Sewage Treatment Research Articles

Profiling the bacterial microbiome diversity and assessing the potential to detect antimicrobial resistance bacteria in wastewater in Kimberley, South Africa

Wastewater treatment plants (WWTPs) are hotspots for pathogens, and can facilitate horizontal gene transfer, potentially releasing harmful genetic material and antimicrobial resistance genes into the environment. Little information exists on the composition and behavior of microbes in WWTPs, especially in developing countries. This study used environmental DNA (eDNA) techniques to examine the microbiome load of wastewater from WWTPs. The DNA was isolated from wastewater samples collected from the treatment trains of three WWTPs in Kimberley, South Africa, and the microbial diversity and composition was compared through 16 S rRNA gene sequencing. The microbes detected were of the Kingdom Bacteria, and of these, 48.27% were successfully identified to genus level. The majority of reads from the combined bacterial data fall within the class Gammaproteobacteria, which is known to adversely impact ecological and human health. Arcobacteraceae constituted 19% of the bacterial reads, which is expected as this family is widespread in aquatic environments. Interestingly, the most abundant bacterial group was Bacteroides, which contain a variety of antibiotic-resistant members. Overall, various antibiotic-resistant taxa were detected in the wastewater, indicating a concerning level of antibiotic resistance within the bacterial community. Therefore, eDNA analysis can be a valuable tool in monitoring and assessing the bacterial microbiome in wastewater, thus providing important information for the optimization and improvement of wastewater treatment systems and mitigate public health risks.

Mathematical model of dissolved microbial products in sewage treatment system

Water is the source of life, but all kinds of water resources in the world are suffering from different degrees of pollution. Water pollution leads to a serious shortage of available fresh water resources, and sewage treatment is the main way to solve water pollution. For the sewage after biological treatment of activated sludge, the organic matter contained in the effluent is mainly the dissolved microbial products (SMPs) produced in the process of microbial metabolism. The composition of SMPs is complex, mainly including macromolecular substances such as protein, polysaccharide, humic acid and DNA and cell fragments. The mathematical model of activated sludge is a quantitative description of the mathematical relationship between substrate degradation parameters and microbial growth. Starting from the Monod equation representing the relationship between substrate consumption and microbial growth, it combines the reactor theory and microbiology theory in the chemical field. Based on the principle of conservation of materials and Monod equation, the mathematical expression of organic degradation model was determined according to the collected data and empirical values of parameters. The general idea of activated sludge model No.1 (ASM1) for activated sludge process simulation was introduced, and the influence of sludge concentration on SBR process water treatment was explored. It was found that the removal rate of COD, ammonia nitrogen, total nitrogen and total phosphorus increases with the increase of sludge concentration. When C/N=8, the removal rate of ammonia nitrogen increased from 62% to 81%, and the removal rate of total nitrogen increased from 64% to 82%, with the most obvious effect.

The role of information and participation in overcoming users’ initial reluctance: a case study of a decentralized wastewater treatment plant

Decentralized wastewater treatment systems are a potential solution to the water crisis. However, in addition to advanced technology, successful implementation of these systems requires broad public willingness to use them. This paper presents the results of a three-phase psychosocial intervention with the users of a business building where a decentralized wastewater treatment plant was installed. The intervention, motivated by complaints from users due to their lack of knowledge about the existence of the plant, aimed at understanding and improving users’ perceptions of the building’s decentralized system. In the first phase, we conducted a focus group with a sample of workers (n = 6) to understand their knowledge and perception of the building’s decentralized wastewater treatment system. Once the main obstacles and facilitators were identified, we designed a second phase where a group of employees (n = 46) were exposed to environmental priming to improve attitudes toward the decentralized plant installed in the building. Finally, in the third phase, a bidirectional informative session was proposed, conducted by experts, to another group of workers (n = 25). Findings suggest that implementing specific psychosocial strategies, such as promoting environmental awareness and providing informative sessions, along with incorporating potential users throughout the process, contributes to better acceptance of the decentralized wastewater treatment plant. This work presents a real case in a pilot plant that can serve as a guide for addressing psychosocial resistance in similar projects.

