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Fluoride is an essential trace element for the human body, but excessive fluoride can cause serious environmental and health problems. Therefore, developing efficient fluoride removal technologies is crucial. This review summarizes the progress made in using microbial materials to remove fluoride from wastewater, covering strategies that involve pure cultures of bacteria, fungi, and algae, as well as modified microbial materials and bioreactors. Live microorganisms exhibit high efficiency in adsorbing low concentrations of fluoride, while modified microbial materials are more suitable for treating high concentrations of fluoride. The review discusses the adsorption mechanisms and influencing factors of these technologies, and evaluates their practical application potential through techno-economic analysis. Finally, future research directions are proposed, including the optimization of modification technologies and the selection of effective microbial species, providing theoretical guidance and a basis for future microbial defluoridation technologies., 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.)

Onsite wastewater treatment systems (OWTS) are a major source of excess nutrients and co-pollutants in watersheds across the United States. In Barnstable County (Cape Cod), Massachusetts, effluent from septic systems and cesspools contributes approximately 80% of the controllable reactive nitrogen (N) load to numerous impaired estuaries and degrades water quality in the region's sole source aquifer, streams and ponds. In unsewered areas, wastewater N loads could be reduced substantially by Innovative/Alternative (I/A) septic systems designed for enhanced removal. Use, however, has been partly limited by the availability of high performing, cost effective options, while conventional septic systems continue to be installed in watersheds with well documented N impairments. This paper describes the strategic replacement of residential OWTS with two I/A models that incorporate woodchip bioreactors to enhance N removal. Systems were installed at 14 neighboring homes in Barnstable, MA, and monitored for field performance. Influent and effluent were sampled monthly and analyzed for N and phosphorus (P), among other water quality indicators. Flow to each system was continuously metered to estimate nutrient loads. Results from the first 25 months of monitoring for 13 systems with at least a full year of data are presented in terms of 1) reductions in nutrient concentrations and mass loads and 2) reliability of the systems for meeting a performance goal of total N (TN) < 10 mg/L. Discussion supports consideration of where and how these technologies may be successfully used to manage excess N in sensitive watersheds., 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., (Published by Elsevier Ltd.)

Industries such as textiles, polymers, pharmaceuticals, papers, and tanneries are the key contributors to the global economy. These industries utilize various types of synthetic dyes in their processes, leading to discharge of dyes-contaminated wastewater. The wastewater generally contains various types of dyes (such as methyl orange, congo red, malachite green, etc.), which have a detrimental impact on the ecosystem and human health due to their toxic, carcinogenic, and mutagenic nature. As the result, it is crucial to treat the dyes-contaminated wastewater to protect the environment and render it suitable for reuse, mitigating the escalating global demand for clean water. This review provides a comprehensive overview of dyes and their treatment technologies (i.e., physical, chemical, and biological treatment). Among various treatment methods, the biological treatment is widely employed due to its energy efficiency and eco-friendliness. However, biological treatment faces challenges such as slow processing rates and limited effectiveness in handling low-biodegradability pollutants (BOD 5 /COD <0.2). This review also highlighted recent advancements in treatment technologies and explored the emerging integrated treatment method that aims to achieve higher removal efficiency for a low biodegradability index dye-contaminated wastewater. Additionally, a techno-economic assessment is presented, analyzing the cost-effectiveness of the emerging technologies in real-world applications. Further, the critical research gaps and future outlooks are also discussed. Overall, the review aims to contribute to the ongoing efforts to improve wastewater treatment processes and promote sustainable water management practices., 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.)

The present study addresses the challenges of uncontrolled temperature and pollution in aquatic environments, with a focus on fish ability to tolerate high temperature. The investigation aimed to determine the role of iron nanoparticles (Fe-NPs) in enhancing the thermal tolerance of Pangasianodon hypophthalmus exposed to high-temperature stress, arsenic (As), and ammonia (NH 3 ) toxicity. Fe-NPs were synthesized using green approaches, specifically from fish gill. The dietary Fe-NPs were formulated and supplemented at 10, 15, and 20 mg kg⁻ 1 of feed. Notably, Fe-NPs at 15 mg kg⁻ 1 diet significantly reduced the critical thermal minimum (CTmin) (14.44 ± 0.21 °C) and the lethal thermal minimum (LTmin) (13.46 ± 0.15 °C), compared to the control and other treatment groups. Conversely, when Fe-NPs at 15 mg kg⁻ 1 were supplemented with or without exposure to stressors (As + NH 3 +T), the critical thermal maximum (CTmax) increased to 47.59 ± 0.16 °C, and the lethal thermal maximum (LTmax) increased to 48.60 ± 0.37 °C, both significantly higher than the control and other groups. A strong correlation was observed between LTmin and CTmin (R 2  = 0.90) and between CTmax and LTmax (R 2  = 0.98). Furthermore, dietary Fe-NPs at 15 mg kg⁻ 1 significantly upregulated the expression of stress-related genes, including HSP70, iNOS, Caspase-3a, CYP450, MT, cat, sod, gpx, TNFα, IL, TLR, and Ig. The enhanced thermal tolerance (LTmin and LTmax) can be attributed to these gene regulations, suggesting the mechanistic involvement of Fe-NPs in improving thermal resilience. Overall, the findings demonstrate that dietary supplementation with Fe-NPs, particularly at 15 mg kg⁻ 1 , improves thermal tolerance and stress response in P. hypophthalmus by enhancing gene expression and overall thermal efficiency under stressor conditions., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Wastewater effluents are a continuous source of pharmaceuticals in water bodies, which pose a serious environmental threat to aquatic ecosystems. This work provides a comprehensive technical, environmental and cost assessments of different advanced quaternary treatments for wastewater effluents, with special focus on novel Non-Thermal Plasma technology. For this porpouse Non-Thermal Plasma, Sand Filtration + Ozonation, Ultrafiltration, Ultrafiltration + Nanofiltration and Ultrafiltration + Reverse Osmosis technologies were compared with UV disinfection-based technology. This work applies the Life Cycle Analysis tool for the impact environmental assessment using both ReciPE 2016(H) method and, for a more detailed analysis of the contribution of pharmaceuticals to freshwater ecotoxicity category of impact, the USETOX method, which was integrated with 7 new characterisation factors. The results obtained showed overall removal efficiency of pharmaceuticals always higher than 80%, with performances in descending order of Ultrafiltration + Reverse Osmosis > Sand Filtration + Ozonation > Ultrafiltration + Nanofiltration > Non-Thermal Plasma, being Sand Filtration + Ultraviolet disinfection and standalone Ultrafiltration comparatively not suitable for pharmaceuticals removal. Regarding the target pharmaceuticals proposed on the EU Directive 271/91 revision, the Non-Thermal Plasma perform better towards venlafaxine than Sand Filtration + Ozonation, and towards diclofenac and carbamazepine than Ultrafiltration + Nanofiltration. Ultrafiltration + Nanofiltration and Non-Thermal Plasma showed better environmental performance than Sand Filtration + Ozonation and Ultrafiltration + Reverse Osmosis in 7 out of 18 categories of impact (ReciPe method), with Ultrafiltration + Nanofiltration being more advantageous than Non-Thermal Plasma in human and ecotoxicity-related categories of impact, and Non-Thermal Plasma more advantageous in Global Warming, Fossil Resource Scarcity, and Fine Particulate Matter Formation. Regrading Freshwater Ecotoxicity (USEtox method), the quaternary treatment configuration and its energy demand affect the Freshwater final value of impact more than the presence of pharmaceuticals. Under the conditions tested, the Non-Thermal Plasma provided the lower OPEX (0.24 € m -3 ) than other tested technologies, showing an interesting compromise between pharmaceuticals removal efficiency, environmental impacts, and economic operational cost., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Elena Surra reports financial support was provided by Polytechnic Institute of Porto School of Engineering. If there are other authors, they 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.)

As industrial and agricultural production depends on water supply, it is crucial for economic development. The available freshwater reserves on Earth are insufficient to meet humanity's growing demands. This study establishes a three-stage anoxic/oxic (A/O)-moving bed biofilm reactor (MBBR) system. The study evaluated the wastewater purification capacity of the system in summer and winter, examined the system's removal efficiency of 10 pharmaceuticals and personal care products (PPCPs) from the water, and analyzed the composition of microbial communities. Results indicate that the system effectively removes pollutants and PPCPs, with the aerobic tanks in the first two A/O stages playing a significant role in PPCP removal. The system is effective in removing four kinds of pollutants: AMP, IBU, CLR, and CAF, and the removal efficiency of CAF is up to 99.2%. Seasonal variations significantly affect the removal of PPCPs and bacterial growth, leading to changes in bacterial species. At the genus level, 41 bacterial types presented different effects in response to temperature changes, with Trichoderma and c&#95;OM190&#95;unclassified being the most affected. This study provides essential theoretical support for reducing pollutant levels and improving water recycling and economic efficiency., Competing Interests: Declaration of competing interest No conflict of interest exits in the submission of this manuscript, and manuscript is approved by all authors for publication. I would like to declare on behalf of my co-authors that the work described was original research that has not been published previously, and not under consideration for publication elsewhere, in whole or in part. All the authors have approved the manuscript that is enclosed., (Copyright © 2024. Published by Elsevier Ltd.)

