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The anaerobic membrane bioreactor (AnMBR) is a promising technology for not only water reclamation but also virus removal; however, the virus removal efficiency of AnMBR has not been fully investigated. Additionally, the removal efficiency estimation requires datasets of virus concentration in influent and effluent, but its monitoring is not easy to perform for practical operation because the virus quantification process is generally time-consuming and requires specialized equipment and trained personnel. Therefore, in this study, we aimed to identify the key, monitorable variables in AnMBR and establish the data-driven models using the selected variables to predict virus removal efficiency. We monitored operational and environmental conditions of AnMBR in Sendai, Japan and measured virus concentration once a week for six months. Spearman's rank correlation analysis revealed that the pH values of influent and mixed liquor suspended solids (MLSS) were strongly correlated with the log reduction value of pepper mild mottle virus, indicating that electrostatic interactions played a dominant role in AnMBR virus removal. Among the candidate models, the random forest model using selected variables including influent and MLSS pH outperformed the others. This study has demonstrated the potential of AnMBR as a viable option for municipal wastewater reclamation with high microbial safety. HIGHLIGHTS Virus removal efficiency in the AnMBR was monitored.; The data-driven model to predict virus removal efficiency was built.; The random forest model had the highest prediction performance.; The pH values of influent and MLSS strongly correlated with virus removal efficiency.;

This study examines the impact of incorporating a mobile bed into a membrane bioreactor (MBR) system on the treatment efficiency of dairy industry effluents. Initially, a conventional MBR system was operated for 60 days, followed by a modification that included a support material and ran for another 60 days under identical conditions. Performance was evaluated based on the removal efficiencies for soluble chemical oxygen demand (CODs), phenolic compounds, and oils and greases (OG), alongside measurements of solid content, dissolved oxygen, temperature, mixed liquor pH, and transmembrane pressure (TMP). The introduction of the mobile bed led to an increase in removal efficiencies for COD and phenolic compounds from 94.4 and 92.7% to 98 and 94.4%, respectively, marking statistically significant improvements (p < 0.05), while OG removal remained the same in both strategies (87.7%) (p > 0.05). Moreover, the modified system showed a more stable TMP profile, reducing the need for cleaning interventions compared to the conventional system, which experienced a notable TMP increase requiring cleaning at a 0.6 bar threshold. The findings suggest that integrating a mobile bed into MBR systems significantly enhances the treatment of dairy effluents, presenting an interesting solution for the upgrade of this type of system. HIGHLIGHTS The integration of a mobile bed into MBR systems significantly increases the removal efficiency of phenolic compounds.; Modified MBR systems with a mobile bed significantly reduce membrane fouling, making MBR operation more stable.; Integrating a mobile bed offers a promising upgrade for dairy effluent treatment.;

A growing human population requires sustainable solutions to regulate and dispose of municipal wastewater. Water treatment facilities in northern Idaho are permitted to apply reclaimed wastewater to forest land during the growing season at specified monthly hydraulic loading rates. We assessed the spatial and temporal variability of drainage below the rooting zone between non-irrigated (control) and irrigated (effluent) stands during the growing and dormant seasons in 2021. No drainage was observed during the two months of annual seasonal drought, but large magnitudes of drainage were recorded during the dormant season (38–94 cm), which was consistent with seasonal precipitation. The overall effect of effluent treatment on the drain gauge measurements did not differ from the controls, as effluent only increased the drainage at some facilities. The measured drainage averaged from 35 to 62 cm among facilities. We then used the drainage measurements to calibrate hydrological models (Hydrus-1D and Water Erosion Prediction Project [WEPP]) and predict the drainage in 50 measurement plots distributed evenly among five forest water reclamation facilities. As with the observed drainage, there were no statistically significant growing season differences in the predicted monthly drainage during the growing season between the effluent and control plots, suggesting the successful use of hydrologic models to support the measured drainage findings. While both models struggled to accurately predict the quantity of drainage during the dormant season, they both successfully predicted that drainage would continue through May. WEPP also successfully predicted that the treated plots began to drain in September and October following late-season irrigation at some facilities. The models showed that the prescribed crop coefficient used by the Idaho Department of Environmental Quality was adequate in avoiding drainage during the peak summer months. [ABSTRACT FROM AUTHOR]

Hog farm wastewater may require novel biological treatment techniques to improve efficiency and reduce costs. Previous studies combining vermifiltration with downstream hydroponics showed the need for a balanced wastewater nutrient content, particularly the nitrogen-to-phosphorus ratio. Here, a deep-water culture hydroponic system, growing lettuce as model culture, was used to remediate hog farm wastewater after an initial vermifiltration stage, aiming to produce an effluent suitable for irrigation. Supplemented vermifiltered wastewater (SVW) with added nutrients was tested against unsupplemented vermifiltered wastewater (VW) over 35 days, using a synthetic nutrient solution (NS) as a control. Supplementation was shown to improve lettuce growth, light use efficiency, and water use efficiency. Nutrient analysis over time showed a better-balanced phosphorus and nitrogen removal in SVW than in VW; in all treatments nitrogen and phosphorus content was reduced to legally acceptable levels for treated wastewater reuse in irrigation: nitrate 5 mgN L−1 in VW and undetectable in SVW and NS; ammonia undetectable in all treatments; and total phosphorus 2.4 mg L−1 in SVW, 0.9 mg L−1 in NS and undetectable in VW. Coliforms increased in VW and SVW during hydroponic treatment, which should be solved by disinfection. Overall, combining vermifiltration with downstream hydroponic culture proved to be a promising treatment to remediate nutrients in hog farm effluent to make it suitable to be reused for irrigation. [ABSTRACT FROM AUTHOR]

Winery wastewater (WW) is a high-volume biowaste and, in the context of Marlborough and New Zealand wineries, there is a growing recognition of the need to improve current WW disposal systems to mitigate negative environmental impacts. The application of WW to land is a low-cost method of disposal, that could significantly reduce the environmental risk associated with WW directly entering surface and groundwater bodies. This study analysed elemental concentrations in WW and soils from three Marlborough vineyards across their annual vintage to determine the loading rates of nutrients into WW and the subsequent accumulation effects of WW irrigation on receiving soils. The findings showed loading rates of approximately 1.8 t ha−1 yr−1 of sodium within WW and a significant increase in soil sodium concentration and pH, attributed to sodium-based cleaning products. A loading rate of approximately 4 t ha−1 yr−1 of total organic carbon was also identified within WW, however, significant losses in soil carbon, nitrogen, magnesium and calcium concentrations were identified. Focusing efforts to retain key nutrients from WW within soils could provide benefits to New Zealand's wine industry, facilitating increased biomass production in irrigation plots, thereby increasing biodiversity and potentially generating incentives for vineyard owners to contribute to increasing biomass carbon stocks and offset agricultural greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