Enhancing Expert Decision-Making for Wastewater Treatment Plants with Seidel Laplacian Energy and Cosine Similarity Measure in Intuitionistic Fuzzy Graphs

Wastewater treatment facilities’ main goal is to protect the public and environment from the hazardous and poisonous materials found in wastewater. Water treatment facilities were developed to speed up the natural process of cleansing water. A novel cosine similarity measure across intuitionistic fuzzy graphs has been proven to be more effective than certain present ones in group decision-making issues using example verification. This paper provides a unique approach for calculating expert-certified, well-known scores by finding the ambiguous information of intuitionistic fuzzy preference relations as well as the regular cosine similarity grades from one separable intuitionistic fuzzy preference relation to another. The new technique considers both "objective" and "subjective" information provided by experts. Using intuitionistic fuzzy preference relations, we provide workable techniques for judging experts’ eligible reputational ratings. This can be used to raise or decrease the relevance of the stated criteria in an evaluation that takes into account several competing elements. We give a solution to a decisional problem by using two effective methods: the newly constructed cosine similarity measure and the Seidel Laplacian energy (SLe+) of an intuitionistic fuzzy graph. Finally, two working procedures and circumstances are offered to show the effectiveness and superiority of the proposed techniques.

Aerobic–anaerobic DHS reactor for enhancing denitrification in municipal wastewater treatment

Providing anaerobic environments can enhance the denitrification capacity of wastewater treatment systems. This study developed an aerobic–anaerobic downflow hanging sponge (DHS) reactor to increase denitrification. A siphon tube was integrated with a conventional DHS to create anaerobic conditions by controlling a water column inside the reactor. The siphon heights were set in the middle of the reactor, representing 2/5 of the total volume. Anaerobic conditions were maintained at the bottom (1/5), whereas aerobic conditions were maintained at the top (2/5). The middle part experienced alternating aerobic–anaerobic conditions within a siphon cycle. The hydraulic retention time (HRT) was 3 h, and the temperature was maintained at 30 °C. The study was divided into the low-loading and standard phases based on the influent soluble chemical oxygen demand (sCOD) concentration. During the low-loading phase, the aerobic–anaerobic DHS exhibited a higher sCOD removal rate (53.6 ± 26.6 %) than the control aerobic DHS (35.6 ± 31.9). However, the removal efficiencies for NH₄+–N and total nitrogen (TN) were lower, averaging 37.1 ± 24.7 % and 31.5 ± 21 %, respectively. In the standard phase, the aerobic–anaerobic DHS achieved an sCOD removal rate of 69.3 ± 14.8 % and an NH₄+–N removal rate of 17.2 ± 11.4 %. The control aerobic DHS showed higher sCOD and NH₄+–N removal at 84.7 ± 10.8 % and 54.1 ± 12.8 %, respectively, possibly due to the reduced aerobic zone volume in the aerobic–anaerobic DHS. The TN removal rates were also lower in the aerobic–anaerobic DHS (17.1 ± 11.4 %) than in the control DHS (25 ± 12.3 %). However, based on the ratio of nitrification to TN removal, the aerobic–anaerobic DHS showed a high denitrification rate of 85 %–100 %. The highest number of denitrifiers was in the middle section of the aerobic–anaerobic DHS, with Rhodocyclaceae the most prominent, followed by Comamonadaceae. Maintaining an anaerobic zone improved the denitrification capacity, indicating the potential of the aerobic–anaerobic DHS for efficient municipal wastewater treatment.

Toward Zero Waste: Sustainable Practices in Waste Management at ETUT

The paper discusses Oguz Han Engineering and Technology University of Turkmenistan's (ETUT) waste management initiatives, particularly its Zero Waste Program aimed at minimizing waste generation and promoting sustainability across campus. Strategies include educational campaigns, eco-friendly purchasing, and collaboration with vendors for waste reduction, reuse, and recycling. ETUT employs structured waste categorization, centralized repositories for reusable items, and a recycling plant with advanced sorting machinery. Innovative methods like paper recycling and composting are used, along with exploring plastic repurposing into fibers and fuel. Organic waste management includes composting, notably reducing landfill waste. Inorganic waste reduction involves paper recycling, plastic conversion, and electronic repair and donation. The program emphasizes waste reduction through recycling and reuse, including upcycling workshops. Hazardous waste from laboratories is managed with local authorities for safe disposal, while relevant associations for environmental safety oversee sewage disposal. These strategies highlight ETUT's commitment to sustainability, positioning it as a regional leader in responsible waste management.