High-salt textile dyeing wastewater is difficult to treat. Magnetic fields can enhance the biodegradation capacity and extreme environmental adaptabilities of microorganisms. Thus, magnetically enhanced bioreactors are expected to improve the treatment efficiency and stability of high-salt textile dyeing wastewater. Accordingly, a novel Built-in Static Magnetic Field - Biological Aerated Filter (BSMF-BAF) was constructed and investigated for treating actual high-salt textile dyeing wastewater in this study. Two other BAFs packed with traditional and magnetic ceramsite carriers, respectively, were simultaneously operated for comparison. The removal of color, chemical oxygen demand (COD), suspended solid (SS) and acute toxicity were monitored. The activities of key enzymes and microbial community structure were analyzed to reveal possible mechanisms for improving the treatment efficiency of traditional BAF using the BSMF. The results showed that the BSMF-BAF possessed the highest removal efficiencies of color, COD, SS and acute toxicity among the three BAFs. The BSMF induced significant increases in the activities of azoreductase and lignin peroxidase, which were responsible for the degradation of azo compounds in the wastewater and the detoxification of toxic intermediates, respectively. Additionally, the BSMF induced the relative enrichment of potentially effective bacteria and fungi, and it maintained a relatively high abundance of fungi in the microbial community, resulting in a high treatment efficiency., Competing Interests: Declaration of competing interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled, “Performance of a novel Built-in Static Magnetic Field – Biological Aerated Filter (BSMF–BAF) for treating high-salt textile dyeing wastewater”., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Constructed Wetlands (CW) have gained popularity over the last decades due to their cost-effectiveness, easy and simple operation and environmental compatibility in wastewater treatment. This ecological engineering technology appears particularly ideal for low-income regions. In this study, three widely used CW types (horizontal flow, vertical flow, and hybrid CW) were constructed and evaluated for their effectiveness in removing various pollution parameters (BOD 5 , COD, TSS, NH 4 -N, NO 3 -N, and TP) from an industrial effluent. Different configurations were tested such as CW type, hydraulic residence time, plants presence, and artificial aeration. Results showed that the hybrid CW configuration (i.e., vertical flow CW followed by horizontal subsurface flow CW) achieved the highest removal rates of all pollutants, i.e., more than 90% of BOD 5 , COD, TSS, and NH 4 -N. The single horizontal flow and vertical flow CW designs showed variations in the removal of NO 3 -N and TP (less than 30%), which were significantly improved (50% and 70%, respectively) by using the hybrid CW system. Artificial aeration significantly improves the performance of the CW system, especially for ammonia nitrogen and organic matter removal, while plants presence is also beneficial in the treatment performance. An 8-days HRT seems to be adequate for high removal rates in passive CW designs, though in aerated wetlands a lower HRT of 4 days seems sufficient. These findings suggest that the hybrid CW system could be a promising option for efficient wastewater treatment in developing regions., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Ali Hasani Bafrani reports financial support was provided by Research Institute of Petroleum Industry of Iran. If there are other authors, they 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.)

Zero-valent iron (ZVI) applied to the remediation of contaminated groundwater (GW) in situ, especially using engineered permeable reactive barriers (PRBs), has been proven to be an effective reactive material. However, many of ZVI brands do not represent tailored reagents specifically regarding destroying pollutants in GW. Thus, their reactivity towards certain contaminants in GW may vary significantly in a wide range even with different production batches of the same ZVI brand. This issue has rarely been known and consequently not addressed to a higher extend so far. Therefore, this study implemented extensive, long-term column experiments followed by short-term batch experiments for chlorinated volatile organic compounds (cVOCs) degradation for developing a semi-empirical test methodology to thoroughly resolve this pivotal issue by achieving an improved quality assurance guidance regarding proper field-scale emplacement of different ZVI brands and their production batches. The results showed that during column experiments perchloroethylene (PCE) led to a significant degradation up to a certain period but sulfate-reducing microorganisms enhanced the dehalogenation and led approximately to 100 % PCE removal. However, the efficacy varied for different ZVI brands, i.e., Gotthart Maier (GM) and Sponge Iron (Responge®). Furthermore, it could be shown that it might even vary among different production batches of the same ZVI brand. It was also observed that evolution of sulfate-reducing microorganisms may improve the efficacy of PCE degradation vastly that occur at different intensities with different ZVI brands and their respective production batches over time. Further, comparing comprehensive long-term column (k obs  = 0.0488 1/h) and short-term batch experiments (k obs = 0.07794 1/h) as well as refined kinetic analyses (k obs  = 0.0424 1/h) clearly prove that an appropriate guidance protocol for successful full-scale in situ remediation is required for properly select the right ZVI brand and production batch before it is loaded to a PRB in the field., Competing Interests: Declaration of competing interest The authors declared that they have no known competing financial interests or personal relationships, which seem to affect the work reported in this article. We declare that we have no human participants, human data, or human issues. We do not have any individual person's data in any form. The authors declare no competing interests., (Copyright © 2024. Published by Elsevier Ltd.)

The risk of pharmaceuticals and personal care products (PPCPs) has been paid more attention after the outbreak of COVID-19, threatening the ecology and human health resulted from the massive use of drugs and disinfectants. Wastewater treatment plants are considered the final stop to restrict PPCPs from wide spreading into the environment, but the performance of conventional treatment is limited due to their concentrations and characteristics. Previous studies have shown the unreplaceable capability of moving bed-biofilm reactor (MBBR) as a cost-effective method with layered microbial structure for treating wastewater even with toxic compounds. The biofilm community and microbial interactions are essential for the MBBR process in completely degrading or converting types of PPCPs to secondary metabolites, which still need further investigation. This review starts with discussing the initiation of MBBR formation and its influencing parameters according to the research on MBBRs in the recent years. Then the efficiency of MBBRs and the response of biofilm after exposure to PPCPs are further addressed, followed by the bottlenecks proposed in this field. Some critical approaches are also recommended for mitigating the deficiencies of MBBRs based on the recently published publications to reduce the environmental risk of PPCPs. Finally, this review provides fundamental information on PPCPs removal by MBBRs with the main focus on microbial interactions, promoting the MBBRs to practical application in the real world of wastewater treatment., 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.)

The anaerobic biological treatment of landfill leachate frequently encounters the souring problems because of the high concentration of organic in landfill leachate. Nonetheless, the performance of anaerobic membrane bioreactor (AnMBR) is commendable in terms of removal of organic compounds. Hence, this study explored the effect of organic concentration and hydraulic retention time(HRT) on the removal performance of actual landfill leachate, additionally, carbon conversion through carbon mass balance analysis was analyzed, in order to determine the optimal treatment potential of AnMBR in treating landfill leachate. For HRT values between 14.5 h and 34.6 h, and the influent COD (Chemical Oxygen Demand) range of 12,773.33-15706.67 mg/L, AnMBR could efficiently treat landfill leachate. As HRT was fixed at 14.5 h and influent COD was around 12,206.7-15,373.33 mg/L, AnMBR achieved a maximum organic removal rate of 18.22 ± 0.51 kg COD/(m 3 ∙d) with methane yield of 0.24 ± 0.01 m 3 CH 4 /kg COD and methane content of 88.26%. Based on carbon mass balance, increasing COD concentration in the influent (less than 16,000 mg/L) boosted the conversion of organic compounds (45.19 ± 4.24%) into CH 4 ; while decreasing HRT (more than 27.0 h) also promoted the conversion of organic compounds into CH 4 (38.36-60.93%) resulting in a decreased TOC (Total Organic Carbon) loss by 2.02-7.19% with outflow. AnMBR may efficiently produce methane while treating landfill leachate by assessing the random forest model (RF) and adjusting the balance between HRT and influent COD concentration., 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.)

The aim of the present study was to assess the effect of hydrothermal pretreatment on the solubilization and anaerobic digestion (AD) of Scenedesmus sp. biomass. At first, the microalgae was cultivated in 5% fresh leachate (FL) to recover nutrients such as nitrogen and phosphorus. Scenedesmus sp. grown in 5% FL obtained 100%, 77% and 97% removal efficiency of ammonium nitrogen (NH 4 + - N), total Kjeldahl nitrogen (TKN) and phosphate phosphorous (PO 4 3- -P), respectively. In the following step, the hydrothermal pretreatment of Scenedesmus sp. biomass was carried out at 120, 150 and 170 °C and retention time of 0, 30 and 60 min to evaluate its solubilization and biogas production through AD in batch test. Soluble chemical oxygen demand (sCOD) increased by 260% compared to untreated microalgae at 170 °C for 60 min. In comparison to untreated microalgae, the highest increase in biogas (70%) and methane yield (100%) was observed for 150 °C and 60 min pretreated microalgae as a consequence of hydrothermal pretreatment. Hydrothermal pretreatment has shown effectiveness in enhancing biomass solubilization and increasing biogas yield. Nevertheless, further research at the pilot scale is necessary to thoroughly evaluate the potential and feasibility of hydrothermal pretreatment for full-scale implementation., 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.)