The anaerobic membrane bioreactor (AnMBR) is a promising technology for not only water reclamation but also virus removal; however, the virus removal efficiency of AnMBR has not been fully investigated. Additionally, the removal efficiency estimation requires datasets of virus concentration in influent and effluent, but its monitoring is not easy to perform for practical operation because the virus quantification process is generally time-consuming and requires specialized equipment and trained personnel. Therefore, in this study, we aimed to identify the key, monitorable variables in AnMBR and establish the data-driven models using the selected variables to predict virus removal efficiency. We monitored operational and environmental conditions of AnMBR in Sendai, Japan and measured virus concentration once a week for six months. Spearman's rank correlation analysis revealed that the pH values of influent and mixed liquor suspended solids (MLSS) were strongly correlated with the log reduction value of pepper mild mottle virus, indicating that electrostatic interactions played a dominant role in AnMBR virus removal. Among the candidate models, the random forest model using selected variables including influent and MLSS pH outperformed the others. This study has demonstrated the potential of AnMBR as a viable option for municipal wastewater reclamation with high microbial safety. [ABSTRACT FROM AUTHOR]

Membrane bioreactor (MBR) is an advanced wastewater treatment technology, which has been established for more than 3 decades. In MBRs, membrane separation allows not only rejecting microorganisms/greater-sized molecules but decoupling hydraulic retention time (HRT) and solid retention time (SRT). Low-pressure driven, porous membranes have been widely used in MBRs, but their performances are mainly limited for wastewater reuse applications. Recently, many attempts have been made to combine desalination technologies to advance hybrid MBR processes for wastewater reclamation. Nanofiltration (NF) and reverse osmosis (RO) have been applied with the MBRs to improve effluent quality, and their advantages and challenges have been well reported in terms of rejection efficiency, operational energy, fouling control and recovery of retentate stream. Alternatively, the direct introduction of nonpressurized desalination technologies such as forward osmosis (FO) and membrane distillation (MD) into MBR processes for wastewater reclamation or probably for microbial activity have been considered substantially due to their low energy consumption and excellent rejection efficiency of solid materials. However, several technical limitations still need to be resolved to commercialize hybrid FO- or MD-MBR processes. This paper reviews recent advances of MBR technology integrated with desalination technologies for wastewater reclamation and suggests perspectives to optimize membranebased hybrid MBR process. [ABSTRACT FROM AUTHOR]

Forward osmosis (FO) technology, though gaining interest in the last two decades, is still regarded as non-economically viable option. In the light of the recent advances in FO membrane technology and potential benefits of its integration with reverse osmosis (RO) for desalination, wastewater treatment and energy recovery, a comprehensive analysis for FO-RO integration was carried out. This integration considers a layout which concentrates FO feed (wastewater) and dilutes the draw solution, producing potable water via RO and methane from the concentrate through upflow anaerobic sludge blanket in a separate energy recovery unit. Compared to mainstream technologies exemplified by the seawater reverse osmosis (SWRO), membrane bioreactor followed by reverse osmosis (MBR-RO), and Hitachi’s REMIX water system, this study reveals that FO-RO integration for both potable water production and energy recovery has become economically viable with a 9% life cost advantage over MBR-RO and a 20% advantage over SWRO and conventional activated sludge process combined. Moreover, the FO-RO integration showed a cost benefit ratio of 1.17, reflecting its economic viability. With ongoing advancements in FO technology and energy recovery and the many overlooked advantages it offers, this integration has the potential to become the new norm for desalination and wastewater treatment.

In the present study, a techno-economic analysis for the reclamation of wastewater in a midstream petrochemical factory (the Miaoli factory of the China Petrochemical Development Company in Taiwan) was investigated. Caprolactam is the main product in this factory. The wastewater to be reclaimed and recycled as cooling water replenishment was the effluent from organic- and inorganic-based wastewater treatment plants, the concentrate from cooling tower units, and water for rinsing use from other units. In addition to the current primary treatment process (Scheme 1), other treatment methods involving various combinations of membrane-based processes of microfiltration (MF), ultrafiltration (UF), reverse osmosis (RO), and electrodialysis reversal (EDR) were proposed, depending on the quality of the wastewater. The three schemes include the combination of MF and EDR (Scheme 2), UF and RO (Scheme 3), and MF, UF and RO (Scheme 4). Based on the capacities and operating costs of various membrane modules, an economic analysis on Schemes 2–4 by the net present worth method demonstrated that Scheme 3 was the best choice under the range of source water price studied (U$ 0.45–0.62/m3). In this case, the total amount of wastewater reclaimed notably increased from 6.6% by the current treatment scheme (Scheme 1) to 30.9% by Schemes1 and 3. Moreover, Scheme 3 had an advantage over Scheme 1 when the source water price exceeds U$ 0.51/m3. [ABSTRACT FROM AUTHOR]

Soil aquifer treatment (SAT) has been widely applied for wastewater reclamation, which cooperates secondary treatment (i.e. A2O process) and disinfection treatment (chlorination) in wastewater treatment plants (WWTPs), to remove organic matter. This study compared dissolved organic carbon (DOC) characteristics, substrate utilisation patterns, and microbial communities between pre-chlorination SAT and SAT columns, and effective removals of DOC were observed in the pre-chlorination SAT and SAT columns. However, the composition of HiA in SAT columns without chlorination was less than in pre-chlorination SAT columns for DOC fraction. In comparison to A2O effluent, different metabolic patterns and the composition of the microbial community were demonstrated by the top layer of SAT column and pre-chlorination SAT column. Furthermore, deeper layers showed similarities in the metabolic pattern and composition of the microbial community. Overall, pre-chlorination minimised the change of the microbial communities from A2O effluent in the top layer of SAT except for deeper layers, and DOC concentrations decreased in pre-chlorination SAT column. Thus, the cooperation of SAT and wastewater treatments could be suitable for wastewater reclamation. [ABSTRACT FROM AUTHOR]

A growing human population requires sustainable solutions to regulate and dispose of municipal wastewater. Water treatment facilities in northern Idaho are permitted to apply reclaimed wastewater to forest land during the growing season at specified monthly hydraulic loading rates. We assessed the spatial and temporal variability of drainage below the rooting zone between non-irrigated (control) and irrigated (effluent) stands during the growing and dormant seasons in 2021. No drainage was observed during the two months of annual seasonal drought, but large magnitudes of drainage were recorded during the dormant season (38–94 cm), which was consistent with seasonal precipitation. The overall effect of effluent treatment on the drain gauge measurements did not differ from the controls, as effluent only increased the drainage at some facilities. The measured drainage averaged from 35 to 62 cm among facilities. We then used the drainage measurements to calibrate hydrological models (Hydrus-1D and Water Erosion Prediction Project [WEPP]) and predict the drainage in 50 measurement plots distributed evenly among five forest water reclamation facilities. As with the observed drainage, there were no statistically significant growing season differences in the predicted monthly drainage during the growing season between the effluent and control plots, suggesting the successful use of hydrologic models to support the measured drainage findings. While both models struggled to accurately predict the quantity of drainage during the dormant season, they both successfully predicted that drainage would continue through May. WEPP also successfully predicted that the treated plots began to drain in September and October following late-season irrigation at some facilities. The models showed that the prescribed crop coefficient used by the Idaho Department of Environmental Quality was adequate in avoiding drainage during the peak summer months.