Surface water quality in Costa Rica: new initiatives and challenges

ABSTRACT Despite Costa Rica's reputation for being a leader in environmental policy and its thriving nature-based tourism industry, the nation has had poor surface water quality. Reasons for poor water quality include the lack of sewerage treatment, overuse of septic tanks, and the application of large quantities of agrichemicals. Although Costa Rica has policies to maintain surface water quality, they have not been sufficiently implemented. Recent initiatives have addressed surface water quality, including an ambitious plan to expand treated sewerage systems in all urban areas. Current efforts to meet this goal have focused on the San Jose metropolitan area and coastal communities. This paper reviews the advances and challenges to Costa Rica's efforts to improve water quality.

Genomic surveillance of Canadian airport wastewater samples allows early detection of emerging SARS-CoV-2 lineages

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has shown wastewater (WW) surveillance to be an effective means of tracking the emergence of viral lineages which arrive by many routes of transmission including via transportation hubs. In the Canadian province of Ontario, numerous municipal wastewater treatment plants (WWTPs) participate in WW surveillance of infectious disease targets such as SARS-CoV-2 by qPCR and whole genome sequencing (WGS). The Greater Toronto Airports Authority (GTAA), operator of Toronto Pearson International Airport (Toronto Pearson), has been participating in WW surveillance since January 2022. As a major international airport in Canada and the largest national hub, this airport is an ideal location for tracking globally emerging SARS-CoV-2 variants of concern (VOCs). In this study, WW collected from Toronto Pearson’s two terminals and pooled aircraft sewage was processed for WGS using a tiled-amplicon approach targeting the SARS-CoV-2 virus genome. Data generated was analyzed to monitor trends of SARS-CoV-2 lineage frequencies. Initial detections of emerging lineages were compared between Toronto Pearson WW samples, municipal WW samples collected from the surrounding regions, and Ontario clinical data as published by Public Health Ontario. Results enabled the early detection of VOCs and individual mutations emerging in Ontario. On average, the emergence of novel lineages at the airport preceded clinical detections by 1–4 weeks, and up to 16 weeks in one case. This project illustrates the efficacy of WW surveillance at transitory transportation hubs and sets an example that could be applied to other viruses as part of a pandemic preparedness strategy and to provide monitoring on a mass scale.

An innovative design and development of Up-flow Compact Constructed Wetland for sewage treatment

The growing demand for sustainable sewage treatment requires technologies that overcome the limitations of energy-intensive and chemical-dependent systems. This study presents an innovative solution addressing both environmental and operational challenges with the design and development of an Up-flow Compact Constructed Wetland (UCCW) based Sewage Treatment Plant (STP). This system integrates preliminary, primary, secondary, and tertiary treatment units into a single setup. The performance of UCCW based STP was evaluated over 720 days under different Hydraulic Retention Times (HRTs), considering seasonal variations in both rectangular and circular configurations. The system achieved significant pollutant removal as Total Suspended Solids (96%), Chemical Oxygen Demand (86%), Biochemical Oxygen Demand (90%), Total Nitrogen (70%), Total Phosphorus (65%), and Fecal Coliforms (99%) at a 36-hour HRT. These parameters meet discharge standards, except FC, which requires disinfection for safe reuse and recycling. Further, Response Surface Methodology (RSM) and Monte Carle Simulation of UCCW based STP confirmed optimal and reliable performance at a 36-hour HRT. Compared to conventional treatment technologies, the UCCW based STP demonstrated higher efficiency, a smaller footprint (1m2/KLD), better operational flexibility, cost-effectiveness, and minimal operation & maintenance to make it sustainable for decentralised treatment.

Magnetoplasmonic core–shell structured Ag@Fe3O4 particles synthesized via polyol reduction process rendering dual-functionality for bacteria ablation and dyes degradation

