 50 s followed by 50 °C/min until 350 s. The experimental temperature profile showed three different heating rates before reaching 300 °C, including 78.3 °C/min (50–120 °C), 30.6 °C/min (121–250 °C), and 105 °C/min (250–300 °C). The results of this study might contribute to the improvement of microwave heating in biomass torrefaction.

Aquaculture produces nearly half of the seafood consumed by the ever-growing world population. There have been attempts to adopt novel technologies into the industry to increase profitability, particularly the Internet of Things (IoT). In aquaculture, it is therefore important to evaluate and address the challenges related to IoT. The purpose of this review is to categorize the challenges associated with implementing IoT systems in aquaculture according to the literature. This work reviewed prototyped IoT systems reported in the literature in the last five years. Moreover, some potential solutions to the reported challenges were discussed with the help of literature that can be used by researchers in the future. Among IoT systems used in aquaculture, some challenges are common, while others are specific to particular species or farms. Due to direct contact with water, maintenance of sensor probes is a common challenge. The literature addressed this problem through different designs that led to self-cleaning mechanisms. There were three categories of specific challenges: infrastructure-related, data-related, and perception-related. Infrastructural challenges primarily relate to electricity availability and internet connectivity. For electricity, energy harvesting technologies are suggested, and for internet connectivity, satellite internet or offline systems are suggested. The data related category covers challenges related to data loss due to device or network errors. Studies have shown that incorporating soft methods can help resolve most of these issues. Perception-related challenges examine barriers that prevent aquaculture farmers from implementing IoT systems. As one potential remedy for this barrier, literature suggests policy makers intervene in promoting the benefits of IoT systems and providing incentives.

Food security and sustainable development of agriculture has been a key challenge for decades. To support this, nanotechnology in the agricultural sectors increases productivity and food security, while leaving complex environmental negative impacts including pollution of the human food chains by nanoparticles. Here we model the effects of silver nanoparticles (Ag-NPs) in a food chain consisting of soil-grown lettuce Lactuca sativa and snail Achatina fulica. Soil-grown lettuce were exposed to sulfurized Ag-NPs via root or metallic Ag-NPs via leaves before fed to snails. We discover an important biomagnification of silver in snails sourced from plant root uptake, with trophic transfer factors of 2.0–5.9 in soft tissues. NPs shifts from original size (55–68 nm) toward much smaller size (17–26 nm) in snails. Trophic transfer of Ag-NPs reprograms the global metabolic profile by down-regulating or up-regulating metabolites for up to 0.25- or 4.20- fold, respectively, relative to the control. These metabolites control osmoregulation, phospholipid, energy, and amino acid metabolism in snails, reflecting molecular pathways of biomagnification and pontential adverse biological effects on lower trophic levels. Consumption of these Ag-NP contaminated snails causes non-carcinogenic effects on human health. Global public health risks decrease by 72% under foliar Ag-NP application in agriculture or through a reduction in the consumption of snails sourced from root application. The latter strategy is at the expense of domestic economic losses in food security of $177.3 and $58.3 million annually for countries such as Nigeria and Cameroon. Foliar Ag-NP application in nano-agriculture has lower hazard quotient risks on public health than root application to ensure global food safety, as brought forward by the United Nations Sustainable Development Goals.

This paper discusses the use of agricultural biomass as a promising resource for renewable energy production, e.g., bio-oil and biogas via pyrolysis and catalysis, among other technologies. In order to prevent the accumulation of agricultural biomass, most countries still use traditional disposal or processing methods, e.g., burning in the field, which not only has a low energy conversion rate, but also releases harmful gases, e.g., CO2, CO, and NH3. These traditional methods are regarded as inefficient with respect to the low utilization of waste; they also pose a threat to human health. The energy conversion of agricultural biomass makes full use of resources and accelerates the development of green energy. In particular, agricultural biomass can lead to the production of high-quality renewable fuels and chemical raw materials through catalytic pyrolysis technologies. The fuel produced using catalytic pyrolysis has a low sulfur and alkali metal contents and techno-economic analysis shows that catalytic pyrolysis greatly reduces the production cost and improves the utilization rate of agricultural biomass. The production of bio-oil and gas via catalytic pyrolysis and agricultural biomass are environmentally friendly and economically feasible for clean energy production. Therefore, additional research is needed to enable the upscaling of renewable energy products.