China is the largest steel producer in the world. Effective methods to alleviate the contradiction between water supply and water demand of the iron and steel industry in China are to implement the recycling of wastewater from the iron and steel industry and develop unconventional water resources. This paper reviews the development of wastewater recycling in the iron and steel industry in China in the past 40 years (1980–2020). During this period, steel output has increased from 36 to 1,053 million tons, freshwater consumption per ton of steel has decreased from 35.9 to 2.45 tons, and water resources reuse has soared from 61.2 to 98.02%. Four typical cases, including the Anyang Steel Group, the Tangshan Steel Group, the Tianjin Steel Group, and the Taihang Steel Group, were analyzed. In addition, a water efficiency research project of iron and steel enterprises in China was carried out in 2019. Statistical analyses on wastewater recycling rate, reuse rate, direct cooling water circulation rate, and other indicators were performed. The recycling of wastewater in the iron and steel industry would be continuously improved by policy drivers, economic drivers, and technical drivers. HIGHLIGHTS History of steel wastewater reuse and typical projects in China were presented.; Effective methods to alleviate the contradiction between water supply and demand were introduced.; Comparisons of the water use efficiency of steel industries in China were conducted.; Perspectives and challenges of future development of the steel industry were proposed.;

Two of the main concerns for wastewater reuse in agricultural irrigation are environmental and human security. Different research studies and practices have been developed recently in order to quantify the risk of possible environmental contamination of surface and groundwater resources as well as the risk to public health from enteric viruses. Other, far from negligible, related issues are largely of a socio-economic and technical character. For example, the social acceptance, especially by farmers, of wastewater reclamation and reuse in agriculture is influenced by specific local cultural, religious and socio-economic conditions. Economic and technical factors should also be taken into consideration, such as the water and wastewater treatment costs, the cost of maintenance, the employment of rural labour, the structure of irrigation networks and crop patterns. In this paper, the concept of sustainability in wastewater reclamation and reuse is formulated by using a general risk analysis framework and by taking into account all the above factors. The paper suggests a methodology for sustainable wastewater reuse in agriculture by considering not only technical and economic factors, but also environmental and social risks. Alternative strategies based on different treatment and irrigation technologies are evaluated using the multicriteria decision analysis technique. The methodology is illustrated in a case study of wastewater reclamation and agricultural reuse in the city of Thessaloniki, Macedonia, Greece

Replenishing reclaimed water into urban rivers, which suffer from reduced flow and deteriorating water quality due to anthropogenic activities, presents an opportunity for water resource management and ecological restoration, while the effect and evaluation need to be considered. This study investigated the feasibility of large-scale reclaimed water reuse in urban rivers, focusing on water quality improvements and reuse scheme evaluation, utilizing modeling software to simulate the water quality after implementing the reclaimed water replenishment scheme. After seven days of reclaimed water replenishment simulated, the water quality in the receiving urban rivers exhibited substantial improvements to different extents, with some rivers showing a decrease of over 90% in chemical oxygen demand (CODMn), ammonia nitrogen (NH3-N), and total phosphorus (TP) concentrations. A comprehensive evaluation method using the physical element extension–analytic hierarchy process (AHP) evaluation model was developed to evaluate the feasibility and efficiency of the large-scale project of reclaimed water reuse in urban rivers. The overall score of the large-scale reclaimed water reuse scenario reaches 89, approaching Level I and indicating a highly scientific and reasonable plan. This study contributes to the field of urban river restoration and water resource management by demonstrating the potential for improving water quality in urban rivers through large-scale reclaimed water reuse. The innovative comprehensive evaluation method offers valuable insights for guiding the implementation of similar projects in other urban river systems, addressing water resource challenges, and promoting ecological restoration in urban areas. [ABSTRACT FROM AUTHOR]

Objective -- As we approach the halfway point since the adoption of the 2030 Sustainable Agenda and the 17 Sustainable Development Goals (SDG), our progress in achieving the objectives remains unsatisfactory. One of which pertains to the sixth SDG that envisions access to clean water, sanitation, and hygiene as the most fundamental requirement for human health and well-being. Methodology -- Per the 2022 SDG report, the global water stress level stayed at an acceptable 18.6% in 2019, but regional disparities exist. Unless progress quadruples, billions will lack access to potable drinking water and sanitation by 2030 due to rapid population increase, urbanization, and rising water demands from the agricultural and industrial sectors. As the effective management of wastewater plays a crucial role in ensuring sustained access to clean water, Malaysia has implemented a series of national policies, legislations, and institutional arrangements to achieve an integrated wastewater legislative and governance framework. Findings -- It is critical that good practices for regulating wastewater treatment and management are analysed to address the gaps that exist that may hamper the promotion of effective and responsible wastewater management for sustainable water resources. This research is a review of Malaysia's existing wastewater governance and legislative framework. Novelty -- It is found that Malaysia's history with wastewater has seen much development to its current status, which enables increased coverage of access to clean water and basic sanitation. Nevertheless, existing problems in the wastewater industry prevent further expansion into niche areas such as wastewater reclamation. [ABSTRACT FROM AUTHOR]

Iron- and steel-making industry is one of the most water-intensive industries. An industrial wastewater purification plant using ultrafiltration and reverse osmosis is utilized by the iron and steel production industry to reclaim wastewater from the manufacturing processes. After sustained operation, the ultrafiltration membranes suffered from severe fouling problems. The frequent and necessary chemical cleaning results in raised operating cost, reduced permeate, and shortened membrane lifetime. The objective of this research was to identify the major foulants that result from long-term real-world operation of the ultrafiltration system. The fouled ultrafiltration membrane samples were collected four times during a 1.5-year period. Scanning electron microscope with energy-dispersive spectrometer, loss on ignition, and fouling resistance analysis were conducted to characterize the foulants. We identify iron (Fe) and manganese (Mn) oxides as the major foulants on the membrane surface and in the pores. We also demonstrate that irrecoverable fouling as the major contributor to fouling resistance, accounting for approximately 43 ~ 47% of the total increase in resistance. Based on our data, the irrecoverable fouling likely begins with the deposit of Fe and Mn ions and oxide particulates within the membrane pores, following by accumulation of additional oxides in part through an autocatalytic process, which ultimately leads to pore clogging. Therefore, pretreatment of the ultrafiltration influent to remove Fe and Mn ions can be a sound strategy to mitigate irrecoverable fouling. [ABSTRACT FROM AUTHOR]

Winery wastewater (WW) is a high-volume biowaste and, in the context of Marlborough and New Zealand wineries, there is a growing recognition of the need to improve current WW disposal systems to mitigate negative environmental impacts. The application of WW to land is a low-cost method of disposal, that could significantly reduce the environmental risk associated with WW directly entering surface and groundwater bodies. This study analysed elemental concentrations in WW and soils from three Marlborough vineyards across their annual vintage to determine the loading rates of nutrients into WW and the subsequent accumulation effects of WW irrigation on receiving soils. The findings showed loading rates of approximately 1.8 t ha−1 yr−1 of sodium within WW and a significant increase in soil sodium concentration and pH, attributed to sodium-based cleaning products. A loading rate of approximately 4 t ha−1 yr−1 of total organic carbon was also identified within WW, however, significant losses in soil carbon, nitrogen, magnesium and calcium concentrations were identified. Focusing efforts to retain key nutrients from WW within soils could provide benefits to New Zealand’s wine industry, facilitating increased biomass production in irrigation plots, thereby increasing biodiversity and potentially generating incentives for vineyard owners to contribute to increasing biomass carbon stocks and offset agricultural greenhouse gas emissions.