Biodegradable plastics are being the substitute for synthetic plastics and widely been used in order to combat plastic pollution. Yet not all biodegradable plastics are degradable especially when it does not meet its favourable conditions, and also when it comes to aquatic environments. Therefore, this review is intended to highlight the types of various biodegradable plastic synthesized and commercialised and identify the limitations and advantages of these micro-bioplastics or residual bioplastic upon degradation in various aquatic environments. This review paper highlights on biodegradable plastic, degradation of biodegradable plastic in aquatic environments, application of biodegradable plastic, polylactic acid (PLA), Polyhydroxyalkanoates (PHA), Polysaccharide derivatives, Poly (amino acid), polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene adipate terephthalate (PBA/T), limitations and advantages of biodegradable plastic degradation in aquatic environment. There is no limit on the period for literature search as this field is continuously being studied and there is no wide range of studies. Biodegradable plastic that is commercially available has its own advantages and limitations respectively upon degradation in both freshwater and marine environments. There is a growing demand for bioplastic as an alternative to synthetic plastic which causes plastic waste pollution. Thus, it is crucial to understand the biodegradation of biodegradable plastic in depth especially in aquatic environments. Moreover, there are also very few studies investigating the degradation and migration of micro-bioplastics in aquatic environments., 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.)

In many industrial processes a large amount of water with high salinity is co-produced whose treatment poses considerable challenges to the available technologies. The produced water (PW) from offshore operations is currently being discharged to sea without treatment for dissolved pollutants due to space limitations. A biofilter on the seabed adjacent to a production platform would negate all size restrictions, thus reducing the environmental impact of oil and gas production offshore. The moving bed biofilm reactor (MBBR) was investigated for PW treatment from different oilfields in the North Sea at 10 °C and 40 °C, corresponding to the sea and PW temperature, respectively. The six PW samples in study were characterized by high salinity and chemical oxygen demand with ecotoxic effects on marine algae S. pseudocostatum (0.4%50 <2.7%). In continuous operation over a year, MBBR achieved a stable COD removal of 64 ± 5% at 10 °C and 68 ± 8% at 40 °C. Batch experiments revealed that most dissolved compounds were removed (up to 63%) within 3 h of treatment. High temperature (40 °C) was a key parameter to achieve a faster kinetics with degradation constant rate (k) up to eight-fold faster compared to 10 °C. Alongside contaminants removal, PW toxicity was also reduced (64-89%) during MBBR at both temperatures, hot and cold. The toxicity reduction was most likely related to the elimination of dissolved organic compounds, such as phenols, naphthalenes and BTEX. The biofilm was able to handle PW with high oil in water content from unstable production, as well as high salinity. Thus, MBBR seems to be a realistic solution to treat PW with complex and variable composition by removing harmful components towards the zero harmful discharge goal., 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 The Authors. Published by Elsevier Ltd.. All rights reserved.)

This work investigated the treatment of azo dye-containing wastewater in an upflow anaerobic sludge blanket (UASB) reactor combined with an electro-membrane bioreactor (EMBR). Current densities of 20 A m -2 and electric current exposure mode of 6'ON/30'OFF were applied to compare the performance of the EMBR to a conventional membrane bioreactor (MBR). The results showed that dye (Drimaren Red CL-7B) removal occurred predominantly in the UASB reactor, which accounted for 57% of the total dye removal achieved by the combined system. When the MBR was assisted by electrocoagulation, the overall azo dye removal efficiency increased from 60.5 to 67.1%. Electrocoagulation batch tests revealed that higher decolorization rates could be obtained with a current density of 50 A m -2 . Over the entire experimental period, the combined UASB-EMBR system exhibited excellent performance in terms of chemical oxygen demand (COD) and NH 4 + -N removal, with average efficiencies above 97%, while PO 4 3- -P was only consistently removed when the electrocoagulation was used. Likewise, a consistent reduction in the absorption spectrum of aromatic amines was observed when the MBR was electrochemically assisted. In addition to improving the pollutants removal, the use of electrocoagulation reduced the membrane fouling rate by 68% (0.25-0.08 kPa d -1 ), while requiring additional energy consumption and operational costs of 1.12 kWh m -3 and 0.32 USD m -3 , respectively. Based on the results, it can be concluded that the combined UASB-EMBR system emerges as a promising technological approach for textile wastewater treatment., 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.)

Metallothioneins (MTs) are cysteine-rich metal-binding proteins whose expression is induced by exposure to essential and non-essential metals, making them potential biological markers for assessing metal pollution in various biomonitoring programs. However, the functional properties of these proteins are yet to be comprehensively characterized in most marine invertebrates. In this study, we identified and characterized an MT homolog from the disk abalone (Haliotis discus discus), referred to as disk abalone MT (AbMT). AbMT exhibited the same primary structural features as MTs from other mollusks containing two β-domains (β2β1-form). AbMT protein demonstrated metal-binding and detoxification abilities against Zn, Cu, and Cd, as evidenced by Escherichia coli growth kinetics, metal tolerance analysis, and UV absorption spectrum. Transcriptional analysis revealed that AbMT was ubiquitously expressed in all analyzed tissues and upregulated in gill tissue following challenge with Vibrio parahaemolyticus, Listeria monocytogenes, and viral hemorrhagic septicemia virus (VHSV). Additionally, overexpression of AbMT suppressed LPS-induced NO production in RAW264.7 macrophages, protected cells against H 2 O 2 -induced oxidative stress, and promoted macrophage polarization toward the M1 phase. Conclusively, these findings suggest an important role for AbMT in environmental stress protection and immune regulation in disk abalone., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Despite the high potential of seagrass restoration to reverse the trend of marine ecosystem degradation, there are still many limitations, especially when ecosystems are severely degraded. In particular, it is not known whether restoring polluted ecosystems can lead to potentially harmful effects associated with contaminant remobilisation. Here, we aimed to investigate the role of P. oceanica transplanted from a pristine meadow to a polluted site (Augusta Bay, Italy, Mediterranean Sea) in two seasons of the year, as a sink or source of trace elements to the environment. The main results showed i) higher accumulation of chromium (Cr), copper (Cu) and total mercury (THg) in plants transplanted in summer than in winter, as well as an increase in Cr and THg in plants from sites with higher trace element loads; ii) an increase in leaf phenolics and a decrease in rhizome soluble carbohydrates associated with As and THg accumulation, suggesting the occurrence of defence strategies to cope with pollution stress; iii) a different partitioning of trace elements between below- and above-ground tissues, with arsenic (As) and Cr accumulating in roots, whereas Cu and THg in both roots and leaves. These results suggest that P. oceanica transplanted to polluted sites can act as both a sink and a source, sequestering trace elements in the below-ground tissues thus reducing their bioavailability, but also potentially remobilising them. However, the amount of trace elements potentially exported from P. oceanica to the environment through transfer into food webs via leaves and detritus appeared to be low under the specific conditions of the study site. Although further research into seagrass restoration of polluted sites would improve current knowledge to support effective ecosystem-based coastal management, the benefits of restoring polluted sites through seagrass transplantation appear to outweigh the potential costs of inaction over time., 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 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Microplastic pollution in the soil environment is of great concern. However, the current research on microplastics (MPs) in Southwest China mainly focuses on their distribution characteristics and sources in soil, making the understanding of the soil properties and land use patterns influencing soil MPs insufficient. In this study, the abundance and distribution characteristics of MPs in the soil of different land use patterns in Guizhou Province were determined. The results revealed that the average abundance of MPs in soils was 2936 items/kg, ranging from 780 to 9420 items/kg. The MPs were mainly small particle size (0-0.5 mm), granular, and black, accounting for 87.5%, 36.6%, and 82.2%, respectively. The most common polymer types of MPs were polypropylene, polyethylene terephthalate, and polyethylene, which accounted for 20.4%, 16.8%, and 16.4%, respectively. As soil bulk density increased, microplastic abundance and small particle size decreased. Soil microplastic abundance slightly decreased with increasing soil porosity. The abundance of MPs increased with the increase in soil pH, but no significant correlation was observed between soil organic matter content and microplastic abundance. pH was the major factor that affected the microplastic distribution, which accounted for 32.5%. This study provides insight into the distribution and influencing factors of soil MPs and also provides a theoretical basis for subsequent research on soil microplastic pollution., Competing Interests: Declaration of competing interest The authors declare that they have no know 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.)