Energy storage is essential to conserve and deliver energy to end-user with continuity and durability. A sustainable energy supply with minimal process losses requires cost-effective and environmentally friendly energy storage material. In this study, self-co-dopes N (3.65 %) and O (6.44 %) porous biochar were produced from pyrolysis of biomass pellets (made from garden wastes) and examined for energy storage application. The presence of co-doped-heteroatoms within the carbon matrix of biochar resulted in enhanced surface wettability, fast charge transfers, increased electrical conductivity, and low internal resistance. Biochar produced at 800 ℃ (i.e. biochar-800) showed desirable pseudocapacitive nature induced by self-co-doped heteroatoms. Two-electrode measurements in aqueous 1 M H2SO4 revealed that biochar-800 possessed 228F g−1 of specific capacitance at a current density of 1 Ag−1. Additionally, biochar-800 exhibited a high energy density of 7.91 Wh kg−1 in aqueous electrolyte and promising cycling stability with 88% capacitance retention after 5000 cycles at 10 A g−1. Enhanced capacitive performance of biochar-800 was assigned to the presence of self-co-doped heteroatom, the high specific surface area of 312 m2g−1, and self-formed mesopores (pore size around 15.2 nm). This study demonstrates the great promise of porous biochar derived from biomass pellets as a low-cost electrode material for high-performance energy storage devices.

There is a growing concern about human health of residents living in areas where mining and smelting occur. In order to understand the exposure to the potentially toxic elements (PTEs), we here identify and examine the cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn) in scalp hair of residents living in the mining area (Bayan Obo, n = 76), smelting area (Baotou, n = 57) and a reference area (Hohhot, n = 61). In total, 194 hair samples were collected from the volunteers (men = 87, women = 107) aged 5–77 years old in the three areas. Comparing median PTEs levels between the young and adults, Ni levels were significantly higher in adults living in the smelting area while Cr was highest in adults from the mining area, no significant difference was found for any of the elements in the reference area. From the linear regression model, no significant relationship between PTEs concentration, log10(PTEs), and age was found. The concentrations of Ni, Cd, and Pb in hair were significantly lower in the reference area when compared to both mining and smelting areas. In addition, Cu was significantly higher in the mining area when compared to the smelting area. Factor analysis (FA) indicated that men and women from the smelting area (Baotou) and mining area (Bayan Obo), respectively, had different underlying communality of log10(PTEs), suggesting different sources of these PTEs. Multiple factor analysis quantilized the importance of gender and location when combined with PTEs levels in human hair. The results of this study indicate that people living in mining and/or smelting areas have significantly higher PTEs (Cu, Ni, Cd, and Pb) hair levels compared to reference areas, which may cause adverse health effects. Remediation should therefore be implemented to improve the health of local residents in the mining and smelting areas.

Abstract The cleaner production of biomass into value-added products via microbial processes adds uniqueness in terms of food quality. The microbe-mediated traditional process for transforming biomass into food is a sustainable practice in Asian food industries. The 18 fermented fish products derived through this process as well as the associated micro-flora and nutritional composition have been focused. This review aims to update the process of green conversion biomass into value-added food products for a more sustainable future. Fish products are classified based on the substrate and source of the enzymes used in fermentation, which includes the three types of technology processing discussed. According to the findings, these fermented fish contain a plethora of beneficial microbiota, making them a valuable source of probiotics that may confer nutritional and health benefits. Bacillus (12 products), Lactobacillus (12 products), Micrococcus (9 products), and Staphylococcus (9 products) were the most common bacterial genera found in 18 fermented fish products. Consuming fermented fish products is beneficial to human health due to their high levels of carbohydrate, protein, fat, and lactic acid. However, biogenic amines, which are produced by certain bacteria as a by-product of their catabolic activity, are a significant potential hazard in traditionally fermented fish.