The Ag nanoparticles demonstrate potent bacteria eradication capabilities; however, their tendency to aggregate in aqueous solutions compromises the antibacterial efficacy. Furthermore, the Ag nanoparticles employed in sewage treatment are challenging to recycle, resulting in environmental pollution and resource wastage. Herein, the Ag-core Fe3O4-shell structured particles (Ag@Fe3O4) are synthesized by leveraging the reduction potential difference between Ag+/Ag0 and Fe3+/Fe2+ through a one-step polyol reduction process. The Fe3O4 shell in the Ag@Fe3O4 composite not only effectively inhibits the agglomeration of Ag, but also enhances the penetration capability of the composite into biofilms, thereby enabling Ag@Fe3O4 to possess remarkable antibacterial efficacy against Escherichia coli (E. coli). The Ag@Fe3O4 demonstrates nearly 100 % inhibition of E. coli at a concentration of 0.24 mg mL−1 (with an Ag content of 0.042 mg mL−1) while still maintaining antibacterial effectiveness of 74.6 % even after undergoing reutilization for 10 cycles. Meanwhile, due to the excellent electron conductivity of Ag and the effective adsorption capability of Fe3O4 shell towards organic dyes, Ag@Fe3O4 facilitates rapid electron transfer to organic dyes and further lead to their reduction and degradation in the presence of NaBH4. The Ag@Fe3O4 can catalytically degrade various organic dyes (including Rhodamine B, Rhodamine 6G, and Methylene blue) within only 15 min, while achieving an impressive degradation efficiency exceeding 90.9 % after 6 cycles of reutilization. The cost-effectiveness (approximately $0.17 per gram), facile magnetic recovery, along with the superior antibacterial and dye-degradation performance showcase the significant potential of Ag@Fe3O4 for medical applications and sewage treatment.

Interactions between SDBS and Hydrilla verticillata − epiphytic biofilm in wetland receiving STPs effluents: Nutrients removal and epiphytic microbial assembly

The fate and effects of sodium dodecyl benzene sulfonate (SDBS) in sewage treatment plants (STPs) effluents on nutrients and submerged macrophytes are far from clear in wetlands. This study conducted a 24-day experiment to investigate changes in nutrients and epiphytic biofilm of Hydrilla verticillata in wetlands receiving effluents with 0.5, 2 and 5 mg L−1 SDBS. The decrease of SDBS in overlying water followed pseudo-first-order kinetic equation, with over 80 % of SDBS removal achieved. 2 and 5 mg L−1 SDBS decreased nutrient removal efficiency, induced oxidative stress response and damaged cells of H. verticillata. SDBS altered bacterial and eukaryotic community diversity. 0.5 mg L−1 SDBS can promote carbon fixation and methane oxidation of microorganisms. Network analysis revealed that 0.5 mg L−1 SDBS decreased the stability of epiphytic ecosystems. Mantel tests indicated significant influences of SDBS, temperature, and total nitrogen on epiphytic microbial communities.

Environmental behavior and risk of the emerging organic contaminants halogenated carbazoles in chemical industrial park clusters

Polyhalogenated carbazoles (PHCZs) are emerging organic contaminants and have attracted extensive concern because of their widespread occurrence and dioxin-like toxicity. However, the distribution characteristics, environmental behavior, and fate of PHCZs are still poorly understood. In this study, 74 composite environmental samples from 21 Chinese cities were collected around industrial parks in the Yangtze River Delta. The PHCZ concentration ranges in sediment and soil samples were 12.7–5.21 × 103 and 34.6–1.81 × 103 ng/g, respectively, which is equivalent to or higher than those of well-known persistent organic pollutants in the similar areas. The dominant congeners of PHCZs in sediment and soil were 3-chlorocarbazole and 3,6-dichlorocarbazole. Industrial emissions, especially from printing and dyeing textiles, were the main contributors to the high PHCZ environmental concentrations. Potential toxic effects of the PHCZs were evaluated using the toxic equivalent (TEQ) method. The TEQs of PHCZs in sediment and soil were up to 550 and 554 pg TEQ/g dry weight, respectively. The estimated TEQ value of sediment and soil exceeded the corresponding safety guideline, which indicated that PHCZs in the Yangtze River Delta posed high health risks. This study provides an important theoretical basis for controlling and reducing the ecological risks of PHCZs in the chemical industry. At the same time, it also provides reference for the priority control and revision of discharge standards for PHCZs in sewage treatment plants in future.

Environmental Protection for Bureaucratic Promotion: Water Quality Performance Review of Provincial Governors in China

We show including quantitative environmental targets for bureaucratic promotion incentivizes government officials to enforce environmental regulation but at significant economic costs. Taking advantage of the gradual expansion of China’s water quality performance review (WQPR) over time and space, we find that WQPR significantly reduced ambient concentrations of criteria pollutants, digestive cancer mortality, and GDP growth rate. WQPR’s effects are more pronounced along provincial borders, which are targeted by WQPR, and when provincial governors have more promotion potential. An important mechanism is investment in wastewater treatment facilities. There is evidence that WQPR passed the benefit-cost test, especially in rural areas.

