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Elemental sulfur autotrophic denitrification (S0AD) processes are temperature-sensitive, presenting a substantial challenge for the practical implementation of S0AD bioreactors. In this study, a comprehensive methodology for designing and operating S0AD bioreactors was developed, effectively managing fluctuations in nitrogen removal efficiency caused by seasonal temperature variations. Initially, the nitrate removal rate was correlated with simulated on-site temperature and nitrate loading, revealing correlation coefficients of k1, k2, k3, and A as 5.42×10-4, -0.41, 0.04, and 0.13, respectively, to establish a mathematical model for predicting S0AD efficiency. Subsequently, by considering influence factors such as dissolved oxygen and dynamic sulfur consumption, the model was employed to accurately design a pilot-scale S0AD bioreactor for a case study. By utilizing an alternative multi-subunit operation, a stable effluent nitrate concentration of less than 8 mg-N/L was maintained throughout the year. Importantly, this approach resulted in a substantial reduction of 76.8% in excessive nitrate removal, sulfur consumption, and sulfate production. This study aims to provide an optimal design and operation strategy for the practical application of S0AD bioreactors, thereby enhancing reliability and cost-effectiveness in the face of seasonal temperature changes.

This study aims to prepare a novel C=C polymerization-oriented magnetic protein molecularly imprinted polymer (MMIP) to improve membrane flux by adsorbing protein-type membrane foulants. The adsorption capabilities of MMIP were assessed by batch experiments, and the oriented polymerization and adsorption mechanisms were further revealed by density functional theory (DFT). The findings suggested that the MMIP exhibited a favorable adsorption capacity (35.9 mg/g) and high specificity (imprinting factor, IF = 2.2) to bovine serum albumin (BSA), and showed an impressive adsorption capacity (21.2 mg/g) to protein-type substances in soluble microbial products (SMPs) derived from a functioning membrane bioreactor. Consequently, the MMIP reduced the filtration resistance by approximately 91.6 % compared to the control group and improved the membrane flux. Moreover, the data confirmed that the adsorption was a monolayer adsorption process in which chemical interactions dominated the rate-limiting step. DFT calculations proved that the functional monomer chain reactions predominantly occurred on C=C bonds in the oriented polymerization and the hydrogen bonding was identified as the main interaction between MMIP and protein in the adsorption. These findings suggested that the MMIP holds great potential as a recyclable adsorbent for effectively improving membrane flux through the selective adsorption of protein-type membrane foulants.

Anaerobic digestion is a resource recovery method for organic waste, gaining attention due to carbon reduction. Disposing of anaerobic digestion effluent (ADE) is crucial for developing anaerobic digestion, but conventional wastewater treatment fails to effectively recover nutrients contained in the ADE. In the present study, the ADE without solid-liquid separation was mixed with sewage sludge and Chinese medicine residue for the composting, where the ADE could be recovered at high temperature through humification. Besides, the nitrogen balance, humification process, and microbial dynamics during the composting process were studied. The results showed that the group supplemented with ADE could increase the nitrogen retention efficiency by 2.21 % compared to the control group. High ammonia nitrogen content and salinity did not negatively affect the maturity and phytotoxicity of compost products and even increase the humification degree of compost products. Moreover, additional ADE may not alter microbial community structure, which could contribute to microbial succession. This is the first time to investigate the substance transformation and shift in microbial community structure while applying composting process for ADE treatment, in which the anaerobic-aerobic collaborative disposal process provides an alternative solution for the recovery of ADE.

The start-up efficiency of the elemental sulfur packing bioreactor (S0PB) is constrained by the slow growth kinetics of autotrophic microorganisms, which is essentially optimized. This study aims to optimize start-up procedures and offer scientific guidance for the practical applications of S0PB. Through comparing the start-up efficiencies under various conditions related to inoculation, backwashing, and EBCT, it was found that these conditions did not significantly influence start-up time, but they did impact denitrification performance in detail. Using activated sludge as the inoculum was not recommended as the 2.5 ± 0.2 mg-N/L higher nitrite accumulation and 26.0 ± 5.1 % lower TN removal rate, compared to self-enrichment. Starting with a long-to-short EBCT (1 → 0.33 h) achieved higher nitrate removal of 11.5 ± 0.6 mg-N/L and eliminated nitrite accumulation compared to constantly short EBCT (0.33 h) conditions. Daily and postponed backwashing were suggested for long-to-short EBCT and constantly short EBCT start-up, respectively. Enrichment of Sulfurimonas was beneficial for the effective nitrite reduction process.

Phosphate recovery from water is essential for reducing water eutrophication and alleviating the phosphorus resource crisis. In this study, spent coffee grounds and CaCl2 were used as raw materials and a modifier, respectively, to create a novel calcium modified biochar (MBC) for removing phosphorus from water. The modified biochar (MBC) was the best at removing phosphorous when the modifier concentration was 1.5 M with theoretically maximum adsorption capacity of 70.26 mg/g. MBC also performed well in the wide pH range of 3-11 under different phosphorus concentration gradients, with phosphorus removal efficiency of more than 50 %. According to kinetic analysis, the adsorption process at low phosphorus concentrations (50-100 mg/L) can be more properly described by the pseudo-first-order model, while the pseudo-second-order model best describes the adsorption process at high concentrations (200-600 mg/L). The thermodynamic analysis indicated that the adsorption process was spontaneous and endothermic. Characterization results revealed that surface precipitation, complexation, and ligand exchange were the dominant mechanisms of phosphorus adsorption. MBC has great potential to recover phosphorus from wastewater.

Catalytic upcycling is a promising waste management strategy that enhances the circularity of polymer wastes by transforming them into high-value-added products. This review presents the latest developments in novel catalysts, their applications and reaction mechanisms in upcycling approaches at various temperatures. High-temperature upcycling approaches include catalytic pyrolysis of polymers with biomass-derived biochar and carbonization with metal-based catalysts, which mainly produce hydrogen gas (H2), mono-aromatic hydrocarbons and carbon nanomaterials. Electro-reforming, photo-reforming, glycolysis and enzyme-assisted depolymerisation take place in the low- and intermediate-temperature with metal-based catalysts, organo-catalysts and biocatalysts. Diverse value-added products are obtained from these approaches, such as terephthalic acid, formic acid, H2, bis(2-hydroxyethyl) terephthalate, mono(2-hydroxyethyl) terephthalate, etc. The biomass-derived biochar has abundant functional groups, porous structure and large surface area that favour the depolymerisation of polymer wastes. However, its catalytic activity declines after long-term reuse due to coke deposition and reduced essential components. Metal-based catalysts, on the other hand, have large amounts of active sites, ensure high electron transport capability, and encourage the generation of electron-hole pairs. However, they can suffer from formation of by-products, accumulation of organic intermediates, and declining activities during the separation process. Biocatalysts have surface regions (e.g., serine residue, tryptophan residue, amino acids) for effective hydrolysis of polymer wastes, but display limited thermostability and low activities at a wide pH range. To advance the field, future research should focus on developing novel catalysts with excellent thermostability and catalytic activities.