Hog farm wastewater may require novel biological treatment techniques to improve efficiency and reduce costs. Previous studies combining vermifiltration with downstream hydroponics showed the need for a balanced wastewater nutrient content, particularly the nitrogen-to-phosphorus ratio. Here, a deep-water culture hydroponic system, growing lettuce as model culture, was used to remediate hog farm wastewater after an initial vermifiltration stage, aiming to produce an effluent suitable for irrigation. Supplemented vermifiltered wastewater (SVW) with added nutrients was tested against unsupplemented vermifiltered wastewater (VW) over 35 days, using a synthetic nutrient solution (NS) as a control. Supplementation was shown to improve lettuce growth, light use efficiency, and water use efficiency. Nutrient analysis over time showed a better-balanced phosphorus and nitrogen removal in SVW than in VW; in all treatments nitrogen and phosphorus content was reduced to legally acceptable levels for treated wastewater reuse in irrigation: nitrate 5 mgN L−1 in VW and undetectable in SVW and NS; ammonia undetectable in all treatments; and total phosphorus 2.4 mg L−1 in SVW, 0.9 mg L−1 in NS and undetectable in VW. Coliforms increased in VW and SVW during hydroponic treatment, which should be solved by disinfection. Overall, combining vermifiltration with downstream hydroponic culture proved to be a promising treatment to remediate nutrients in hog farm effluent to make it suitable to be reused for irrigation.

Marimo is a type of microalgal-bacterial granular sludge (MBGS) that exists in natural water bodies. For the first time, this paper explored the feasibility of marimo in real wastewater effluent polishing, focusing on nutrient removal as compared with MBGS. The results showed that the color of marimo gradually darkened during a 21-day experiment, and the chlorophyll content increased significantly. Although marimo and MBGS showed fairly similar removal performance in terms of NO3−-N and TN, marimo exhibited better phosphate removal as compared to MBGS. Marimo and MBGS contained different algae but the same bacterial phylum of Proteobacteria, including denitrifiers. In addition, marimo had a higher relative abundance of nitrite reductase than MBGS, suggesting that the denitrification process might also happen in addition to assimilation. This study is expected to initiate the application of marimo for wastewater effluent polishing and reclamation, shedding light on nature-based wastewater self-purification technology in the era of carbon neutrality. [ABSTRACT FROM AUTHOR]

This paper focuses on a process for dairy wastewater treatment by mixotrophic cultivation of microalgae Nannochloris sp., using cheese whey obtained as a side flow from cheese production as an organic carbon source. The microalgae samples were prepared by adding to the standard growth medium increasing amounts of cheese whey, calculated to ensure a lactose concentration between 0 and 10 g/L. The samples were incubated at a constant temperature of 28 °C and 175 rpm stirring speed for a total time of seven days. Two LED (Light Emitting Diode) illumination schemes were applied in order to assess the effect of this parameter on microalgae development and bioactive compound accumulation: continuous illumination (light stress) versus alternative cycles of 12 h light—12 h dark (day–night cycle). The growth medium was analyzed before and after microalgae cultivation in order to determine the reduction of carbon, nitrogen, and phosphorus. The results obtained for this process, after a seven-day cultivation period, were as follows: reduction of 99–100% of lactose from the growth medium, up to 96% reduction in chemical oxygen demand, up to 91% reduction in nitrogen content, and up to 70% reduction in phosphorus content. [ABSTRACT FROM AUTHOR]

Chlorine disinfection has been reported to be ineffective in controlling RO membrane biofouling in some projects. Feed water temperature is a crucial factor in the formation of RO membrane biofouling. It has a positive impact on the wide application of the RO process to ascertain whether chlorine disinfection can alleviate the membrane biofouling at low temperatures. In this study, the effects of chlorination on the RO membrane biofouling at low feed water temperature (10 °C) were investigated by a lab-scale RO apparatus. The final normalized flux was 0.33 and 0.29 with and without chlorination, respectively. According to the normalized flux decline curve, chlorination could not alleviate the RO membrane fouling at low temperature. Based on the intermediate blocking model, chlorination increased the membrane fouling potential of the feed water. At low temperature, the biofilm on the membrane with chlorination was thinner and denser than that without chlorination. In addition, the membrane with chlorination contained more foulants and dissolved organic matter than that without chlorination. Chlorination failed to continuously prevent bacteria accumulation on RO membrane at low temperature, but screened out bacteria that were potentially more suitable for the low-temperature membrane environment. HIGHLIGHTS Effects of chlorination on RO membrane biofouling at low temperature were studied.; Chlorine disinfection could not alleviate the RO membrane fouling at low temperature.; The biofilm with chlorination was thinner but had more foulants at low temperature.; Chlorine disinfection failed to prevent bacterial accumulation at low temperature.; Chlorination changed the microbial community structure at low temperature.;

Thailand constantly faces the problem of water scarcity, resulting from an imbalance between available water supply and increasing water demand for economic and community expansion, as well as climate change. To address this shortage, wastewater reclamation is being planned and implemented throughout the country, along with a 20-year, long-term integrated water resource management plan. Significant opportunities from municipal wastewater treatment plants (WWTPs) are dependent on the following factors: the establishment of a reuse water framework and a tangible target for treated wastewater set by local government authorities; widespread recognition and adaptation of wastewater reuse measures in the agriculture, industry, tourism and service sectors regarding climate change and water stress; and the implementation of joint investment water reuse projects between private and government agencies. However, wastewater reclamation faces some significant challenges, specifically: the limitations of regulation and monitoring for specific reuse purposes; a lack of public confidence in the water quality; the limited commercial development of reclaimed wastewater research; and difficulties in self-sustaining business models through adapting circular economy principles. This study aims to provide an overview of the wastewater reclamation, present research trends, currently operating WWTPs as well as opportunities and challenges to speed up water reuse activities in Thailand. HIGHLIGHTS Thailand's long-term integrated water resource management plan is presented and analyzed.; There are significant opportunities for wastewater reuse and application.; Challenges to success of the plan are detailed.;

In this study, the effect of electric fields applied to a quartz sand bed on electrokinetics and the disinfection performance of an E-slow sand filter (reduction of Escherichia coli) were investigated. Results of electrokinetic experiments have shown that coliforms are electroosmotically transported to the cathode with a velocity of 0.6 cm h−1 (E = 4 V cm−1). In the absence of an electric field and at electric field strengths of