The Geysers Is a Unique Geothermal Resource Presenting Equally Unique Challenges to Drillers

_ For drillers, The Geysers is a unique sort of hell. It is one of the only places on Earth where a shallow well can reach a highly fractured reservoir so hot that it only produces steam. That steam powers 18 power plants generating 835 MW of electricity, making this 45-square-mile area the world’s most prolific geothermal power producer. High drilling costs there also stand out. Drilling a well requires 60 days or so and generates a lot of damaged drill bits and drillpipe. The drilling rigs have the size and power of modern onshore rigs, but a close look reveals there’s no topdrive. Below the rig floor there is a rotary table, known as a Kelly drive because it can spin drilling pipe without being in the line of fire of the steam flowing out when running slotted casing into the steam-production zone. When they get to that zone, they switch from drilling fluid and mud to injecting a high-pressure stream of air because of the enormous fluid losses anticipated when they reach that highly fractured level. A drill bit that lasts 500 ft in this harsh, highly fractured rock has had a long run. And the rugged terrain—mountains to a Texan but hills to a Californian—makes this a hard place to move a rig. “The Geysers is its own animal, for sure,” said Sam Noynaert, a Texas A&M professor who was a key member of a team of drilling experts and scientists that drilled a well in The Geysers to test if faster drilling methods from the oil business could work there. The two upper sections went pretty well, considering. As they went deeper, they repeatedly had to deal with severe fluid losses. Still, they had shaved nearly 6 days off the average drilling time. But when they reached the highly fractured steam-producing payzone and their drilling method changed to air drilling, things got worse with drill bits failing after runs as short as 21 ft. As a Geysers drilling paper presented at the Stanford Geothermal Workshop earlier this year delicately put it: “The air section proved to be more challenging.” The Blob The Geysers has a long history. The heat source is “a large blob of silica-rich magma (which) forced its way through Earth’s crust beneath the Coast Range,” according to the description of an image from NASA. That flow about 1.3 million years ago from deep within the earth heated the overburden, making the rock brittle and prone to fracturing. Over time, water seeped into those hot fissures, creating hot springs that were awed by Native Americans and later attracted tourists to a nearby resort hotel. By the 1960s drillers were tapping the steam in those payzones for commercial power generation, which peaked at 2,000 MW in 1987. It declined from there as steam production depleted the reservoir. Eventually, the output was stabilized at its current level by injecting water from sewage-treatment plants into the production zone.

Performance of a pilot-scale microbial electrolysis cell coupled with biofilm-based reactor for household wastewater treatment: simultaneous pollutant removal and hydrogen production.

The septic tank is the most commonly used decentralized wastewater treatment systems for household wastewater treatment in on-site applications. The removal rate of various pollutants is lower in different septic tank configurations. The integration of a microbial electrolysis cells (MEC) into septic tank or biofilm-based reactors can be a green and sustainable technology for household wastewater treatment and energy production. In this study, a 50-L septic tank was converted into a 50-L MEC coupled with biofilm-based reactor for simultaneous household wastewater treatment and hydrogen production. The biofilm-based reactor was integrated by an anaerobic packed-bed biofilm reactor (APBBR) and an aerobic moving bed biofilm reactor (aeMBBR). The MEC/APBBR/aeMBBR was evaluated at different organic loading rates (OLRs) by applying voltage of 0.7 and 1.0V. Result showed that the increase of OLRs from 0.2 to 0.44kg COD/m3 d did not affect organic matter removals. Nutrient and solids removal decreased with increasing OLR up to 0.44kg COD/m3 d. Global removal of chemical oxygen demand (COD), biochemical oxygen demand (BOD), total nitrogen (TN), ammoniacal nitrogen (NH4+), total phosphorus (TP) and total suspended solids (TSS) removal ranged from 81 to 84%, 84 to 85%, 53 to 68%, 88 to 98%, 11 to 30% and 76 to 88% respectively, was obtained in this study. The current density generated in the MEC from 0 to 0.41 A/m2 contributed to an increase in hydrogen production and pollutants removal. The maximum volumetric hydrogen production rate obtained in the MEC was 0.007 L/L.d (0.072 L/d). The integration of the MEC into biofilm-based reactors applying a voltage of 1.0V generated different bioelectrochemical nitrogen and phosphorus transformations within the MEC, allowing a simultaneous denitrification-nitrification process with phosphorus removal.

