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Although the textile industry is crucial to economic development, it is a significant polluter of global water sources through its wastewater discharge, which endangers aquatic ecosystems and neighboring communities. This study focuses on stakeholder perceptions from farming and fishing communities related to wastewater management in the Bangladesh textile industry. Using focus group discussions with stakeholders that focused on sustainability values and a Resource Nexus framing, the results emphasise the adverse effects of textile wastewater on neighbouring communities, spanning agriculture, livestock, and ecological resources. The findings also underscore a significant need for collaboration between the textile industry and neighbouring communities, emphasising the ongoing obligation of governance resources, such as monitoring, regulations, and proactive measures and advocates for engaging different stakeholders in the formulation of robust policies, stringent regulations, and concerted efforts across industry, government, and communities to deliver improved governmental monitoring, enforcement of regulations and transparency in wastewater management practices in the textile industry of Bangladesh. The study suggests that a Water-Energy-Ecosystems-Food (WEEF) Resource Nexus approach can enhance decision-making, promoting sustainable energy infrastructure, encourage increased treated wastewater reuse, and facilitate effective management for environmental resilience and socio-ecological systems sustainability. This study contributes valuable insights elicited from a WEEF Resource Nexus approach, offering guidance for policymakers, industry practitioners, and researchers in the textile industry and beyond, aiding in the understanding of resilient industry-community ecosystems. [ABSTRACT FROM AUTHOR]

TiO2 photocatalyst has the advantages of high catalytic activity, suitable energy band potential, high chemical stability, high photoelectric conversion efficiency, high safety and non-toxicity, which exhibits excellent performances in photocatalytic degradation of organic wastewater. However, it is difficult to separate and recover TiO2 photocatalyst from the reactive system. Interestingly, magnetic TiO2 prepared by combining TiO2 with superparamagnetic ferromagnetic particles can overcome this shortcoming. In this review, the preparation method and the photocatalytic mechanism of magnetic TiO2 were summarized. Moreover, the catalytic mechanisms of the modified binary, ternary and multicomponent magnetic TiO2 composite photocatalysts were compared, and the effects of different magnetic substrates on the degradation activity were discussed. Besides the applications in the wastewater treatment, the development trend and application prospects were prospected. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs), as a new type of carbon material with complete molecular structure, have great application potential in the field of nanocomposites. In this study, carbon nanotubes were first surface modified to give them good hydrophilicity. Subsequently, the nanocomposite coagulant (PASS-T) with different modified CNTs (m-CNTs) contents was prepared by alkaline titration method. The CNT, m-CNT, PASS and PASS-T were characterized by FTIR, XRD and XRF. Then the coagulant was applied to oily sewage, and the coagulation results showed that the PASS-T (0.1%) had the best oil reduction rate (92%) and turbidity reduction rate (97%). Appropriate addition of m-CNT can increase the local concentration of coagulant at the molecular level, making the flocs of oily sewage larger. It can be found by SEM that PASS-T produces large and knotted flocs in oily sewage. Finally, the residual turbidity and oil removal rate of the different coagulants were statistically analyzed. [ABSTRACT FROM AUTHOR]

Abstract\nNOVELTYThis study investigates the treatment of combined wastewater from Hattar Industrial Estate using Biofilm Wetlands (BW) planted with monoculture species: Eichhornia crassipes (EAC), Pistia stratiotes (WL), and Arundo donax (GR). Each species showed distinct capabilities in organic degradation, metal uptake, and pH stabilization. BW2, planted with EAC, achieved the highest total solids (TS) and total suspended solids (TSS) removal efficiencies of 66% and 65%, respectively. GR effectively reduced initial COD concentrations from 232 mg/L to 58.67 mg/L, while EAC and WL reached reductions to 72.78 mg/L and 70.67 mg/L, respectively. Overall, the plant efficiency ranking was EAC > GR > WL. These findings underscore the potential of these plant species in synergistic BW systems, highlighting their role as natural solutions for remediating complex industrial effluents. This research contributes to advancing eco-friendly wastewater treatment approaches, suggesting promising applications for sustainable practices in industrial contexts.RESEARCH HIGHLIGHTSThis research assessed the effectiveness of phytoremediation using Eichhornia crassipes, Pistia stratiotes, and Arundo donax for removing pollutants i.e. heavy metals (Cd, Pb, Ni, K, Ca, Mg, Na, Fe, Hg) nitrates, phosphates and sulfates from combined industrial wastewater of Hattar Industrial Estate Pakistan.It highlighted the potential of selected plant species’ as natural treatment systems, providing crucial insights into their efficiency.Findings contribute to understanding nature-based solutions for complex industrial effluents.This research assessed the effectiveness of phytoremediation using Eichhornia crassipes, Pistia stratiotes, and Arundo donax for removing pollutants i.e. heavy metals (Cd, Pb, Ni, K, Ca, Mg, Na, Fe, Hg) nitrates, phosphates and sulfates from combined industrial wastewater of Hattar Industrial Estate Pakistan.It highlighted the potential of selected plant species’ as natural treatment systems, providing crucial insights into their efficiency.Findings contribute to understanding nature-based solutions for complex industrial effluents.This study harnessed the potential of three macrophytes to tackle industrial effluents, marking their debut in wastewater treatment. By championing environmentally conscious practices, it underscores the need for effective industrial wastewater management while promoting greener and more sustainable approaches within the industrial sector. [ABSTRACT FROM AUTHOR]

Triclosan (TCS) is an anti-microbial widely used in personal care and medical antibacterial products. Despite the widespread occurrence of TCS in municipal sewage sludge, understanding toward the fate of TCS within sewage treatment and environmental risks in the eventual land application is still limited. This review summarizes the TCS loads and transfer mechanisms in the sewage treatment process, sludge management process, land application, and its potential environmental impacts. TCS transfer from sewage to sludge mainly occurs in the primary sedimentation process, representing 2.50 to 4.58 times more compared to the secondary sedimentation process. This transfer is facilitated through adsorption because of the presence of humic acid-like and protein-like substances in sludge. Both anaerobic digestion and aerobic composting contribute to the degradation of TCS with aerobic composting being more effective, exhibiting TCS degradation rates 1.04–2.87 times higher than those observed in anaerobic digestion. After sludge land application, TCS majorly dissipates in the soil through biodegradation by fungi and bacteria, potentially posing environmental risks, such as inhibiting the seedling growth of plant species. Additionally, the degradation of TCS, coupled with the formation and subsequent degradation of MeTCS, is observed, with MeTCS exhibiting a higher half-life and greater toxicity than its parent compound (TCS). Overall, this research offers vital insights to enhance understanding of TCS's migration and degradation processes in sewage treatment and soil. It also provides guidance in environmental protection and sustainable resource management. [ABSTRACT FROM AUTHOR]