The presence of toxic heavy metals contributes towards the deterioration in the quality of water resources. In this work, microwave steam activation (MSA) was conducted to convert palm kernel shell into activated carbon (PKSAC). MSA provided a rapid heating rate (up to 140 °C/min) at 700 °C under a steam flow rate of 5 g/min for 45 min. PKSAC was obtained, showing high BET surface area (539.75 m2/g) with low H/C and O/C ratios, indicating a high degree of carbonization and stability of PKSAC to act as a durable adsorbent. The PKSAC was then applied to remove heavy metals (i.e. Cd2+ and Pb2+) present in landfill leachate (LL). Batch experiments were performed to investigate the effects of initial ion concentrations and contact times on Cd2+ and Pb2+ adsorption under optimal condition. Maximum Cd2+ and Pb2+ removal of 116.0 mg/g and 59.9 mg/g, respectively were obtained at pH 3, initial concentration of 100 mg/L, and adsorbent dose of 0.2 g. Results showed that the adsorption kinetics of Cd2+ and Pb2+ can be described by the pseudo second order kinetics model, while Freundlich isotherm was well fitted to the Cd2+ and Pb2+ adsorption data. Overall, the PKSAC produced by MSA is a promising and cost-effective adsorbent for removal of Cd2+ and Pb2+.

Yellow mealworm (Tenebrio molitor) is a supplementary protein source for food and feed and represents a promising solution to manage grain contaminated with Aflatoxin B1 (AFB1). In this study, AFB1 present in different concentrations in wheat bran was treated and removed via bioconversion by yellow mealworm of different instars, with emphasis on the bioconversion performance and metabolism of AFB1. Upon application of wheat bran spiked with 100 μg/kg AFB1 to 5th–6th instar yellow mealworms, the conversion rate of AFB1 was up to 87.85 %. Low level of AFB1 (

Modeling is regarded as a suitable tool to improve biomass pyrolysis in terms of efficiency, product yield, and controllability. However, it is crucial to develop advanced models to estimate products' yield and composition as functions of biomass type/characteristics and process conditions. Despite many developed models, most of them suffer from insufficient validation due to the complexity in determining the chemical compounds and their quantity. To this end, the present paper reviewed the modeling and verification of products derived from biomass pyrolysis. Besides, the possible solutions towards more accurate modeling of biomass pyrolysis were discussed. First of all, the paper commenced reviewing current models and validating methods of biomass pyrolysis. Afterward, the influences of biomass characteristics, particle size, and heat transfer on biomass pyrolysis, particle motion, reaction kinetics, product prediction, experimental validation, current gas sensors, and potential applications were reviewed and discussed comprehensively. There are some difficulties with using current pyrolysis gas chromatography and mass spectrometry (Py-GC/MS) for modeling and validation purposes due to its bulkiness, fragility, slow detection, and high cost. On account of this, the applications of Py-GC/MS in industries are limited, particularly for online product yield and composition measurements. In the final stage, a recommendation was provided to utilize high-temperature sensors with high potentials to precisely validate the models for product yield and composition (especially CO, CO2, and H2) during biomass pyrolysis.