Visible light-assisted S-doped red mud-based Fe-Co PBA derivatives activated PMS for efficient degradation of oxytetracycline from acidic to alkaline conditions: Degradation mechanism, degradation pathways and toxicity evaluation

Building an economically efficient, adaptable, and environmentally friendly advanced oxidation system is crucial for the treatment of antibiotic wastewater. In this study, we prepared a sulfur-doped red mud (RM) based Fe-Co Prussian blue analog derivative material (SRPD) using solid waste RM. Due to the doping of sulfur, SRPD possessed more abundant active sites (Co2+/Fe2+) and superior photocatalytic performance compared to other materials. Therefore, the SRPD/peroxymonosulfate (PMS)/Vis system exhibited the best degradation performance for oxytetracycline (OTC), with good reusability, resistance to impurity anions, adaptability to different water qualities, no secondary pollution, and maintained excellent performance under acidic, neutral, and alkaline conditions. Analysis has shown that the participation of surface S2- species in active sites regeneration was an important reason for achieving satisfactory degradation efficiency under neutral and alkaline conditions. In addition, there were significant differences in the charge transfer ability, surface morphology, and surface composition of SRPD in different pH systems, which affected the amount and types of main reactive oxygen species generated by PMS activation. As a result, the degradation pathways of OTC in SRPD/PMS/Vis systems with different pH values were somewhat different, but the detoxification ability towards OTC was excellent. This study exhibits certain reference significance for improving the degradation performance under neutral and alkaline conditions, and is an excellent candidate system for practical wastewater treatment.

Strategic carbon emission assessment in sludge treatment: A dynamic tool for low-carbon transformation

The carbon–neutral target presents a significant challenge for the sewage sludge treatment and disposal (SSTD) industry, necessitating strategic planning for a low-carbon transition. However, flexible and comprehensive carbon emission analysis tools to support this goal remain lacking. This study presents a carbon emission analysis tool to evaluate the carbon emission characteristics and future mitigation potentials of SSTD. The tool integrates life cycle inventory (LCI) modeling-based analysis, sensitivity analysis, regression analysis, and scenario analysis. Carbon emissions are dynamically calculated based on sludge properties, technological level, and industry external parameters, providing a foundation for adaptable evaluation tailored to local conditions. The framework considers the potential effects of multi-parameter and multi-aspect changes in scene design, both within and outside the industry, to achieve dynamic and comprehensive simulations. A case study conducted in Wuhan, China, demonstrated the usability and application processes of the framework. The results indicated that carbon emissions from SSTD are projected to more than double from 2021 to 2060 without interventions. Among the mitigation measures, energy and chemical savings would yield the largest reduction potential, followed by the technical layout adjustment and the promotion of energy efficiency. Operational optimization in the sludge industry and outside the industry would contribute the least. With all mitigation measures applied, emissions could decrease to –82.91 kt CO2-eq in 2060, equivalent to 13.03% compensation for emissions from the sewage treatment line. Among all the processes, incineration routes are recommended due to their current and future low carbon emissions. The cooperative resource route of anaerobic digestion and land use also shows promise as it progressively demonstrates superior performance with increasing organic matter and nutrient content of sludge. Critical factors, sub-processes, and emission types for different routes were identified and can be optimized accordingly. The developed method demonstrates sufficient flexibility to be applied to other cities and larger-scale regions, thereby offering technical and strategic support for SSTD towards carbon–neutral operation.

Integrated respiratory toxicity of municipal wastewater to human bronchial epithelial cells and 3D bronchospheres

Respiratory symptoms have been reported in wastewater treatment workers and residents living close to sewage treatment plant. However, toxicological research about the respiratory hazards of municipal wastewater is scarce. The present study aims to gain insight into the comprehensive respiratory hazards induced by the contaminant mixtures in municipal wastewater. The integrated respiratory hazards of effluents from four secondary wastewater treatment plants (SWTPs), a tertiary wastewater treatment plant (TTP), and a constructed wetland (CW) were evaluated using normal human bronchial epithelial cells (NHBE) bioassay, and toxicity reduction efficiency of various treatment techniques was analyzed. Effluents caused cytotoxicity, oxidative damage, inflammation response with the increased levels of IL-6 and CXCL8, and impaired barrier integrity with decreased expressions of ZO-1 and occludin in NHBE. Further, the effluents inhibited the development of 3D bronchospheres, increased irregular surface and cell debris, and suppressed the formation of luminal structures. TTP E effluent significantly increased the expression of MUC5AC in bronchospheres. The integrated biomarker response (IBR) of the influent was removed by 40.2% at SWTPs, 18.2% at TTP, and 36.6% at CW, respectively. The IBR of the final effluents from SWTPs, TTP, and CW were 7.2, 7.7, and 7.7, respectively. Significant correlation with toxicity biomarkers was frequently observed for stearyl alcohol, o-cresol, phenanthrene, butylated hydroxytoluene, and dimethyl phthalate. The present study provided human relevant evidence concerning the adverse respiratory effects associated with discharge. The necessity for deep water treatment, performance optimization, and the potential means were suggested for improving water quality and protecting respiratory health.