A collaborative analysis of constructed wetlands in Latin America and the Caribbean, published in Spanish, brought together insights from 10 different countries in the region. The collective reports focused on both subsurface and surface flow wetlands. Treatment targets included industrial and agricultural discharges, yet the emphasis was on the treatment of domestic wastewater as a pollutant, and a lack of sufficient municipal wastewater treatment infrastructure. Common macrophyte genera as well as unique species were highlighted for their potential contributions to treatment and ecological diversity. Finally, a growing body of legal frameworks for establishment and protection were reported. [ABSTRACT FROM AUTHOR]

The unplanned and rapid expansion of metropolitan areas reduces accessibility to existing and often outdated centralized water and wastewater systems. In this context, sanitation policies that focus exclusively on centralized systems become expensive and unfeasible. Using Q methodology, we identified three different social perspectives on onsite wastewater treatment systems (OWTS) in the metropolitan area of the Lerma Valley in northern Argentina. We focused our analysis on the legal, environmental, and technical aspects of onsite sanitation. The perspectives found were: 'OWTS have advantages', 'Hard path for sewerage', and 'Process before technology'. We describe the perspectives identified and we provide an analysis of their differences and similarities to discuss their possible policy implications for our study area and comparable regions in the country and beyond. [ABSTRACT FROM AUTHOR]

The present work investigates the performance of a biofilm reactor filled with a new type of combined packing used to treat wastewater and explores a new technology approach for the application of coral sand and waste non-woven fabric. The combined packing was made of coral sand and waste non-woven fabric, which was used as a biofilm carrier to treat sewage. The experimental results showed that the removal efficiencies of COD, NH4+-N and TN in the biofilm reactor containing the combined packing were 92.9%, 72.9% and 63.2%, respectively. The maximum removal efficiencies of COD, NH4+-N and TN in the biofilm reactor containing single packing were 89.0%, 63.4% and 55.2%, respectively. The properties of the combined packing were characterized by Fourier Transform Infrared (FTIR), specific surface area, SEM and dehydrogenase activity. Infrared analysis showed that there were hydroxyl, carboxyl and carbonyl groups on the surface of coral sand and non-woven fabric which were beneficial for biofilm growth and wastewater treatment. The large pores in the interior of coral sand and non-woven fabric could provide a comfortable environment for microbes to grow and reproduce. The dehydrogenase activity of the biofilm on the surface of coral sand in the third biofilm reactor was 49.91 μgTF·g−1·h−1, which was significantly higher than that of the other two biofilm reactors. The new type of combined packing is suitable for biofilm carriers with low cost, which can be applied to actual sewage treatment projects. This study provides a reference for the practical application of the technique. [ABSTRACT FROM AUTHOR]

Three brown algal biomasses namely, Sargassum latifolium, Padina pavonica and Dictyota dichotoma were used in the uranium biosorption from the processing effluent of Gattar pilot plant project, Eastern Desert, Egypt. Biosorption enhancement process was studied, and the uranium loading capacities were optimised at 1 h contact time, 1/1000 solid/liquid ratio, 200 ppm uranium as initial feed concentration, pH 4 and all experiments were at room temperature. The maximum capacities reached 190, 177 and 170 mg/g for Sargassum latifolium, Padina pavonica and Dictyota dichotoma, respectively. SEM examination for the three concerned algae showed different morphological and surface structural changes such as shrinking and appearance of large cavities. FTIR study revealed that, there are many functional groups contributed in uranium biosorption mechanism such as carboxylic, sulphonate, hydroxyl and amine groups. The obtained experimental data for the three concerned algal biomasses were comparable with pseudo-second-order model and best described by Langmuir isotherm model. 0.1 N HCl was used for desorption of the loaded uranium on the three algal masses. By applying the most effective alga (Sargassum latifolium) with fixing the optimum concluded conditions in the treatment of Gattar pilot plant effluent, it was clear that almost all elements and nearly uranium complete concentrations were recovered from the waste water and the water can be safely reused again. The present work concluded that the phyco-sorption is a sufficient, low costing, eco-friendly way for the recovery of variable elements and purification of waste water solutions. [ABSTRACT FROM AUTHOR]

The United States Environmental Protection Agency (EPA) classified the phenylurea herbicide Diuron (C9H10Cl2N2O) as possibly carcinogenic to humans. This research is focused on the adsorbent performances of a Algerian sodium Montmorillonite (Mont-Na), for the removal of Diuron in aqueous solutions. The material is characterised before and after processing using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), specific surface area (SBET) and thermal analysis (TGA/DTA). The tests were firstly realised at 25°C and pH = 6.3. Until 61 hours of experiment, no removal was obtained in this case. After that, the experiments were carried out on Mont-Na at high temperature and medium pH (T = 45°C, pH = 6.3) and then at ambient temperature and basic pH (T = 25°C, pH = 11). The removal was increased from 74% to 91%, respectively. The equilibrium is reached after 5 hours and the adsorption capacity is between 0.74 mg/g at 45°C and 0.91 mg/g at pH = 11. The kinetic modelling shows that the pseudo-first order describes the experimental data of the Diuron adsorption on Mont-Na and the equilibrium data are modelled perfectly by applying the Elovich model. The thermodynamic quantities indicate that the adsorption process on Mont-Na at pH = 6.3 is spontaneous (ΔG < 0) and endothermic (ΔH = 31.80 kJ.mol−1). In conclusion, under the operating conditions used, local Mont-Na proved to be an excellent material for the adsorption of Diuron in aqueous solutions. That could be very promising for sewage treatment. [ABSTRACT FROM AUTHOR]