The consumption of biologically-contaminated water annually leads to hundreds of thousands of deaths, most of which occur among children in developing countries. Solar-based water desalination systems are emerging as a promising, low-cost, and environmentally friendly solution to provide safe drinking water. The use of nanostructured materials in solar stills and solar interfacial evaporation systems is considered a highly effective method for performance improvement. These nanomaterial-assisted solar desalination systems can eliminate biological contaminants in water through various mechanisms. This paper presents, for the first time, an extensive review of the effectiveness of solar stills and solar interfacial evaporators aided by various forms of nanomaterials in combating biological contamination, including viruses, bacteria, protozoa, fungi, and antimicrobial resistance (AMR) pathogens. We specifically focus on pathogens with global catastrophic biological risk (GCBR) characteristics, particularly viruses and AMR pathogens. Special attention is given to the role of AMR pathogens and their potential transmission routes in the environment and water bodies, as they pose significant potential for future pandemics. The effectiveness of solar stills and solar interfacial steam generation methods is examined in light of their inactivation mechanisms, operational principles, crucial environmental parameters, and pathogen characteristics. Challenges and potential directions for future research are also discussed and proposed.

Green microalgae are highly efficient and cost-effective in the removal of heavy metals from water. However, dissolved organic matter (DOM), such as fulvic acid (FA), can impact their growth and heavy metal accumulation. Nonetheless, the specific mechanisms underlying these effects remain poorly understood. This study investigated the effects of different FA concentrations on the development, metabolism, and chromium (Cr) enrichment of Chlorella vulgaris, a standard green microalga. The findings revealed that low FA concentrations alleviated Cr-induced stress, stimulated microalgal growth, and enhanced energy conservation by suppressing chlorophyll synthesis. The highest chromium enrichment and reduction rates of 38.73% and 57.95% were observed when FA concentration reached 20 mg/L of total organic carbon (TOC). Furthermore, FA facilitated chromium removal by C. vulgaris through extracellular adsorption. Examination of microalgal cell surface functional groups and ultrastructure indicated that FA increased adsorption site electrons by promoting extracellular polymeric substance (EPS) secretion and enhancing the oxygen content of acidic functional groups. As a result, FA contributed to elevated enrichment and reduction rates of Cr in microalgal cells. These findings provide a theoretical basis for the prevention and control of heavy metal pollution in water environments.

The characteristic of sustainable agriculture is to minimize damage to the environment while being profitable, which is not easy to achieve. “Sustainable agriculture” tries to explore a series of protective agricultural practices that can decrease the adverse pressures of land intensification. Various raw materials have different physiochemical properties of biochar. The common approaches for biochar generation include pyrolysis, gasification, and hydrothermal carbonization. Biochar can be modified by purification of acids, alkalis, oxidants, gases, and so on. Additionally, the practical application of biochar for environmental remediation should pay attention to the mobilization of heavy metals and organic pollution from biochar in the environment. The main objective of this chapter is to provide an important scientific report of the present knowledge about the impact of biochar on soil characteristics, changes, and functions. A wider range of issues were discussed, including atmospheric gases emissions related to biochar production and treatment, and the impact of application on soil respiration.

Swine wastewater (SWW) is a mixture of organic matter, nutrients, pollutants, and heavy metals that can pose significant risks to the environment and human health if left untreated. Hence, it is crucial to adopt suitable treatment processes to ensure effluent quality and resource recovery. This paper provides an overview of the most commonly used SWW biological treatment technologies, including natural processes, aerobic, and anaerobic processes. The removal performance and mechanisms of each process in treating SWW are discussed in detail. Additionally, this paper analyzes the key factors that affect the operational performance, such as temperature, organic loading rate, heavy metals, salinity, and other inhibitors, and explores optimization strategies to enhance SWW treatment performance. Finally, considering the current concerns in treating SWW, this paper proposes future perspectives on SWW treatment. By presenting a comprehensive analysis, this paper can aid in the development and application of SWW treatment technologies in the future.

The production of Integrated circuits (ICs) generates wastewater with a high concentration of residual fluoride ions, necessitating highly efficient fluorine removal methods. In this study, a novel composite carrier was developed using a hydrothermal synthesis method to load Al-MOF and biochar (BC) onto polyurethane foam (PUF), resulting in the composite foam of Al-MOF-PUF@BC. The results showed that the composite carrier exhibited a stable fluoride removal effect, with a maximum adsorption capacity of 16.52 mg/g at room temperature. The adsorption isotherm curves were consistent with the Langmuir isotherm model, and the adsorption kinetics were well-described by the pseudo-first-order model. The mechanism of fluorine adsorption on Al-MOF-PUF@BC was ligand exchange with hydroxyl groups and the formation of FAl bonds. Density functional theory (DFT) calculations revealed that the adsorption energy reached -246.7 eV, indicating stable adsorption for fluoride ions. The composite foam demonstrated excellent regenerative properties and was effective for fluoride removal in actual IC wastewater.

This study demonstrates the complementarity between alkaline-thermal treatment and zero-valent iron immobilized in biochar (BC-ZVI) for enhanced degradation of perfluorooctanoic acid (PFOA). New and complementary research techniques, including 19F-NMR and density functional theory (DFT) analysis were used to evaluate defluorination efficiency and elucidate possible degradation mechanisms. The defluorination of PFOA was governed primarily by alkaline strength while BC-ZVI could enhance reaction kinetics by 2.4 times. Adsorption of the intermediates to BC-ZVI resulted in near-complete removal of all fluorinated compounds (with the exception of perfluoracetic acid) in the aqueous phase within 15 min of reaction. After 4 h of alkaline hydrothermal treatment (240 °C and 250 mM NaOH) with BC-ZVI, defluorination efficiency of PFOA of 99.7% was observed. Perfluoracetic acid was the only persistent byproduct but accounted only for less than 1% of the initial PFOA. DFT analysis also showed that strong alkaline conditions could decrease the reaction energy barrier by 73.9% due to the decarboxylation of PFOA via nucleophilic substitution. In addition to Kolbe decarboxylation, the profile of intermediate products and DFT analysis results suggest that PFOA was degraded by other mechanisms leading to near-complete and effective defluorination.

The sulfur fluidizing bioreactor (S0FB) has significant superiorities in treating nitrate-rich wastewater. However, substantial self-acidification has been observed in engineering applications, resulting in frequent start-up failures. In this study, self-acidification was reproduced in a lab-scale S0FB. It was demonstrated that self-acidification was mainly induced by sulfur disproportionation process, accounting for 93.4 % of proton generation. Supplying sufficient alkalinity to both the influent (3000 mg/L) and the bulk (2000 mg/L) of S0FB was essential for achieving a successful start-up. Furthermore, the S0FB reached 10.3 kg-N/m3/d of nitrogen removal rate and 0.13 kg-PO43-/m3/d of phosphate removal rate, respectively, surpassing those of the documented sulfur packing bioreactors by 7-129 times and 26-65 times. This study offers a feasible and practical method to avoid self-acidification during restart of S0FB and highlights the considerable potential of S0FB in the treatment of nitrate-rich wastewater.

