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The aquaculture industry is under the framework of the food-water-energy nexus due to the extensive use of water and energy. Sustainable practices are required to support the tremendous growth of this sector. Currently, the aquaculture industry is challenged by its reliance on capture fisheries for feed, increased use of pharmaceuticals, infectious outbreaks, and solid/liquid waste management. This review posits microalgal technology as a comprehensive solution for the current predicaments in aquaculture in a sustainable way. Microalgae are microscopic, freshwater and marine photosynthetic organisms, capable of carbon mitigation and bioremediation. They are indispensable in aquaculture due to their key role in marine productivity and their position in the marine food chain. Microalgae are nutritious and are currently used as feed in specific sectors of aquaculture. Due to their bioremediation potential, direct application of microalgae in shellfish ponds and in recirculating systems have been adopted to improve water quality and aquatic animal health. The potential of microalgae for integration into various aspects of aquaculture processes, namely hatcheries, feed, and waste management has been critically analyzed. Seamless integration of microalgal technology in aquaculture is feasible, and this review will provide new insights into using microalgal technology for sustainable aquaculture., 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. Published by Elsevier Ltd.)

The wettability of the surface of hydrophilic cotton fabrics was modified using a one-step protocol with tannic acid (TA) to provide its excess catechol groups to be grafted with 1-eicosanamine at pH 8.5 and room temperature with catalysts CuSO 4 /H 2 O 2 . The modification over the synthesis conditions revised the contact angles of water and diiodomethane droplets from 132.68 ± 0.49° to 143.95 ± 0.80° and from 100.08°±1.42° to 82.96 ± 1.38°, respectively. The corresponding dispersive of the so-yielded cotton surface ranged from 8.6 to 16.0 mJ/m 2 , and the polar components ranged from 0.08 to 2.7 mJ/m 2 , much lower than polytetrafluoroethylene. The modified cotton fabrics are omniphobic and can repel water and commercial oil products. The absorption tests revealed that the modified cotton fabrics absorbed 1.10 g hexane/g cotton by contacting hexane (top)-water (bottom) layers and absorbed 1.26 g hexane/g cotton by contacting water first for 30 s, then hexane for another 30 s. The modified fabrics reveal good absorption reusability as hexane absorbent is even pre-saturated with water. This conclusion is also valid for commercial unleaded gasoline #95 and diesel. A parametric study revealed that the added catalysts and prolonged reaction time would enhance the hydrophobicity of the surface. These modified cotton fabrics can absorb oil from water and oil spills. Mechanisms corresponding to this observation are discussed., 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 Ltd. All rights reserved.)

Plastics have become an essential part of life. When it enters the environment, it migrates and breaks down to form smaller size fragments, which are called microplastics (MPs). Compared with plastics, MPs are detrimental to the environment and pose a severe threat to human health. Bioremediation is being recognized as the most environmentally friendly and cost-effective degradation technology for MPs, but knowledge about the biodegradation of MPs is limited. This review explores the various sources of MPs and their migration behavior in terrestrial and aquatic environments. Among the existing MPs removal technologies, biodegradation is considered to be the best removal strategy to alleviate MPs pollution. The biodegradation potential of MPs by bacteria, fungi and algae is discussed. Biodegradation mechanisms such as colonization, fragmentation, assimilation, and mineralization are presented. The effects of MPs characteristics, microbial activity, environmental factors and chemical reagents on biodegradation are analyzed. The susceptibility of microorganisms to MPs toxicity might lead to decreased degradation efficiency, which is also elaborated. The prospects and challenges of biodegradation technologies are discussed. Eliminating prospective bottlenecks is necessary to achieve large-scale bioremediation of MPs-polluted environment. This review provides a comprehensive summary of the biodegradability of MPs, which is crucial for the prudent management of plastic waste., 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 © 2023 Elsevier Ltd. All rights reserved.)