Our research aims to study the properties of real shark skin in accordance with its topographical features and the biomimicry for friction reduction. In this paper, we are focusing on antifouling surface modification based on the surface roughness and frictional resistance inspired from the shark’s denticule arrangements. Biomimetic shark skins were prepared using the silicone laminated transfer molding method to investigate the antifouling effects. Anti-algae formations were investigated to examine and assess the antifouling properties of the biomimetic shark skin surface microstructure. The results indicated that the effect of microreplication with shark skin on the surface had reduced 13% - 40% of algae formation. The characteristics of the hydrophobic properties for shark skin had also been investigated through the analysis of the contact angle (CA). Scanning electron microscopy (SEM) is used to observe the surfaces morphologies of the shark skin as well as the biomimetic shark skin. In addition to that, the frictional resistance experiment was carried out to evaluate the friction of coefficient (COF) of different surface modifications. The frictional resistance experiment for real shark skin and replicated shark skin demonstrated lowered COF value ranging from μ = 0 to 1, compared to the COF for controlled surface whereby the value ranges from μ = 0 to 5.

Abstract In this work, we proposed a facile approach to fabricate a superhydrophobic surface for anti-icing performance in terms of adhesive strength and freezing time. A hierarchical structure was generated on as-received Al plates using a wet etching method and followed with a low energy chemical compound coating. Surfaces after treatment exhibited the great water repellent properties with a high contact angle and extremely low sliding angle. An anti-icing investigation was carried out by using a custom-built apparatus and demonstrated the expected low adhesion and freezing time for icephobic applications. In addition, we proposed a model for calculating the freezing time. The experimented results were compared with theoretical calculation and demonstrated the good agreement, illustrating the importance of theoretical contribution in design icephobic surfaces. Therefore, this study provides a guideline for the understanding of icing phenomena and designing of icephobic surfaces.

Increasing discharge and inadequate removal of pharmaceutical compounds pose significant concerns over global aquatic systems and human health. The accomplishment of affordable and safe water requires a stringent elimination of these micropollutants. This study evaluated the performance of Visible/N-doped TiO2 and Visible/N-doped TiO2/H2O2 processes using a submerged photocatalytic membrane reactor (SMPR) with suspended N-doped TiO2 to address the removal of diclofenac (DCF). The kinetic and pathway of photodegradation of DCF were of particular interest in this study. The initial DCF concentrations upon the experiments were also examined using a wide range of 5–50 mg/L and 20–100 mg L−1 for Vis/N-doped TiO2, and Vis/N-doped TiO2/H2O2 process, respectively. The results indicated that higher initial concentration reduces the efficiency of the process, but one with H2O2 demonstrated an enhanced performance. The experimental data were found to fit well a pseudo-first-order kinetic model. Our findings demonstrated the analogous pathways of DCF for both processes. The Vis/N-doped TiO2/H2O2 process tends to hasten the degradation rate as evidenced by the disappearance of some DCF byproducts at a similar irradiation period as compared to the other. The study provided useful information of the degradation rate and the potential formation of DCF intermediates upon the hybrid photocatalytic systems, therefore being of importance for scaling-up as well as evaluating potential detoxification of DCF upon the novel photocatalytic system.

Design of highly active catalysts plays a critical role in catalytic fast pyrolysis (CFP) of lignocellulosic biomass. Advanced catalysts can improve the deoxygenation rate of pyrolysis vapors and boost the production of fuel precursors. Zeolites are suitable frameworks for catalyzing pyrolysis vapors into species of transportation fuel value. However, their nano-sized structure limits the diffusion of reactants into pores and over active sites. Consequently, the aggregation of large molecules outside micropores leads to a massive coke formation, blocking pore channels, and thus, preventing the accessibility to acid sites. This could cause quick deactivation and instability of the catalyst, necessitating frequent catalyst regeneration and replenishment. Hierarchical micro/mesopore-structured zeolites are promising candidates to cope with the mentioned challenges. In addition to their adjusted pore structure and increased accessibility of acid sites, the formation of mesoporosity in zeolites provides an adequate room for the deposition of additional active phases such as metal nanoparticles, further boosting the catalytic activity. Different strategies used for preparing hierarchical zeolites can tremendously alter their attributes, and consequently affect product selectivity during CFP of biomass. Focusing on the precursors of transportation fuels (i.e., aromatic hydrocarbons and olefins), the present paper critically reviews the impacts of methods used for synthesizing hierarchical zeolite, on CFP of bio-based feedstocks. Moreover, the role of metal addition to hierarchical zeolites in biomass catalytic pyrolysis is also discussed briefly. Among the different synthesis techniques, desilication treatment using alkaline solutions is the most promising owing to its simplicity, high productivity, and scalability. In terms of product selectivity, the addition of Ga species to hierarchical zeolites can increase aromatic hydrocarbons while Ce incorporation can increase the yield of valuable oxygenates such as furan. Despite the advantages of mono-metallic hierarchical zeolites in producing cherished chemicals, future studies should scrutinize the influence of bi-metallic hierarchical zeolites in bio-based CFP processes.