Hydrothermal carbonization (HTC) is a promising method for converting wet solid waste into value-added products. Despite the extensive research on the HTC solid fraction, the HTC aqueous phase (AP) has received limited attention. Due to the complex composition of HTC-AP, conventional decontamination technologies are often expensive and inefficient, while causing a waste of resources. This review aims to explore the characteristics of HTC-AP, identify the governing factors, and evaluate various valorization pathways to enable the utilization of HTC-AP. The review also proposes strategies to address the challenges in existing technologies for HTC-AP valorization and treatment, considering their merits and demerits. With the future prospects of valorizing HTC-AP, this review contributes to making HTC a more sustainable and economically viable process for waste management.

Sulfur-packed beds (SPBs) have been increasingly incorporated into constructed wetland systems to overcome limitations in achieving satisfactory nitrate removal efficiency. However, the underlying impact of hydraulic regimes on SPB performance remains understudied. This study investigated the performance of a pilot-scale SPB, encompassing sulfur autotrophic denitrification (SAD) and sulfur disproportionation (SDP) processes, under various horizontal flow (HF) and vertical flow (VF) regimes. The HF regime exhibited superior SAD efficiency, achieving 3.1-4.4 mg-N/L of nitrate removal compared to 0.9-2.8 mg-N/L under VF regimes. However, greater sulfide production of 3.8-5.6 mg/L was observed, in contrast to only 1.5-2.3 mg/L under VF regimes when SDP occurred. Employing current computational fluid dynamics simulations could predict general regimes but lacked precision in detailing sulfur layer dynamics. In contrast, determining the spatial distribution of SAD substrates and SDP products offered a viable solution, revealing stagnate, short-circuit, and back flows. Moreover, the feasibility of an aeration approach to reduce sulfide emissions below 0.5 mg/L in case of accidental SDP occurrence was confirmed. This study offers a method for assessing detailed hydraulic regimes within SPBs. Additionally, it provides guidance on optimizing the packing of sulfur-based materials when implementing SPBs in constructed wetland systems and presents a strategy for mitigating excessive sulfide emissions.

Polycyclic aromatic hydrocarbons (PAHs) have been reported as priority pollutants due to their teratogenicity, genotoxicity, and carcinogenicity. Efficient remediation techniques are being sought for effective treatment and reuse of PAHs contaminated sediments. Biochar application for such purposes has been recently imposed as a sustainable and innovative technology. Biochar is actively involved in the sorption and consequent removal of PAHs from contaminated environmental samples. This chapter detailed the production and properties of biochar obtained from the pyrolysis of different raw materials. The application of biochar in the remediation of PAHs obtained from different sources is discussed. Biochar in combination with capping agents has been utilized, and its application in soil ecosystems increases the removal of PAHs. The insights into the knowledge gaps and future perspectives have been discussed. This suggests that biochar application offers new avenues for PAHs remediation while simultaneously providing a sustainable solution to the waste biomass problem.

Large volumes of biowastes including municipal solid waste, agricultural residues, animal manure, and biosolids are generated continually with the growth of global population. These biowastes can pose a huge threat to the ecosystem and human health if managed inappropriately. Commonly, conventional strategies for biowastes management such as burning, open dumpling, and landfilling can cause a lot of environmental issues like greenhouse gas (GHG) emissions, water, and soil pollutions that are hazardous to all living beings including humans. However, these biowastes can be considered as valuable resources if they are handled responsibly that will not only reduce the problem of biowastes management, but also generate value-added products and bioenergy to meet the ever-increasing resource and energy demands. The conversion of biowastes to biochar with the production of bio-oil as byproducts has been considered as a potential alternative for biowastes management, which is economically viable and environmentally sustainable. This chapter focuses on sources of biowastes, the comparison of environmental impacts of biowaste management between biochar productions and the conventional management methods, as well as technologies for the sustainable biochar production from biowastes. Furthermore, environmental benefits of biochar production from biowastes are discussed in this chapter as well. Future perspectives on commercial biochar production from biowastes are discussed.

Currently, heavy metal pollution, mining, and farming have caused many serious impacts on soils. Looking for sustainable and effective methods to mitigate soil pollution is significant. Biochar as a carbon-rich solid is generated from organic residues, and the use of biochar has been considered as an intense subject of investigation for soil remediation, and is probably going to keep on being for a long time. Moreover, the application of biochar derived from biowaste sources is a promising strategy for sustainable waste management. In this book chapter, the impacts of biochar on the soil are evaluated in terms of biological, chemical and physical properties, and environmental risks. Studies on the relationship between biochar and bioeconomy were reviewed. Further research on the biochar development has been proposed as well as current challenges.

Due to characteristics of easy access, stability, high organic carbon content, high specific surface area, high porosity, etc., biochar has been increasingly prepared and used for multiple applications in the environmental field over the world. Although the number of biochar-related studies is booming, the long-term sustainability behaviors of biochar were much less explored. The sustainability of the biochar could affect its practical applications and further development and improvement of technologies and management strategies. This study investigates the biochar applications in different environmental fields and gives notable illustrations for environmental pollution control and emission reduction. Afterward, a comprehensive framework for sustainability assessment of biochar was proposed, which addresses the concerns from technical, environmental, economic, and social aspects. The associated indices for different parts were further demonstrated, and the use of possible evaluation tools such as life cycle analysis, net present value, and multiple attribute decision making for quantification and comparison was highlighted. Finally, more field investigations on the applicability and effectiveness of biochar in different environmental conditions are further needed. The results from the study can provide theoretical and applicable information for the comprehensive evaluation and management of biochar toward sustainability.

This book chapter reviews the storm water reuse, harvesting issues, characterization of storm water, potential of reuse, and the quantity and characteristics of lignocellulosic biomass, and its modified products. Storm water is a resource that can help solve the global water scarcity problem. The pollutants such as heavy metals, organic pollutants, pathogens that exist in storm water, however, prevent it from becoming more readily used in drinking and other applications. Subsequently, the modifying techniques for biochar production involving various target contaminants removal will be presented. The application of biochar for storm water is also discussed in detail. Finally, conclusions and future perspectives on the sustainable application of biochar for storm water reuse will be showed.

Efficient solutions for storing and converting energy sources with sustainable and environment-friendly materials play an increasingly important role in ensuring energy security and promoting the development of sustainable energy sectors. Biochar-based materials have been known as promising materials for energy storage and conversion applications owing to their superior structural properties (e.g., the porosity and large surface area) and diversity of functional groups, which can be exploited for safe, modern, and environment-friendly materials. In addition, owing to the abundance of raw materials (in particular, waste biomass sources), biochar-based materials for energy storage and conversion applications can be produced at a reasonable cost. This chapter presents a critical overview of the importance of biochar for energy storage and conversion applications and the presented biochar production and modification techniques. The potential applications and challenges of these biochar materials in the energy storage and conversion field are also discussed to make relevant judgments for the future.

