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In urban areas with dense populations and high water demands, effective management of water resources is crucial for sustainable development. It includes optimizing water usage and recycling wastewater to balance supply and demand. Urban rivers, which now carry sewage year-round due to increased urban water consumption, are increasingly used for irrigation in peri-urban regions. This study aims to assess the suitability of an urban stream for irrigation compared to catchment groundwater, using hydrochemical parameters to evaluate water quality indices. Analysis of major ion distribution from upstream to downstream reveals a significant increase of TDS (r2 = 0.65; p < 0.001) in the surface water and a decrease (r2 = 0.93; p < 0.001) in groundwater samples. The calculated Weighted Arithmetic-Water Quality Index (WA-WQI) indicates that around 85% and 75% of surface water and groundwater samples from the Musi river are classified as very poor to unsuitable for any use, highlighting critical pollution levels. Based on irrigation suitability indices, only 16% of the surface water samples and 60% of the groundwater samples are suitable for irrigation. The nitrate concentration increased from less than 10 mg l−1 in the upstream region to over 100 mg l−1 in the urban stretch. Nitrogen-Phosphate-Potassium (NPK) ratios across the basin are exceptionally higher, representing crops irrigated using the Musi river water might not require fertilizer applications. The adoption of fertilizer application concerning supplied water hydrochemistry, particularly the NPK ratio, might limit the excess usage of fertilizer and benefit farmers. Additionally, this practice may also limits the excess input of nitrate to the groundwater in the Musi river basin. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance (AMR) is global health concern escalating rapidly in both clinical settings and environment. The effluent from pharmaceuticals and hospitals may contain diverse antibiotics, exerting selective pressure to develop AMR. To study the aquatic prevalence of drug-resistant staphylococci, sampling was done from river Yamuna (3 sites) and wastewater (7 sites) near pharmaceutical industries in Delhi-NCR, India. 59.25% (224/378) were considered presumptive staphylococci while, methicillin resistance was noted in 25% (56/224) isolates. Further, 23 methicillin-resistant coagulase negative staphylococci (MR-CoNS) of 8 different species were identified via 16S rRNA gene sequencing. Multidrug resistance (MDR) was noted in 60.87% (14/23) isolates. PCR based detection of antibiotic resistance genes revealed the number of isolates containing mecA (7/23), blaZ (6/23), msrA (10/23), aac(6′)aph (2”) (2/23), aph(3′)-IIIa (2/23), ant(4′)-Ia (1/23), dfrG (4/23), dfrA(drfS1) (3/23), tetK (1/23) and tetM (1/23). The current research highlights the concerning prevalence of MDR-CoNS in aquatic environment in Delhi. [ABSTRACT FROM AUTHOR]

Abstract In urban areas with dense populations and high water demands, effective management of water resources is crucial for sustainable development. It includes optimizing water usage and recycling wastewater to balance supply and demand. Urban rivers, which now carry sewage year-round due to increased urban water consumption, are increasingly used for irrigation in peri-urban regions. This study aims to assess the suitability of an urban stream for irrigation compared to catchment groundwater, using hydrochemical parameters to evaluate water quality indices. Analysis of major ion distribution from upstream to downstream reveals a significant increase of TDS (r2 = 0.65; p

IntroductionThe challenges of climate change and increasing greenhouse gas emissions have led to consequences such as global warming and successive droughts. Additionally, the rise in agricultural activities has significantly increased the pressure on available water resources. Consequently, it has become essential to consider wastewater resources. To make appropriate management decisions and find solutions to reduce CO2 emissions in the agricultural sector, it is crucial to understand how soil moisture and sources of irrigation affect greenhouse gas (GHG) emissions, particularly CO2. Therefore, the aim of this research was to evaluate the effects of water stress and irrigation management on soil CO2 emissions, water productivity, and soybean yield and yield components.Materials and MethodsThis research was carried out at Sari University of Agricultural Sciences and Natural Resources with latitude (36° 33′ N) and longitude (53° 00׳ E), elevation (14 m, above sea level), average temperature (17.9°C) and total of precipitation (650 mm), during the growing season (2022-2023). The experiment was carried out in the form of a split plot based on a randomized complete block design in three replications in growth season 1402-1403, Sari. Experimental treatments include; the main factor was water stress in three levels ((non-stress, FC100), FC75 and FC50) and the sub factor was irrigation management in two levels (Urban Wastewater (UWW) and Well Water (WW).Results and DiscussionBased on the findings, the highest amount of CO2 emission in the middle and end stages of sampling in 60, 75, 90 and 105 day after sowing in non-stress conditions-FC100 was observed with 535.9, 534.5, 543.6 and 444.5 ppm.min-1, respectively. In addition, its lowest amount was related to water stress-FC50 with 505.3, 499.8, 506.5 and 409.8 ppm.min-1, respectively. The results showed that the highest amount of Co2 emission was assigned to irrigation with urban wastewater with 536.5, 540.1, 538 and 516.9, respectively. Due to the increase in the plant growth rate and approaching the grain maturity, the amount of CO2 emission increased with the increase in temperature, root system development, plant roots respiration and the soil microorganism’s activities. The highest amount of water productivity was observed in the non-stress condition FC100 with a 0.62 kg.m-3. Which compared to water stress conditions-FC75 and FC50 increased by 43.5% and 51.6%, respectively. Also, the results showed that in the non-stress condition-FC100 and irrigation with urban wastewater, the highest pod number (304.8), grain number of per pod (665.1), 100-grain weight (18.7 g), grain yield (1060.4 kg.ha-1) and total dry matter (743.3 kg.ha-1) were obtained. In the condition of irrigation with urban wastewater, the highest number of pods, grain number of per pod, 100-grain weight, grain yield and total dry matter was observed with 234.5, 495.8, 18.5 g, 679.4 kg.ha-1 and 645.7 kg.ha-1, respectively. While their lowest amount was assigned to water stress conditions-FC50 with 218.6, 483.3, 17.7 g, 555.1 kg.ha-1 and 625.5 kg.ha-1, respectively. Optimum soil moisture conditions under non-stress conditions-FC100 and water stress conditions-FC75, especially when irrigating with urban wastewater, increased the yield and yield components by providing nutrients needed by the plant.ConclusionThe results showed that in the early stages of soil sampling, irrigation management (source of irrigation) did not significantly affect the amount of CO2 emission. However, in the middle and final stages of sampling, the growth and development of plant organs and increased soil respiration due to the development of the root system caused the release of CO2. This effect was more pronounced during irrigation with wastewater than with well water. Based on the findings, considering the water scarcity crisis and the challenge of water stress during the soybean growth season, it appears that accurate management and efficient use of wastewater resources is both inevitable and a suitable solution.AcknowledgementSari Agricultural sciences and Natural Resources University (SANRU) financially supported this research under contract number: 02-1397-05.