Antibiotic contamination could cause serious risks of ecotoxicity and resistance gene induction. Advanced oxidation processes (AOPs) such as Fenton, photocatalysis, activated persulfate, electrochemistry and other AOPs technologies have been proven effective in the degradation of high-risk, refractory organic pollutants such as antibiotics. However, due to the limited mineralization ability, a large number of degradation intermediates will be produced in the oxidation process. The residual or undiscovered ecological risks of degradation products are potential safety hazards and problems necessitating comprehensive studies. In-depth investigations especially on the full assessments of ecotoxicity and resistance genes induction capability of antibiotic degradation products are important issues in reducing the environmental problems of antibiotics. Therefore, this review presents an overview of the current knowledge on the efficiency of different AOPs systems in reducing antibiotics toxicity and antibiotic resistance., 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 Ltd. All rights reserved.)

Lactic acid is an essential platform chemical with various applications in the chemicals, food, pharmaceutical, and cosmetic industries. Currently, the demand for lactic acid is driven by the role of lactic acid as the starting material for the production of bioplastic polylactide. Microbial fermentation for lactic acid production is favored due to the production of enantiomerically pure lactic acid required for polylactide synthesis, as opposed to the racemic mixture obtained via chemical synthesis. The utilization of first-generation feedstock for commercial lactic acid production is challenged by feedstock costs and sustainability issues. Macroalgae are photosynthetic benthic aquatic plants that contribute tremendously towards carbon capture with subsequent carbon-rich biomass production. Macroalgae are commercially cultivated to extract hydrocolloids, and recent studies have focused on applying biomass as a fermentation feedstock. This review provides comprehensive information on the design and development of sustainable and cost-effective, algae-based lactic acid production. The central carbon regulation in lactic acid bacteria and the metabolism of seaweed-derived sugars are described. An exhaustive compilation of lactic acid fermentation of macroalgae hydrolysates revealed that lactic acid bacteria can effectively ferment the mixture of sugars present in the hydrolysate with comparable yields. The environmental impacts and economic prospects of macroalgal lactic acid are analyzed. Valorization of the vast amounts of spent macroalgal biomass residue post hydrocolloid extraction in a biorefinery is a viable strategy for cost-effective lactic acid production., 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 Ltd. All rights reserved.)

The composite materials based on graphitic carbon nitrides (g-C 3 N 4 ) are remarkably better semiconductors, but the inherent photocatalytic performance in its generic synthesis form is not up to the mark. Eminence efforts have been made to improve its performance and photocatalytic efficiencies. Recently, extensive investigations have been performed to develop their texturally modified and highly porous structures to get around the big flaws of bulk g-C 3 N 4 . One significant disadvantage is the increase in the polycondensation while preparation at 550 °C results in g-C 3 N 4 materials with restricted specific surface area (SSA) (<10 m 2 /g) and no textured pores. Textural modification has emerged as an efficient and progressive way to improve optical and electronic characteristics. The final texture and shape of CN are influenced by the precursor's interaction with the template. Researchers are interested in developing CN materials with high SSA and changeable textural properties (pore volume and pore size). Based on the literature review it is concluded that the soft templating approach is relatively simple, and straightforward to induce textural changes in the g-CN type materials. This review focused on improving the textural properties of bulk g-C 3 N 4 via templating method, and the major advances in the modified g-C 3 N 4 materials for the treatment of wastewater. The procedures and mechanisms of numerous approaches with varying morphologies are thoroughly explained., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Chlortetracycline (CTC) is a tetracycline derivative antibiotic that has been widely used in the livestock industry for prophylactic and therapeutic purposes. Effective measures should be taken to decrease the environmental risks associated with CTC-rich waste. Biochar produced by biomass waste showed great potential for organic contaminants removal by adsorption and catalytic degradation. This study prepared iron oxide-modified coffee grounds biochar (CGF) at different temperatures for enhanced CTC removal by adsorption and degradation. The main mechanism for CTC removal was found to be electrostatic interaction. In addition, pore diffusion, hydrogen bonds, and π-π bonds also contributed to CTC adsorption. Maximum CTC adsorption capacity was 223.63 mg/g for CGF800 (CGF prepared at 800 °C pyrolysis). The free radical content of CGF600 (CFG prepared at 600 °C pyrolysis) was higher than CGF800, and there were no significant advantages in using biochar prepared at a higher temperature for persulfate activation. The ion mass-to-charge ratio (M/z) is used to describe the ratio of mass to charge of an ion or peak, which can infer compound structure. The structure of CTC degradation products was analyzed by UPLC-MS, and the M/z values were determined as 444, 273, and 154. Thus, pyrolysis of coffee grounds at higher temperatures increased CTC adsorption capacity, and CGF can indirectly assist in CTC degradation by persulfate activation., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