Every year a huge amount of zinc carbon batteries is discarded as waste and the management of such waste has become a growing concern all over the world. However, from these waste carbon batteries different kinds of valuable materials could be recovered. On the other hand, different industries discharged large volumes of dye wastewater into the environment which has a profound impact on environment and as well as human health. In this study, ZnO was recovered from the waste carbon batteries through pyrometallurgy process and utilized it for the treatment of methylene blue and methyl orange dye water. The batch adsorption process was carried out to observe the effect of adsorbent dosage, pH, contact time, stirring speed and temperature. Under the obtained optimal conditions adsorption kinetics (Pseudo-first order and pseudo-second order) and adsorption isotherms (Langmuir, Freundlich and Temkin) were analyzed. The results disclosed that 0.5 g and 0.6 g of ZnO showed maximum removal efficiency for MB and MO dye solution (50 ppm) whereas pH 13 and 6 were the optimal for MB and MO respectively. Kinetic studies indicate that both the adsorption processes were pseudo-second order. It was also revealed that based on regression coefficient R 2 value the adsorption of MB and MO on ZnO is followed Langmuir model. Furthermore, the findings revealed that the MO adsorption on ZnO is a chemical adsorption process and MB adsorption is a physical adsorption process., 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 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Urban stormwater runoff is a significant source of nutrient pollution that is very costly to treat. Water quality trading (WQT) is a market-based strategy that can be used to lower the costs associated with meeting stormwater quality regulations. While many WQT programs have experienced low participation, Virginia's program has seen high participation due to the inclusion of land developers and other regulated stormwater dischargers. However, the extent to which WQT is used as a compliance option by regulated stormwater dischargers is not well understood, particularly when compared with the adoption of traditional compliance options. To address this knowledge gap, we collated a novel dataset comprising site characteristics and stormwater compliance methods for all development projects in the City of Roanoke, Virginia from December 2015 to March 2022. We analyzed this dataset to characterize the adoption of nutrient offset credits and other compliance methods being used, including best management practices (BMPs) and improved land covers associated with reduced nutrient export. Results show that credits are the preferred compliance option in Roanoke and were used as the only treatment compliance method for 59% of projects with treatment requirements. Projects using credits corresponded with a lower median disturbed area (1.36 acres) and lower median nutrient load reduction requirement (0.69 pounds of total phosphorus per year) compared with other compliance methods. Furthermore, we found that 58% of the projects that used credits achieved stormwater quantity compliance using methods other than implementing stormwater control devices. By mapping buyers and sellers of credits, we found that all credit sellers are downstream of the development projects. We discuss how this downstream trading could be a cause for concern, as part of a larger discussion of the advantages of tracking stormwater compliance methods, drawing on Roanoke as a case study., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Jonathan Goodall reports financial support was provided by Virginia Department of Transportation. Jacob Nelson reports financial support was provided by Virginia Department of Transportation. Marcus Aguilar reports a relationship with City of Roanoke that includes: employment., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The pyrolysis of mint stalks and lemon peels was performed to synthesize mint-stalks (MBC) and lemon-peels (LBC) derived biochars for adsorbing methylene blue (MB). The preparation, characterization, and application of MBC in adsorption have not been reported in the literature. MBC showed higher surface area and carbon content than that of LBC. The removal ratios of MB were 87.5% and 60% within 90 min for MBC and LBC, respectively at pH 7, temperature of 30 o C, adsorbent dose of 0.5 g/L, and MB concentration of 5 mg/L. The optimal MBC dose was 1 g/L achieving a removal efficiency of 93.6% at pH 7, temperature of 30 o C, contact time of 90 min, and initial dye concentration of 5.0 mg/L. The adsorption efficiency decreased from 98.6% to 31.33% by raising the dye concentration from 3.0 mg/L to 30 mg/L. Further, the increase of adsorbent dose to 10 g/L could achieve 94.2%, 90.3%, 87.6%, and 84.1% removal efficiencies of MB in the case of initial concentrations of 200 mg/L, 300 mg/L, 400 mg/L, and 500 mg/L, respectively. MBC showed high stability in adsorbing MB under five cycles, and the performed analyses after adsorption reaffirmed the stability of MBC. The adsorption mechanism indicated that the adsorption of MB molecules on the biochar's surface was mainly because of the electrostatic interaction, hydrogen bonding, and π-π stacking. Pseudo-second-order and Langmuir models could efficiently describe the adsorption of MB on the prepared biochar. The adsorption process is endothermic and spontaneous based on the adsorption thermodynamics. The proposed adsorption system is promising and can be implemented on a bigger scale. Moreover, the prepared biochar can be implemented in other applications such as photocatalysis, periodate, and persulfate activation-based advanced oxidation processes., 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.)

The increased load of plastic in waste streams after the COVID-19 pandemic outbreak has increased the possibility of microplastics (MPs) contamination channelling through the rivers and infiltrating the aquatic ecosystems. MPs in packaged water, community-stored water, groundwater, and surface water of Kaveri River (KR), Thamirabarani River (TR), Adyar River (AR), and Cooum River (CR) in Tamil Nadu were therefore investigated about 2 years after the COVID-19 pandemic outbreak. Using μFTIR and μRaman spectroscopy, polyamide, polypropylene, polyethylene, ethylene vinyl alcohol copolymer resin, and polyvinyl chloride were identified as the primary polymer types. The average number of MPs was 2.15 ± 1.9 MP/L, 1.1 ± 0.99 MP/L, 5.25 ± 1.15 MP/L, and 4 ± 2.65 MP/L in KR, TR, AR, and CR, respectively, and 1.75 ± 1.26 MP/L in groundwater, and 2.33 ± 1.52 MP/L in community stored water. Only LDPE was detected in recycled plastic-made drinking water bottles. More than 50% of MPs were found to be of size less than 1 mm, with fibrous MPs being the prevalent type, and a notable prevalence of blue-coloured microplastics in all the sample types. The Pollution Load Index (PLI) was >1 in all the rivers. Toxicity rating based on the polymer risk index (PORI) categorized AR and TR at medium risk (category II), compared to KR and CR at considerable risk (category III). Overall pollution risk index (PRI) followed a decreasing trend with CR > AR > KR > TR of considerable to low-risk category. Ecological risk assessment indicates a negligible risk to freshwater biota, except for four sites in the middle and lower stretches of Adyar River (AR - 2, AR - 4) and upper and lower stretches of Cooum River (CR - 1, CR - 3), located adjacent to direct sewer outlets, and one location in the lower stretch of Kaveri River (KR - 9), known for fishing and tourist activities., Competing Interests: Declaration of competing interest The authors declare no financial and non-financial competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The research presented herein explores the development of a novel iron-carbon composite, designed specifically for the improved treatment of high-concentration antibiotic wastewater. Employing a nitrogen-shielded thermal calcination approach, the investigation utilizes a blend of reductive iron powder, activated carbon, bentonite, copper powder, manganese dioxide, and ferric oxide to formulate an efficient iron-carbon composite. The oxygen exclusion process in iron-carbon particles results in distinctive electrochemical cells formation, markedly enhancing wastewater degradation efficiency. Iron-carbon micro-electrolysis not only boosts the biochemical degradability of concentrated antibiotic wastewater but also mitigates acute biological toxicity. In response to the increased Fe 2+ levels found in micro-electrolysis wastewater, this research incorporates Fenton oxidation for advanced treatment of the micro-electrolysis byproducts. Through the synergistic application of iron-carbon micro-electrolysis and Fenton oxidation, this research accomplishes a significant decrease in the initial COD levels of high-concentration antibiotic wastewater, reducing them from 90,000 mg/L to about 30,000 mg/L, thus achieving an impressive removal efficiency of 66.9%. This integrated methodology effectively reduces the pollutant load, and the recycling of Fe 2+ in the Fenton process additionally contributes to the reduction in both the volume and cost associated with solid waste treatment. This research underscores the considerable potential of the iron-carbon composite material in efficiently managing high-concentration antibiotic wastewater, thereby making a notable contribution to the field of environmental science., 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.)

The selection of different organic ligands when synthesizing metal organic framework (MOFs) can change their effects on the adsorption performance. Here, four La-MOFs adsorbents (La-SA, La-FA, La-TA and La-OA) with different organic ligands and structures were synthesized by solvothermal method for phosphate adsorption, and the relationship between their adsorption properties and structures was established. Among four La-MOFs, their phosphate adsorption capacities and adsorption rates followed La-SA > La-FA > La-TA > La-OA. The results indicated that average pore diameter played a key role in phosphate adsorption and there was a positive correlation between average pore diameter and adsorption capacity (R 2  = 0.86). Coexisting ion experiments showed that phosphate adsorptions on three La-MOFs (La-SA, La-FA and La-TA) were inhibited in the presence of CO 3 2- and HCO 3 - . The inhibition of CO 3 2- was the most pronounced and the results of redundancy analysis pointed out that it was mainly due to the change of pH value. In contrast, La-OA showed enhanced phosphate adsorption in the presence of CO 3 2- and HCO 3 - , and the combination of pH experiments showed that phosphate adsorption by La-OA was increased under alkaline conditions. Further combined with FT-IR, XRD, high resolution energy spectra of XPS (La 3d, P 2p and O 1s) and XANES, the adsorption mechanisms were derived electrostatic attraction, chemical precipitation and inner sphere complexation, and the last two were identified as the main mechanisms. Moreover, it can be identified from XPS 2p that the phosphate adsorption on La-FA and La-OA were mainly in the LaPO 4 state, while La-SA and La-TA mainly existed in the form of LaPO 4 ·xH 2 O crystals and inner sphere complexes. From the perspective of material morphology, this work provides a thought for the rational design of MOFs with adjustable properties for phosphate adsorption., 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.)