The global population increase during the last century has significantly amplified freshwater demand, leading to higher wastewater (WW) production. European regulations necessitate treating WW before environmental. Microalgae have gained attention for wastewater treatment (WWT) due to their efficiency in remediating nutrients and pollutants, alongside producing valuable biomass. This study investigates the phycoremediation potential of a Chlorella-like strain isolated from urban WW in a 600L-scale system under winter conditions. Experiments in December 2021 and February 2022 tested the strain's adaptability to varying environmental conditions, particularly temperatures (min-max temperature range: from −3.69 to 10.61 °C in December and −3.96 to 17.61 °C in February), and its ability to meet legal discharge limits. In December, low temperatures algal growth. Nitrates showed an RE of about 92%, while ammonia slightly decreased (RE, about 32%), and phosphorous remained unchanged. In February, mild temperatures increased algal density (33.3 × 106 cell mL−1) and, at the end of experiment, all nutrients were below legal limits with very high RE % (NH4+, 91.43; PO43− 97.32). Both trials showed an E. coli RE, % = 99%. The study highlights the potential of microalgae for WWT and the importance of considering seasonal variations when implementing these systems. [ABSTRACT FROM AUTHOR]

Ensuring the protection of the aquatic environment and addressing the water scarcity and degradation of water quality in the Mediterranean region pose significant challenges. This study specifically aims to assess the impact of urban and industrial pollution on the ZAT River water quality. The study exploits a combination of field measurements and mathematical simulations using the PEGASE model. The objective is to evaluate how water quality changes throughout the different seasons and to determine whether olive oil factories discharge industrial wastewater into the river. The study reveals that the river water quality remains relatively stable along its course, up to km 64 in winter and km 71.77 in summer, where poor water quality is recorded. This degradation can be attributed to multiple factors. One of these factors is the discharge of industrial wastewater, which accounts for 47% of the COD pollution load. This industrial wastewater is released into the river without treatment during the production period (January–February) and inactivity period (March–May). The combined impact of urban and industrial wastewater is also associated with the decrease in water flow resulting from water withdrawals due to irrigation canals and groundwater recharge, which both contribute to the observed changes in river water quality. Importantly, field measurements combined with results obtained from the calibrated model provide compelling evidence of unauthorized wastewater discharges from the olive oil factories into the river. These results emphasize the need for stricter regulation, such as developing water quality monitoring strategies based on the use of modeling methodologies. They also emphasize the importance of improving wastewater management practices, such as setting up treatment plants for different sources of pollution or developing a co-treatment plant to mitigate the adverse impact of industrial pollution on river water quality. [ABSTRACT FROM AUTHOR]

Wastewater-based epidemiology, during the COVID-19 pandemic years, has been applied as a complementary approach, worldwide, for tracking SARS-CoV-2 virus into the community and used as an early warning of the prevalence of COVID-19 infection. The present study presents the results of the 2-year surveillance project, in the city of Patras, Greece. The purpose of the study was to monitor SARS-CoV-2 and implement WBE as an early warning method of monitoring Public Health impact. The presence of SARS-CoV-2 was determined and quantified in 310 samples using RT-qPCR assays. For the years 2022 and 2023, 93.5% and 78.7% of samples were found positive, respectively. Comparison of detection methods have been conducted to select the method with the highest recovery of the viral load. A seasonal variation of the virus was recorded, showing a recession in summer months confirming the country's epidemiological data as indicated by positive correlation of wastewater viral load with registered cases of COVID-19 infections during these years (p < 0.05) and moreover sealed with a significant negative correlation observed with Daily Average (p < 0.01) and Daily Maximum Temperature (p < 0.01). More research was carried out to elucidate a possible association of physicochemical characteristics of wastewater with viral load showing positive correlation with Chlorides (p < 0.01) advocating possible increased use of chlorine-based disinfectants and Electrical Conductivity (p < 0.01) indicates that wastewater during periods of increased infections is more heavily loaded with ions from chemical and biological pollutants. No correlation found with rainfall and physicochemical indicators, such as COD, BOD5, Total Phosphorus, Total Nitrogen, and Total Suspended Solids. According to the findings, WBE represents a useful tool in the management of epidemics based on an environmental approach and it can also shed light on the interacting parameters that capture Public Health since any infections that may lead to epidemics lead to a parallel change in the use of pharmaceuticals, antimicrobials, disinfectants, and microbial load in urban wastewater. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive analysis of samples from urban wastewater treatment plants using anoxic/oxic processes in Slovakia and Taiwan, focusing on microbiome, resistome, mobilome, and virulome, which were analyzed using a shotgun metagenomic approach. Distinct characteristics were observed; in Taiwan, a higher abundance and diversity of antibiotic resistance genes were found in both influent and effluent samples, while there was a higher prevalence of mobile genetic elements and virulence factor genes in Slovakia. Variations were noted in microbial community structures; influent samples in Taiwan were reflected from fecal and hospital sources, and those in Slovakia were derived from environmental elements. At the genus level, the samples from Taiwan's sewage treatment plants were dominated by Cloacibacterium and Bacteroides, while Acinetobacter was predominant in samples from Slovakia. Despite similar antibiotic usage patterns, distinct wastewater characteristics and operational disparities influenced microbiome, resistome, mobilome, and virulome compositions, with limited reduction of most resistance genes by the studied anoxic/oxic processes. These findings underscore the importance of region-specific insights into microbial communities for understanding the dynamics of antimicrobial resistance and pathogenicity in urban wastewater treatment systems. Such insights may lay the groundwork for optimizing treatment processes and reducing the dissemination of antibiotic resistance and pathogenicity genes for safeguarding public health.

The target in this perusal was to remove nitrate from municipal effluent by a composite of orange peel activated carbon/chitosan/iron synthesized via sono-chemical method. The chitosan was synthesized from prawn shells via sono-chemical method. Identification of the composite functional groups, the morphology of its surface and pores, and porosity properties were investigated by FTIR, SEM, and BET techniques. The effect of solution pH (1–6), adsorbent amount (0.05–0.15 g), and pollutant concentration (20–100 mg/L) on the nitrate adsorption operation was investigated via the batch process and the optimal operating conditions were determined using the central composite design (CCD). The breakthrough curves of the continuous adsorption process were investigated through Thomas, Yoon-Nelson, and Bohart-Adams patterns. The results offered that the adsorption confirmed the pseudo-second-order kinetics (R2 = 1). Also, among the studied isotherms, the Langmuir pattern described well the adsorption of nitrate upon the composite (R2 = 0.9999) and the maximum adsorption valence was 263.157 mg/g composite. The optimum pH of nitrate uptake was 2.023. Nitrate uptake was increased by decreasing temperature, indicating that the process was exothermic. Nitrate removal efficiency with composite was estimated to be 99.58%. The equilibrium capacity of the Thomas model in the continuous process is close to the experimental adsorption capacity (qeq) obtained from the breakthrough curves. In general, it can be said that the composite of orange peel activated carbon/prawn shell chitosan/iron has a good performance in the process of nitrate ion adsorption in a discontinuous (batch) and continuous adsorption process. [ABSTRACT FROM AUTHOR]

Rapid urbanization has caused a worldwide increase in the discharge of wastewater effluent. Although Nepal has a noteworthy history of wastewater management, progress in this field has been hindered by persistent issues. These problems encompass insufficient sewer coverage, deficient treatment and sludge disposal facilities, inadequate treatment infrastructure, lack of coherent institutional frameworks, and a lack of comprehensive planning. This review provides a glimpse into Nepal's current urban wastewater landscape while also offering a concise historical overview of its wastewater management trends. The study gathered data, information from government organizations, as well as related research, review articles, and reports from 1999 to 2023. Our findings reveal that more than 85% of urban households in Nepal rely on onsite sanitation, with limited access to septage treatment facilities. The ratio of wastewater treatment to generation is disconcertingly low, further emphasized by the concentration of centralized treatment plants in the capital city. This low ratio underscores the inadequacy of the existing wastewater system and the novice approaches of the government, which contribute to the poor sewerage facilities in Nepal. This study unequivocally highlights the imperative need for functional and institutional hierarchy emphasizing local communities, substantial changes in resource allocation, governance practices, and technical infrastructure. HIGHLIGHTS Nepal is struggling with urban wastewater challenges due to a lack of infrastructure.; Over 85% of urban households are mainly relying on onsite sanitation systems.; Two of seven provinces provide public sewerage systems covering about 10% of the total households.; Advanced treatment technologies are suggested in conjunction with conventional ones.; Proper resource allocation, good governance, and technical skills enhancement are urgent in countries like Nepal, to achieve SDG-6.;