In regard to membrane-based technologies of wastewater reclamation, the reported key foulants were faced with dilemma that they could not be effectively separated and extracted from reclaimed water for thorough investigation. In this study, the crucial foulants were proposed as “critical minority fraction (FCM)”, representing the fraction with molecular weight (MW) > 100 kDa which could be easily separated by physical filtration using MW cut-off membrane of 100 kDa with fairly high recovery ratio. FCM with low dissolved organic carbon (DOC) concentration (∼1 mg/L) accounted for less than 20% of the total DOC in reclaimed water, while contributed to more than 90% of the membrane fouling, and thus FCM could be considered as a “perfect criminal” causing membrane fouling. Furthermore, pivotal fouling mechanism was attributed to the significant attractive force between FCM and membranes, which led to severe fouling development due to the aggregation of FCM on membrane surface. Fluorescent chromophores of FCM were concentrated in regions of proteins and soluble microbial products, with proteins and polysaccharides accounted for 45.2% and 25.1% of the total DOC, specifically. FCM was further fractionated into six fractions, among which hydrophobic acids and hydrophobic neutrals were the dominant components in terms of DOC content (∼80%) as well as fouling contribution. Regarding to these pronounced properties of FCM, targeted fouling control strategies including ozonation and coagulation were applied and proved to achieve remarkable fouling control effect. High-performance size-exclusion chromatography results suggested that ozonation achieved distinct transformation of FCM into low MW fractions, while coagulation removed FCM directly, thus leading to effective fouling alleviation. Therefore, the investigation of the critical foulants was expected to help glean valuable insight into the fouling mechanism and develop targeted fouling control technologies in practical applications.

[Display omitted] • Novel bMBBR setup for bio-conversion of SCOD from wastewater into ALE. • Stable SCOD reduction (conversion) rate of 87.7 ± 0.6 % achieved. • High ALE yield of 298.6 ± 51.3 mg/g VSS observed. • Blockage of nitrification could potentially achieve 0.12 kWh/m3 energy saving. • Profit evaluation revealed the potential of ALE harvesting from the bMBBR. With rapid development of global climate change and resource scarcity, the demand for sustainable wastewater reclamation technologies is growing rapidly. Alginate like exopolymers (ALE) are value-added biopolymers that can be recovered from excess biomass. In this study, a novel biopolymer value-driven moving bed biofilm reactor (bMBBR) was constructed to achieve high-efficiency conversion of organics to Alginate like exopolymers (ALE). The results revealed that excellent COD and low NH 4 +-N reduction could be achieved, with the reduction efficiencies of 87.7 ± 0.6 % and 12.6 ± 0.8 %, respectively. It is indicated that high-rate organics conversion and blockage of nitrification activity for energy saving could be simultaneous achieved in this process. Additionally, the superior settleability (SVI 30 < 80 mL/g) and functional genera related to extracellular polymeric substances (EPS) secretion were observed, making it promising for ALE recovery from residual biomass. The yields of ALE extraction from biofilm and suspended biomass ranged of 232.9–381.5 mg/g VSS. The property analyses demonstrated that the biopolymer had a similarity functional group between two samples and commercial alginate. Meanwhile, the profit evaluation results suggested that the net profit could be reached of 0.54 CNY/kg SS in the present study, which was higher than that of conventional waste activated sludge (−1.92 CNY/kg SS). Moreover, the economic value of ALE (0.38 CNY/m3 wastewater treated) was also 2.93 times of that obtained from CH 4 (0.13 CNY/m3 wastewater treated). In general, the present study provides a prove of concept that bio-refinery of organics into value-added biopolymers could offer a promising direction towards next generation of sustainable wastewater treatment plants. [ABSTRACT FROM AUTHOR]

Replenishing reclaimed water into urban rivers, which suffer from reduced flow and deteriorating water quality due to anthropogenic activities, presents an opportunity for water resource management and ecological restoration, while the effect and evaluation need to be considered. This study investigated the feasibility of large-scale reclaimed water reuse in urban rivers, focusing on water quality improvements and reuse scheme evaluation, utilizing modeling software to simulate the water quality after implementing the reclaimed water replenishment scheme. After seven days of reclaimed water replenishment simulated, the water quality in the receiving urban rivers exhibited substantial improvements to different extents, with some rivers showing a decrease of over 90% in chemical oxygen demand (CODMn), ammonia nitrogen (NH3-N), and total phosphorus (TP) concentrations. A comprehensive evaluation method using the physical element extension–analytic hierarchy process (AHP) evaluation model was developed to evaluate the feasibility and efficiency of the large-scale project of reclaimed water reuse in urban rivers. The overall score of the large-scale reclaimed water reuse scenario reaches 89, approaching Level I and indicating a highly scientific and reasonable plan. This study contributes to the field of urban river restoration and water resource management by demonstrating the potential for improving water quality in urban rivers through large-scale reclaimed water reuse. The innovative comprehensive evaluation method offers valuable insights for guiding the implementation of similar projects in other urban river systems, addressing water resource challenges, and promoting ecological restoration in urban areas.

Globally, sustainable water management is required to minimize water security, and soil aquifer treatments (SATs) are widely applied in wastewater reclamation. Clogging problems limit the sustainable operation of SATs (i.e., the decrease of infiltration rate), and Physical clogging has been widely studied. However, the effect of biological clogging on the operation of SATs is still unclear. Thus, this study focuses on the effects of biological clogging in an SAT system and demonstrates that the clogging process in an SAT column. In this study, the infiltration rate in the A2O ​+ ​NaN3 water column decreased slightly, to 6–7 ​cm/h with an average rate of 0.01 ​cm/h per month after 240 ​d, compared with an average rate of 0.3 ​cm/h per month in the columns fed by filtered A2O water. The fastest reduction in infiltration rate, caused by biological clogging, occurred in the first 60 ​d and corresponded to the highest reduction in hydraulic conductivity of 0–2.5 ​cm layer. For alleviating clogging, this study illustrated that removing suspended solids from A2O water by filtration helped reduce approximately 25% of polysaccharides and heterotrophic bacteria. In comparison, pre-ozonation of A2O water helped to reduce approximately 70% of the biomass in the surface layer of the A2O ​+ ​O3 column. Thus, ozonation of wastewater effluent helps control biological clogging in SAT.

It is highly anticipated that efforts will be made to raise the level of industrial effluent reclamation on the background of continuously minimizing waste stream based on preconcentration tool. For this purpose, a triple-doped nanocomposite (TFN-tri) membrane through partially alternative doping spiro-structured 2,2'-dimethyl-1,1'-biphenyl-4,4'-diamine dihydrochloride and flexible 4,4'-bipiperidyl dihydrochloride and continuous incorporating of molybdenum disulfide quantum dots was successfully fabricated. With the assistance of self-synthesized biodegradable flocculant pretreatment, raw hairwork dyeing effluent (HDE) was stably recycled up to 95.1% on the premise of meeting the requirements of the relevant national standard. As a deep processing unit, TFN-tri membrane displayed accurate salt rejection of nearly 66% as expected. More impressively, it also exhibited permeability basically increased by 2.5 folds, while fouling layer thickness, running time and specific energy consumption decreased by 5 μm, 54.7% and 72.5%, respectively, than its counterpart in long-term reuse testing. These changes may mainly be due to the finely expand sub-nanopores coupled with an enhanced electrostatic exclusion and the improved fouling resistance brought about by other critical skin features in terms of smoothness and hydrophilicity optimization. In brief, this study has taken a vigorous and reliable step towards heavily polluted HDE reclamation approaching zero liquid discharge., 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.)