Biofiltration utilizes natural mechanisms including biodegradation and biotransformation along with other physical processes for the removal of organic micropollutants (OMPs) such as pharmaceuticals, personal care products, pesticides and industrial compounds found in (waste)water. In this systematic review, a total of 120 biofiltration studies from 25 countries were analyzed, considering various biofilter configurations, source water types, biofilter media and scales of operation. The study also provides a bibliometric analysis to identify the emerging research trends in the field. The results show that granular activated carbon (GAC) either alone or in combination with another biofiltration media can remove a broad range of OMPs efficiently. The impact of pre-oxidation on biofilter performance was investigated, revealing that pre-oxidation significantly improved OMP removal and reduced the empty bed contact time (EBCT) needed to achieve a consistently high OMP. Biofiltration with pre-oxidation had median removals ranging between 65% and >90% for various OMPs at 10-45 min EBCT with data variability drastically reducing beyond 20 min EBCT. Biofiltration without pre-oxidation had lower median removals with greater variability. The results demonstrate that pre-oxidation greatly enhances the removal of adsorptive and poorly biodegradable OMPs, while its impact on other OMPs varies. Only 19% of studies we reviewed included toxicity testing of treated effluent, and even fewer measured transformation products. Several studies have previously reported an increase in effluent toxicity because of oxidation, although it was successfully abated by subsequent biofiltration in most cases. Therefore, the efficacy of biofiltration treatment should be assessed by integrating toxicity testing into the assessment of overall removal., 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 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The present study investigates the treatment of real coke plant effluent utilising several ultrasound-based hybrid oxidation approaches including Ultrasound (US) alone, US + catalyst, US + H 2 O 2 , US + Fenton, US + Ozone, and US + Peroxone, with main objective as maximizing the reduction of chemical oxygen demand (COD). Ultrasonic horn at power of 130 W, frequency as 20 kHz and duty cycle as 70% was applied. Study with varying catalyst (TiO 2 ) dose from 0.5 g/L - 2 g/L revealed 1 g/L as the optimum dose resulting in 65.15% reduction in COD. A 40 ml/L dose of H 2 O 2 was shown to be optimal, giving an 81.96% reduction in COD, based on the study of varied doses of H 2 O 2 from 20 ml/L to 60 ml/L. US + Fenton reagent combination at optimum Fe 2+ /H 2 O 2 (w/v) ratio of 1:1 resulted in a COD reduction of 85.29% whereas reduction of COD as 81.75% was obtained at the optimum flow rate of ozone as 1 LPM for US + Ozone approach. US + Peroxone demonstrated the best efficiency (90.48%) for COD reduction. To find the toxicity effects, the treated (US + peroxone) and non-treated samples were tested for the growth of bacterial cultures. It was observed that the toxicity of the treated sample increased only marginally after treatment. High-resolution liquid chromatography mass spectrometry (HR-LCMS) analysis was also performed to establish intermediate compounds. Overall, the coupling of ultrasound with oxidation processes produced better results with US + Peroxone established as best treatment approach for coke plant effluent., 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.)

The combination of chlorine-mediated electrochemical advanced oxidation (Cl-EAO) and ultraviolet (UV) radiation (UV-E/Cl) can efficiently remove ammonia from wastewater. However, the synergistic mechanisms between Cl-EAO and UV need to be explored in more detail. Thus, in this study, the ammonia oxidation performance of Cl-EAO and UV-E/Cl systems were compared, while the synergistic mechanisms were identified by the performance of UV/chlorine oxidation (UV-ClO) system and the results of electron paramagnetic resonance (EPR) analysis, free radical inhibition assays, and determination of steady-state concentration of free radicals. It was found that, compared with the Cl-EAO system, UV increased the ammonia removal rate by 42.85% and reduced the active chlorine concentration (56.64%) and nitrate yield (53.61%). In the Cl-EAO, and UV-E/Cl systems, Cl • were detected, and the free radical inhibition assays and determination of steady-state concentration of free radicals suggested that UV increased the concentration of Cl • by 51.47%, resulting in Cl • becoming the major contributor to ammonia oxidation in the UV-E/Cl system. Besides, UV also increase the concentrations of HO • and Cl 2 •- , which further promoted the organic matter removal in the real domestic wastewater. This study also discussed the ammonia oxidation performance of the UV-E/Cl system in real domestic wastewater, even with the presence of significant levels of organic and inorganic anions in the wastewater, UV increased the ammonia oxidation by 21.95%. The results of this study thus clarify the mechanisms and potential applications of UV-E/Cl technology., 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.)

Co-pyrolysis of orange peel and chicken eggshell was performed for the synthesis of the composite, a co-pyrolysis technique used to promote natural fabrication and to allow the raw material elemental combination effect and the preparatory conditions such as pyrolysis temperature, residence time, and eggshell/orange peel mixing ratio, to be optimized with the response surface methodology through Box-Behnken Design(BBD). BBD involved a randomized series of 17 experimental runs, and the best optimal conditions were found with a pyrolysis temperature of 300 °C, a residence time of 1 h, and 0.5 as the mixing ratio. These conditions gave a maximum adsorption capacity of 167 mg/g for removal of the modal pollutant methylene blue. FTIR spectra of the composite showed new functional peaks of oxygenated groups, at two different bands. XRD confirmed an amorphous surface with inorganic component peaks, while SEM-EDS revealed rich defects sites along with an enhanced percentage of oxygen elements on the surface; the surface area was enhanced from 1 m 2 with unmodified peel to 64 m 2 with composite. The adsorption behavior of the composite was studied for dye removal and the adsorption behavior was well explained by the Langmuir isotherm model., 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.)

As a widespread environmental pollutant, microplastics pose a great threat to the tissues and organs of aquatic animals. The carp's muscles are necessary for movement and survival. However, the mechanism of injury of polyethylene microplastics (PE-MPs) to carp muscle remains unclear. Therefore, in this study, PE-MPs with the diameter of 8 μm and the concentration of 1000 ng/L were used to feed carp for 21 days, and polyethylene microplastic treatment groups was established. The results showed that PE-MPs could cause structural abnormalities and disarrangement of muscle fibers, and aggravate oxidative stress in muscles. Exposure to PE-MPs reduced microRNA (miR-21) in muscle tissue, negatively regulated Interleukin-1 Receptor Associated Kinase 4 (IRAK4), activated Nuclear Factor Kappa-B (NF-κB) pathway, induced inflammation, and led to endoplasmic reticulum stress and apoptosis. The present study provides different targets for the prevention of muscle injury induced by polyethylene microplastics., 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. All authors have read the manuscript and have agreed to submit it in its current form for consideration for publication in FISH & Shellfish Immunology., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Phosphate concentrations in eutrophic surface waters are usually low, and efficient removal of low concentration phosphate remains a challenge. In this study, Ca-doped LaMnO 3 synthesized at doping ratios, designated as Ca x La 1-x MnO 3 (x = 0, 0.2, 0.4, 0.7), were compared. It was found that, the adsorption capacity of Ca 0.4 La 0.6 MnO 3 material reached 63.01 mg/g at pH = 5, increased by 63.6% over the undoped LaMnO 3 perovskite. For long-term adsorption, Ca 0.4 La 0.6 MnO 3 could constantly adsorb phosphate to avoid phosphate accumulation (<0.05 mg/L). This proves that Ca 0.4 La 0.6 MnO 3 has the ability to control dynamic water eutrophication. Characterization and density functional theory results confirmed that Ca x La 1-x MnO 3 can increase the content of mesopores and oxygen vacancies, providing additional active sites. This reduces the adsorption energy of the La site, promotes electron transfer, and increases its affinity. It provides a new method for removing low-concentration phosphates., 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.)