Introduction and purpose: Leachate of the urban waste landfill is one of the most contaminated wastewaters that can pollute surface and groundwater sources, especially the environment. The production trend of urban wastewater is also increasing with a sharp rise in population and the development of urbanization. To address this environmental issue, the present study aimed to consider the simultaneous treatment of mixed landfill leachate and urban wastewater using the electrochemical coagulation process. Methods: The present laboratory study was carried out on the effluent produced from the landfill and urban wastewater produced in Qaemshahr. In this study, effective parameters in the electrochemical coagulation process, including the type of electrodes (iron and aluminum), electrode arrangement (monopolar series-parallel and bipolar series), current intensity (0.5, 1, and 2 amperes), and the initial pH of the wastewater (3.2, 6.1, and 11.4) were investigated for the reduction of chemical oxygen demand (COD) in wastewater containing a mixture of landfill leachate and urban wastewater (in equal proportions). After the appropriate electrode selection under default conditions (current intensity of 1 ampere, wastewater pH, and a duration of 120 min), the impacts of the current intensity and the initial pH of the wastewater on the COD removal rate in various electrode arrangements were assessed. Furthermore, the results were reported after three repetitions for validation purposes. Results: Under optimal conditions, the iron electrode in a monopolar series arrangement with a current intensity of 2 amperes under the wastewater pH and a duration of 120 min resulted in a 57.8% COD removal. Conclusion: Regarding the acceptable performance of the electrochemical coagulation process, it is possible to utilize its potential to treat municipal wastewater and landfill leachate.

The focus on emerging contaminants (ECs) in wastewater has intensified due to the considerable risks they present to human health and wildlife. This paper presents the results of the technical–economic assessment of the Clean Up solution, carried out in the framework of the project entitled "Validation of Adsorbent Materials and Advanced Oxidation Techniques to Remove Emerging Pollutants in Treated Wastewater". The viability of the Clean Up system is evaluated by being applied as an advanced treatment system for treated urban wastewater, that is, for the elimination of pathogens and emerging pollutants (EPs), while considering the established quality criteria by current regulations. In this sense, it is a technology that has been successfully validated at an experimental level, and that offers similar removal performance compared to that of the most efficient alternatives available on the market. The technical–economic assessment has been conducted through a systematic process. Initially, the estimation involved the calculation of treatment costs for the Clean Up system when applied at an industrial scale. Subsequently, the treatment costs were estimated for the most favorable technological alternative to the Clean Up system from a technical–economic standpoint, also applied at an industrial scale, within identical scenarios and conditions as those assumed for the Clean Up system. The final step involved a comprehensive comparison of treatment costs between both alternatives, implemented uniformly under analogous conditions and assumed similar performance across all cases. [ABSTRACT FROM AUTHOR]

This work evaluates the efficiency of three biochar samples toward the adsorption of manganese, iron, and selenium present in a sample of urban wastewater. The biochar was produced from the pyrolysis of rice husks at 350 °C for 6 h (RHB) and subsequently modified using HCl (RHBHCl) or NaOH (RHBNaOH) to increase its surface area. The RHBNaOH sample exhibited the highest removal efficiency for the three metals. The metals' adsorption removal efficiency for RHBNaOH was in the order Mn (76%), Se (66%), and Fe (66%), while for RHBHCl, it was Fe (59%), Mn (30%), and Se (26%). The results show that the as-prepared RHB can remove the metals, even if in low amounts (Fe (48%), Mn (3%), and Se (39%)). The adsorption removal for the three types of adsorbents follows the Langmuir isotherm model. Pseudo-first-order and pseudo-second-order models were used to determine the adsorption mechanism for each of the three adsorbents. Both models showed a good fit with R2 (>0.9) for the RHBNaOH and RHB sorption of Fe, Mn, and Se. Overall, this work demonstrates the potential of biochar for the removal of metals from real wastewater. [ABSTRACT FROM AUTHOR]

This study aimed to monitor abiotic factors at three stations in the Oum Er Rbia estuary, not far from the mouth. The stations were situated upstream (S1), in front (S2) and downstream (S3) from the discharge of urban wastewater from the town of Azemmour, which is discharged directly without treatment near the estuary mouth. The selection of these stations appeared appropriate to assessing the quality of the waters, which are influenced by both marine hydrodynamics resulting from very low freshwater inflows and sewage discharges. Monitoring of several parameters, including temperature, pH, dissolved oxygen, conductivity, salinity, turbidity, as well as the content of chlorophyll a and pheopigments, enabled the examination of the impact of marine hydrodynamics and the and the specific characteristics of the three surveyed stations. The analyses were performed using R software version 4.2.0. The results obtained indicate that the studied physico-chemical and biological parameters exhibited variations with significant correlations. Statistical approaches allowed the determination of profiles for stations S1, S2 and S3. It is evident that S1 (located slightly far from the discharge) showed a profile that tended to differ from the other two stations, S2 and S3, especially for certain parameters (temperature, pH, turbidity, and chlorophyll a). On the other hand, all stations were impacted to some extent by the discharge of wastewater during rising tides. The present study can serve as an assessment tool to support decision-making regarding the physico-chemical quality of the waters of the Oum Er Rbia estuary. [ABSTRACT FROM AUTHOR]

This study investigated the ability of the multi-media-layering (MML) to reduce Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) levels in domestic wastewater. MML used in this study is comprised of two MMLs (MML-1 and MML-2) with a total volume for each MML of 0.056 m³. Every MML was filled with gravel media, zeolite, activated carbon, and silica sand. The differences between MML-1 and MML-2 were only found at the height of the media, especially the height of gravel and zeolite media. This study showed that MML-1 had the highest efficiency in reducing BOD₅ (95.47%) and COD (93.10%) compared with MML-2 (BOD₅ of 85.39% and COD of 89.65%). Overall, MML showed promising results in removing pollutants from domestic wastewater. The study also suggested that the height of the gravel media and pH greatly influenced the removal of BOD₅ and COD levels in domestic wastewater.

Ensuring the protection of the aquatic environment and addressing the water scarcity and degradation of water quality in the Mediterranean region pose significant challenges. This study specifically aims to assess the impact of urban and industrial pollution on the ZAT River water quality. The study exploits a combination of field measurements and mathematical simulations using the PEGASE model. The objective is to evaluate how water quality changes throughout the different seasons and to determine whether olive oil factories discharge industrial wastewater into the river. The study reveals that the river water quality remains relatively stable along its course, up to km 64 in winter and km 71.77 in summer, where poor water quality is recorded. This degradation can be attributed to multiple factors. One of these factors is the discharge of industrial wastewater, which accounts for 47% of the COD pollution load. This industrial wastewater is released into the river without treatment during the production period (January–February) and inactivity period (March–May). The combined impact of urban and industrial wastewater is also associated with the decrease in water flow resulting from water withdrawals due to irrigation canals and groundwater recharge, which both contribute to the observed changes in river water quality. Importantly, field measurements combined with results obtained from the calibrated model provide compelling evidence of unauthorized wastewater discharges from the olive oil factories into the river. These results emphasize the need for stricter regulation, such as developing water quality monitoring strategies based on the use of modeling methodologies. They also emphasize the importance of improving wastewater management practices, such as setting up treatment plants for different sources of pollution or developing a co-treatment plant to mitigate the adverse impact of industrial pollution on river water quality.