Waste palm shell is a large-volume biomass waste produced from palm oil mills, representing a resource to be treated and converted into a value-added product. In this study, an improved microwave wet torrefaction (low-temperature pyrolysis) incorporating microwave radiation and steam was performed to torrefied the waste palm shell into higher porous biochar. The biochar and catalytic effect of using microwave radiation and steam over a range of process temperature (250–350 °C) were investigated. The microwave wet torrefaction demonstrated a significantly faster heating rate (up to 120 °C/min) and compared to that shown by microwave heating without steam (45 °C/min, 15 min). Microwave wet torrefaction exhibited relatively lower mass yield (63.5 wt%) compared to microwave torrefaction (72.5 wt%). However, the biochar obtained from microwave wet torrefaction produced higher surface area (308.0 m2/g) compared to microwave torrefaction (110.8 m2/g). Our results demonstrate that microwave wet torrefaction shows potential as a catalytic approach to treat waste palm shell in providing a fast heating rate, lower process temperature, and generating a higher yield of a torrefied product with improved properties.

Cassava stem waste is abundantly available after starch extraction, hence posing disposal problem and potential risk to environmental pollution. Alternative ways are needed to dispose the waste instead of landfilling and open burning. Microwave vacuum pyrolysis was examined as an alternative method to convert the cassava stem waste into biochar. The cassava stem was first characterized by several analyses followed by conversion into biochar using microwave vacuum pyrolysis over different microwave power. The cassava stem contained high contents of carbon (49.5 wt%) and considerable amount of fixed carbon (27 wt%), indicating its suitability to be used as pyrolysis feedstock. The biochar yield from microwave power of 550 W, 650 W and 750 W were 77%, 73% and 70% respectively. The surface morphology of biochar shows that it consists abundant pores on the surface, suggesting its suitability to be used as catalyst support for energy application, and also as adsorbent for use in adsorption-related process such as dye and heavy metal removal in wastewater treatment or nutrient retention in crops cultivation. The calorific value of the biochar ranged from 19.24 to 20.55 MJ kg−1, showing high energy content for potential use as solid fuel. Our results show that cassava stem can be transformed into biochar for useful energy applications rather than burned as low-grade fuel in boiler or disposed by landfilling.

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Biomass plays a crucial role in mitigating the concerns associated with increasing fossil fuel combustion. Among various types of biomass, forest biomass has attracted considerable attention given its abundance and variations. In this work, an overview is presented on different pathways available to convert forest biomass into bioenergy. Direct use of forest biomass could reduce carbon dioxide emissions associated with conventional energy production systems. However, there are certain drawbacks to the direct use of forest biomass, such as low energy conversion rate and soot emissions and residues. Also, lack of continuous access to biomass is a severe concern in the long-term sustainability of direct electricity generation by forest biomass. To solve this problem, co-combustion with coal, as well as pelletizing of biomass, are recommended. The co-combustion of forest biomass and coal could reduce carbon monoxide, nitrogen oxides, and sulfide emissions of the process. Forest biomass can also be converted into various liquid and gaseous biofuels through biochemical and thermochemical processes, which are reviewed and discussed herein. Despite the favorable features of forest biomass conversion processes to bioenergy, their long-term sustainability should be more extensively scrutinized by future studies using advanced sustainability assessment tools such as life cycle assessment, exergy, etc.