Relative efficacy of five common weeds—of the kind that are either rooted in soil or which freely float over water—was assessed in rapid, effective and sustainable treatment of sewage at pilot plant scale in the recently developed and patented SHEFROL® bioreactors. The plants were utilized in a unit of capacity 12,000 liters/day (LPD) which, after two years of use, was enlarged to handle 40,000 LPD of sewage. It was then further expanded after an year to treat 57,000 LPD. All the five weeds, of which none has previously been tested in a pilot-scale SHEFROL, were able to foster highly efficient primary treatment (in terms of suspended and total solids) and secondary treatment (in terms of BOD and COD) to levels exceeding 85% in most cases. Additionally, the weeds also helped in achieving significant tertiary treatment. At different hydraulic retention times, and at steady state, the five weeds achieved treatment of BOD, COD, suspended solids, nitrogen, phosphorous, copper, nickel, zinc, and manganese in the ranges, 80–95, 79–91, 82–95, 61–71, 51–73, 37–43, 30–38, 39–47, and 27–35%, respectively. It all occurred in a single process step and without the use of any machine or chemical. This made the system not only simple and inexpensive to install but also to maintain. Over continuous long-term operation for four years, the system was seen to be very robust as it was able to handle wide variations in the volumes and characteristics of sewage, as well as absorb shock loads without compromising the reactor performance. The sustainability of the system can be further enhanced by upgrading it to a circular biorefinery. Energy sources in the form of volatile fatty acids (VFAs) can be extracted from the weeds removed from SHEFROL and then the weeds can be converted into organic fertilizer using high-rate vermireactors recently developed by the authors. A novel and inexpensive, yet very efficient sewage treatment system is presented. The versatility and robustness of the system has been assessed at pilot plant scale for several years. The long-term continuous studies establish the efficacy of five common weeds—not hitherto explored at pilot plant level—which can serve as the main bioagent(s) in the sewage treatment system. The system has the potential of being transformed in to a closed-loop-no-waste biorefinery [ABSTRACT FROM AUTHOR]

Phosphorus (P) is an indispensable nutrient for agriculture. Recovery and recycling of phosphorus from waste streams is necessary to ensure a circular P economy and reduce dependence on disproportionately distributed mineral P resources. In this study, a new process called 'PULSE' is presented for the recovery of P from sewage sludge, which can handle high metal contents. The process involves drying of sludge prior to acidic leaching to overcome the challenge of solid–liquid separation at low pH and to reduce the overall material flows. Another key point of the process is the removal of metals using reactive extraction to obtain a high-quality product with good plant availability. Laboratory experiments were conducted to evaluate and select the best process options. A chemical equilibrium tool was developed to simulate the unit operations of the process for optimization. Dissolution of P from sludge depends on leaching pH and the fraction of inorganic P in the sludge. The maximum P leaching efficiency for the sludge used in the study was between 65 and 70%. Under the tested conditions, Fe, Cd, Cu, Hg, Pb, and Zn were successfully removed from the sludge leach liquor by reactive extraction. The recovered product has a nutrient mass fraction of about 51% that includes Ca, PO43-, Mg, and K. Pot trials confirmed that the agronomical efficiency of the product is comparable to that of triple superphosphate. [ABSTRACT FROM AUTHOR]

Down-flow hanging sponge (DHS) reactors, employed in domestic wastewater treatment, have demonstrated efficacy in eliminating Escherichia coli and other potentially pathogenic bacteria. The aim of this study was to elucidate the mechanism of removal of E. coli by employing a cube-shaped polyurethane sponge carrier within a compact hanging reactor. An E. coli removal experiment was conducted on this prepared sponge. Escherichia. coli level was found to decrease by more than 2 logs after passing through five nutrient-restricted DHS sponges. Conversely, a newly introduced sponge did not exhibit a comparable reduction in E. coli level. Furthermore, under conditions of optimal nutritional status, the reduction in E. coli level was limited to 0.5 logs, underscoring the crucial role of nutrient restriction in achieving effective elimination. Analysis of the sponge-associated bacterial community revealed the presence of a type VI secretion system (T6SS), a competitive mechanism observed in bacteria. This finding suggests that T6SS might play a pivotal role in contributing to the observed decline in E. coli level. [ABSTRACT FROM AUTHOR]

This paper compares water and sanitation services in municipalities that entered into a concession arrangement with a private operator versus those in a comparable control group that continued with a public operator. We explore five variables of interest: average tariff; water coverage; sewage collection; sewage treatment; and water losses. Our empirical strategy improves on existing techniques: after controlling for municipality idiosyncrasies, we adopt a difference-in-differences model with nearest-neighbor matching to evaluate private sector management impacts on these variables. We find a large drop in tariff after the concession switching to a private operator, but tariff increases are greater than public operator during the first four years. There is economical and statistical evidence of increasing sewage collection and treatment over time, but only economical evidence of improvements in water coverage; and no convincing evidence of reduction in water losses. The results suggest huge positive economic impact of switching services from public to private. [ABSTRACT FROM AUTHOR]

The emergence and persistence of antibiotic resistance genes (ARGs) in wastewater treatment plants (WWTPs) has aroused growing public concern for its risk to human health and ecological safety. Moreover, heavy metals concentrated in sewage and sludge could potentially favour co-selection of ARGs and heavy metal resistance genes (HMRGs). In this study, the profile and abundance of antibiotic and metal resistance genes in influent, sludge and effluent were characterized based on the Structured ARG Datebase (SARG) and Antibacterial Biocide and Metal Resistance Gene Datebase (BacMet) by metagenomic analysis. Sequences were aligning against the INTEGRALL, ISFinder, ICEberg and NCBI RefSeq databases to obtain the diversity and abundance of mobile genetic elements (MGEs, e.g.plasmid and transposon). Among them, 20 types of ARGs and 16 types of HMRG were detected in all samples, the influent metagenomes contained many more resistance genes (both ARGs and HMRGs) than the sludge and the influent sample, large reductions in the relatively abundance and diversity of ARG were achieved by biological treatment. ARGs and HMRGs cannot be completely eliminated during the oxidation ditch. A total of 32 species of the potential pathogens were detected, relative abundances of pathogens had no obvious changes. It is suggested that more specific treatments are required to limit their proliferation in the environment. This study can be helpful for further understanding the removal of antibiotic resistance genes in the sewage treatment process via metagenomic sequencing. [ABSTRACT FROM AUTHOR]