Wastewater treatment plants (WWTPs) are considered reservoirs of antibiotic resistance genes (ARGs). Given that plasmid-mediated horizontal gene transfer plays a critical role in disseminating ARGs in the environment, it is important to inspect the transfer potential of transmissible plasmids to have a better understanding of whether these mobile ARGs can be hosted by opportunistic pathogens and should be included in One Health’s considerations. In this study, we used a fluorescent-reporter-gene based exogenous isolation approach to capture extended-spectrum beta-lactamases encoding mobile determinants from sewer microbiome samples that enter an urban water system (UWS) in Denmark. After screening and sequencing, we isolated a ∼73 Kbp IncN plasmid (pDK_DARWIN) that harboured and expressed multiple ARGs. Using a dual fluorescent reporter gene system, we showed that this plasmid can transfer into resident urban water communities. We demonstrated the transfer of pDK_DARWIN to microbiome members of both the sewer (in the upstream UWS compartment) and wastewater treatment (in the downstream UWS compartment) microbiomes. Sequence similarity search across curated plasmid repositories revealed that pDK_DARWIN derives from an IncN backbone harboured by environmental and nosocomial Enterobacterial isolates. Furthermore, we searched for pDK_DARWIN sequence matches in UWS metagenomes from three countries, revealing that this plasmid can be detected in all of them, with a higher relative abundance in hospital sewers compared to residential sewers. Overall, this study demonstrates that this IncN plasmid is prevalent across Europe and an efficient vector capable of disseminating multiple ARGs in the urban water systems.

Urban areas comprise less than 1% of the Earth's land surface, yet they host more than half the global population and are responsible for the majority of global energy use and related CO2 emissions. Urbanization is increasing the speed and local intensity of water cycle exploitation, with a large number of cities suffering from water shortage problems globally. Wastewater (used water) contains considerable amounts of embedded energy and recoverable materials. Studies and applications have demonstrated that recovering or re-capturing water, energy, and materials from wastewater is a viable endeavor, with several notable examples worldwide. Reclaiming all these resources through more widespread application of effective technological approaches could be feasible and potentially profitable, although challenging from several points of view. This paper reviews the possibilities and technical opportunities applicable to the mining of resources within the urban water cycle and discusses emerging technologies and issues pertaining to resource recovery and reuse applications. The present and future sustainability of approaches is also discussed. Since sewage management issues are not "one size fits all", local conditions must be carefully considered when designing optimal local resource recovery solutions, which are influenced not just by technology but also by multiple economic, geographical, and social factors. [ABSTRACT FROM AUTHOR]

Rapid urbanization has substantially increased freshwater consumption and consequent wastewater generation. The produced wastewater is an abundant resource of phosphorus, nitrogen, and organics. Currently, well-established activated sludge processes are utilized in conventional wastewater treatment plants to remove organics. However, removing nitrogenous and phosphorus compounds continues to be challenging and energy-intensive for urban wastewater treatment plants. Therefore, the current study aims to understand how photosynthetic microalgae can recover phosphorus and nitrogen from urban wastewater and how wastewater-grown microalgae biomass may be used as a biofertilizer and biostimulant. Utilizing microalgae biomass treated with urban wastewater as a biofertilizer promotes plant growth in a manner similar to other organic manures and conventional fertilizers while minimizing nutrient loss to the soil. Furthermore, the microalgal recovery of nutrients from urban wastewater could have potential energy reductions of 47% and 240% for nitrogen and phosphorus, respectively. In addition to producing treated wastewater suitable for a variety of irrigation systems, microalgae biomass is a potential sustainable alternative resource that could reduce conventional inorganic fertilizer usage. [ABSTRACT FROM AUTHOR]

This study investigated the ability of the multi-media-layering (MML) to reduce Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) levels in domestic wastewater. MML used in this study is comprised of two MMLs (MML-1 and MML-2) with a total volume for each MML of 0.056 m2. Every MML was filled with gravel media, zeolite, activated carbon, and silica sand. The differences between MML-1 and MML-2 were only found at the height of the media, especially the height of gravel and zeolite media. This study showed that MML-1 had the highest efficiency in reducing BOD5 (95.47%) and COD (93.10%) compared with MML-2 (BOD5 of 85.39% and COD of 89.65%). Overall, MML showed promising results in removing pollutants from domestic wastewater. The study also suggested that the height of the gravel media and pH greatly influenced the removal of BOD5 and COD levels in domestic wastewater. [ABSTRACT FROM AUTHOR]

Regarding the development of cities and the production of large volumes of urban wastewater and the lack of a suitable wastewater disposal system, leakage from wastewater pipes and wells, in addition to environmental hazards, changes the physical and mechanical parameters of the soil over time. Therefore, as the first phase, negative effects of the wastewater on geotechnical parameters and clay soil microstructure were investigated. Atterberg limits the experiments, triaxial compression, consolidation, XRD and SEM analysis were conducted on samples contaminated with 20%, 60%, and 100% of urban wastewater after 1, 3 and 5 months curing. As the second phase, for soil remediation, the mentioned experiments were performed after adding 0.5–4% N.A(α-Aluminum oxide nanoparticles), N.I(α-Iron oxide nanoparticles), and AI nanohybrid into the contaminated soil. The results show that the wastewater reduces maximum dry density (17.3–15.6 kN/m3), plasticity index (14.8–7.8%), and cohesion (42.3–17.3 kPa), and increases the liquid limit (30.4–35.2%), plastic limit (15.6–27.4%) optimum moisture content (18.7–24.1%), internal friction angle (7.1–9.6°) and compression index (0.139–0.258). Besides, XRD analysis showed a decline in mineral amounts and SEM analysis indicated an increase in pores and flocculated clay structure formation in contaminated soil. Furthermore, by adding the nanoparticles to contaminated soil, soil structure remediation, growth in some minerals amount, and soil-nanoparticles bonding creation were observed in microstructural analysis, resulting in the increase of maximum dry density (15.6–18.5 kN/m3), cohesion (17.3–46.9 kPa), and internal friction angle (9.6–19.1°), and decline in soil optimum moisture content (24.1–17.2%), liquid limit (35.2–22.6%), plastic limit (27.4–17%), plasticity index (7.8–4.4%), and compression index (0.258–0.108). Finally, the mentioned method is recommended to remediate the wastewater-contaminated soils. Finally, utilizing AI nanohybrid as an effective factor to improve wastewater-contaminated soil is recommended, it improves the engineering behavior of contaminated soils and decreases the destructive effects of this type of pollution in the earth's environment. [ABSTRACT FROM AUTHOR]

Abstract Background Hospital sewage is a significant reservoir of antimicrobial-resistant pathogens and genes that pose a huge public health threat. In this study, we determined the occurrence of multidrug-resistant Escherichia coli and Klebsiella pneumoniae in sewage flowing from a referral hospital through the urban sewage system to the point of discharge in the Indian Ocean. Results A total of 400 sewage samples were collected, yielding 517 isolates. Of these, 32.3% (167/517) were from hospital sewage, while 67.7% (350/517) were from the community. E. coli was the most common isolate (44.5% (230/517)), followed by K. pneumoniae at 27.3% (141/517), and other gram-negative bacteria constituted 28.2% (146/517) of the isolates. Multidrug resistance (MDR) was seen in 80.9% (186/230) E. coli and 71.6% (101/141) K. pneumoniae. Of the MDR isolates, 27.2% (78/287) were resistant to four different classes of antibiotics, while 6.9% (20/287) exhibited resistance to eight classes. The most frequent MDR pattern was PEN/CEP/TET/QNL/SUL, seen in 14.2% (38/287) of the isolates. The isolation frequency of MDR E. coli and K. pneumoniae at different sampling sites was high, being 47.6% in hospital chambers, 62.0% in hospital ponds, 58.1% in the treated hospital wastewater, and 55.6% in the community stream draining into the Indian Ocean. Extended spectrum beta-lactamase production was observed in 40% (92/230) of E. coli and 36.2% (51/141) of K. pneumoniae isolates. Resistance to quinolones among E. coli was 54.8% (126/230) and was 39.7% in K. pneumoniae (56/141). Carbapenem resistance in E. coli was 39.6% (91/230), while among K. pneumoniae isolates was 32.6% (46/141). Conclusions We found high proportions of multidrug-resistant E. coli and K. pneumoniae in the wastewater flowing from the hospital through the community sewage system to the point where it enters the Indian Ocean. Biological treatment did not significantly reduce the proportion of resistant bacteria, posing a very serious public health threat. The release of these highly resistant pathogens into the Indian Ocean is of international concern.