Blood plasma was collected during 2016–2018 from healthy incubating eiders (Somateria molissima, n = 183) in three Danish colonies, and healthy migrating pink-footed geese (Anser brachyrhynchus, n = 427) at their spring roost in Central Norway (Svalbard breeding population) and their novel flyway through the Finnish Baltic Sea (Russian breeding population). These species and flyways altogether represent terrestrial, brackish and marine ecosystems spanning from the Western to the Eastern and Northern part of the Baltic Sea. Plasma of these species was analysed for seroprevalence of specific avian influenza A (AI) antibodies to obtain information on circulating AI serotypes and exposure. Overall, antibody prevalence was 55% for the eiders and 47% for the pink-footed geese. Of AI-antibody seropositive birds, 12% (22/183) of the eiders and 3% (12/427) of the pink-footed geese had been exposed to AI of the potentially zoonotic serotypes H5 and/or H7 virus. AI seropositive samples selected at random (n = 33) showed a low frequency of serotypes H1, H6 and H9. Future projects should aim at sampling and isolating AI virus to characterize dominant serotypes and virus strains (PCR). This will increase our understanding of how AI exposure may affect health, breeding and population viability of Baltic common eiders and pink-footed geese as well as the potential spill-over to humans (zoonotic potential).

The Baltic/Wadden Sea Flyway of common eiders has declined over the past three decades. Multiple factors such as contaminant exposure, global warming, hunting, white-tailed eagle predation, decreased agricultural eutrophication and infectious diseases have been suggested to explain the decline. We collected information on body mass, mercury (Hg) concentration, biochemistry and untargeted metabolomics of incubating birds in two colonies in the Danish Straits (Hov Røn, n = 100; Agersø, n = 29) and in one colony in the Baltic proper (Christiansø, n = 23) to look into their metabolisms and energy balance. Body mass was available from early and late incubation for Hov Røn and Christiansø, showing a significant decline (25–30%) in both colonies with late body mass at Christiansø being the lowest. Whole blood concentrations of total mercury Hg were significantly higher in birds at Christiansø in the east compared to Hov Røn in the west. All birds in the three colonies had Hg concentrations in the range of ≤1.0 μg/g ww, which indicates that the risk of effects on reproduction is in the no to low risk category for wild birds. Among the biochemical measures, glucose, fructosamine, amylase, albumin and protein decreased significantly from early to late incubation at Hov Røn and Christiansø, reflecting long-term fastening as supported by the decline in body mass. Untargeted metabolomics performed on Christiansø eiders revealed presence of 8,433 plasma metabolites. Of these, 3,179 metabolites changed significantly (log2-fold change ≥1, p ≤ 0.05) from the early to late incubation. For example, smaller peptides and vitamin B2 (riboflavin) were significantly down-regulated while 11-deoxycorticosterone and palmitoylcarnitine were significantly upregulated. These results show that cumulative stress including fasting during incubation affect the eiders’ biochemical profile and energy metabolism and that this may be most pronounced for the Christiansø colony in the Baltic proper. This amplify the events of temperature increases and food web changes caused by global warming that eventually accelerate the loss in body weight. Future studies should examine the relationship between body condition, temperature and reproductive outcomes and include mapping of food web contaminant, energy and nutrient content to better understand, manage and conserve the populations.