Carbamazepine (CBZ) is a common antiepileptic drug. CBZ enters the environment through unreasonable and standardized ways such as human and animal metabolites, discarded drugs, and more than half of its metabolites are released into the environment. Since CBZ is not easy to be degraded, continuous input of CBZ into the water environment will cause long-term impact on the water ecological environment and seriously endanger human health. Aiming at how to degrade wastewater containing carbamazepine, studies were conducted on the degradation of carbamazepine by ultrasound/zero-valent iron/persulfate system (US/ ${\rm F}{\rm e}^0$ F e 0 /PS). Firstly, the removal effects of carbamazepine by different systems, such as ultrasound/sodium persulfate (US/PS), zero-valent iron/persulfate system (${\rm F}{\rm e}^0$ F e 0 /PS) and US/ ${\rm F}{\rm e}^0$ F e 0 /PS, were compared; Secondly, the influence of factors, such as ultrasonic power, sodium persulfate dosage, zero-valent iron dosage, reaction temperature, pH, etc., on the reaction was investigated by the control variables method. Results show that ultrasound power, PS concentration, pH and temperature have a great influence on the removal of carbamazepine in US/Fe0/PS reaction system. Besides, the optimum parameters for degradation of carbamazepine with US/ ${\rm F}{\rm e}^0$ F e 0 /PS reaction system were determined ([CBZ]0 = 0.025 mM; [PS]0 = 0.4 mM; Fe0 = 4.0 mg/L; ultrasonic power = 40 W; T = 30 ℃; initial pH = 5.0). Finally, the intermediates and degradation pathways of carbamazepine by US/ ${\rm F}{\rm e}^0$ F e 0 /PS system were analyzed and speculated. It was inferred that two intermediates were generated during the degradation of carbamazepine, mainly through the ring opening and decyclization of piperazine rings. It was proved that process US/ ${\rm F}{\rm e}^0$ F e 0 /PS has a very important application value in the degradation of antibiotic-containing wastewater. [ABSTRACT FROM AUTHOR]

The costs associated with microalgal biomass production can be reduced by leveraging alternative and cheap growth media. Digestate from fermentation reactors is a particularly interesting candidate for use in cultivating mixotrophic species. The aim of the present study was to assess whether pre-digested milk-industry effluent can be harnessed to grow Tetraselmis subcordiformis and produce hydrogen. The experimental series with 25% and 50% effluent in the growth medium performed the best, producing more than 2000 mgVS biomass/dm3. The biogas produced in these variants contained over 60% hydrogen. Increasing the effluent in the medium to 75% led to significant deterioration of performance, both in terms of T. subcordiformis biomass growth and biohydrogen production. The highest efficiency of nitrogen and phosphorus removal, respectively 98.1 ± 1.9% and 97.1 ± 1.4%, was observed in the system to which 25% of sewage was introduced. Increasing the share of fermented wastewater directly reduced the efficiency of removing biogenic compounds. A very strong negative correlation was found between initial N-NH4 in the growth medium and T. subcordiformis biomass production rates (R2 = 0.9177). [ABSTRACT FROM AUTHOR]

With the continuous development of society, the demand for treating oily wastewater in oil fields to achieve resource recovery and reuse is becoming increasingly urgent. Membrane materials have become one of the most promising materials for treating oily wastewater due to their high separation efficiency and low energy consumption.Graphene and its derivatives have the characteristics of ultra-high water flux, special physical, chemical properties, adjustable layered structure, gradually becoming a new generation of membrane materials that can be used for sewage treatment. The interlayer transport channels of graphene oxide (GO) membranes can be artificially modified and regulated to achieve separation of oil-water emulsions. This article adopts the method of vacuum filtration to prepare a series of GO membranes. The experimental procedure is concise, with mild reaction conditions and simple operations. The ethylenediamine-modified graphene oxide (EGO) membrane exhibits the highest water flux (879.2 L/m2 h), which is 1.5 times that of the original GO membrane. Moreover, the EGO membrane demonstrates remarkable oil-water separation capabilities, achieving separation efficiencies of over 90% for coal oil-in-water emulsions, petroleum etherin-water emulsions, and lubricating oil-in-water emulsions. The separation efficiency for soybean oil-in-water emulsions is also around 80%. This study will provide new ideas for the treatment of oily wastewater. [ABSTRACT FROM AUTHOR]

Since 24 February 2022, the Russian-Ukrainian war has impacted Ukrainian water resources including river pollution. In this perspective paper, our proposition is that the Russian-Ukrainian war causes likely more river pollution with untreated urban waste compared to the pre-war period. In order to check this assumption, we synthesize the current knowledge with a focus on the Dnipro Basin, containing 80% of the national water resources. Our synthesis reveals three main arguments. First, water-related infrastructures that were damaged as a result of the Russian-Ukrainian war are the important causes of pollutant release to water systems. These infrastructure damages are estimated, on average, for rural (30% of irrigation systems) and urban (35–40% of treatment plants and sewage connections) areas or both (40–90% of bridges and dams). Second, water pollution sources tend to change towards direct inputs of untreated urban waste with multiple pollutants compared to the pre-war period. Third, our illustrative example for nutrients, a painkiller, an antibacterial agent, and microplastics from urban waste showed an increase of 2–34% in their loadings into the Dnipro River due to damaged sewage pipes and wastewater treatment plants in 2022. In addition, 20–62% of those pollutants are from untreated urban waste (point sources). We propose a framework for future steps including visualizing (V) and integrating (I) the impacts into tools for quantification as well as translating (T) those quantified insights into actionable strategies and assessing (A) their feasibilities for pollution reduction. The Russian-Ukrainian war damaged 30–90% of water infrastructures in the Dnipro Basin River pollution sources tend to change towards untreated urban waste compared to the pre-war period River pollution is estimated to increase by 2–34% in the Dnipro Basin due to damaged sewage and treatment Untreated urban waste is responsible for 20–62% of pollutants in rivers of the Dnipro Basin The VITA framework is proposed for actionable pollution reduction strategies [ABSTRACT FROM AUTHOR]

The study aimed to assess the impacts on four township areas under Emfuleni Local Municipality of poor water quality from inadequate wastewater management. The failure of the municipality to upgrade and maintain the wastewater treatment facilities has been ongoing for many years and raw sewage spills have been observed on the streets. The objectives of the study were addressed through questionnaires directed at obtaining feedback from household and small business participants. In total, 260 respondents participated, and the results showed differences in the perceptions of impacts due to poor water quality per area of residence; these were significant at 99% confidence interval. Results showed concerns about the impact of wastewater and poor infrastructure on the livelihoods of both residents and business owners. In conclusion, the infrastructural problems resulting in water quality issues have caused severe socio-economic strain on residents and businesses alike. [ABSTRACT FROM AUTHOR]