An alternative source of water in drought conditions is treated urban wastewater which can be used in the cultivation of some crops if properly managed. However, farmers consume it with no regard to its treatment, which will have dangerous consequences for the health of humans and the environment. Accordingly, this research aimed to study farmers' behavior in using urban wastewater considering perceived social risks. The study was conducted on farmers in the Sistan plain, Iran (N = 6000). The sample (361 farmers) was taken by the proportionally allocated stratified randomization technique. The extended Health Belief Model (HBM) was used to investigate the farmers' behavior. The results revealed that perceived social risks (health, environmental, and socio-ethical risks) had significant effects on the HBM components. Also, perceived susceptibility, perceived severity, perceived benefits, perceived barriers, and perceived self-efficacy had positive and significant effects on the farmers' behavior in using urban wastewater. The results may have practical consequences for policymaking and designing interventions for modifying farmers’ behaviors in using urban wastewater.

Sustainable water management is essential to guaranteeing access to safe water and addressing the challenges posed by climate change, urbanization, and population growth. In a typical household, greywater, which includes everything but toilet waste, constitutes 50–80% of daily wastewater generation and is characterized by low organic strength and high volume. This can be an issue for large urban wastewater treatment plants designed for high-strength operations. Segregation of greywater at the source for decentralized wastewater treatment is therefore necessary for its proper management using separate treatment strategies. Greywater reuse may thus lead to increased resilience and adaptability of local water systems, reduction in transport costs, and achievement of fit-for-purpose reuse. After covering greywater characteristics, we present an overview of existing and upcoming technologies for greywater treatment. Biological treatment technologies, such as nature-based technologies, biofilm technologies, and membrane bioreactors (MBR), conjugate with physicochemical treatment methods, such as membrane filtration, sorption and ion exchange technologies, and ultraviolet (UV) disinfection, may be able to produce treated water within the allowable parameters for reuse. We also provide a novel way to tackle challenges like the demographic variance of greywater quality, lack of a legal framework for greywater management, monitoring and control systems, and the consumer perspective on greywater reuse. Finally, benefits, such as the potential water and energy savings and sustainable future of greywater reuse in an urban context, are discussed.

Aerobic granular sludge is an interesting alternative to the conventional activated sludge (CAS) system and modified-Ludzack–Ettinger (MLE) process for biological wastewater treatment, as it allows a more cost-effective and simultaneous removal of carbon (C) and nitrogen (N) compounds in a single stage. In this study, (micro)aerobic C and N removal from synthetic urban wastewater was investigated in a continuous-double-column-upflow aerobic granular sludge blanket (UAGSB) system. The UAGSB reactor was operated under different dissolved oxygen (DO) ranges (0.01–6.00 mg∙L−1), feed C/N ratios (4.7–13.6), and hydraulic retention times (HRTs) (6–24 h). At a DO range of 0.01–0.30 mg∙L−1, feed C/N ratio of 13.6, and HRT of 24 h, the UAGSB achieved the highest chemical oxygen demand (COD), N-NH4+, and total inorganic nitrogen (TIN) removal efficiencies of 86, 99, and 84%, respectively. A preliminary assessment of the energy and economic savings associated with the process investigated was also carried out. The impact of capital and operating costs mainly related to the energy consumption of the aeration was taken into account. The assessment reveals that the capital and energy expenses of the UAGSB reactor would result in cost savings of around 14 and 7%, respectively, compared with a MLE system. [ABSTRACT FROM AUTHOR]

This article presents the results of a study on the oestrogenicity and androgenicity of urban wastewater in Lodz, and the possibility of their removal by the Group Wastewater Treatment Plant (GWWTP). Wastewater samples were taken at five points of the sewer system in the city and at the inlet and outlet of the GWWTP. The study was conducted using Yeast Oestrogen Screen (YES)/Yeast Androgen Screen (YAS) tests, which allow a general assessment of the content of compounds with (anti-)oestrogenic and (anti-)androgenic effects in wastewater, without identifying specific substances. Wastewater samples taken from the sewage network did not show (anti-)oestrogenic activity, while oestrogenic and antagonistic properties to androgens were detected in most of them. In the influent of the treatment plant, oestrogen agonistic activity was detected only in one sample (oestrogen equivalent—EEQ equal to 1.31 × 105 ng 17 β–oestradiol/L) and was 100% removed. The purification efficiencies in GWWTP for oestrogen and androgen antagonistic activity were 51.5–99.2% and 39.4–47.1%, respectively. Although no oestrogenic activity was detected in general wastewater in Lodz, observed high-antagonistic–androgenic activities may adversely affect the water body and cause, among others, the feminization of fish, especially in the case of discharge of untreated wastewater by combined sewer overflows. [ABSTRACT FROM AUTHOR]

This study investigated the elimination of organic matter from water by the coagulation process using a biomaterial “acorns barks” as a coagulantaid with the presence of aluminium sulphate in low concentration. The removal of gallic acid from water was first studied by two processes: the adsorption on activated acorns barks, and coagulation by aluminium sulphate, separately. The hybrid system was then studied, and the optimal operating conditions were determined. The performance of the hybrid system (coagulation/adsorption) mainly depends on the initial concentration of gallic acid, the coagulant dose and the mass of coagulant-aid. A full factorial design 23 was used to determine the optimum conditions for gallic acid removal. The maximum removal of gallic acid in water was 92.48 %, achieved at 20 mg L-1 of initial gallic acid concentration, 50 mg L-1 of aluminium sulphate coagulant concentration and 1.5 g of activated acorns barks adsorbent mass. The application of these optimal conditions on urban wastewater for the elimination of organic matter has shown the performance of this hybrid system treatment.

Background: Hospital sewage is a significant reservoir of antimicrobial-resistant pathogens and genes that pose a huge public health threat. In this study, we determined the occurrence of multidrug-resistant Escherichia coli and Klebsiella pneumoniae in sewage flowing from a referral hospital through the urban sewage system to the point of discharge in the Indian Ocean. Results: A total of 400 sewage samples were collected, yielding 517 isolates. Of these, 32.3% (167/517) were from hospital sewage, while 67.7% (350/517) were from the community. E. coli was the most common isolate (44.5% (230/517)), followed by K. pneumoniae at 27.3% (141/517), and other gram-negative bacteria constituted 28.2% (146/517) of the isolates. Multidrug resistance (MDR) was seen in 80.9% (186/230) E. coli and 71.6% (101/141) K. pneumoniae. Of the MDR isolates, 27.2% (78/287) were resistant to four different classes of antibiotics, while 6.9% (20/287) exhibited resistance to eight classes. The most frequent MDR pattern was PEN/CEP/TET/QNL/SUL, seen in 14.2% (38/287) of the isolates. The isolation frequency of MDR E. coli and K. pneumoniae at different sampling sites was high, being 47.6% in hospital chambers, 62.0% in hospital ponds, 58.1% in the treated hospital wastewater, and 55.6% in the community stream draining into the Indian Ocean. Extended spectrum beta-lactamase production was observed in 40% (92/230) of E. coli and 36.2% (51/141) of K. pneumoniae isolates. Resistance to quinolones among E. coli was 54.8% (126/230) and was 39.7% in K. pneumoniae (56/141). Carbapenem resistance in E. coli was 39.6% (91/230), while among K. pneumoniae isolates was 32.6% (46/141). Conclusions: We found high proportions of multidrug-resistant E. coli and K. pneumoniae in the wastewater flowing from the hospital through the community sewage system to the point where it enters the Indian Ocean. Biological treatment did not significantly reduce the proportion of resistant bacteria, posing a very serious public health threat. The release of these highly resistant pathogens into the Indian Ocean is of international concern. [ABSTRACT FROM AUTHOR]