Microalgae harvesting methods are generally not efficient and cost-effective due to the inherent characteristics of microalgae. These problems can be addressed by membrane technology for effective microalgae harvesting and nutrient removal. This chapter focuses on the performance of membrane-based systems, membrane fouling, and fouling control approaches during the microalgae harvesting process. Operational parameters (i.e., hydraulic retention time, light conditions, etc.) should be optimized to obtain better performance. Alginate-immobilized microalgae beads and solid carriers accelerate microalgae growth and mitigate membrane fouling by the adsorption and degradation of foulants. A membrane bioreactor combined with microalgae photobioreactor effectively treats various types of wastewaters and enhances microalgae cultivation. Membrane modification and in situ physical cleaning methods (i.e., patterned membrane, turbulent jet-assisted microfiltration, etc.) remove foulants from the membrane surface and improve membrane permeability, thereby reducing the specific energy demand and harvesting cost. Development of novel carriers and techno-economic analyses of different membrane-based systems is needed in future studies.

Biohydrogen is a promising clean fuel but with a low yield. This study aims to enhance biohydrogen production from synthetic swine wastewater by employing crude enzymes obtained from different fruit peels (orange, mandarin, and banana) to improve the biohydrogen-formation processes of dark fermentation. Results indicated that dosing with crude enzymes affected volatile fatty acids (VFAs) and biogas composition insignificantly, while increased biohydrogen yield from 1.62 ± 0.00 (blank) to 1.90 ± 0.08 (orange peel), 2.01 ± 0.00 (mandarin peel), and 1.96 ± 0.01 (banana peel) mol H2/mol glucose, respectively. Banana peel crude enzyme was the most effective additive, with 1 g/L protein improving 97.41 ± 3.72 % of biohydrogen yield. The crude enzymes wielded less influence on acetic acid and butyric acid pathways but enhanced other biohydrogen production pathways. These observations demonstrated that fruit peel-based crude enzymes as additives are advantageous to improving biohydrogen yield towards higher biohydrogen production.

Antibiotics in wastewater can affect the structures and functions of bacterial communities, subsequently influencing how well a biological process performs. Therefore, the characteristics of bacterial community were investigated in a hybrid moving bed biofilm reactor-membrane bioreactor system when treating domestic wastewater containing sulfadiazine (SDZ). Results indicated total nitrogen removal reduced by 10.2%, 9.1%, 2.7% and 2.9%, respectively, with increasing carbon to nitrogen (C/N) ratios (2.5, 4, 6 and 9) when SDZ was present (0.5 mg/L). The microbial communities' analysis revealed that the abundance of nitrogen removal-related bacteria increased with C/N. Specifically, the abundance of ammonia-oxidizing bacteria (0.46%-0.90%) was low, and the nitrite-oxidizing bacteria (2.16%-7.13%) and denitrifying bacteria showed a significant increase (Hyphomicrobium: 0.57%-3.54%) when C/N ratio increased. The abundance of denitrifying bacterial declined by 4.82-8.56% at different C/N ratios, while nitrifying bacterial rose by 0.70-5.67%. Interestingly, the denitrifying bacteria Enterobacter, Sphingomonas and Gemmatimonas acted as mutualistic bacteria that stabilized denitrification.

Newly arising concepts such as the circular economy and carbon neutrality motivate resource recovery from wastewater. This paper reviews and discusses state-of-the-art microbial electrochemical technologies (METs), specifically microbial fuel cells (MFCs), microbial electrolysis cells (MECs) and microbial recycling cells (MRCs), which enable energy generation and nutrient recovery from wastewater. Mechanisms, key factors, applications, and limitations are compared and discussed. METs are effective in energy conversion, demonstrating advantages, drawbacks and future potential as specific scenarios. MECs and MRCs exhibited greater potential for simultaneous nutrient recovery, and MRCs offer the best scaling-up potential and efficient mineral recovery. Research on METs should be more concerned with lifespan of materials, secondary pollutants reduction and scaled-up benchmark systems. More up-scaled application cases are expected for cost structures comparison and life cycle assessment of METs. This review could direct the follow-up research, development and successful implementation of METs for resource recovery from wastewater.

To relieve the serious membrane fouling caused by natural organic matter (NOM) in ultrafiltration (UF) process, in this study, magnetic biochar-iron cross-linking alginate (MBCA) beads were prepared using alginate doped with coffee grounds. These MBCA-beads when combined with peroxymonosulfate (PMS) served as an UF pretreatment to alleviate membrane fouling. Results demonstrated that membrane fouling caused by humic acid (HA) can be completely alleviated at a speed of 3 rpm, and dosages of 0.5 g and 25 mg/L for MBCA-beads and PMS, respectively. When HA (10 mg/L) and sodium alginate (SA, 5 mg/L) were present together, the MBCA-beads/PMS pretreatment could remove UV254 of 98% and DOC of 68%. The main mechanisms for HA and SA removal were radicals oxidation and coagulation with in situ generated Fe(III). The contribution of •OH was about 14.83% and the joint effect of SO4−• and coagulation accounted for about 50%. Additionally, the pathways of pretreatment to mitigate HA-SA induced membrane fouling were attributed to the reduced cake layer fouling and intermediate blocking. Finally, when treating real river water, the pretreatment significantly reduced 50% of total fouling, and about 60% of the reversible fouling after 10 h filtration. This also displayed long-lasting membrane fouling mitigation ability.

In this study, researchers successfully developed a novel Magnetic Molecularly Imprinted Polymer of Boronate Affinity Controllable-Oriented Dextran (MMIP-Dextran) to enhance membrane flux by selectively adsorbing polysaccharide-type substances. The structure and components of the MMIP-Dextran were thoroughly investigated using various techniques such as Transmission Electron Microscopy (TEM), Vibrating Sample Magnetometer (VSM), Brunauer-Emmett Teller (BET), Fourier Transform Infrared (FT-IR), and Thermogravimetric Analysis (TGA). Batch experiments were conducted to assess the adsorption performance and mechanisms. Results showed that the MMIP-Dextran exhibited a high adsorption capacity of 31.2 mg g−1 and good specific recognition performance (imprinting factor, IF=2.83) for the Dextran template. Furthermore, the MMIP-Dextran had a superior polysaccharide adsorption capacity of 22.10 mg g−1 compared to the Non-Imprinted Polymer (NIP) in soluble microbial products (SMPs) derived from a bioreactor, showing a 2.45-fold improvement. Meanwhile, the Specific Filtration Resistance (SFR) tests indicated that the membrane flux improvement by MMIP-Dextran (15.2 %) is 2.1 times better than NIP (7.2 %). Adsorption kinetics and thermodynamics analyses revealed that the spontaneous adsorption process was predominantly governed by chemically rate-limiting steps. Density Functional Theory (DFT) analysis further revealed that the spatial configuration transformation of the Boric Acid Ligand (BAL) played a crucial role in the adsorption/desorption process. Overall, this study offers a promising approach to promoting the permeate flux of membrane and provides a deeper understanding of the antifouling mechanism using MMIPs.