As a special type of wastewater produced in the landfill, leachate is mainly composed of organic pollutants, inorganic salts, ammonia nitrogen and heavy metals, and featured by high pollutants concentration, complex composition and large fluctuations in water quality and volume. Biological, chemical and physical methods have been proposed to treat landfill leachate, but much attention has been paid to the advanced oxidation processes (AOPs), due to their high adaptability and organic degradation efficiency. This paper summarizes the recent findings on the AOPs based on hydroxyl radical (OH) (e.g., ozonation and catalyzed ozone oxidations, Fenton and Fenton-like oxidations) and sulfate radical (SO 4 - ) (e.g., activated and catalyzed persulfate oxidations), especially the production routes of free radicals and mechanisms of action. When dealing with some special landfill leachates, it is difficult for a single advanced oxidation technology to achieve the expected results, but the synergistic combination with biological or physical methods can produce satisfactory outcomes. Therefore, this paper has summarized the application of these combined treatment technologies on landfill leachate., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Metal mediator Z-scheme photocatalyst comprises three elements: two semiconductors and a sandwiched metal mediator, so the catalyst can effectively degrade pollutants using visible lights. Proper design and synthesis of Z-scheme with targeted performance has not been systematically proposed. This work proposed the protocol to design and synthesize a Z-scheme photocatalyst with targeted performance. A novel metal mediator Z-scheme photocatalyst CuFe 2 O 4 /Cu/UiO-66-NH 2 was used to implement the design proposal. After determining synthesis protocol from the theory, the concentrations of three reagents - glucose, l-cysteine, and precursor of UiO-66-NH 2 for synthesizing Z-scheme photocatalyst were revised to achieve successful photocatalyst. Dropwise photocatalytic tests were performed to confirm the activities of the synthesized catalysts using 0.112 mmol/mL UiO-66-NH 2 precursor, 10 mmol/mL glucose, and 1 mmol/mL l-cysteine yielded effective photocatalyst to degrade rhodamine 6G. The dye degradation tests and EPR tests confirmed the successful synthesis of the designed Z-scheme photocatalyst., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Utilizing wastewaters as feedstock for microalgal cultivation has the dual benefits of water-saving and low nutrient costs, with simultaneous remediation of pollutants and generation of value-added biochemical products. This study employed two different strategies to treat raw dairy wastewaters with moderate and high chemical oxygen demand (COD) levels. For moderate-COD dairy wastewater, the wastewater was directly utilized as feedstock for algal cultivation, in which the effects of wastewater dilution ratios and algal inoculum sizes were investigated. The results show that the microalga strain used (Chlorella sorokiniana SU-1) was capable of obtaining a high biomass concentration of 3.2 ± 0.1 g/L, accompanied by 86.8 ± 6%, 94.6 ± 3%, and 80.7 ± 1%, removal of COD, total phosphorus (TP) and total nitrogen (TN), respectively. Meanwhile, the obtained microalgal biomass has lipids content of up to 12.0 ± 0.7% at a wastewater dilution ratio of 50% and an inoculum size of 2 g/L. For high-COD dairy wastewater, an integrated process of anaerobic digestion and microalgal phycoremediation was employed, and the effect of inoculum sizes was also studied. The inoculum size of 2 g/L gave highest biomass production of 4.25 ± 0.10 g/L with over 93.0 ± 2.0% removal of COD, TP, and TN. The harvested microalgal biomass has lipids and protein content of 12.5 ± 2.2% and 18.0 ± 2.2%, respectively. The present study demonstrated potential microalgal phycoremediation strategies for the efficient COD removal and nutrients recovery from dairy wastewater of different COD levels with simultaneous production of microalgal biomass which contains valuable components, such as protein and lipids., (Copyright © 2021. Published by Elsevier Ltd.)