Antibiotics are among the most common medicine groups since they are used to treat infectious diseases, as nutritional supplements in livestock breeding, and for preservation in the food industry. Turkey is among the highest antibiotic consumers in the world. In the present study, the most popular 14 antibiotics available in Turkey were monitored in one hospital sewage and two urban wastewater treatment plant influents and effluents seasonally in Istanbul province, the largest metropolitan center in Turkey. The present research aimed to develop a robust analytical method to determine 14 antibiotics, including six chemical groups, in environmental matrices which are considered significant antibiotic pollution sources, namely hospital sewage and urban wastewater. Solid-phase extraction (SPE) and UPLC-MS/MS analysis parameters included optimized column temperature, eluent, mobile phase, and flow rate. Three SPE cartridges were employed in recovery studies. The antibiotic recovery rates varied between 40 and 100%, and all analytes were identified within 3 min with UPLC-MS/MS under optimal conditions. It was determined that method detection limits (MDLs) varied between 0.07 and 2.72 µg/L for the antibiotics. In all seasons, the highest beta-lactam group antibiotic concentrations were identified in hospital sewage. The season with the greatest variety of antibiotics in urban wastewater was spring. Clarithromycin and ciprofloxacin were the antibiotics determined at the highest concentration in the influent and effluent of the wastewater treatment plant in all seasons. This study showed that the most widely used beta-lactam group antibiotics were found in high amounts in hospital sewage wastewater but in low concentrations in the treatment plants, and hence, it is seen that the degradability of beta-lactam group antibiotics was high. The presence of clarithromycin, ciprofloxacin, lincomycin, levofloxacin, and trimethoprim antibiotics in hospital sewage in higher amounts and also in inlet and outlet of wastewater treatment plants proves that those are resistant antibiotics. [ABSTRACT FROM AUTHOR]

Activated sludge processes contain various groups of microorganisms with different metabolic properties, which are responsible for contaminants removal. Therefore, it is important to elucidate the general structure and functional properties of biomass in activated sludge processes. For this purpose, a full-scale domestic biological wastewater treatment plant in Tunceli (Turkey), Tunceli WWTP (wastewater treatment plant), was monitored to observe seasonal variations in process performance and biomass properties for a year. It was observed that nitrifying bacteria developed abundantly in the rainy and cool spring season as they were suppressed in summer because their large losses took place due to an environment containing high alkalinity values. In September, aerobic heterotrophic, nitrify, denitrify, and anaerobic activities increased. It can be said that the biomass contained young and mature microorganism in this environment in which the sludge volume index (SVI) value increased to 196 mL/g. As a result of the improvement in the structural and functional properties of biomass, the nitrogen removal efficiency reached 99%. Throughout the whole study, the structural improvement observed in biomass was reflected in its removal activity. The amount of biomass and removal activity decreased with the abundance of organic matter in the influent at the period in which biomass was closer to being categorized in the aged sludge class. The results showed that as the lowest mixed liquid suspended solids (MLSS) and mixed liquid volatile suspended solids (MLVSS) values of the year were 530 and 400 mg/L, respectively, in November 2017, MLSS and MLVSS values reached the highest amount (1700 and 1400 mg/L, respectively) in December 2017 when aerobic heterotrophic activity accelerated with a decrease in organic matter level. [ABSTRACT FROM AUTHOR]

ABSTRACT The increasing prevalence of antibiotic-resistant bacteria is an emerging threat to global health. The analysis of antibiotic-resistant enterobacteria in wastewater can indicate the prevalence and spread of certain clonal groups of multiresistant bacteria. In a previous study of Escherichia coli that were isolated from a pump station in Norway over 15 months, we found a recurring E. coli clone that was resistant to trimethoprim, ampicillin, and tetracycline in 201 of 3,123 analyzed isolates (6.1%). 11 representative isolates were subjected to whole-genome sequencing and were found to belong to the MLST ST2797 E. coli clone with plasmids carrying resistance genes, including blaTEM-1B, sul2, dfrA7, and tetB. A phenotypic comparison of the ST2797 isolates with the uropathogenic ST131 and ST648 that were repeatedly identified in the same wastewater samples revealed that the ST2797 isolates exhibited a comparable capacity for temporal survival in wastewater, greater biofilm formation, and similar potential for the colonization of mammalian epithelial cells. ST2797 has been isolated from humans and has been found to carry extended spectrum β-lactamase (ESBL) genes in other studies, suggesting that this clonal type is an emerging ESBL E. coli. Collectively, these findings show that ST2797 was more ubiquitous in the studied wastewater than were the infamous ST131 and ST648 and that ST2797 may have similar abilities to survive in the environment and cause infections in humans. IMPORTANCE The incidence of drug-resistant bacteria found in the environment is increasing together with the levels of antibiotic-resistant bacteria that cause infections. The COVID-19 pandemic has shed new light on the importance of monitoring emerging threats and finding early warning systems. Therefore, to mitigate the antimicrobial resistance burden, the monitoring and early identification of antibiotic-resistant bacteria in hot spots, such as wastewater treatment plants, are required to combat the occurrence and spread of antibiotic-resistant bacteria. Here, we applied a PhenePlate system as a phenotypic screening method for genomic surveillance and discovered a dominant and persistent E. coli clone ST2797 with a multidrug resistance pattern and equivalent phenotypic characteristics to those of the major pandemic lineages, namely, ST131 and ST648, which frequently carry ESBL genes. This study highlights the continuous surveillance and report of multidrug resistant bacteria with the potential to spread in One Health settings.

Industrial pollution discharges from washing fuel oils pose severe problems for the environment, particularly for the marine environment receiving these discharges. This work evaluates the biological treatment performance of wastewater (90 m3/h) rich in organic matter with low biodegradability using a sequential batch reactor (SBR) on a laboratory scale. The test using SBR was carried out for 25 days on a continuous cycle of 24 h (30 min of filling, 17 h of aeration, 4 h of anoxia, 2 h of settling, and 30 min of emptying). The feasibility of alternative sources of microorganisms from urban wastewater. The performance of the batch sequencing reactor was evaluated using turbidity, total suspended solids, chemical oxygen demand (COD), biological oxygen demand (BOD), ammonium, nitrate, and phenol as indicators. The results obtained showed that the COD/BOD ratio and the pollutant load vary from one campaign to another. The removal efficiency of COD, BOD, TSS (Total suspended solids), ammonium, nitrate, and phenol varies from 81%, 91%, 72%, 100%, 52%, and 63%. Thus, SBR-type treatment could be an interesting way to reduce pollution due to its simplicity, less space occupation, low energy consumption, and not requiring highly qualified personnel. [ABSTRACT FROM AUTHOR]