Anaerobic co-digestion of deoiled food waste (dFW) and waste activated sludge (WAS) can address the challenges derived from mono-digestion of FW. In the present study, a pilot-scale methanogenic bioreactor of a two-phase anaerobic digestion system was developed to explore the impact of dFW/WAS volatile solids ratios on the overall performance, microbial community, and metabolic pathways. Besides, the tech-economic of the system was analyzed. The results showed that the degradation efficiency of soluble chemical oxygen demand (SCOD) was more than 84.90% for all the dFW/WAS ratios (v/v) (1:0, 39:1, 29:1, 19:1 and 9:1). Moreover, the dominant genus of bacteria and archaea with different ratios were Lactobacillus (66.84-98.44%) and Methanosaeta (53.66-80.09%), respectively. Co-digestion of dFW and WAS (29: 1 in v/v ratios) obtained the highest yield of methane (0.41 L CH4/Ladded) with approximately 90% of SCOD being removed. In the pilot-scale experiment, the co-digestion of FW and WAS makes positive contribution to reusing solid waste for improving solid management.

The COVID-19 pandemic has caused significant disruptions to the world since 2020, with over 647 million confirmed cases and 6.7 million reported deaths as of January 2023. Despite its far-reaching impact, the effects of COVID-19 on the progress of global climate change negotiations have yet to be thoroughly evaluated. This discussion paper conducts an examination of COVID-19's impact on climate change actions at global, national, and local levels through a comprehensive review of existing literature. This analysis reveals that the pandemic has resulted in delays in implementing climate policies and altered priorities from climate action to the pandemic response. Despite these setbacks, the pandemic has also presented opportunities for accelerating the transition to a low-carbon economy. The interplay between these outcomes and the different levels of governance will play a crucial role in determining the success or failure of future climate change negotiations.

In recent years utilizing nanoparticles in black paint (nano-paint) of solar desalination absorbers has become a topic growing interest. However, in most of studies, only the effect of using different types of nanoparticles brought into the spotlight, while in those limited studies that discussed on optimum concentration of nanoparticles, the results were controversial and not conclusive. Herein, an experimental study to find the optimum concentration of nanoparticles (silver, 1–5%) in solar absorbers in summer, spring and autumn with/without reflectors was conducted. To find the optimum concentration, performance of the systems from different viewpoints including energetic, exergetic, economic, productivity, exergoeconomic, energy-matrices, and environmental (amount of CO2/SO2/NO emission/reduction) analysis for each season and thorough its lifetime was examined thoroughly. Ascribe the highly variable of parameters; two Matlab codes have been developed to precisely calculate the economic and exergoeconomic parameters for different scenarios. The results showed that increasing the nanoparticle concentration to 5% from an economic viewpoint was reasonable just in summer, while for autumn and spring, 2.5% was optimum. The same was valid for productivity and exergy analysis. Importantly, the embodied energy of nanoparticles for the first time considered in calculation to obtain more accurate results in terms of environmental analysis and energy-matrices. Finally, it was concluded that even though using 5% nanoparticle in limited cases led to better results, the 2.5% concentration with reflector was optimum for all seasons and through the lifetime. This work would be a cornerstone for future researches in the context of using nano-paint in solar absorbers.

Nowadays, conductive iron-containing materials (i.e., Fe3O4 and zerovalent iron) have attracted greatly attention in improving medium-chain carboxylic acids (MCCA) from waste activated sludge (WAS). However, the feasibility and mechanism of semi-conductive iron oxide, i.e., ferric oxide (Fe2O3), in stimulating MCCA synthesis from WAS via ethanol-driven chain elongation (CE) has been unclear. Therefore, this work is aimed to fill up the knowledge gap. Results showed that the MCCA yield in the Fe2O3-supplemented fermenter attained at 9162 mg COD/L (i.e., 6268 mg COD/L caproate and 2895 mg COD/L caprylate), which was 2.4 times that of the control system. Kinetic analysis proved that Fe2O3 enhanced both the potential and rate of MCCA synthesis. Mechanism analysis indicated that Fe2O3 facilitated the individual steps for MCCA production, i.e., hydrolysis, acidification and CE. Further investigation disclosed that the dissimilatory iron reduction (DIR) induced by Fe2O3 corrosion and released ferrous ions improved enzymes activities of hydrolysis and acidification, while the promotion of CE was mainly ascribed to increased electron transfer efficiency by crystalline Fe2O3. Further, Fe2O3 promotes electron transfer through several mechanisms, including stimulating extracellular polymeric substance (EPS) excretion, increasing EPS electroactivity, and enhancing electron transport system activity. Microbial analysis revealed that Fe2O3 induced microflora structure shifting towards substrates transformation, iron reduction and MCCA generation, and up-regulated the key enzymes in CE pathways. This work provides an efficient strategy for MCCA generation and WAS management.

Emerging contaminant microplastics (MPs) are getting worldwide attention for their ubiquitous occurrence and potential risk to the environment. However, the seasonal influence on freshwater MP pollution remains poorly understood. To better understand and evaluate the riverine MPs in different seasons, this study conducted the risk assessment of MPs in an urban river, Houjin River, during the different seasons. The present study found that the MPs (0.1-5 mm, mostly 0.1-2 mm) were more abundant in the dry season (183.33 ± 128.95 items/m3) compared with the wet season (102.08 ± 45.80 items/m3). Similarly, the mixture of different MPs polymers was more diverse in the dry season. The related pollution indices such as the contamination factor (CF) and pollution load index (PLI) showed that average CF and PLI were 5.15 and 2.10 in the dry season, which significantly decreased to 1.58 and 1.25, respectively, in the wet season (p < 0.05). Additionally, significant difference of the average risk quotient (RQ) was observed, which was 0.037 in the dry season and 0.021 in the wet season (p < 0.05). To sum up, the results of this study indicate the seasonal effects on the pollution and risk of multiple compositions of MPs in the urban river, suggesting higher impacts of riverine MPs pollution in the dry season, as well as the potential increase of MPs, may lead to environmental risk in the future.

The limits of resource availability are currently driving the changes in the world’s production systems, and in turn changing how wastewater is treated. As we now head toward a circular economy, the recovery of nutrients has become an important global strategy in wastewater treatment due to the need for appropriate recycling of key minerals/materials from waste to create a sustainable and viable modern society. It is a promising strategy for reducing the depletion of nonrenewable resources and damage done to the environment which is to their extraction and manufacture. This chapter reviews state-of-the-art technologies that enable nutrients (e.g., nitrogen, phosphorus, and potassium) to be recovered throughout the wastewater treatment cycle, focusing on the latest technological advances. The mechanism, configurations, impact factors, potentials, as well as limitations of different technologies are discussed. These include: the physicochemical processes (e.g., crystallization, stripping, and absorption); anaerobic processes (e.g., anaerobic digestion and anaerobic MBR); photo-bioprocesses (e.g., microalgae-based technologies and photosynthetic bacteria-based technologies); and microbial electrochemical technologies such as microbial electrolysis cells, microbial fuel cells and microbial recycling cells. Although nutrient recovery technologies are still developing, further research is required to make the processes as efficient as possible and investigate the integration of resource recovery methods to enhance the commercial applicability of these technologies. More benchmark enlarged-scale and life cycle studies must be conducted, which will significantly benefit the application of nutrients recovery technologies in wastewater treatment to achieve the ideal of a circular economy.