Biochar is a promising material and fuel for environmental sustainability. Microalgal biochar is produced using catalytic microwave torrefaction of Chlorella vulgaris FSP-E residue with magnesium oxide as a microwave absorber to enhance heating. Using Taguchi experimental design (TED) and Analysis of Variance (ANOVA), the effects of microwave power, catalyst concentration, and duration on energy yield are investigated. Both TED and ANOVA confirm the significant effects of microwave power and catalyst concentration, while only a slight effect from duration. The calorific values of produced biochar (21.12-26.22 MJ⋅kg -1 ) are close to coal. The maximum deoxygenation and carbonization extents are 56.69% and 35.23%, respectively. The optimal parameter combination of low microwave power (450 W), low duration (25 min), and high catalyst concentration (10 wt% MgO) poses the highest upgrading energy index (UEI) value. This confirms that better energy efficiency leans towards light torrefaction conditions with maximized catalyst concentration to produce the maximum energy yield while consuming the least electricity input., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Hydrogen as a clean energy that is conducive to energy and environmental sustainability, playing a significant role in the alleviation of global climate change and energy crisis. Biohydrogen generation from microalgae has been reported as a highly attractive approach that can produce a benign clean energy carrier to achieve carbon neutrality and bioenergy sustainability. Thus, this review explored the mechanism of biohydrogen production from microalgae containing direct biophotolysis, indirect biophotolysis, photo fermentation, and dark fermentation. In general, dark fermentation of microalgae for biohydrogen production is relatively better than photo fermentation, biophotolysis, and microbial electrolysis, because it is able to consecutively generate hydrogen and is not reliant on energy supplied by natural sunlight. Besides, this review summarized potential algal strains for hydrogen production focusing on green microalgae and cyanobacteria. Moreover, a thorough review process was conducted to present hydrogen-producing enzymes targeting biosynthesis and localization of enzymes in microalgae. Notably, the most powerful hydrogen-producing enzymes are [Fe-Fe]-hydrogenases, which have an activity nearly 10-100 times better than [Ni-Fe]-hydrogenases and 1000 times better than nitrogenases. In addition, this work highlighted the major factors affecting low energy conversion efficiency and oxygen sensitivity of hydrogen-producing enzymes. Noting that the most practical pathway of biohydrogen generation was sulfur-deprivation compared with phosphorus, nitrogen, and magnesium deficiency. Further discussions in this work summarized the recent advancement in biohydrogen production from microalgae such as genetic engineering, microalgae-bacteria consortium, electro-bio-hydrogenation, and nanomaterials for developing enzyme stability and hydrolytic efficiency. More importantly, this review provided a summary of current limitations and future perspectives on the sustainable production of biohydrogen from microalgae., (Copyright © 2021. Published by Elsevier Ltd.)