As a proxy for pollutants that may be simultaneously present in urban wastewater streams, the effects of two microplastics—polystyrene (PS; 10, 80 and 230 μm diameter) and polymethylmethacrylate (PMMA; 10 and 50 μm diameter)—on fertilisation and embryogenesis in the sea urchin Arbacia lixula with co-exposure to the pyrethroid insecticide cypermethrin were investigated. Synergistic or additive effects were not seen for plastic microparticles (50 mg L−1) in combination with cypermethrin (10 and 1000 μg L−1) based on evaluation of skeletal abnormalities or arrested development and death of significant numbers of larvae during the embryotoxicity assay. This behaviour was also apparent for male gametes pretreated with PS and PMMA microplastics and cypermethrin, where a reduction in sperm fertilisation ability was not evidenced. However, a modest reduction in the quality of the offspring was noted, suggesting that there may be some transmissible damage to the zygotes. PMMA microparticles were more readily taken up than PS microparticles, which could suggest surface chemical identity as potentially modulating the affinity of larvae for specific plastics. In contrast, significantly reduced toxicity was noted for the combination of PMMA microparticles and cypermethrin (100 μg L−1), and may be related to less ready desorption of the pyrethroid than PS, as well as cypermethrin activating mechanisms that result in reduced feeding and hence decreased ingestion of microparticles. [ABSTRACT FROM AUTHOR]

AbstractOne of the environmental problems is soil pollution with heavy metals from urban and industrial wastewater, and the treatment of these pollutants by plants is a cost-effective and environmentally friendly method. In this study, an experiment was conducted to evaluate the phytoremediation rate of Aloe vera in terms of metal accumulation index (zinc, chromium, lead, copper, manganese, nickel, magnesium, cadmium, mercury) and its morphological characteristics under two types of urban and industrial wastewater treatment. The design was completely randomized with three replications. The results showed that urban and industrial wastewater treatments caused significant changes (P≤0.05) in all examined parameters including leaf fresh weight, leaf dry weight, relative leaf water content, leaf length, leaf gel weight, the ratio of gel to leaf, root fresh weight, fresh plant weight, total biomass, root length, plant height, number of ramets, ramets height, ramets weight and root tolerance index in Aloe vera. The highest index of metal accumulation was observed in plants treated by urban wastewater and all the mentioned parameters showed a more significant decrease by treatment of urban wastewater than industrial wastewater. In the industrial wastewater treatment, all parameters decreased, but the average number of ramets increased compared to the control. In general, based on the parameters studied in this study, it can be said that the Aloe vera plant had better performance in soils containing industrial wastewater than in soils containing urban wastewater. IntroductionOne of the environmental problems is soil pollution with heavy metals from urban and industrial wastewater. Human activities such as the disposal of household waste and industrial activities mainly import heavy metals into the soil (European Commission, 2013; USEPA, 2021). Heavy metal pollution of soil can harm human life and the ecosystem through direct intake or entering the food chain (soil-plant-human or soil-plant-animal-human) (European Commission, 2013). Phytoremediation is a biological and cost-effective method to remove or reduce environmental pollutants. Some plants can remove, stabilize or transfer contaminants of soil or groundwater (Gajic and Pavlovic, 2018). Therefore, choosing a suitable plant for phytoremediation can be a crucial step in eliminating pollution based on region and type of pollution and expansion of urban wastewater.The province of Guilan, located in the north of Iran, has a humid subtropical climate and is a fertile province in terms of agriculture. The increased urban population in this province can cause pollution transfer into the river or land fields. This problem threatens the agricultural products of Guilan and causes a critical challenge. It seems that the cultivation of plants with high phytoremediation ability and the creation of a green belt in the landfill site of urban and industrial wastewaters is the most feasible and low-cost method to decrease the risk of soil and water pollution. In this study, we examined the ability of Aloe vera for phytoremediation of urban and industrial wastewater (UWW and IWW) and the possible alterations of, its morphological and physiological characteristics under wastewater pollution. Materials and Methods For this study, Aloe vera plants gathered from the local nursery were planted in the pots containing 11 kilos of soil suitable for A. vera cultivation. After a month of transferring the plants to the pots and adapting them to the new conditions, they were divided into three groups. Each group was irrigated for 14 months (every twice a week) with 300 mL of one type of solutions consideredas treatments for this experiment, including urban water (drinking water), UWW collected from the landfill site of Saravan, and IWW collected from the paper factory. Moreover, pots without plants were irrigated like pots with plants to determine the amounts of heavy metals (zinc, chromium, lead, copper, manganese, nickel and magnesium) after wastewater addition to the soil and compare it with maximum standard levels, pots with plants.Soil samples were homogenized and dried in an oven at 30°C for 24h and the concentration of heavy metals was determined. The relative water content (RWC) of leaves was measured before harvesting plants (Barrs and Weatherley, 1962). After harvesting the whole plants, leaf fresh weight, leaf length, leaf gel weight, ratio gel to leaf, root fresh weight, plant fresh weight, root length, plant height, number of ramets, ramets height, ramets weight, and tolerance index were measured. Leaf dry weight and total biomass were determined after drying plant tissues (oven 50 ºC for 72 hours). All dried plant tissues were turned into powder. Then the concentration of metal elements in plant samples was determined using ICP-OES based on the method of Salt et al. (1998) and Al-Oud Saud (2003).Metal Accumulation Index (MAI) was calculated using the following formula to determine the amount of metals accumulated in plants. (Liu et al., 2007): Results and discussionComparison of means showed that urban and industrial wastewater treatments caused significant changes in all examined parameters, including the fresh weight of leaf, root, whole plant, and ramets, dry weight of leaf, length of leaf and roots, the height of plants and ramets, relative leaf water content, leaf gel weight, ratio gel to leaf, total biomass, number of ramets and root TI. The highest index of MAI was observed in plants treated by UWW, and the reduction of all mentioned parameters was more under treatment with UWW than IWW. Under the IWW treatment, all parameters decreased, but the average number of ramets increased compared to the control.Considering that MAI shows the overall performance of plants for co-accumulation of metal elements (Liu et al., 2007), A. vera was successful in accumulating Zn, Cr, Pb, Cu, Mn, Ni, and Mg. Previous studies have reported that plant species with a high MAI value should be used as barriers between contaminated and vulnerable areas, such as parks and residential areas (Nadgorska–Socha et al., 2017). It has been reported that high levels of metals in the soil inhibit various metabolic functions of plants and cause a delay in growth. The toxicity of heavy metals in different plants varies according to factors such as the type of plant, the bioavailability of metals, and the amount of metal displacement in the plant organs (Wang et al., 2006; Usman et al., 2005).The results indicate that an increase in the concentration of heavy metals probably decreases the amount of plant production, the size of the cells, and the dry weight of the organs. (Sharma and Dubey, 2005; Yadollahi et al., 2016). ConclusionAccording to MAI, morphological and physiological characteristics of the A.vera under UWW and IWW treatments, A.vera can be a good refining plant for cultivating and creating a green belt in contaminated soils. Due to the remarkable purifying ability of A.vera in removing heavy metals from contaminated soils, it is recommended to cultivate A.vera in areas polluted with industrial and urban wastewater to prevent the spread of pollution to the surrounding lands. AcknowledgementThis article is extracted from the results of Sareh Ebrahimi Nokande’s Ph.D. thesis from the Faculty of Sciences, University of Mohaghegh Ardabili, Ardabil, Iran. The authors would like to thank University of Guilan for the technical supports.