Environmental and economic assessment of urban wastewater reclamation from ultrafiltration membrane-based tertiary treatment: Effect of seasonal dynamic

This study aimed to assess the environmental and economic performance of an ultrafiltration (UF) tertiary treatment of effluent from an urban wastewater treatment facility. Data from a UF demonstration plant composed of commercially available equipment, including industrial hollow-fiber membranes was used to project a full-scale facility. The results from the demonstration plant recommended different ranges of transmembrane fluxes and sparging air demands under summer and winter conditions to prevent excessive fouling. The energy balance of the full-scale facility would be 0.308 ± 0.112 kWh·m−3 in summer and 0.140 ± 0.040 kWh·m−3 in winter, with blowers' being the main consumers (86–93 %). CAPEX accounted for €0.030 ± 0.002·m−3 in summer and €0.027 ± 0.002·m−3 in winter and membrane acquisition represented 66–69 % of the investment cost. Energy expenditure was the major OPEX cost (66–79 %), with a total operating cost of €0.077 ± 0.023·m−3 and €0.042 ± 0.008·m−3 in summer and winter, respectively. The final average value obtained for the TAC was €0.107 m−3 in summer and €0.068 m−3 in winter. The environmental assessment confirmed optimizing energy consumption and membrane requirements as the main factors influencing environmental sustainability. Specifically, summer and winter emissions of 0.079–0.175 and 0.043–0.079 kgCO2eq·m−3 (Global warming potential); 8.1 · 10−4–1.7 · 10−3 and 4.8 · 10−3–8.1 · 10−3 m3·m−3 (water consumption); 0.019–0.041 and 0.010–0.019 kg oileq·m−3 (fossil fuel scarcity); and 1.4 · 10−4–2.9 · 10−4 and 7.7 · 10−4–1.4 · 10−4 kg Cueq·m−3 (mineral resource scarcity) were calculated, respectively. The obtained permeate quality complied with the most stringent Spanish and EU regulations.

Insights into the efficiencies of different biological treatment systems for pharmaceuticals removal: A review.

This review presents a comprehensive analysis of current research on biological treatment processes for removing pharmaceutical compounds (PhCs) from wastewater. Unlike previous studies on this topic, our study specifically delves into the effectiveness and drawbacks of various treatment approaches such as traditional wastewater treatment facilities (WWTP), membrane bioreactors (MBRs), constructed wetlands (CW), and moving bed biofilm reactors (MBBR). Through the examination and synthesis of information gathered from more than 200 research studies, we have created a comprehensive database that delves into the effectiveness of eliminating 19 particular PhCs, including commonly studied compounds such as acetaminophen, ibuprofen, diclofenac, naproxen, ketoprofen, indomethacin, salicylic acid, codeine, and fenoprofen, amoxicillin, azithromycin, ciprofloxacin, ofloxacin, tetracycline, atenolol, propranolol, and metoprolol. This resource provides a depth and scope of information that was previously lacking in this area of study. Notably, among these pharmaceuticals, azithromycin demonstrated the highest removal rates across all examined treatment systems, with the exception of WWTPs, while carbamazepine consistently exhibited the lowest removal efficiencies across various systems. The analysis showcases the diverse results in removal efficiency impacted by factors such as system configuration, operation specifics, and environmental circumstances. The findings emphasize the critical need for continued innovation and research, specifically recommending the integration of advanced oxidation processes (AOPs) with existing biological treatment methods to improve the breakdown of recalcitrant compounds like carbamazepine. PRACTITIONER POINTS: Persistent pharmaceuticals harm aquatic ecosystems and human health. Biological systems show varying pharmaceutical removal efficiencies. Enhancing HRT and SRT improves removal but adds complexity and costs. Tailored treatment approaches needed based on contaminants and conditions.