This research tries to fill the gap of empirical studies to demonstrate how water, both in terms of its role as a resource and disaster, is integrally related to the value of land. This study involves four water-related measures categories: source, disaster, supply, and infrastructure. The eight independent variables were tested upon Jakarta's 3,725 land value zone samples. It is found that areas with more accessibility to wastewater management infrastructure have land value of IDR 476 per square meter higher than average. In contrast, land value in areas with higher risk of being affected by a flood is IDR 470.91 per square meter lower than average. This research signifies the importance of integral policy of clean water provision as well as water-related disaster prevention in urban areas. [ABSTRACT FROM AUTHOR]

The performance of two tropical plants, Rhynchospora corymbosa L. (RC) and Coix lacryma-jobi, L (CL) in treatment of primary sewage effluent in lab-scale vertical-flow constructed wetlands (VFCW) along with no plant control wetland was investigated. A batch-flow VFCWs were operated under batch fill and drain hydraulic loading system with hydraulic retention times (HRT) of 0.5, 1, and 2 days and fill rate of 8 L/day. Removal of solids, organics, nutrients, and pathogens were monitored. The volumetric contaminant removal rates were best described by 1st order kinetics except for ammonia and phosphate, which was best described by Stover-Kincannon kinetics. Influent TSS, PO43−, COD, BOD5, and total coliform concentration were low but high in NH4+ concentration. CL was better in nutrient removal as HRT increases compared to RC. RC was more efficient at TSS, turbidity, and organics removal. Pathogen removal was independent of plant type but HRT. Solids and organic removal were lower in CL planted CWs due to preferential flow paths created by their bulky root. CL planted CWs removed more nutrients followed by RC planted CWs and then no-plant control CWs. The results of these tests demonstrate that both CL and RC are suitable for the treatment of municipal wastewater in VFCW system. [ABSTRACT FROM AUTHOR]

This study proposed an AO-SBR (Anaerobic Aerobic Sequencing Batch Reactor) combined with iron-carbon micro-electrolysis (ICME) particles system for sewage treatment at low temperature and explored the dephosphorisation mechanism and microbial community structure. The experimental results illustrated that ICME particles contributed to phosphorus removal, metabolic mechanism of poly-phosphorus accumulating organism (PAO) and microbial community structure in the AO-SBR system. The optimal treatment effect was achieved under the conditions of pH 7, DO 3.0 mg/L and particle dosage of 2.6 g Fe-C/g MLSS, and the removal rates of COD, TP, NH4+-N and TN reached 80.56%, 91.46%, 69.42% and 57.57%. The proportion of phosphorus accumulating organisms (PAOs) increased from 4.54% in the SBR system to 10.89% in the ICME-SBR system at 10°C. Additionally, the metabolic rate of PAOs was promoted, and the activities of DHA and ETS both reached the maximum value of 13.34 and 102.88 μg·mg−1VSS·h−1. These results suggest that the ICME particles could improve the performance of activated sludge under low-temperature conditions. This technology provides a new way for upgrading the performance of sewage treatment in the cold area. [ABSTRACT FROM AUTHOR]

In California, wastewater systems have adapted to water conservation and drought for decades. Yet, few studies have investigated how past design assumptions influence potential mitigation and adaptation actions. This paper evaluates adaptation pathways for wastewater management in California and addresses two questions. First, are wastewater facilities experiencing challenges from mismatches in design flow values and current rates of influent flow? Second, what, if any, adaptation actions are underway or planned? To answer these questions, we compiled historical literature and conducted surveys and interviews with wastewater system managers. Approximately half of respondents indicated that they are experiencing challenges associated with changing water use rates. Aging systems have implemented many types of mitigation and adaptation actions, including operational changes, chemical additions, and facility rebuilds. California's wastewater industry is largely pursuing an incremental adaptation pathway to manage drought and climate change. The paper demonstrates an engaged approach to research on climate change adaptation. [ABSTRACT FROM AUTHOR]

The paper describes the setting up and long-term continuous operation of the first real-life, pilot scale, sewage treatment plant based on the recently patented phytoremediation technology, trademarked as SHEFROL®. The unit was about three times cheaper to install, operate and maintain than the least expensive of the other wetland-based technologies presently in vogue. Its semi-permanent version is 30 times cheaper. Monitoring of flow rates and levels of treatment intermittently over a 3 year course of continuous operation indicated the constancy and robustness of the reactor in treating total solids, suspended solids, chemical oxygen demand, biological oxygen demand, total Kjeldahl nitrogen, and soluble phosphorous to the average extents of 94, 84, 79, 70, 62 and 28% respectively. Earlier experience with bench-scale SHEFROL® units has indicated that removal of metals like Cu, Ni, Co, Zn, and Mn also takes place to the extent of 25–45% in these systems. These primary, secondary, and tertiary treatments occurred in a single unit process with no necessity of any pumping, aeration, or recycling. Models based on artificial intelligence were developed which enable forecasting the reactor performance in terms of secondary and tertiary treatment, respectively. The paper describes the setting-up, long-term (3 years) performance evaluation at pilot scale, and modeling of a recently patented novel and unprecedented phytoremediation-based sewage treatment technology. The system is seen to be much more robust, versatile, space efficient, and economical, than existing macrophyte-based sewage treatment systems. [ABSTRACT FROM AUTHOR]

Sphaeropleales is an order of fast-growing microalgae with high oil content and high efficiency in sewage treatment, in which photosynthesis plays a critical role. We isolated a strain of Sphaeropleales, Chlorolobion braunii ITBB-AG6 from an azolla community in a sewage pond, and sequenced its chloroplast genome. The complete genome has a length of 154 kb with a GC content of 31.7%. A total of 89 genes were annotated, including 56 protein-coding genes, 30 tRNA genes, and three rRNA genes. Out of the protein coding genes, 64.3% are involved in photosynthesis, 28.6% are involved in protein synthesis, and 7.1% are involved in ATP synthesis. Transfer RNA genes for 20 amino acids were identified, in which tRNA genes for methionine, leucine, and arginine are tripled, whereas tRNA genes for glutamic acid, glycine, serine, and threonine are doubled. Terminal inverted repeats of 27.9 kb containing 10 genes related to photosynthesis and chloroplast division are present in the genome, suggesting that photosynthesis was strengthened in the evolutionary history. Phylogenetic analysis indicates that C. braunii ITBB-AG6 falls in the family Selenastraceae and is most closely related to Monoraphidium neglectum. [ABSTRACT FROM AUTHOR]