Here we review contaminant exposure and related health effects in six selected Baltic key species. Sentinel species included are common eider, white-tailed eagle, harbour porpoise, harbour seal, ringed seal and grey seal. The review represents the first attempt of summarizing available information and baseline data for these biomonitoring key species exposed to industrial hazardous substances focusing on anthropogenic persistent organic pollutants (POPs). There was only limited information available for white-tailed eagles and common eider while extensive information exist on POP exposure and health effects in the four marine mammal species. Here we report organ-tissue endpoints (pathologies) and multiple biomarkers used to evaluate health and exposure of key species to POPs, respectively, over the past several decades during which episodes of significant population declines have been reported. Our review shows that POP exposure affects the reproductive system and survival through immune suppression and endocrine disruption, which have led to population-level effects on seals and white-tailed eagles in the Baltic. It is notable that many legacy contaminants, which have been banned for decades, still appear to affect Baltic wildlife. With respect to common eiders, changes in food composition, quality and contaminant exposure seem to have population effects which need to be investigated further, especially during the incubation period where the birds fast. Since new industrial contaminants continuously leak into the environment, we recommend continued monitoring of them in sentinel species in the Baltic, identifying possible effects linked to climate change, and modelling of population level effects of contaminants and climate change.

Here we investigate if lead may be a contributing factor to the observed population decline in a Baltic colony of incubating eiders (Somateria mollissima). Body mass and blood samples were obtained from 50 incubating female eiders at the Baltic breeding colony on Christiansø during spring 2017 (n = 27) and 2018 (n = 23). All the females were sampled twice during early (day 4) and late (day 24) incubation. The full blood was analysed for lead to investigate if the concentrations exceeded toxic thresholds or changed over the incubation period due to remobilisation from bones and liver tissue. Body mass, hatch date and number of chicks were also analysed with respect to lead concentrations. The body mass (mean ± SD g) increased significantly in the order: day 24 in 2018 (1561 ± 154 g)

Transforming waste to energy is essential in view of the need to search for greener and more sustainable energy sources. Such transformation of energy is also aligned with the aim of reducing excessive waste generation whilst creating potential biofuel pathways for power generation. In the present study, animal waste in the form of horse manure is being used as feedstock to undergo microwave-induced pyrolysis via a fixed-bed pyrolysis rig. The relationship of the pyrolysis parameters such as pyrolysis temperature of 350 and 550 ?C, carrier gas flow rate of 0.5 and 1.5 L/min and ratio of horse manure to activated carbon blend of 1:2 and 1:1, with the yield of pyrolysed products is studied. The derived pyrolysis products in the form of solid, liquid and gaseous are characterised and quantified. Result shows that the highest yield of solid, liquid and gaseous products obtained are 78.8 wt%, 24.7 wt% and 34.2 wt%. Solid yield is observed to decrease with increasing pyrolysis temperature while gaseous yield shows a reverse trend. Higher carrier gas flow rate is observed to lower the generation of gaseous and liquid yield while increasing the solid yield. Higher amount of activated carbon within the feedstock is seen to lower the solid yield but increase the gaseous and liquid yields. The liquid yield is found to contain 55.78 wt% of phenolic compounds while gaseous product consists of up to 55 vol% of syngas. The control of the operating conditions in pyrolysis rig enables the production of pyrolysis end products in different phases, generating useful bioenergy and biofertilizer products in the context of circular economy.

Being the second-largest country in the production of palm oil, Malaysia has a massive amount of palm kernel expeller (PKE) leftover. For that purpose, black soldier fly larvae (BSFL) are thus employed in this study to valorize the PKE waste. More specifically, this work elucidated the effects of the pre-fermentation of PKE via different amounts of Rhizopus oligosporus to enhance PKE palatability for the feeding of BSFL. The results showed that fermentation successfully enriched the raw PKE and thus contributed to the better growth of BSFL. BSFL grew to be 34% heavier at the optimum inoculum volume of 0.5 mL/10 g dry weight of PKE as compared to the control. Meanwhile, excessive fungal inoculum induced competition between BSFL and R. oligosporus, resulting in a reduction in BSFL weight. Under optimum feeding conditions, BSFL also registered the highest lipid yield (24.7%) and protein yield (44.5%). The biodiesel derived from BSFL lipid had also shown good compliance with the European biodiesel standard EN 14214. The high saturated fatty acid methyl esters (FAMEs) content (C12:0, C14:0, C16:0) in derived biodiesel made it highly oxidatively stable. Lastly, the superior degradation rate of PKE executed by BSFL further underpinned the sustainable conversion process in attaining valuable larval bioproducts.