Wastewater reclamation is regarded as a primary solution for efficient water resource management because of its environmental friendliness and energy efficiency. Membrane capacitive deionization (MCDI) has shown great promise as a practical technology for wastewater reclamation, but challenges remain for the large-scale deployment of this technology due to gaps in understanding its technical and environmental performance. This study presents a pilot-scale MCDI-based wastewater treatment and reclamation system that includes sand filtration (SF), ultrafiltration (UF), MCDI, and ultraviolet (UV) units. Additionally, this research aims to investigate the overall environmental impacts and trade-offs of the system through a life cycle assessment (LCA) approach to identify impact hotspots with the potential for system improvement. Over long-term operation, the water quality characteristics showed significant improvements in conductivity, ammonia-N content, and total hardness, satisfactorily meeting the standards for wastewater reclamation. Results from the impact assessment revealed that the production of 1 m 3 of desalinated water for reclamation in the MCDI-based system generates a global warming potential of approximately 2.77 kg CO 2  eq, primarily due to electricity consumption and the use of high-impact chemicals. Electricity and chemical consumption contribute nearly 81 % and 15 %, respectively, to the overall impacts. These inputs also have remarkable impacts on marine aquatic ecotoxicity, human toxicity and abiotic depletion. The impacts from material and chemical usage are average out during the scaling-up process due to the increase in water productivity. As demonstrated, the integration of emerging water treatment technologies with high energy efficiency could significantly improve the environmental performance of the system. The results from the present study can offer valuable insights for advancing future wastewater reclamation systems aimed at improving environmental outcomes., (Copyright © 2024. Published by Elsevier B.V.)

The availability of freshwater is evolving as a serious threat to the living community throughout the world due to rapid industrialization, urbanization, and rising population. The depletion of groundwater due to excessive water withdrawal and reduced recharge and pollution of the water sources also contributes to this water crisis. The rising pressure on water supplies encourages the use of treated wastewater as an alternative resource. In this study, a global outlook of the developments in water reuse is presented with a focus on the Indian scenario. It can be observed that though there is a scope for water reuse in India owing to the generation of a high volume of wastewater, it is often squandered due to limited research and guidance, and unreliable institutional framework. It is suggested that the reuse of wastewater requires the development of an integrated approach considering all the factors related to technical feasibility, financial viability, and social acceptance together with a guiding management structure that may augment the existing water supplies. HIGHLIGHTS Provides an overview of factors influencing water reuse throughout the world.; Discusses regional challenges with regard to the implementation of water reuse schemes worldwide.; Provides insight to the existing reuse scenario and future opportunities in India.;

Marimo is a type of microalgal-bacterial granular sludge (MBGS) that exists in natural water bodies. For the first time, this paper explored the feasibility of marimo in real wastewater effluent polishing, focusing on nutrient removal as compared with MBGS. The results showed that the color of marimo gradually darkened during a 21-day experiment, and the chlorophyll content increased significantly. Although marimo and MBGS showed fairly similar removal performance in terms of NO3−-N and TN, marimo exhibited better phosphate removal as compared to MBGS. Marimo and MBGS contained different algae but the same bacterial phylum of Proteobacteria, including denitrifiers. In addition, marimo had a higher relative abundance of nitrite reductase than MBGS, suggesting that the denitrification process might also happen in addition to assimilation. This study is expected to initiate the application of marimo for wastewater effluent polishing and reclamation, shedding light on nature-based wastewater self-purification technology in the era of carbon neutrality.

Climate change, global population growth, and rising standards of living have put immense strain on natural resources, resulting in the unsecured availability of water as an existential resource. Access to high-quality drinking water is crucial for daily life, food production, industry, and nature. However, the demand for freshwater resources exceeds the available supply, making it essential to utilize all alternative water resources such as the desalination of brackish water, seawater, and wastewater. Reverse osmosis desalination is a highly efficient method to increase water supplies and make clean, affordable water accessible to millions of people. However, to ensure universal access to water, various measures need to be implemented, including centralized governance, educational campaigns, improvements in water catchment and harvesting technologies, infrastructure development, irrigation and agricultural practices, pollution control, investments in novel water technologies, and transboundary water cooperation. This paper provides a comprehensive overview of measures for utilizing alternative water sources, with particular emphasis on seawater desalination and wastewater reclamation techniques. In particular, membrane-based technologies are critically reviewed, with a focus on their energy consumption, costs, and environmental impacts.

The economic evaluation is basic for any reclaimed water reuse project. Nevertheless, the calculation tools for this evaluation have scarcely been developed due to the lack of application of the existing models and the need to consider more circumstances that the actually used for the evaluations. The authors develop a comprehensive tool, comprising several steps, as follows: analysis of the basics of any project; socioeconomic characterization; building, operation and maintenance of the facility; and evaluation of the positive and negative externalities. [ABSTRACT FROM AUTHOR]

The reverse osmosis (RO) system is widely applied to produce reclaimed water for high-standard industrial use. Chlorine disinfection is the main biofouling control method in the RO systems for wastewater reclamation. However, researchers reported the adverse effects of chlorine disinfection which aggravated biofouling in laboratory-scale RO systems. In this study, four parallel 4-inch spiral wound RO membranes were used to study the effect of chlorine on biofouling in a pilot-scale RO system. The free chlorine dosages in four experimental groups were 0, 1, 2 and 5 mg/L, respectively. After continuous chlorination and dechlorination, the feed water entered the RO system. It was found that chlorine pretreatment caused a 1.9–36.7% increase in relative feed water pressure of the RO system, suggesting that chlorine aggravated the membrane fouling in the pilot-scale RO system. The microbial community structures of living bacteria in the feed water of the RO system were determined by the PMA (propidium monoazide)-PCR method and showed that the relative abundance of chlorine-resistant bacteria (CRB) was significantly increased after disinfection. Nine major genera which maintained higher relative abundance in experimental groups with high chlorine dosage were considered as possible key species causing membrane fouling, including Pedobacter, Clostridium and Bradyrhizobium. HIGHLIGHTS Revealed the effects of chlorine disinfection on fouling of a pilot-scale RO system.; Chlorine disinfection aggravated the membrane fouling in the pilot RO system.; Analyzed community structure of residual bacteria after disinfection in feed water.; Identified key chlorine-resistant bacteria (CRB) causing RO membrane fouling.;

In recent years, water scarcity has posed significant challenges to oil refineries. The escalating water demands of developing oil refineries in pace with the progressively stringent environmental, economic, and technical regulatory and suitability constraints necessitate seeking sustainable water and wastewater management strategies that encourage minimizing fresh water consumption through treated wastewater reuse. Thus, the main scope of the present study is to investigate a general procedure using innovative post treatment technologies in order to attain an almost zero discharge water management in real life - Kermanshah's oil refinery case study. The results obtained are proofs enough that the selected post treatment scenario can effectively minimize the overall fresh water demand.