Co-culture of microalgae-activated sludge has the potential to purify wastewater while reduce energy demand from aeration. In this work, a mechanically stirred membrane photobioreactor (stirred-MPBR) was used to evaluate the impact of the biomass retention time (BRT) on the treatment performance and membrane fouling. Results showed that stirred-MPBR was affected by BRT during treating domestic wastewater at a flux of 16.5 L m-2 h-1. The highest productivity was attained at BRT 7d (102 mg L-1 d-1), followed by BRT 10d (86 mg L-1 d-1), BRT 5d (85 mg L-1 d-1), and BRT 3d (83 mg L-1 d-1). Statistical analysis results showed that BRT 7d had a higher COD removal rate than BRT 10d, however, there is no difference in total nitrogen removal rate. The highest TP removal occurred when the biomass operated at BRT as short as 3d. Reduced BRTs caused a change in the microalgae-activated sludge biomass fraction that encouraged nitrification activity while simultaneously contributing to a higher fouling rate. The bound protein concentrations dropped from 31.35 mg L-1 (BRT 10d) to 10.67 mg L-1 (BRT 3d), while soluble polysaccharides increased from 0.99 to 1.82 mg L-1, respectively. The concentrations of extracellular polymeric substance fractions were significantly altered, which decreased the mean floc size and contributed to the escalating fouling propensity. At the optimum BRT of 7d, the stirred-MPBR showed sufficient access to light and nutrients exchange for mutualistic interactions between the microalgae and activated sludge.

The mobility of biochar in saturated quartz sand under a direct current (DC) electric field was investigated by column transport test. The effects of biochar preparation temperature (350 and 550 °C), solution chemistry (pH of 4, 7, and 10, and ion strength of 1, 10, 100 mM) and voltage gradient (0, 0.5 and 1.0 V cm-1) on the mobility of biochar were explored. It was found that DC electric field could significantly promote the migration of biochar, and the recovery rate of particles could be improved by 0.5-6.1 folds under 0.5 V cm-1. Higher voltage potential, solution pH and ionic strength were more favorable for biochar migration. The transport of biochar could be well interpreted by deterministic nonequilibrium convection-dispersion equation model. The enhanced mobility caused by DC electric field was attributed to the following reasons: enhanced electromigration following electrostatic attraction from the anode; increasing surface negative charges and functional groups on biochar surface as a result of electrochemical oxidization; reducing size blocking of biochar particles by decreasing particle size. Moreover, the interaction between biochar particles and electrode could alter solution chemistry, in particular, increasing solution pH, which in turn facilitated the transport of biochar. This study provided a perspective to modulate the transport behavior of biochar particle in the soil for the remediation of polluted sites.

A hybrid process of controlled nitrification by a membrane aerated biofilm (MAB), partial denitrification (PD) by activated sludge, and anaerobic ammonia oxidation (ANAMMOX) by granular sludge was proposed for synthetic low strength and COD/N wastewater treatment to address the challenges of stable nitritation and limited carbon source for nitrogen removal in this study. Batch tests with different aeration pressures showed that MAB achieved an ammonia-nitrogen removal of around 57% and nearly full nitrification under aeration pressure of 6 kPa and reaction time of 9 h, resulting in appropriate conditions for subsequent PD and ANAMMOX. Batch tests with different COD/N ratios revealed that PD activated sludge achieved an average 88% conversion from nitrate to nitrite and a nitrite-nitrogen production rate of 1.24 mg L−1 min−1 under the optimal initial COD/N of 3.5 and MLVSS of 1.3 g L−1. Batch tests on ANAMMOX showed a nitrite-nitrogen consumption rate of 0.13 mg L−1 min−1 under granular sludge MLVSS of 13 g L−1. Furthermore, batch tests mixing PD activated sludge and ANAMMOX granular sludge demonstrated an optimal seeding sludge weight ratio of 1 : 10 for simultaneous nitrate and ammonia removal. Finally, the hybrid process of controlled nitrification by MAB, PD by activated sludge, and ANAMMOX by granular sludge was established to treat synthetic low strength and COD/N wastewater (COD of 175 mg L−1, ammonia-nitrogen of 100 mg L−1). After 10 cycles of operation with a reaction time of 9 h, the effluent ammonia-nitrogen decreased to below 10 mg L−1, nitrate and nitrite nitrogen were below 3 mg L−1, and COD was below 50 mg L−1, achieving simultaneous carbon and nitrogen removal capacity of 0.36 gCOD L−1 d−1 and 0.23 gN L−1 d−1, respectively.

Disinfection is essential in water and wastewater treatment process as a guarantee for microbial safety. This study systematically investigated: (i) the inactivation characteristics of bacteria widely existed in water, including Gram-negative bacteria (Escherichiacoli) and Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis spores), by sequential UV and chlorine disinfection processes (UV-Cl and Cl-UV), simultaneous UV and chlorine disinfection process (UV/Cl); and (ii) the disinfection mechanisms on different bacteria. The combination of UV and chlorine disinfection could inactive bacteria at lower doses, but showed no synergistic effect on E. coli. Contrarily, disinfection results indicated that UV/Cl performed an obvious synergistic effect on highly disinfectant-resistant bacteria (e.g. S. aureus and B. subtilis spores). Specifically, UV/Cl at the UV dose of 9 mJ/cm2 and chlorine dose of 2 mg-Cl/L could inactivate S. aureus completely. Moreover, the effectiveness of UV/Cl on the removal of indigenous bacteria in actual water conditions was also confirmed. In short, the study provides significant theoretical and practical implications for ensuring microbial safety during water treatment and use.

Viruses found in the effluent and on the membrane surface during ultrafiltration (UF) processes will introduce hidden biosecurity dangers to drinking water. Fe3+ coagulation coupled with H2O2 to create an in situ membrane cleaning method, and MS2 bacteriophage was used as a model to investigate virus removal by UF when humic acid (HA) was present. The results showed that MS2 was removed by HA based on size exclusion, hydrophobicity, and electrostatic repulsion. Meanwhile, HA slightly reduced MS2 accumulation on the membrane surface by inhibiting MS2 adsorption. Fe3+ pretreatment (0.08 mmol/L) eliminated MS2 in the effluent by the adsorption and size exclusion of iron flocs. MS2 retained on the membrane surface was reduced through electrostatic repulsion. Iron flocs-H2O2 cleaning destroyed viral protein capsids through HO· oxidation and eliminated all MS2. The mitigation efficiency of membrane fouling was greatly improved with a flux recovery of 97.8%. Moreover, the use of H2O2 was significantly saved (3%) compared to no Fe3+ pretreatment (12%). This study provides a potentially useful and economically enhanced membrane cleaning method for virus-containing water treatment by UF, which could not only eliminate viruses and mitigate membrane fouling in the UF system but also reduce the use of membrane cleaning agents to save costs.