Unplanned, high-density settlements in low-middle income countries often lack functional wastewater management systems. Nature-based solutions, such as constructed wetlands, are an option for the treatment of greywater, provided they are used by and useful to the community. We explored the effectiveness of iterative design for two pilot constructed wetlands in an informal settlement in Johannesburg, South Africa. Using ergonomics and human factors (E/HF) design approaches, this study evaluated the usability and postural risks associated with interactions with the constructed wetlands to motivate (and evaluate) design changes to increase use and reduce the risk of musculoskeletal pain. An elevated work area reduced musculoskeletal risks and a larger work area allowed more users at one time. The raised work areas provided other benefits such as stormwater and sewerage protection. The value of E/HF as part of a broader transdisciplinary team was demonstrated by embedding the design in the activities of the community. [ABSTRACT FROM AUTHOR]

Phosphorus recovery from sewage sludge as secondary raw materials or as a direct P-rich fertiliser is one of the top frontrunner solutions to tackle Phosphorus (P) scarcity and depletion. However, the efficiency of this P recovery process greatly depends on its phosphorus dissolution potential, which in return relies on the phosphorus speciation in the sewage sludge. This article investigates the potential correlation between P speciation in sewage sludge and the iron-based P removal technologies used in sewage treatment plants (STP) through an innovative sequential extraction method based on the SEDEX method that distinguishes quantitatively between ferrous bound phosphate and ferric bound phosphate. XRD and SEM-EDX were also used to characterise P and Fe species in the studied sludge qualitatively. Principal component analysis showed that the sludge characterised by P bound to ferric iron (as the dominant P fraction) are mostly correlated with sludge produced from the CPR process (chemical phosphorus removal) and primary sludge. Moreover, sludge with a non-negligible amount of P bound to ferrous iron were correlated with sludge from the mixed EBPR-CPR process (Enhanced Biological P Removal assisted with CPR). However, Vivianite was only found in CPR sludge with Fe/P molar ratio higher than 0.6. [ABSTRACT FROM AUTHOR]

Granular sludge processes are frequently used in domestic and industrial wastewater treatment. The granule buoyant density and biomass density are important parameters for the design and operation of granular sludge reactors. Different methods to measure the granule density include the pycnometer method, the Percoll density gradient method, the dextran blue method, and the settling velocity method. In this study, a comparison was made between these four methods to measure granule density for granules from a full-scale granular sludge plant treating domestic sewage. The effect of salinity on granule density was assessed as well. Three out of the four evaluated methods yielded comparable results, with granule buoyant densities between 1025.7 and 1028.1 kg/m3 and granule biomass densities between 71.1 and 71.5 g/L (based on volatile suspended solids (VSS)). The settling velocity method clearly underestimated the granule density, due to the complex relation between granule properties and settling velocity. The pycnometer method was the most precise method, but it was also quite susceptible to bias. The granule buoyant density increased proportionally with salinity, to 1049.2 kg/m3 at 36 g/L salinity. However, the granule biomass density, based on VSS, remained constant. This showed that the granule volume was not affected by salinity and that the buoyant density increase was the result of diffusion of salts into the granule pores. Overall, the granule density can be measured reliably with most methods, as long as the effect of salinity is considered. The results are discussed in light of operational aspects for full-scale granular sludge plants. [ABSTRACT FROM AUTHOR]

In this study, treatment performance was investigated based on chemical oxygen demand (COD), ammonium nitrogen (NH4+-N), total inorganic nitrogen (TIN) and simultaneous nitrification and denitrification (SND) parameters in a zeolite-added anoxic/aerobic sequencing batch reactor. Response surface methodology (RSM) was used to model treatment performance, determine the impact of operating conditions, and optimize them. The effect of zeolite size, dosage and COD/NH4+-N (C/N) ratio as operating parameters were evaluated in the central composite design (CCD). Variance analysis (ANOVA) results of the quadratic model, high coefficients of determination and low values of the root mean square error (RMSE) for dependent variables indicated the validity of the model in predicting experimental results. The desirability function showed that optimum conditions were 0.80mm for zeolite size, 3.05 g/L for zeolite dosage and 9.8 for C/N. Under these conditions, the maximum COD, NH4+-N, TIN removal efficiencies and SND efficiency were 92.85%, 93.3%, 77.33% and 82.96%, respectively. The results of the study showed that the most effective independent variable on dependent variables was the C/N ratio. [ABSTRACT FROM AUTHOR]

The main hindrance to implementation of domestic sewage treatment plant-network integration in China is the separated assessment method. The assessment method of plant-network integration links payment for sewage treatment to incoming pollutants, and payment for maintenance of the pipe network to the concentration of pollutants in incoming water. It helps establish an interactive link between the city and district, and motivates operation and management stakeholder groups. The method contains index system formulation, target value determination, assessment payment plan specification and city-district payment proportion clarification. It provides a solution for the current drainage management by promoting plant-network integration. [ABSTRACT FROM AUTHOR]

Oily wastewater is produced from many processes in petrochemical, food, pharmaceutical, mining, and metal industries. Proper management of oily wastewater discharges is required to mitigate their environmental impacts. Basalt fabric has been reported as being uniquely suitable for oily wastewater purification via solar evaporation due to its robust structure and surface chemistry. In this study, an efficient, low-cost, and scalable 3D photothermal evaporator was prepared by surface modification of basalt fabric with TiO2 nanoparticles for oily wastewater treatment and solar steam generation. The basalt membrane was coated with two types of TiO2 (Degussa P25 and nitrogen-doped TiO2) to enhance its hydrophilicity and photocatalytic properties important for fouling control. The basalt membranes were then tested for their impacts on water evaporation under various salinities and concentrations of gasoline constituents and crude oil. In pure water, the modified membrane system achieved an evaporation rate of 1.65 kg‧m−2‧h−1 under 1 sun irradiation, which is higher than the theoretical value of 1.47 kg‧m−2‧h−1 due to the 3D nature of the structure capable of harvesting energy from the environment. Crude oil significantly decreased the evaporation rate of the unmodified basalt membrane. However, the coating of TiO2 nanoparticles was found to ameliorate the fouling effect by increasing the membrane evaporation efficiency from 0.75 kg‧m−2‧h−1 to 1.42 kg‧m−2‧h−1 in a 2.0 g/L oily water composition. This technology is promising as a new approach to manage oily wastewater storage tanks and evaporation ponds in industry in addition to improving the efficiency of resource recovery. [ABSTRACT FROM AUTHOR]