This revision work focuses on the recent advances in the separation of microcontaminants from urban wastewaters, using ultrafiltration and Nanofiltration membranes. Conventional systems show advantages such as low pressure and fouling, competitive energetic- and maintenance costs compared to reverse osmosis, and higher rejection rates of organic microcontaminants compared to membrane distillation. However, these rejection rates strongly depend on temperature, flow, and pressure, as well as surface charge and concentration, challenging the adequate treatment of more complex matrices. Recent advances in material science strongly improved the implementation possibilities of different membrane types. In conventional industrial processes and especially in wastewater treatment, offering not only cost reducing solutions for urban wastewaters, but also more efficiency for the remediation of a high variety of industrial wastewaters. Moreover, membrane separation systems show great potential and applicability for added value substance recovery from wastewaters for the agricultural, chemical and consumer industry, for more sustainable natural resources use. Finally, perspectives on promising technologies for the implementation and combination of different membrane separation methods in treatment trains, such as advanced oxidation processes, are given, also aiming for zero-liquid discharge, to prevent microcontaminants and valuable resources from passing through conventional methods and focusing on closing the water cycle.

This paper focuses on a process for dairy wastewater treatment by mixotrophic cultivation of microalgae Nannochloris sp., using cheese whey obtained as a side flow from cheese production as an organic carbon source. The microalgae samples were prepared by adding to the standard growth medium increasing amounts of cheese whey, calculated to ensure a lactose concentration between 0 and 10 g/L. The samples were incubated at a constant temperature of 28 °C and 175 rpm stirring speed for a total time of seven days. Two LED (Light Emitting Diode) illumination schemes were applied in order to assess the effect of this parameter on microalgae development and bioactive compound accumulation: continuous illumination (light stress) versus alternative cycles of 12 h light—12 h dark (day–night cycle). The growth medium was analyzed before and after microalgae cultivation in order to determine the reduction of carbon, nitrogen, and phosphorus. The results obtained for this process, after a seven-day cultivation period, were as follows: reduction of 99–100% of lactose from the growth medium, up to 96% reduction in chemical oxygen demand, up to 91% reduction in nitrogen content, and up to 70% reduction in phosphorus content.

Microalgae are considered sustainable resources for the production of biofuel, feed, and bioactive compounds. Among various microalgal genera, the Tetraselmis genus, containing predominantly marine microalgal species with wide tolerance to salinity and temperature, has a high potential for large-scale commercialization. Until now, Tetraselmis sp. are exploited at smaller levels for aquaculture hatcheries and bivalve production. However, its prolific growth rate leads to promising areal productivity and energy-dense biomass, so it is considered a viable source of third-generation biofuel. Also, microbial pathogens and contaminants are not generally associated with Tetraselmis sp. in outdoor conditions due to faster growth as well as dominance in the culture. Numerous studies revealed that the metabolite compositions of Tetraselmis could be altered favorably by changing the growth conditions, taking advantage of its acclimatization or adaptation ability in different conditions. Furthermore, the biorefinery approach produces multiple fractions that can be successfully upgraded into various value-added products along with biofuel. Overall, Tetraselmis sp. could be considered a potential strain for further algal biorefinery development under the circular bioeconomy framework. In this aspect, this review discusses the recent advancements in the cultivation and harvesting of Tetraselmis sp. for wider application in different sectors. Furthermore, this review highlights the key challenges associated with large-scale cultivation, biomass harvesting, and commercial applications for Tetraselmis sp. [Display omitted] • Tetraselmis strains are able to grow in a wider range of salinity and temperature. • Optimization of different strategies improves Tetraselmis sp. biomass production. • Tetraselmis could be a promising algal strain for aquaculture wastewater reclamation. • Integrated biorefinery of Tetraselmis biomass is needed for its broader applications. [ABSTRACT FROM AUTHOR]

The study explores the synthesis and utilization of biochar (BC) and multi-layer MXene to MXene/biochar (MB) composites for wastewater treatment. Simultaneously, it also investigates their energy generation potential through biomass and soil property assessments. The integrated column and batch treatments have shown significant results, elevating total dissolved solids from 63.7 to 125.5 mg L−1 with column treatment, while reducing them to 6.37 % and 1.35 % with BC and MB treatment, respectively. BC with high carbon content, demonstrated increased hydrophobicity, which was amplified by the integration of MXene, thereby enhancing its potential for advanced wastewater treatment. Treated wastewater exhibited elevated nutrient concentrations (Ca, Cu, Fe, K, Na, and NH 4 +), promoting the growth of Pennisetum purpureum. WW_B shows promising energy potential, with a higher heating value of 25.03 MJ kg−1 and a lower heating value of 23.57 MJ kg−1. They demonstrated high volatile matter exceeding 70.9 wt %, and a fixed carbon from 10.02 to 27.53 wt %, signifying their potential for efficient conversion and bio-oil yield during pyrolysis. The ultimate analysis emphasized significant carbon, with oxygen content ranging from 43.42 to 47.78 wt %., influencing combustion characteristics. MT_B exhibited its suitability for energy production through thermochemical conversion, underlined by its high flammability and low volatile ignition values. In the absence of BC, the E a ranged from 24.77 to 77.88 kJ mol−1 in wastewater and from 21.67 to 69.6 kJ mol−1 in MB treated wastewater. Meanwhile, when soil contained BC and was irrigated with wastewater, the E a varied from 24.66 to 80.91 kJ mol−1. In the case of MB treated wastewater, it ranged from 25.01 to 75.79 kJ mol−1. The research thereby affirms the potential of MB composites to advance water and energy sustainability setting us for broader nexus-based applications. [Display omitted] • Wastewater reclamation within the context of sustainable energy generation was studied. • Pennisetum purpureum exhibited promising bioenergy production potential using MT_B. • Crops, with WW_B having even higher VM, exhibited high VM exceeding 70.9 %. • WW_B's high HHV (25.03 MJ kg − 1 ) and LHV (23.57 MJ kg − 1 ) indicate promising energy potential for thermochemical conversion. [ABSTRACT FROM AUTHOR]

Contemporary wastewater reclamation units entail several diverse treatment and extraction processes, with a multitude of monitored quality characteristics, controlled by a variety of key operational parameters directly affecting the efficiency of treatment. The conventional optimization of this highly complex system is time- and energy- consuming, frequently relying on intuitive decision making by operators, and does not predict or forecast efficiency changes and system maintenance. In this paper, we introduce intelligent solutions to enhance the operational control of the unit with minimal human intervention and to develop an AI-powered DSS that is installed atop the sensors of a water treatment module. The DSS uses an expert model, both to assess the quality of water and to offer suggestions based on current values and future trends. More specifically, the quality of the produced water was successfully visualized, assessed and rated, based on a set of input operational variables (pH, TOC for this case), while future values of monitored sensors were forecasted. Additionally, monitoring services of the DSS were able to identify unexpected events and to generate alerts in the case of observed violation of operational limits, as well as to implement changes (automatic responses) to operational parameters so as to reestablish normal operating conditions and to avoid such events in the future. Up to now, the DSS suggestion and forecasting services have proven to be adequately accurate. Though data are still being collected from early adopters, the solution is expected to provide a complete water treatment solution that can be adopted by a vast range of parties. [ABSTRACT FROM AUTHOR]