Sulfur-modified biochar was prepared and used to efficiently remove Chromium (Cr) from water. It was found that the sulfur-modified biochar prepared from lower primary pyrolysis temperature (<400°C), higher secondary pyrolysis temperature (>400°C), appropriate secondary pyrolysis time, and S/C ratio was favorable for Cr removal. According to the response surface methodology analysis, the biochar prepared under the primary pyrolysis temperature of 350°C, secondary pyrolysis temperature of 450°C, secondary pyrolysis time of 60 min, and S/C ratio of 2:1 could achieve the maximum Cr removal (92%). The S-modified biochar prepared under the optimum condition exhibited greater capacity of adsorbing Cr(VI) or reducing Cr(VI) into Cr(III) compared with the biochar without the S modification. The enhanced Cr(VI) adsorption and reduction were likely because some of the sulfur-containing groups formed on the modified biochar could bind and interact with the Cr(VI). Besides, the enhanced surface area by the sulfur modification also played a role in prompting the removal and reduction of Cr(VI).

Enhanced methane production and sustainable reduction of pollutants from anaerobic digestate are crucial for swine wastewater treatment. In this study, anaerobic dynamic membrane bioreactor (AnDMBR) was introduced to enhance methane production, then microalgae were cultivated on the digestate for nutrients recovery and lipid production. Results showed that pollutants can be effectively removed under various hydraulic retention time (HRT) conditions during long-term operation. Methanogenesis was enhanced with the reduction of HRT from 20 days to 10 days (0.23 L-CH4/g-CODremoved), but inhibited by shortening HRT to 5 days (0.09 L-CH4/g-CODremoved). Ammonia and phosphate in the digestate were effectively removed after microalgae cultivation. In addition, the highest microalgal biomass and lipid productivity (1.7 g/L and 17.5 mg/(L·d), respectively) were obtained using digestate ratio of 20 %, while microalgal growth was seriously restricted at high digestate content (>50 %). This work provides a prospective pathway for pollutants control and energy production from swine wastewater through integrating of AnDMBR technology with microalgae cultivation.

Efficient cleaning strategies play a key role in implementing sustainable and economic membrane operations during water treatments and purification. We proposed in this paper to construct the functional layers on the surface of PES substate using MoS2 nanosheets synthesized by a hydrothermal method, namely MoS2/PES membrane. The membrane structure and properties were characterized by SEM, XRD, EDS and FTIR. This is then followed by an evaluation of the membrane fouling of the functional layers, and in turn exploring the membrane cleaning strategy. The specific catalytic effects between MoS2 nanosheets with peroxidase-like activity, and the cleaning agent (H2O2) was subtly combined to endow MoS2 functional layers with specific catalysis. Humic acid (HA, as a representative organic foulant) having the filtration efficiency (~91 %) of MoS2/PES membrane was ~6 % higher than that of the pristine PES membrane. The flux recovery rate of MoS2/PES membrane (~75 %) was significantly larger than the PES membrane (~16 %) under optimized conditions. Results of 7 cycles of consecutive membrane fouling and cleaning demonstrated MoS2 functional layers not only relieved membrane fouling but also exhibited higher water flux. The outstanding performance of MoS2 functional layers could be explained by their stacked honeycomb pore-like structure and the catalytic characteristics of MoS2-like peroxidases. H2O2 was used to trigger the in-situ catalytic function of MoS2 layers, generating strong ROS and oxygen for the enhanced removal of organic foulants. This study provides new insights into devising a novel membrane cleaning strategy using advanced functional nanomaterials.

Shrimp farming has strongly developed in recent years, and became an important economic sector that helps create jobs and increase incomes for Vietnamese. However, the aquatic environment has also been greatly affected by the development due to the amount of wastewater discharged from shrimp farms. Among biological processes used for treating shrimp farming wastewater, the application of microalgae-bacteria co-culture is considered high potential due to its treatment and energy saving. Consequently, a photobioreactor operated with microalgae-bacteria co-culture was employed to treat shrimp farming wastewater. The salinity of wastewater and the operating condition (ratio of biomass retention time and hydraulic retention time, BRT/HRT) are the major factors affecting pollutant removal. Thus, this study investigated the effects of salinities of 0.5-20 ppt and BRT/HRT ratios of 1.5-16 on the removal performance. The results indicated that the nutrient removal was reduced when PBR operated under salinity over than 10 ppt and BRT/HRT over 5.5. Particularly, the nitrogen and phosphorus removal rates were achieved 6.56 ± 1.33 gN m-3 d-1 and 1.49 ± 0.59 gP m-3 d-1, and the removal rates decreased by 2-4 times under a salinity >10 ppt and 2-6 times under a BRT/HRT ratio >5.5. Whereas, organic matter treatment seems not to be affected when the removal rate was maintained at 28-34 gCOD m-3 d-1 under various conditions.

Promoting direct interspecies electron transfer (DIET) for methanogenesis via conductive materials is an effective strategy to enhance anaerobic digestion (AD) for methane production. In situ growth of iron trioxide (ITO) and zero-valent iron (ZVI) on carbon felts (CF) was first prepared as composite CF@ITO and CF@ZVI for AD application in this study via hydrothermal deposition and co-precipitation, respectively. The optimal preparation conditions of 2-fold concentration and 120℃ for CF@ITO and of 1-fold concentration for CF@ZVI were determined via batch AD tests adding different iron-carbon composites. Methane production was increased by 47.73% and 34.98%, respectively, for the optimally prepared CF@ITO and CF@ZVI compared to the control. The mechanisms behind were further explored in a more systematic and profound way. Cyclic voltammetry measurements showed that CF@ITO and CF@ZVI had around 10 times higher double-layer capacitance than CF, demonstrating the enhanced conductivity of iron-carbon composites. Fe and fluorescence analysis revealed that both composites increased Fe bioavailability and sludge conductivity potentially via enriching electrochemically active microorganisms and stimulating the secretion of protein-like substances, which enhanced microbial activity for methanogensis. Metagenomic sequencing analysis indicated that both composites enriched the functional genes associated with energy production and conversion, carbon and methane metabolism, and polysaccharide lyase activity. Iron reducing bacteria enhancing carbohydrate metabolic activity were more enriched in sludge after adding composites. Methanothrix capable of undertaking DIET for methanogenesis and electron carrier proteins associated genes were significantly enriched in biofilm on CF@ITO and CF@ZVI, implying the mediation of DIET via both composites and electron carrier proteins. Methanocorpusculum and Methanobacterium via interspecific hydrogen transfer (IHT) for methanogenesis were only

Urbanization, storms, and floods have compromised the benefits derived from various types of sand dune landscapes, particularly in developing countries located in humid monsoon tropical regions. One pertinent question is which driving forces have had a dominant impact on the contributions of sand dune ecosystems to human well-being. Has the decline in sand dune ecosystem services (ES) been primarily due to urbanization or flooding hazards? This study aims to address these issues by developing a Bayesian Belief Network (BBN) to analyze six different sand dune landscapes worldwide. The study uses various data types, including multi-temporal and -sensor remote sensing (SAR and optical data), expert knowledge, statistics, and GIS to analyze the trends in sand dune ecosystems. A support tool based on probabilistic approaches was developed to assess changes in ES over time due to the effects of urbanization and flooding. The developed BBN has the potential to assess the ES values of sand dunes during both rainy and dry seasons. The study calculated and tested the ES values in detail over six years (from 2016 to 2021) in Quang Nam province, Vietnam. The results showed that urbanization has led to an increase in the total ES values since 2016, while floods only had a minimal impact on dune ES values during the rainy season. The fluctuations of ES values were found to be more significant due to urbanization than floods. The study's approach can be useful in future research on coastal ecosystems.