One of the ways to reduce the amount of wastewater pollution is the use of constructed wetlands. In this research, the performance of a hybrid constructed wetland with pumice ore and vetiver plant on urban wastewater has been investigated. Hybrid wetlands with these specifications were constructed in the vicinity of wastewater treatment at the Isfahan University of Technology. To evaluate the performance of constructed wetland the effects of three and six days of retention time on the removal efficiency were studied using a completely randomized design. On average, for three days of retention time, in the wetland with the vertical flow, the horizontal flow, and hybrid wetland, fecal coliform was 47.4, 98.3, and 99.1 percent, BOD5 was 7.6, 20.9, and 26.9 percent, and the COD was 4.6, 40.0, and 42.7 percent decreased, respectively. Also, during the six days of retention time in the wetland with the vertical flow, the horizontal flow, and hybrid wetland, fecal coliform was 61.6, 99.3, and 99.8 percent, BOD5 was 10.7, 29.9, and 37.4 percent, and COD was 16.0, 86.8, and 88.9 percent decreased, respectively. The combination of Pumice as a porous material with the ability to absorb the elements as well as vetiver as a plant capable of phytoremediation indicated a very suitable performance during low retention time.

• The effectiveness of tannin and calcium residues in microalgae UF antifouling strategies was investigated. • Steel industry residues enhance filtration over commercial coagulants. • Bag filter powder reduces fouling resistance by 30 % • Steel industry residues altered clake morphology, impacting cake layer structure and flow reversibility. This study aimed to assess the impact of various coagulants and alternative sources of Ca2+ as pre-treatment on a microalgae suspension undergoing ultrafiltration. Two commercial coagulants, namely aluminum polychloride (PAC) and Tanfloc SL, were compared against two calcium-rich residues from the steel industry: blast oxygen furnace slag and bag filter powder. The filterability of the samples was assessed through permeate flux measurement, analysis of added membrane resistances, and examination of fouling formation mechanisms. Additionally, the characteristics of the formed deposit, including membrane surface morphologies and functional groups, were characterized. Coagulation-flocculation significantly influenced floc characteristics, thereby impacting the filterability of the microalgae samples. Both aluminum polychloride and Tanfloc demonstrated a slight reduction in flux decay, except at 40 mg.L-1 doses, which notably increased normalized final flux. However, Tanfloc exhibited poorer performance compared to coagulated filtrations with calcium-rich residues in terms of fouling. Bag filter powder displayed a 30 % lower fouling resistance than the microalgae suspension without a coagulant. The predominant mechanism observed in fouling formation was attributed to cake layer formation, with the observed fouling being mostly reversible. [ABSTRACT FROM AUTHOR]

Ammonium (NH4+) recirculation from the streams generated in the dehydration stage of the sludge generated in the anaerobic digestion of urban wastewater treatment plants (WWTPs), known as centrate or sidestream, produces a reduction in the efficiency of WWTPs. Given this scenario and the formulation that a WWTP should be considered a by-product generating facility (biofactory), solutions for ammonia/ammonium recovery are being promoted. These include a nitrogen source that reduces the need for ammonia production through the Haber–Bosch process. Therefore, the recovery of nutrients from urban cycles is a potential and promising line of research. In the case of nitrogen, this has been aimed at recovering NH4+ to produce high-quality fertilizers through membrane or ion exchange processes. However, these techniques usually require a pretreatment, which could include an ultrafiltration stage, to eliminate suspended solids and organic matter. In this case, the coagulation/flocculation (C/F) process is an economical alternative for this purpose. In this work, the sidestream from Vilanova i la Geltrú WWTP (Barcelona, Spain) was characterized to optimize a C/F process before being treated by other processes for ammonium recovery. The optimization was performed considering a bibliographic and experimental analysis of several operating parameters: coagulant and flocculant agents, mixing velocity, and operation time, among others. Then, the removal efficiency of control parameters such as turbidity, chemical oxygen demand (COD), and total suspended solids (TSS) was calculated. This optimization resulted in the use of 25 mg/L of ferric chloride (FeCl3) combined with 25 mg/L of a flocculant composed of silicon (SiO2 3%), aluminum (Al2SO4 64.5%), and iron salts (Fe2O3 32.5%), into a 1 min rapid mixing process at 200 rpm and a slow mixing for 30 min at 30 rpm, followed by a final 30 min settling process. The numerical and statistical results of the process optimization reached 91.5%, 59.1%, and 95.2% removal efficiency for turbidity, COD, and TSS, respectively. These efficiencies theoretically support the enhanced coagulation/flocculation process as a pretreatment for a higher NH4+ recovery rate, achieving 570.6 mgNH4+/L, and a reduction in the dimensioning or substitution of other membrane processes process due to its high TSS removal value. [ABSTRACT FROM AUTHOR]

The shortcomings of conventional processes for treating urban wastewater subjected to secondary treatment, in order to use this water for irrigation, are well known. Alternative advanced treatment techniques are required instead. This study aims to use single‐stage ultrafiltration (UF) or nanofiltration (NF) membrane processes to produce irrigation water from biologically treated urban wastewater. For this purpose, the effects of four process variables (membrane type, cross flow velocity, temperature, and transmembrane pressure) on process performance parameters (permeate flux, concentrations/removal efficiencies of contaminants) are analyzed through Taguchi experiment design. Temperature and membrane type are found to have the biggest effect on UF, whereas the membrane type is the most significant variable for the NF. Moreover, the use of membrane permeate for landscaping and agricultural irrigation based on optimal conditions is assessed with reference to the criteria imposed by national regulation/international guidelines. Water in various quality categories is produced using different settings for 28 distinct specific parameters with reference to the membrane type, process performance, and the irrigation method. The results indicate that single‐stage UF or NF membranes with high recovery rates can be used for wastewater subjected to secondary treatment, to recover irrigation water at low pressure and high water permeate flux. [ABSTRACT FROM AUTHOR]

Background: The microbial community composition of urban environments is primarily determined by human activity. The use of metagenomics to explore how microbial communities are shaped in a city provides a novel input that can improve decisions on public health measures, architectural design, and urban resilience. Of note, the sewage system in a city acts as a complex reservoir of bacteria, pharmaceuticals, and antimicrobial resistant (AMR) genes that can be an important source of epidemiological information. Hospital effluents are rich in patient-derived bacteria and can thus readily become a birthplace and hotspot reservoir for antibiotic resistant pathogens which are eventually incorporated into the environment. Yet, the scope to which nosocomial outbreaks impact the urban environment is still poorly understood. Results: In this work, we extensively show that different urban waters from creeks, beaches, sewage spillways and collector pipes enclose discrete microbial communities that are characterized by a differential degree of contamination and admixture with human-derived bacteria. The abundance of human bacteria correlates with the abundance of AMR genes in the environment, with beta-lactamases being the top-contributing class to distinguish low vs. highly-impacted urban environments. Indeed, the abundance of beta-lactamase resistance and carbapenem resistance determinants in the urban environment significantly increased in a 1-year period. This was in line with a pronounced increase of nosocomial carbapenem-resistant infections reported during the same period that was mainly driven by an outbreak-causing, carbapenemase-producing Klebsiella pneumoniae (KPC) ST-11 strain. Genome-resolved metagenomics of urban waters before and after this outbreak, coupled with high-resolution whole-genome sequencing, confirmed the dissemination of the ST-11 strain and a novel KPC megaplasmid from the hospital to the urban environment. City-wide analysis showed that geospatial dissemination of the KPC megaplasmid in the urban environment inversely depended on the sewage system infrastructure. Conclusions: We show how urban metagenomics and outbreak genomic surveillance can be coupled to generate relevant information for infection control, antibiotic stewardship, and pathogen epidemiology. Our results highlight the need to better characterize and understand how human-derived bacteria and antimicrobial resistance disseminate in the urban environment to incorporate this information in the development of effluent treatment infrastructure and public health policies. 2A5ZQFmXmKxDXginhFNeyT Video Abstract [ABSTRACT FROM AUTHOR]