In this study, industrial swine slaughterhouse effluents were treated by an electrocoagulation process (EC) with aluminum and iron electrodes. Batch and semicontinuous operation were performed. EC tests were carried out in batch operating mode for 2.5 h using fixed current densities (j = 10, 20, and 30 mA cm -2 ) in sulfate and chloride media. At the laboratory scale, higher TOC removal efficiencies were observed using aluminum electrodes at 20 mA cm -2 without the addition of a supporting electrolyte (82.7%). However, the EC process with Fe electrodes consumed 43.6% less energy. After the best operating parameters were found at the laboratory scale, the process was tested as a semicontinuous prepilot process using a filter-press FM01-LC-type electrochemical reactor equipped with flat plate aluminum electrodes. In this stage, current densities and mean linear flow rates were assessed. The highest TOC removal efficiency of 72.7% (i.e., residual TOC concentration of 85.18 mg L -1 ) in the semicontinuous process was achieved by the application of j = 25 mA cm -2 and u r  = 0.64 cm s -1 with an energy consumption of 19.80 kW h m -3 . The residual COD and TP concentrations met the international standard limits. Moreover, complete decoloration and disinfection were accomplished. EDXRF, SEM, EDAX, XRD, and FTIR analyses indicated that pollutants were removed by adsorption on aluminum/iron hydroxides/oxyhydroxides., 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.)

Biochar (BC) has been used to remove antibiotics from wastewater. Microplastics are emerging contaminants of wastewater. The capacities of microplastics for adsorbing antibiotics and the effects of microplastics of different types and particle sizes on antibiotic adsorption by BC have not been studied. Here, adsorption isotherm and kinetics experiments were performed to investigate tetracycline and aureomycin adsorption to polyvinyl chloride particles with diameters of 10, 100, 500, and 2000 μm, polylactic acid particles with diameters of 30, 100, 500, and 2000 μm (PLA30, PLA100, PLA500, and PLA2000, respectively), and wheat straw BC. The highest tetracycline adsorption capacity (25.00 mg g -1 ) was found for a PLA30 + BC. The tetracycline adsorption capacities of the other microplastic particles were 20.44-24.57 mg g -1 . The highest aureomycin adsorption capacity (39.50 mg g -1 ) was found for 10 μm polyvinyl chloride particles and BC. The aureomycin adsorption capacities of the other microplastic particles were 32.21-38.42 mg g -1 . The tetracycline adsorption capacities were 13.69%, 6.28%, 5.49%, and 4.54% higher for PLA30 + BC, PLA100 + BC, PLA500 + BC, and PLA2000 + BC, respectively, than for only BC. This may have been because there were more sites available per unit mass of microplastic for adsorbing tetracycline and dissolved organic carbon on small microplastic particles than large microplastic particles. The results indicated that microplastics can adsorb antibiotics and increase the amounts of antibiotics adsorbed by BC. Therefore, it is essential to consider potential interactions between BC and microplastics when BC is used to remove antibiotics from wastewater., 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.)

Municipal solid waste (MSW) leachate is one of the most hazardous waste streams leading to great potential risk to environment, and a renewable resource with high concentrations of organic contaminant and ammonia. High energy consumption and chemical input are still the challenges for ammonia recovery from MSW leachate. Here, a single-stream microbial desalination cell (SMDC) was successfully developed for simultaneous energy extraction from organic contaminant and in-situ energy utilization for ammonia recovery. 70% of the organic contaminant from the actual MSW leachate was removed, and 24.9% of the total ammonia was recovered as high-purity (NH 4 ) 2 SO 4 . The additional desalination chamber introduced into the SMDC can potentially enhance the NH 4 + migration that was determined by the NH 4 + concentration gradient and electric field. More than 30% of the total nitrogen was lost, as revealed by nitrogen mass balance analysis, probably resulting from the anodic denitrification process driven by denitrifying microorganisms, e.g., Thauera, which thrived in the anode chamber. Concomitantly, the chemical input for ammonia stripping can be reduced by up to 68% due to the relatively low buffer capacity of the catholyte and the OH - production from the cathode reaction. This SMDC can be an effective and environmentally sustainable solution for MSW leachate treatment and resource recovery., 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.)

Shale gas flowback water (SGFW), which is an inevitable waste product generated after hydraulic fracturing during development, poses a severe threat to the environment and human health. Managing high-salinity wastewater with complex physicochemical compositions is critical for ensuring environmental sustainability of shale gas development. Desalination processes have been recommended to treat SGFW to adhere to the discharge limits. However, organic fouling has become a significant concern in the steady operation of desalination processes, and the effective removal of organic compounds is challenging. This study aimed to develop an effective oxidation method to mitigate membrane fouling in real SGFW treatment process. It adopted the peroxymonosulfate (PMS)/ferrate (Fe(VI)) process, involving both free and non-free radical pathways that can alleviate the negative effects of high-salinity environments on oxidation. The operating parameters were optimized and removal effects were examined, while the synergistic oxidation mechanism and organic conversion of the PMS/Fe(VI) process were also analyzed. The results showed that the PMS/Fe(VI) process exhibited a synergistic effect compared with the PMS and Fe(VI) processes alone, with a total organic carbon (TOC) removal efficiency of 46.8% under optimal reaction conditions in real SGFW. In the Fe(VI)/PMS process, active species such as Fe(V)/Fe(IV), ·OH, and SO 4 - · were jointly involved in the oxidation of organic matter. Additionally, 99.5% of the total suspended solids and 95.2% of Ba 2+ in the SGFW were removed owing to the formation of a coagulant (Fe 3+ ) and SO 4 2- during the reaction. Finally, an ultrafiltration membrane fouling experiment proved that oxidation processes can increase the membrane-specific flux and alleviate fouling resistance. This study can serve as a reference for the design of real SGFW treatment processes and is significant for the environmental management of shale gas development., 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.)

Microplastics (MPs) have already spread across the globe and have been found in drinking water and human tissues. This may pose severe threats to human health and water environment. Therefore, this study accurately evaluated the removal effect of metal-modified biochar on polystyrene microplastics (PS-MPs) (1.0 μm) in the water environment using a high-throughput fluorescence quantification method. The results indicated that Fe-modified biochar (FeBC) and Fe/Zn-modified biochar (Fe/ZnBC) had good removal efficiencies for PS-MPs under the dosage of 3 g/L, which were 96.24% and 84.77%, respectively. Although pore effects were observed (such as "stuck", "trapped"), the electrostatic interaction was considered the main mechanism for the adsorption of PS-MPs on metal-modified biochar, whereas the formation of metal-O-PS-MPs may also contribute to the adsorption process. The removal efficiency of PS-MPs by FeBC was significantly reduced under alkaline conditions (pH = 9 and 11) or in the presence of weak acid ions (PO 4 3- , CO 3 2- , HCO 3 - ). A removal efficiency of 72.39% and 78.33% of PS-MPs was achieved from tap water (TW) and lake water (LW) using FeBC when the initial concentration was 20 mg/L. However, FeBC had no removal effect on PS-MPs in biogas slurry (BS) and brewing wastewater (BW) due to the direct competitive adsorption of high concentrations of chemical oxygen demand (COD). The findings of this study highlighted that metal-modified biochar had a potential application in purifying tap water or lake water which contaminated by MPs., 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.)

From the surface of the earth to the depths of the ocean, microplastics are a hazard for both aquatic and terrestrial habitats. Due to their small size and vast expanse, they can further integrate into living things. The fate of microplastics in the environment depends upon the biotic components such as microorganisms which have potential enzymes to degrade the microplastics. As a result, scientists are interested in using microorganisms like bacteria, fungi, and others to remediate microplastic. These microorganisms release the cutinase enzyme, which is associated with the enzymatic breakdown of microplastics and plastic films. Yet, numerous varieties of microplastics exist in the environment and their contaminants act as a significant challenge in degrading microplastics. The review discusses the cutinases enzyme degradation strategies and potential answers to deal with existing and newly generated microplastic waste - polyethylene (PE), polyethylene terephthalate (PET), poly-ε-caprolactone (PCL), polyurethanes (PU), and polybutylene succinate (PBS), along with their degradation pathways. The potential of cutinase enzymes from various microorganisms can effectively act to remediate the global problem of microplastic pollution., 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.)

Bio-nanocomposites have attracted increasing research attention because they are able to integrate bio- and nano-related functions, and subsequently demonstrate potentially beneficial environmental applications. Here, a functional bionanomaterial based on Burkholderia cepacian (FZ) immobilized on GO/ZIF-8 was developed and used to remove malachite green (MG), with functions based on both biodegradation and adsorption. XRD and FTIR results showed that in situ production of GO/ZIF-8 by combining Zn 2+ in ZIF-8 with the carboxyl group on the GO surface, led to FZ immobilized in GO/ZIF-8 through covalent bonding. Zeta analysis showed that the surface of FZ and GO/ZIF-8 had different charges under pH = 9.12, suggesting immobilization also occurred via electrostatic action. BET results confirmed that the specific surface area of GO/ZIF-8 was much larger than that of GO and ZIF-8, but the reduced specific surface area of FZ@GO/ZIF-8 could be due to FZ loading on its surface. The efficiency of FZ@GO/ZIF-8 in the removal of MG reached 99% and furthermore retained good stability after five cycles. The efficiency in removing multiple ions in river water reached more than 80%, which is evidence strongly suggesting that FZ@GO/ZIF-8 is an environmental bionanomaterial with effective application potential., 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.)