The influent and effluent data from wastewater treatment plants being highly correlated with multi-variable coupling and time-varying features may degrade the performance of conventional soft sensors over time. Adaptive strategies based on just-in-time learning (JIT), moving windows (MW), and time difference (TD) are used in this work to develop an adaptive soft sensor. Multi-output Gaussian-process regression (MGPR) is selected and hybrid methods such as TD JIT, MW TD, and JIT MW TD along with TD and MGPR methods are implemented. Data from the benchmark simulation model No.1, closed-loop architecture after applying PI controller, and real-time data from the Rithala Plant of Delhi are obtained. The improved error percentage is 15.03% for total phosphorus (open-loop) using the JIT TD method when compared with the MW TD method. Fair results are observed with JIT TD on real time data with a strong correlation between predicted and observed values, above 0.8 for any variable being estimated. [ABSTRACT FROM AUTHOR]

Spatial-temporal monitoring of the presence of pesticides and pharmaceuticals in water requires rigor in the choice of matrix to be analyzed. The use of matrices, isolated or combined, may better represent the real state of contamination. In this sense, the present work contrasted the effectiveness of using epilithic biofilms with active water sampling and with a passive sampler—POCIS. A watershed representative of South American agriculture was monitored. Nine sites with different rural anthropic pressures (natural forest, intensive use of pesticides, and animal waste), and urban areas without sewage treatment, were monitored. Water and epilithic biofilms were collected during periods of intensive pesticide and animal waste application. After the harvest of the spring/summer crop, a period of low agrochemical input, the presence of pesticides and pharmaceuticals was monitored using the POCIS and epilithic biofilms. The spot water sampling leads to underestimation of the level of contamination of water resources as it does not allow discrimination of different anthropic pressures in rural areas. The use of endogenous epilithic biofilms as a matrix for the analysis of pesticides and pharmaceuticals is a viable and highly recommended alternative to diagnose the health of water sources, especially if associated with the use of POCIS. [ABSTRACT FROM AUTHOR]

Derbendikhan reservoir is located on the southeast of Sulaimani city 35° 6' 35" N, 45° 41' 20" E, it is the second largest reservoir in the Iraqi Kurdistan region at an altitude of 485 m above sea level. It was formed when the dam was constructed in1956–1961. The area is about 114.30 km2 with the maximum depth of 75.0 m. Silurus triostegus is one of twenty genera of fish that are endemic to Derbendikhan reservoir, Seasonal sampling for 64 samples of fish for 11 sites was carried out from November 2018 to August 2019, Fishing was performed with gill nets of 18, 25, 33, 40, and 55 mm inner mesh sizes. The goal of this research is to determine the level of PAHs in, fish muscle of Silurus triostegus, because fish as an important food source for man and it's the primary indicator of the toxification of streams and lakes, on the other hand, PAH will cause many health problems including cancer, in addition, this information may be used as a database for any environmental modeling in the future, this study was carried out. Results indicate increasing in PAH in the spring season, although, as a result of fishing activities using old boats and ships at a high rate, in addition to the changes of water temperature in different season. PAH in the muscle of fish (0.098–1.271 μg/g) were above the WHO maximum permissible limit of 0.001 μg/g. The main conclusion is that the fish muscle contains high amounts of PAHs through bioaccumulation and biomagnifications. Finally, the lake needs immediate attention to reduce improper waste disposal and improve on measures against indiscriminate dumping of petroleum products and domestic waste in the water, which are the major sources of petrogenic and pyrogenic PAHs should be minimized, and the treatment of the sewage before its discharge into the reservoir. [ABSTRACT FROM AUTHOR]

Uncontrolled wastewater discharges have social and environmental consequences and generate increased operational costs. Wastewater treatment plants (WWTPs) are vulnerable infrastructure and require the implementation of risk and safety analyses in the context of climate change and flooding. Therefore, making decisions in changing weather conditions is one of the most important but also most difficult tasks for operators to maintain proper management of wastewater infrastructure facilities. The aim of the research was to develop a decision-making tool based on soft sensor methods to allow inflows to be classified into two classes of WTTP operating conditions. The quality of the regression models was maintained at 90.0%, while the classifier based on the coarse decision tree had a testing accuracy of 92.4%. The results can contribute to a reduction in wastewater load, which is significant in the context of ongoing climate change, and to an improvement in WWTP operation through automation. [ABSTRACT FROM AUTHOR]

Long-term changes in municipal wastewater production may disrupt wastewater reuse plans. However, no model/method has been developed to quantify the risks of climate change impacts on changes in wastewater production under relevant uncertainties. Accordingly, this research proposed a hybrid algorithm to analyze these risks under greenhouse gas concentration scenarios. This algorithm included a fuzzy risk assessment model based on six risk components and a framework for quantification of these components, which increased the relative confidence of decision-makers about risk values by 10%. The results showed that 'considering' and 'ignoring' the adaptive capacity to climate change under Representative Concentration Pathway scenarios in the risk analysis process lead to two completely different interpretations of risk. The risk difference based on these two approaches for Tehran was 50%, which was due to the occurrence of 11%–22% of untreated excess wastewater beyond capacity of wastewater reuse system under the temperature increase of 1.29°C. [ABSTRACT FROM AUTHOR]

In this study, the performance of polyethersulfone (PES) membranes, fabricated by modifying the iron nano-particles (M-Fe3O4), was investigated to remove heavy metals (HM) and Direct red 16 (DR16) dye from water. In this new research work, amine groups were first fixed on nano-particles by modifying iron nano-particles using TEOS and APTES methods. In the next step, M-Fe3O4 was used in the structure of membranes, and their effect on surface properties, hydrophilicity (HD), pure water (PW) flux, roughness (Ra), water permeability and removal rate of copper ion (CI) and DR16 dye were investigated. Also, characterization methods such as X-ray powder diffraction (XRD), scanning force microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), and antifouling properties have been used to evaluate the synthetic membranes. Thus, the performance of composite membranes showed that the pure water (PW) flux of the membrane M-Fe3O4 increased 1.9 times compared to the pure membrane. Moreover, the anti-fouling tests showed that the mixed matrix membranes (MMM) with 0.1 wt% of M-Fe3O4 showed the best anti-fouling properties with a 90% recovery rate and 55.98% fouling resistance. On the other hand, results showed that 0.1 wt% composite membrane resulted in the removal of CIs 92% and dye 99%. [ABSTRACT FROM AUTHOR]