Offering a potential solution for global food security and mitigating environmental issues caused by the expansion of land-based food production, the carbon-hunger and nutrient-rich microalgae emerged as a sustainable food source for both humans and animals. Other than as an alternative source for protein, microalgae offer its most valuable nutrients, omega-3 and 6 long-chain polyunsaturated fatty acids where the content can compete with that of marine fish with lower chemicals contamination and higher purity. Furthermore, the colorful pigments of microalgae can act as antioxidants together with many other health-improving properties as well as a natural colorant. In addition, the supplementation of algae as animal feed provides plentiful benefits, such as improved growth and body weight, reduced feed intake, enhanced immune response and durability towards illness, antibacterial and antiviral action as well as enrichment of livestock products with bioactive compounds. The significant breakthrough in algal biotechnology has made algae a powerful "cell factory" for food production and lead to the rapid growth of the algal bioeconomy in the food and feed industry. The first overview of this review was to present the general of microalgae and its potential capability. Subsequently, the nutritional compositions of microalgae were discussed together with its applications in human foods and animal feeds, followed by the exploration of their economic feasibility and sustainability as well as market trends. Lastly, both challenges and future perspectives were also discussed., 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 © 2021 Elsevier Ltd. All rights reserved.)

Recent trend to recover value-added products from wastewater calls for more effective pre-treatment technology. Conventional landfill leachate treatment is often complex and thus causes negative environmental impacts and financial burden. In order to facilitate downstream processing of leachate wastewater for production of energy or value-added products, it is pertinent to maximize leachate treatment performance by using simple yet effective technology that removes pollutants with minimum chemical added into the wastewater that could potentially affect downstream processing. Hence, the optimization of coagulation-flocculation leachate treatment using multivariate approach is crucial. Central composite design was applied to optimize operating parameters viz. Alum dosage, pH and mixing speed. Quadratic model indicated that the optimum COD removal of 54% is achieved with low alum dosage, pH and mixing speed of 750 mgL -1 , 8.5 and 100 rpm, respectively. Optimization result showed that natural pH of the mature landfill leachate sample is optimum for alum coagulation process. Hence, the cost of pH adjustment could be reduced for industrial application by adopting optimized parameters. The inherent mechanism of pollutant removal was elucidated by FTIR peaks at 3853 cm -1 which indicated that hydrogen bonds play a major role in leachate removal by forming well aggregated flocs. This is concordance with SEM image that the floc was well aggregated with the porous linkages and amorphous surface structure. The optimization of leachate treatment has been achieved by minimizing the usage of alum under optimized condition., 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 © 2020 Elsevier Ltd. All rights reserved.)

The covalent organic framework (COF) is made light elements linked by covalent networks. This study synthesize and characterized, and for the first time applied the produced EB-COF:Br as adsorbent for phosphate and arsenate removal from nearly neutral waters. The synthesized COF was first proven structurally stable in solutions of 75% H 3 PO 4 , 6 M HCl, or 6 M NaOH. Then the phosphate adsorption onto the EB-COF:Br was shown to be an endothermic process with maximum adsorption capacity at 25, 35 and 45 °C as 25.3, 34.7 and 35.3 mg/g COF, respectively; and the corresponding arsenate adsorption process being an exothermic process with maximnum adsorption capacity as 53.1, 27.5 and 5.1 mg/g, respectively. The synthesized COF could also effectively adsorb phosphate and arsenate ions from river water (pH 7.45) but at reduced adsorption capacities. The electrostatic interactions between the negative charge on phosphate or arsenate ions and the positively charged (N + -) of COF, and the hydrogen bondings between H atom on phosphate or arsenate ions and the (-CO) group of COF were the dominating mechanisms for the present adsorption process. The strong electrostatic interactions for arsenate contributed to its higer adsorption capacity than noted for phosphate at 25 °C. However, the disturbed hydrogen bonding induced by mismatched sizes of arsenate ion and the adsorption sites surrounded by the (N + -) and the (-CO) groups reduced the stability of arsenate to against temperature and external anion challenges. The use of the EB-COF; Br as industrial adsorbent was also discussed., 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 © 2020 Elsevier Ltd. All rights reserved.)