This investigation is centered on the effectiveness of methylene blue (MB), a cationic dye, adsorbed from an aqueous media by H 3 PO 4 activated papaya skin/peels (PS PAC ), with initial pH (2-10), contact time (30-180 min), MB dye concentration (varying from 10 to 50 mg/L), and MB dose (0.1-0.5 gm). The findings show that the best optimal conditions for MB dye removal occur at a 6 pH, 0.3 gm dose of PS PAC adsorbent for 10 mg/L MB dye concentration, with 90 min of contact time. To optimize and validate the extraction efficiency of MB dye, a response surface methodology (RSM) study was conducted using a central composite design (CCD) with a regression model showing R 2  = 0.9940. FT-IR spectroscopy shows, CO, and O-H stretching functional groups while FE-SEM is assessed to supervise morphological features of the PS PAC adsorbent. The peak adsorption capacity with 46.95 mg/g for the Langmuir isotherm model conveniently satisfies the adsorption process with R 2  = 0.9984 while with R 2  = 0.999, a kinetic model, pseudo-second-order, confirms MB dye adsorption by PS PAC adsorbent. Moreover, thermodynamic parameters including ΔGᵒ, ΔH°, and ΔS° were computed and found to be spontaneous and exothermic. Furthermore, regeneration studies employed with NaOH (0.1 M) and HCl (0.1 M) solution media show an acceptable MB removal efficiency consecutive up to three cycles. The study highlights that H 3 PO 4 papaya skin/peel (PS PAC ) is an effectual, sustainable, reasonably available biosorbent to remove industrial cationic dyes disposal., Competing Interests: Declaration of competing interest The authors confirm that they have no known financial conflicts or personal connection that could have perceived to influence the work reported in this manuscript., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Biochar, a promising carbon-rich and carbon-negative material, can control water pollution, harness the synergy of sustainable development goals, and achieve circular economy. This study examined the performance feasibility of treating fluoride-contaminated surface and groundwater using raw and modified biochar synthesized from agricultural waste rice husk as problem-fixing renewable carbon-neutral material. Physicochemical characterizations of raw/modified biochars were investigated using FESEM-EDAX, FTIR, XRD, BET, CHSN, VSM, pH pzc , Zeta potential, and particle size analysis were analyzed to identify the surface morphology, functional groups, structural, and electrokinetic behavior. In fluoride (F-) cycling, performance feasibility was tested at various governing factors, contact time (0-120 min), initial F- levels (10-50 mg L -1 ), biochar dose (0.1-0.5 g L -1 ), pH (2-9), salt strengths (0-50 mM), temperatures (301-328 K), and various co-occurring ions. Results revealed that activated magnetic biochar (AMB) possessed higher adsorption capacity than raw biochar (RB) and activated biochar (AB) at pH 7. The results indicated that maximum F- removal (98.13%) was achieved using AMB at pH 7 for 10 mg L -1 . Electrostatic attraction, ion exchange, pore fillings, and surface complexation govern F- removal mechanisms. Pseudo-second-order and Freundlich were the best fit kinetic and isotherm for F- sorption, respectively. Increased biochar dose drives an increase in active sites due to F- level gradient and mass transfer between biochar-fluoride interactions, which reported maximum mass transfer for AMB than RB and AB. Fluoride adsorption using AMB could be described through chemisorption processes at room temperature (301 K), though endothermic sorption follows the physisorption process. Fluoride removal efficiency reduced, from 67.70% to 53.23%, with increased salt concentrations from 0 to 50 mM NaCl solutions, respectively, due to increased hydrodynamic diameter. Biochar was used to treat natural fluoride-contaminated surface and groundwater in real-world problem-solving measures, showed removal efficiency of 91.20% and 95.61%, respectively, for 10 mg L -1 F- contamination, and has been performed multiple times after systematic adsorption-desorption experiments. Lastly, techno-economic analysis was analyzed for biochar synthesis and F- treatment performance costs. Overall, our results revealed worth output and concluded with recommendations for future research on F- adsorption using biochar., 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.)

An integrated lab-scale wastewater treatment system consisting of an anaerobic Moving Bed Biofilm Reactor (AnMBBR) and an aerobic Membrane Bioreactor (AeMBR) in series was used to study the removal and fate of pharmaceuticals during wastewater treatment. Continuous-flow experiments were conducted applying different temperatures to the AnMBBR (Phase A: 35 °C; Phase B: 20 °C), while batch experiments were performed for calculating sorption and biotransformation kinetics. The total removal of major pollutants and target pharmaceuticals was not affected by the temperature of the AnMBBR. In Phase A, the average removal of dissolved chemical oxygen demand (COD), biological oxygen demand (BOD), and ammonium nitrogen (NH 4 -N) was 86%, 91% and 96% while in Phase B, 91%, 96% and 96%, respectively. Removal efficiencies ranging between 65% and 100% were observed for metronidazole (MTZ), trimethoprim (TMP), sulfamethoxazole (SMX), and valsartan (VAL), while slight (<30%) or no removal was observed for carbamazepine (CBZ) and diclofenac (DCF), respectively. Application of a mass balance model showed that the predominant mechanism for the removal of pharmaceuticals was biotransformation, while the role of sorption was of minor importance. The AeMBR was critical for VAL, SMX and TMP biodegradation; the elimination of MTZ was strongly enhanced by the AnMBBR. In both bioreactors, Bacteroidetes was the dominant phylum in both bioreactors over time. In the AnMBBR, Cloacibacterium and Bacteroides had a higher abundance in the biocarriers compared to the suspended biomass., 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.)

The proposal of effluent treatment systems, based on circular economy principles, is a great challenge that leads to the reduction of waste from other activities, thus reducing the environmental and economic cost of the global process. In this work, buildings demolition waste is proposed to be used for metals removal from industrial effluents. To validate these hypotheses, tests were carried out on batch reactors using Copper, Nickel, and Zinc solutions, in concentrations between 8 and 16 mM. As results, removals greater than 90% were obtained. With these preliminary outcomes, it was decided to use equimolar multicomponent solutions with 8 and 16 mM of these metals in a column packed with demolition waste as adsorbent. From the breakthrough curves, it was observed that the adsorption occurs in the order Copper > Nickel > Zinc. The columns' saturated filler could be safely disposed of by incorporating it into conventional or special mortars and concrete. Preliminary studies on the leaching and resistance of mortars prepared with exhausted adsorbents are also promising. It is concluded that these materials emerge as an economic and sustainable alternative for metal contaminants removal., 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.)

There is an urgent need for developing eco-friendly adsorbents for dye wastewater treatment with high efficiency and low cost. Meanwhile, organoclay has received an increasing attention as a natural adsorbent for dye removal. However, no comprehensive investigation has been conducted to evaluate the feasibility of this approach in terms of operation cost and removal efficiency. In this research, we intend to answer this question: could organoclay be used as an efficient and cost-effective approach for dye wastewater treatment? In line with that, after characterization of the Na-bentonite and modified clay by using SEM, EDX, FTIR and XRD, the performance of the organoclay was optimized in terms of AO7 dye removal efficiency and adsorption cost using response surface methods (RSM). Then, the organoclay performance was compared with other typical adsorbents activated carbon and chitosan. The characterization results proved that Na-bentonite was successfully modified by CTAB. According to RSM results, the maximum dye removal of 95% and the minimum adsorption cost of 0.009 $/g were achieved under optimum conditions of: pH: 5, AO7 concentration: 56 mg/L, contact time: 53 min and organoclay dosage: 0.8 g/L. While, in the case of other adsorbents of Na-bentonite, chitosan and activated carbon the maximum removal of 11%, 84% and 92% were achieved with 0.0136, 0.0324 and 0.1011 $/g, respectively. The adsorption kinetics and isotherms analyses revealed that the experimental data fitted well with the pseudo-second-order (R 2  = 0.993) and Langmuir (R 2  = 0.988). This study proved that organoclay can be used as a promising adsorbent for dye removal with low cost and high removal efficiency., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

A high amount of easily degradable organics and the absence of trace metals (TMs) in household food waste (HFW) lowered the stability and efficiency of anaerobic digestion (AD) of HFW. Leachate addition to the AD of HFW can provide ammonia nitrogen and TMs to address the accumulation of volatile fatty acids and the lack of TMs. To study the effect of leachate addition on increasing organic loading rate (OLR), both mono-digestion of HFW and AD of HFW with leachate addition were evaluated using two continuously stirred tank reactors. The OLR of the mono-digestion reactor only reached 2.5 g COD/L/d. However, with the addition of ammonia nitrogen and TMs, the OLR of the failed mono-digestion reactor increased by 2 and 3.5 g COD/L/d, respectively. The specific methanogenic activity increased by 94.4% and the hydrolysis efficiency increased by 135%. Finally, the OLR of mono-digestion of HFW reached 8 g COD/L/d, with a hydraulic retention time (HRT) of 8 days and methane production rate of 2.4 L/L/d. In the leachate addition reactor, the OLR reached 15 g COD/L/d, while the HRT and methane production were 7 days and 3.4 L/L/d, respectively. This study demonstrates that leachate addition substantially improves the AD efficiency of HFW. The two main mechanisms of increasing the OLR of an AD reactor are the buffer capacity of ammonia nitrogen and the stimulation of methanogen by TMs from leachate., 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.)