The present study aimed to develop a pilot-scale integrated system composed of anaerobic biofilter (AF), a floating treatment wetland (FTW) unit, and a vertical flow constructed wetland coupled with a microbial fuel cell (CW-MFC) and a reactive bed filter (RBF) for simultaneously decentralized urban wastewater treatment and bioelectricity generation. The first treatment stage (AF) had 1450 L and two compartments: a settler and a second one filled with plastic conduits. The two CWs (1000 L each) were vegetated with mixed plant species, the first supported in a buoyant expanded polyethylene foam and the second (CW-MFC) filled with pebbles and gravel, whereas the RBF unit was filled with P adsorbent material (light expanded clay aggregate, or LECA) and sand. In the CW-MFC units, 4 pairs of electrode chambers were placed in different spacing. First, both cathode and anode electrodes were composed of graphite sticks and monitored as open circuit. Later, the cathode electrodes were replaced by granular activated carbon (GAC) and monitored as open and closed circuits. The combined system efficiently reduced COD (> 64.65%), BOD5 (81.95%), N-NH3 (93.17%), TP (86.93%), turbidity (94.3%), and total coliforms (removal of three log units). Concerning bioenergy, highest voltage values were obtained with GAC electrodes, reaching up to 557 mV (open circuit) and considerably lower voltage outputs with closed circuit (23.1 mV). Maximum power densities were obtained with 20 cm (0.325 mW/m2) and 30 cm (0.251 mW/m2). Besides the electrode superficial areas, the HRT and the water level may have influenced the voltage values, impacting DO and COD concentrations in the wastewater. [ABSTRACT FROM AUTHOR]

The widespread implementation of municipal wastewater treatment and reuse must first ensure the safety of reused wastewater. The effluent of the municipal wastewater treatment plant contains a large amount of dissolved organic matter (DOM), which adversely affects the reuse of wastewater. In this study, the ultrafiltration (UF) + reverse osmosis (RO) process was used to treat the secondary effluent from wastewater treatment plants. The relationship between the removal performance, membrane fouling of the UF + RO process, and DOM removal characteristics of influent were studied. The results show that DOM can be removed effectively by UF + RO process. The UF mainly removes DOM with a molecular weight greater than 10 kDa, while RO has a significant removal effect on low-molecular-weight DOM, which mainly causes UF and RO membrane fouling. The UF + RO process has a significant removal rate on fulvic acid, humic acid, tyrosine, and tryptophan, and the order is humic acid > fulvic acid > tyrosine > tryptophan. Fulvic acid contributed the most to the UF membrane fouling, while fulvic acid and protein-like proteins contributed mainly to the RO membrane fouling.

This study examines the impact of incorporating a mobile bed into a membrane bioreactor (MBR) system on the treatment efficiency of dairy industry effluents. Initially, a conventional MBR system was operated for 60 days, followed by a modification that included a support material and ran for another 60 days under identical conditions. Performance was evaluated based on the removal efficiencies for soluble chemical oxygen demand (CODs), phenolic compounds, and oils and greases (OG), alongside measurements of solid content, dissolved oxygen, temperature, mixed liquor pH, and transmembrane pressure (TMP). The introduction of the mobile bed led to an increase in removal efficiencies for COD and phenolic compounds from 94.4 and 92.7% to 98 and 94.4%, respectively, marking statistically significant improvements ( p < 0.05), while OG removal remained the same in both strategies (87.7%) ( p > 0.05). Moreover, the modified system showed a more stable TMP profile, reducing the need for cleaning interventions compared to the conventional system, which experienced a notable TMP increase requiring cleaning at a 0.6 bar threshold. The findings suggest that integrating a mobile bed into MBR systems significantly enhances the treatment of dairy effluents, presenting an interesting solution for the upgrade of this type of system., Competing Interests: The authors declare there is no conflict., (© 2024 The Authors This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY 4.0), which permits copying, adaptation and redistribution, provided the original work is properly cited (http://creativecommons.org/licenses/by/4.0/).)

The anaerobic membrane bioreactor (AnMBR) is a promising technology for not only water reclamation but also virus removal; however, the virus removal efficiency of AnMBR has not been fully investigated. Additionally, the removal efficiency estimation requires datasets of virus concentration in influent and effluent, but its monitoring is not easy to perform for practical operation because the virus quantification process is generally time-consuming and requires specialized equipment and trained personnel. Therefore, in this study, we aimed to identify the key, monitorable variables in AnMBR and establish the data-driven models using the selected variables to predict virus removal efficiency. We monitored operational and environmental conditions of AnMBR in Sendai, Japan and measured virus concentration once a week for six months. Spearman's rank correlation analysis revealed that the pH values of influent and mixed liquor suspended solids (MLSS) were strongly correlated with the log reduction value of pepper mild mottle virus, indicating that electrostatic interactions played a dominant role in AnMBR virus removal. Among the candidate models, the random forest model using selected variables including influent and MLSS pH outperformed the others. This study has demonstrated the potential of AnMBR as a viable option for municipal wastewater reclamation with high microbial safety., Competing Interests: The authors declare there is no conflict., (© 2024 The Authors This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY 4.0), which permits copying, adaptation and redistribution, provided the original work is properly cited (http://creativecommons.org/licenses/by/4.0/).)

There have been multiple reports of COVID‐19 virus, SARS‐CoV‐2 RNA presence in influent wastewater of water reclamation facilities (WRFs) across the world. In this study, the removal of SARS‐CoV‐2 RNA was investigated in a WRF by collecting samples from various stages relayed to hydraulic retention time (HRT) and analyzed for viral RNA (N1 and N2) gene markers and wastewater characteristics. SARS‐CoV‐2 RNA was detected in 28 out of 28 influent wastewater and primary effluent samples. Secondary effluent showed 4 out of 9 positive samples, and all tertiary and final effluent samples were below the detection limit for the viral markers. The reduction was significant (p value < 0.005, one‐way analysis of variance [ANOVA] test) in secondary treatment, ranging from 1.4 to 2.0 log10 removal. Adjusted N1 viral marker had a positive correlation with total suspended solids, total Kjeldahl nitrogen, and ammonia concentrations (Spearman's ρ = 0.61, 0.67, and 0.53, respectively, p value < 0.05), while demonstrating a strongly negative correlation with HRT (Spearman's ρ = −0.58, p value < 0.01). Practitioner points: Viral RNA was present in all samples taken from influent and primary effluent of a WRF.SARS‐CoV‐2 gene marker was detected in secondary effluent in 4 out of 9 samples.Tertiary and final effluent samples tested nondetect for SARS‐CoV‐2 gene markers.Up to 0.5 and 2.0 log10 virus removal values were achieved by primary and secondary treatment, respectively. [ABSTRACT FROM AUTHOR]