ArsH encodes an oxidoreductase, an NAD(P)H-dependent mononucleotide reductase, with an unknown function, frequently within an ars operon, and is widely distributed in bacteria. Novel arsenite-oxidizing bacteria have been isolated from arsenic-contaminated groundwater and surface soil in Vietnam. We found that ArsH gene activity, with arsenite oxidase in the periplasm; it revealed arsenic oxidation potential of the arsH system. Batch experiment results revealed Citrobacter freundii strain VTan4 (DQ481466) and Pseudomonas putida strain VTw33 (DQ481482) completely oxidized 1 mM of arsenite to arsenate within 30-50 h. High concentrations of arsenic were detected in groundwater and surrounding soil obtained from Vinh Tru village in Ha Nam province (groundwater: 11.0 μg/L to 37.0 μg/L; and soil: 2.5 mg/kg, 390.1 mg/kg), respectively. An arsH gene encoding an organoarsenical oxidase protein was observed in arsenite-oxidizing Citrobacter freundii strain VTan4 (DQ481466), whereas arsB, arsH, and arsH were detected in Pseudomonas putida strain VTw33 (DQ481482). arsH gene in bacteria was first reported from Vietnam for resistance and arsenite oxidase. We proposed that residues, Ser 43, Arg 45, Ser 48, and Tyr 49 are required for arsenic binding and activation of arsH. The ars-mediated biotransformation strongly influenced potential arsenite oxidase enzyme of the operon encoding a homogeneous arsH. Results suggest that the further study of arsenite-oxidizing bacteria may lead to a better understanding of arsenite oxidase responses, such as those of arsH, that may be applied to control biochemical properties; for example, speciation, detoxification, bioremediation, biotransformation, and mobilization of arsenic in contaminated groundwater., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The p53 mutation in salamanders can be used as an indicator of arsenic contamination. The influence of arsenic exposure was studied on mutation of tumor suppressor gene in salamanders collected from several As-contaminated mine areas in Korea. Salamander eggs and larvae were exposed to arsenic in a toxicity test, and teratogenic salamanders found in heavy metal- and As-contaminated water from As-Bi mines were evaluated using PCR-SSCP to determine if they would be useful as an ecological indicator species. Changes in amino acids were shown to have occurred as a result of an arsenic-accumulating event that occurred after the DNA damage. In addition, both of the Hynobius leechii exposed groups were primarily affected by forms of skin damage, changes in the lateral tail/dorsal flexure and/or abnormality teratogenesis. Single-base sense mutation in codons 346 (AAG: Lys to ATG: Met), 224 (TTT: Phe to TTA: Leu), 211 (ATG: Met to AAG: Lys), 244 (TTT: Phe to TTTG: insertion), 245 (Glu GAG to Gln CAG) and 249 (TGT Cys to TGA stop) of the p53 gene were simultaneously found in mutated salamanders. Based on the results of our data illustrating the effect of arsenic exposure on the p53 mutation of salamanders in arsenic-contaminated mine areas, these mutated salamanders can be used as potential ecological indicators in the arsenic-contaminated ecosystems.

The aerobic biodegradation potential of phenanthrene (a polycyclic aromatic hydrocarbon [PAH]) in river sediment was investigated in the laboratory. Biodegradation rate constants (k1) and half-lives (t1/2) for phenanthrene (5 microg/g) in sediment samples collected at five sites along the Keelung River in densely populated northern Taiwan ranged from 0.12 to 1.13 l/day and 0.61 to 5.78 day, respectively. Higher biodegradation rate constants were noted in the absence of sediment. Two of the sediment samples were capable of biodegrading phenanthrene at initial concentrations 5-100 microg/g; lower biodegradation rates occurred at higher concentrations. Optimal biodegradation conditions were determined as 30 degreesC and pH 7.0. Biodegradation was not significantly influenced by the addition of such carbon sources as acetate, pyruvate, and yeast extract, but was significantly influenced by the addition of ammonium, sulfate, and phosphate. Results show that anthracene, fluorene, and pyrene biodegradation was enhanced by the presence of phenanthrene, but that phenanthrene treatment did not induce benzo[a]pyrene biodegradation during a 12-day incubation period.