Contaminant removal from (waste)waters by magnetite is a promising technology. In the present experimental study, a magnetite recycled from the steel industry waste (zero-valent iron powder) was used to investigate the sorption of As, Sb and U in phosphate-free and -rich suspensions, i.e. as a remediation for the acidic phosphogypsum leachates derived from the phosphate fertilizer industry. The results showed up to 98% U removal under controlled pH conditions, while phosphate did not hinder this immobilisation. In contrast, the results confirmed the limited uptake of As and Sb oxyanions by magnetite in presence of phosphate as the competing anion, displaying only 7-11% removal, compared to 83-87% in the phosphate-free sorption experiments. To limit this wastewater problem, raw ZVI anaerobic oxidation was examined as mechanism to increase the pH and as a source of Fe 2+ in a first step, and in a second step to remove phosphate via vivianite precipitation, therefore prior to the reaction with magnetite. UV-Vis, XRD and SEM-EDS showed that vivianite precipitation is feasible at pH > 4.5, mainly depending on the phosphate concentration. The higher the [PO 4 3- ], the lower is the pH at which vivianite precipitates and the higher the % removal of phosphate from solution. It is anticipated that an optimum 3-steps design with separate reactors controlling the conditions of ZVI oxidation, followed by vivianite precipitation and finally, reaction with magnetite, can achieve high contaminant uptake in field applications., 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.)

Nitrogen (N) reduction processes including denitrification and dissimilatory nitrate reduction to ammonium (DNRA) are critical for the eutrophication in the lake water. However, the understanding about the dominant pathways of N cycling keep limited due to the high complexity of N cycle processes in lacustrine environment. The N fractions in sediments collected from Shijiuhu Lake were measured using high-resolution (HR)-Peeper technique and chemical extraction method in varied seasons. The abundance and microbial community compositions of functional genes involved in various N-cycling processes were also obtained using high-throughput sequencing. The results showed that NH 4 + concentrations in the pore water remarkably increased from the upper layer toward the deeper layer and from winter to spring. This trend suggested that higher temperature facilitated the accumulation of NH 4 + in the water. Decreased NO 3 - concentrations were also detected at deeper sediment layers and higher temperature, indicating the intensification of N reduction on anaerobic conditions. The NH 4 + -N concentrations reduced in spring along with the slight change of NO 3 - -N in solid sediment, indicating the desorption and release of mobile NH 4 + from solid phase to the solution. Remarkably decreased absolute abundances of functional genes were found in spring with DNRA bacteria nrfA gene as dominant genus and Anaeromyxobacter as the most dominant bacterium (21.67 ± 1.03%). Higher absolute abundance (146.2-788.1 × 10 5 Copies/g) of nrfA gene relative to other genes was mainly responsible for the increase of bio-available NH 4 + in the sediments. Generally, microbial DNRA pathway predominated the N reduction and retention processes in the lake sediment at higher temperature and water depth even experiencing the suppression of DNRA bacteria abundance. These results suggested the existence of ecological risk via N retention by the action of the DNRA bacteria in the sediment on the condition of higher temperature, further provided valuable information for N management of eutrophic lakes., 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.)

To enhance the value of wheat straw derivatives, wheat straw ash (WSA) was used as a reactant for the first time to synthesize spirocyclic alkoxysilane, an important organosilicon raw material, using an energy-saving and environmentally friendly non-carbon thermal reduction method. After spirocyclic alkoxysilane extraction, the biochar in the wheat straw ash prepared an adsorbent for Cu 2+ . The maximum copper ion adsorption capacity (Q m ) of silica-depleted wheat straw ash (SDWSA) was 31.431nullmg/g, far exceeding those of WSA and similar biomass adsorbents. The effects of the pH, adsorbent dose, and contact time on the adsorption behaviour of the SDWSA for Cu 2+ adsorption were systematically investigated. The adsorption mechanism of Cu 2+ by the SDWSA was investigated using the Langmuir, Freundlich, pseudo-first-order kinetic, pseudo-second-order kinetic, and Weber and Morris models by combining the preliminary experimental data and characterization results. The adsorption isotherm and Langmuir equation matched perfectly. The Weber and Morris model can describe the mass-transfer mechanism of Cu 2+ adsorption by SDWSA. Both film and intraparticle diffusion are rapid control steps. Compared to WSA, SDWSA has a larger specific surface area and a higher content of oxygen-containing functional groups. A large specific surface area provides more adsorption sites. Oxygen-containing functional groups react with Cu 2+ through electrostatic interactions, surface complexation, and ion exchange, which are the possible adsorption mechanisms for SDWSA. These methods improve the added value of wheat straw derivatives and promote wheat straw ash recovery and centralized treatment. This makes it possible to use the thermal energy of wheat straw and facilitates the treatment of exhaust gases and carbon capture., 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.)

Sodium oleate (NaOl) is widely used as collector for oxidised ore flotation, and residual NaOl in mineral processing wastewater is a serious threat to mine environment. In this work, the feasibility of electrocoagulation (EC) as an alternative for chemical oxygen demand (COD) removal from NaOl-containing wastewater was demonstrated. Major variables were evaluated to optimise EC, and related mechanisms were proposed to interpret the observations in EC experiments. The initial pH of the wastewater greatly affected the COD removal efficiency, which was likely to be related to the variation of predominant species. When the pH was below 8.93 (original pH), liquid HOl (l) was the predominant specie, which could be rapidly removed by EC thought charge neutralisation and adsorption. At original pH or higher, Ol - could react with dissolved Al 3+ to form insoluble Al(Ol) 3 , which was subsequently removed through charge neutralisation and adsorption. The presence of fine mineral particles could reduce repulsion force of the suspended solids and promote flocculation, whereas the presence of water glass had an opposite effect. These results demonstrated that EC can be employed as an effective process to purify NaOl-containing wastewater. This study will contribute to deepening our understanding of EC technology for NaOl removal and provide useful information to researchers in mineral processing industry., 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.)

This research work represents a holistic approach of separation of aqueous lead through dynamic adsorption on cucumber peel in fixed bed column bioreactor and highlights the biological perspective of mode of interaction between adsorbent and adsorbate. Additionally attempt has been made to elucidate the importance of this process in preservation of aquatic ecosystem. The study illustrates influence of design parameters, periodic surveillance of generated effluents, statistical and mathematical model analyses of results and desorption. The findings exhibited a direct association between quality of treated effluent and speed of the feed solution, feed concentration and height of the fixed bed. Lead removal percentage was at its best (99.25%) at 8 cm bed height, 20 mL min -1 (0.9 L h -1 ) flow rate and 50 mg L -1 feed concentration whereas adsorption capacity reached its peak (300.26 mg g -1 ) when feed concentration was doubled up to 100 mg L -1 . Time bound monitoring confirmed concentration of lead in treated effluents remained within satisfactory level. Adsorbed lead was recovered up to ∼95%. Experimentation with actual industrial effluents demonstrated that lead removal percentage remained in the range of 99.97-99.46% and 99.96-99.17% up to the entire phase of bioreactor operation. In summation proper combination of design parameters of column bioreactor played important role in generating superior quality effluent, multiple reuse of the bioreactor bed was dependent on proper eluant treatment and practicability of the study was ascertained by its ability to maintain concentration of lead in actual industrial effluents within permissible limit for prolonged duration., 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.)

In the era of rapid and conspicuous progress of water treatment technologies, combined adsorption and membrane filtration systems have gained great attention as a novel and efficient method for contaminant removal from aqueous phase. Further development of these techniques for water/wastewater treatment applications will be promising for the recovery of water resources as well as reducing the water tension throughout the world. This review introduces the state-of-the-art on the capabilities of the combined adsorption-membrane filtration systems for water and wastewater treatment applications. Technical information including employed materials, superiorities, operational limitations, process sustainability and upgradeing strategies for two general configurations i.e. hybrid (pre-adsorption and post-adsorption) and integrated (film adsorbents, low pressure membrane-adsorption coupling and membrane-adsorption bioreactors) systems has been surveyed and presented. Having a systematic look at the fundamentals of hybridization/integration of the two well-established and efficient separation methods as well as spotlighting the current status and prospectives of the combination strategies, this work will be valuable to all the interested researchers working on design and development of cutting-edge wastewater/water treatment techniques. This review also draws a clear roadmap for either decision making and choosing the best alternative for a specific target in water treatment or making a plan for further enhancement and scale-up of an available strategy., 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.)