A low-cost in-situ micro laser transmission (IMLT) analysis system for particle size monitoring based on the principle of laser transmission extinction was developed to monitor the flocculation process. In this study, the IMLT system was used to obtain the voltage generated with the changes of flocculant dosage and floc sizes in different flocculation stages. A typical machine learning model, convolution neural network (CNN) method was built to manage the flocculant dosage, detection voltage and floc size to improve the accuracy of the correlation between the them. Results of IMLT revealed that the particle size of flocs was inversely proportional to the voltage, and a larger final voltage R value indicated better effects of flocculation and sedimentation. The correlation between the particle size obtained by CNN training and measured particle size was 42.4 % and 30.5 % higher than that without training at low and high concentrations, respectively. IMLT is effective in reflecting the floc sedimentation, stability and dynamic influence of the coagulant aid on flocculation system.

Wastewater is an abundant source of nutrients and energy. Under the circumstances of circular economy and carbon neutrality, resource recovery from wastewater has recently been motivated. The microalgal process is a promising alternative for resource recovery from wastewater, and it possesses potential for the cost reduction of wastewater treatment and fertilizer production, energy generation, and greenhouse gas emissions reduction. This paper reviews and discusses state-of-the-art microalgal process development, including microalgal species screening, configuration, biotic consortia construction, infection avoidance, nutrients balancing, operational parameter optimization, and biomass harvesting enhancement. Due to the lack of literature on practical applications, the microalgal process lacks economic and environmental feasibility assessments. Life cycle assessments from the perspective of circular economy and carbon neutrality on upscaled microalgal processes are required for various wastewater scenarios. To promote the upscaled application and successful implementation, efforts are also suggested to establish utilization guidelines, advanced recommendations, reliable standards, and proper safety evaluation criteria. This work could provide a reference and direct the follow-up research, development, and application of microalgae (MA)-based processes for resource recovery from wastewater.

Mercury is a highly toxic pollutant and persistent in the sediment, which highlights the needs for remediation of sediment Hg pollution. However, the effects of remedial actions on the pollution and ecological risk of Hg in sediment are less investigated. Therefore, this study conducted an environmental risk assessment before and after corrective actions in the brine water storage pond of a closed alkali-chlorine plant with high Hg pollution in the sediment. The results showed that the accumulation of Hg in the sediment (2.59–443 mg/kg), fish and crabs (1.10–8.54 mg/kg) in the polluted pond was higher than the regulation limit in Taiwan. After implementing the corrective actions such as institutional/engineering control and remediation, we found that the Hg concentration and pollution factor (CF), in the sediment were significantly decreased by 74% and 73% (p=0.02), respectively. In addition, the geoaccumulation index (I-geo) were decreased to lower pollution class after corrective actions (p=0.009). The risk related indices such as potential ecological risk index (RI) and risk quotient (RQ) also showed significant decreases (p=0.03) after corrective actions (71% and 73%, respectively). Although the values of pollution and risk indices were still high after remediation, the results of this study demonstrated the effectiveness of corrective actions on amelioration of sediment Hg pollution. It suggests that corrective actions should be continuously implemented to reduce the pollution and risk levels in all aspects to an acceptable level for stakeholders.

Composting with food waste was assessed for its efficacy in decontaminating Bisphenol A (BPA). In a BPA-treated compost pile, the initial concentration of BPA 847 mg kg-1 fell to 6.3 mg kg-1 (99% reduction) over a 45-day composting period. The biodegradation rate was at its highest when bacterial activity peaked in the mesophilic and thermophilic phases. The average rate of total biodegradation was 18.68 mg kg-1 day-1. Standard methods were used to assess physicochemical parameters of the compost matrix and gas chromatography combined with mass spectrometry (GC/MS) was used to identify BPA intermediates. Next-generation sequencing (NGS) was used to detect BPA degraders and the diverse bacterial communities involved in BPA decomposition. These communities were found consist of 12 phyla and 21 genera during the composting process and were most diversified during the maturation phase. Three dominant phyla, Firmicutes, Pseudomonadota, and Bacteroidetes, along with Lactobacillus, Proteus, Bacillus, and Pseudomonas were found to be the most responsible for BPA degradation. Different bacterial communities were found to be involved in the food waste compost biodegradation of BPA at different stages of the composting process. In conclusion, food waste composting can effectively remove BPA, resulting in a safe product. These findings might be used to expand bioremediation technologies to apply to a wide range of pollutants.

Human health/socioeconomic development is closely correlated to environmental pollution, highlighting the need to monitor contaminants in the real environment with reliable devices such as biosensors. Recently, variety of biosensors gained high attention and employed as in-situ application, in real-time, and cost-effective analytical tools for healthy environment. For continuous environmental monitoring, it is necessary for portable, cost-effective, quick, and flexible biosensing devices. These benefits of the biosensor strategy are related to the Sustainable Development Goals (SDGs) established by the United Nations (UN), especially with reference to clean water and sources of energy. However, the relationship between SDGs and biosensor application for environmental monitoring is not well understood. In addition, some limitations and challenges might hinder the biosensor application on environmental monitoring. Herein, we reviewed the different types of biosensors, principle and applications, and their correlation with SDG 6, 12, 13, 14, and 15 as a reference for related authorities and administrators to consider. In this review, biosensors for different pollutants such as heavy metals and organics were documented. The present study highlights the application of biosensor for achieving SDGs. Current advantages and future research aspects are summarized in this paper.Abbreviations: ATP: Adenosine triphosphate; BOD: Biological oxygen demand; COD: Chemical oxygen demand; Cu-TCPP: Cu-porphyrin; DNA: Deoxyribonucleic acid; EDCs: Endocrine disrupting chemicals; EPA: U.S. Environmental Protection Agency; Fc-HPNs: Ferrocene (Fc)-based hollow polymeric nanospheres; Fe3O4@3D-GO: Fe3O4@three-dimensional graphene oxide; GC: Gas chromatography; GCE: Glassy carbon electrode; GFP: Green fluorescent protein; GHGs: Greenhouse gases; HPLC: High performance liquid chromatography; ICP-MS: Inductively coupled plasma mass spectrometry; ITO: Indium tin oxide; LAS: Linear alkylbenzene sul