This research focuses on the optimum design of fluid dynamic bearing (FDB) named modified spiral design. The objective is to improve the pressure and velocity distribution inside the FDB. In this paper, the current spiral design has 12 number of grooves while the modified spiral design has 24 number of grooves. Both design can be classified into two, bearing with seal and without seal. Air was chosen to replace the oil as the lubricant. Results show that the modified spiral bearing design has comparable characteristics compared to conventional spiral design in terms of pressure and velocity distribution. Modified spiral geometries also shows a tendency to replace the function of seals in FDB. This makes it possible to simplify bearing design without using any seal just by modifying its geometries based on novel modified spiral geometries. Experimental verifications also proved that the modified spiral bearing design has better air leakage control compared to the conventional ones. This phenomenon occurs in both design parameters, where when the designs are compared with respect to increase of rotational speed and air film thickness.

The aim of this study was to compare the relative nutritional benefit of edible Malaysian fishes from the coast of Terengganu in Malaysia, as well as to perform a taxonomical characterization and metal assessment. Discrimination between species was carried out by a morphological and molecular approach by evaluating the total concentrations of metals by ICP-MS analyses and the fatty acids (FA) composition using the GC–MS approach on the fish fillet tissues. The taxonomical studies detected fishes of 11 families and 13 species. The heavy metal assessment showed that all detected elements did not exceed the regulatory limit stated by Malaysian Food Regulations. The proportion of saturated fatty acids (SFA) ranged from 33 to 58.34%, followed by the polyunsaturated fatty acids (PUFA) values from 24 to 51.8%, and the lowest proportion was of monounsaturated fatty acids (MUFA), ranging from 12.7 to 35.9%. The ω-3/ω-6 PUFA and PUFA/SFA ratios were determined in the range 1.1 to 7.4 and 0.35 to 1.6, respectively. The C20:5 ω-3 and C22:6 ω-3 acids were detected at levels comparable to those found in the corresponding species from similar tropical marine ecosystems. The high FA values can be useful biochemical tools for comparing the relative nutritional benefits of these biodiverse and non-toxic edible Malaysian fishes.

The process and energy intensifications for the synthesis of glycerol carbonate (GC) from glycerol and dimethyl carbonate (DMC) using an eggshell-derived CaO heterogeneous catalyst were investigated. The transesterification reaction between glycerol and DMC was typically limited by mass transfer because of the immiscible nature of the reactants. By varying the stirring speed, it was observed that the mass transfer limitation could be neglected at 800 rpm. The presence of the CaO solid catalyst made the mass transport-limited reaction process more prominent. Mass transfer intensification using a simple kitchen countertop blender as an alternative to overcome the external mass transfer limitation of a typical magnetic stirrer was demonstrated. A lower amount of the catalyst and a shorter reaction time were required to achieve 93% glycerol conversion or 91% GC yield, and the turnover frequency (TOF) increased almost 5 times from 1.5 to 7.2 min−1 when using a conventional magnetic stirrer and countertop blender, respectively. In addition, using a simple kitchen countertop blender with 7200 rpm, the reaction temperature of 60 °C could be reached within approximately 3 min without the need of a heating unit. This was the result of the self-frictional heat generated by the high-shear blender. This was considered to be heat transfer intensification, as heat was generated locally (in situ), offering a higher homogeneity distribution. Meanwhile, the trend toward energy intensification was promising as the yield efficiency increased from 0.064 to 2.391 g/kJ. A comparison among other process intensification techniques, e.g., microwave reactor, ultrasonic reactor, and reactive distillation was also rationalized.