Municipal sludge is the main by-product in the process of sewage treatment, and the primary problem to be solved for its harmless disposal or energy utilization is its poor dehydration property. In this paper, biological conditioning technology was used to ferment municipal sludge with methanogens under different carbon to nitrogen ratios (C/N) through an anaerobic fermentation system. The mechanism of improving sludge dewatering performance under fermentation and the effect of C/N of sludge on its dehydration property were investigated. The results showed that the flocculent structure of the sludge was destroyed by the fermentation of methanogens, the sludge's inherent moisture was released, and the dehydration property was promoted. With the change of C/N from 8 to 20, the hydrophilic oxygen-containing functional group content of the sludge decreased first and then increased. When C/N was 16, the content of hydrophilic oxygen-containing functional groups diminished to the lowest level. Meanwhile, the surface of the sludge showed dense microscopic cavities and small holes, indicating that the sludge flocs had been cracked to a large extent, and thus the ability of the sludge to bind water was weakened. The bound water content of the fermented sludge from low to high was 48.9, 59.0, 64.3, and 71.7% respectively, with C/N of 16, 12, 20, and 8. Therefore, within the scope of this experiment, the optimal C/N for the sludge dehydration property could be identified as around 16, which could reduce the bound water content of the sludge from 87% to 48.9%. [ABSTRACT FROM AUTHOR]

The present study aimed to determine linear alkylbenzenes (LABs) concentrations as organic molecular marker for sewage pollution in the sediment samples collected from Coast of Port Dickson and Kim Kim River, Peninsular Malaysia. The adverse effects of anthropogenic inputs into the rivers and coastal environment could be detected by molecular organic markers such as LABs. The sediments were processed; their sources were identified and tested by gas chromatography-mass spectrometry (GC-MS). The significance of the differences among sampling stations for LAB concentrations and distribution at p < 0.05 was performed by analysis of variance and Post Hoc Tests, LSD procedures (ANOVA) and Pearson correlation coefficient. LABs indices which include internal to external (I/E) congeners, long to short chains L/S and homologs C13/C12 were used to identify the sewage treatment and degradation levels. Results of this study are statistically uncovered that the range of ΣLABs concentration in the investigated locations was between 112.0; 88.3 and 256.0; 119.0 ng·g−1 dw, respectively. There was significant difference (p < 0.05) of LAB homologs with high percentage of C13-LAB homologs along sampling locations. The calculated LAB ratios (I/E) were within the range between 2.0; 1.7 and 4.1, 2.0, demonstrated that, the treated effluents from primary and secondary sources were discharged to the study areas. The degradation of LABs was 40–64% and 34–38% in the studied locations. The findings of this study suggested the powerfully indicators of LABs in tracing anthropogenic sewage contamination and the necessity of continuing wastewater treatment system improvement. [ABSTRACT FROM AUTHOR]

Anaerobic ponds have the potential to contribute to low carbon wastewater treatment, however are currently restricted by long hydraulic residence time (HRT) which leads to large land requirements. A two-stage anaerobic pond (SAP) design was trialled against a single-stage control (CAP) over four HRTs down to 0.5 days, to determine the lowest HRT at which the ponds could operate effectively. No statistical differences were observed in particulate removal between the ponds over all four HRTs, suggesting solids loading is not a critical factor in AP design. Significantly higher biogas production rates were observed in the SAP than the CAP at 1.5 d and 1.0 d HRT, and microbial community profiling suggests the two-stage design may be facilitating spatial separation of the anaerobic digestion process along reactor length. Hydrogenotrophic methanogensis dominated over aceticlastic, with acetate oxidisation a likely degradation pathway. Experimental tracer studies were compared to CFD simulations, with the SAP showing greater hydraulic efficiency, and differences more pronounced at shorter HRTs. Greater flow recirculation between baffles was observed in CFD velocity profiles, demonstrating baffles can dissipate preferential flow patterns and increase effective pond volume, especially at high flow rates. The study demonstrates the potential of APs to be operated at shorter HRTs in psychrophilic conditions, presenting an opportunity for use as pre-treatments (in place of septic tanks) and primary treatment for full wastewater flows. Two-stage designs should be investigated to separate the stages of the anaerobic digestion process by creating preferential conditions along the pond length. [ABSTRACT FROM AUTHOR]

This paper explores how spatial judgments impacted planning and policy-making by studying how stakeholders on Cape Cod, Massachusetts considered cross-scale relationships between local, regional, and state jurisdictions and hydro-geologically defined watersheds. Analysis of video data from participatory planning workshops illustrates how these judgments were made as stakeholders developed a regional wastewater management plan. Detailed analysis of their deliberations illustrates the complex and dynamic nature of their scalar judgements as they addressed mismatches between watersheds and towns. Findings illustrate how their judgments were part of the process that led to the development of innovative policy tools for collective action that embraced, rather than erased, mismatches. This paper also demonstrates the application of spatial judgments of non-expert stakeholders as they made plans and proposed actions for a complex social-ecological system. [ABSTRACT FROM AUTHOR]

Conventional activated sludge (AS) systems are widely used to treat domestic sewage worldwide. However, the removal of nitrogen in the AS system is limited, and its concentration in the effluent exceeds the recommended values in the discharge standards. In this study, a pilot experiment was conducted to improve nitrogen removal during municipal sewage treatment by operating AS and anaerobic–aerobic (AO) systems under low dissolved oxygen (DO) conditions of less than 0.5 mg L−1 and by adding denitrifying granular sludge. The low DO operation of the AS and AO systems led to the sludge washout and increased the organic content and ammonia and nitrate concentration of the effluent. In contrast, the nitrate concentrations of the effluents produced by the AS and AO systems were 9.4 ± 3.6 and 8.4 ± 0.7 mg-N L−1, respectively, indicated that denitrifying granular sludge addition enhanced denitrification during sewage treatment. The total nitrogen (TN) removal efficiency increased by 13% and 9% for the AS and AO systems despite a decrease in the temperature of 6 °C for the water in the aeration tank. Thus, adding denitrifying granular sludge to the aeration tank is a simple and effective approach to improve organic and nitrogen removal during wastewater treatment. [ABSTRACT FROM AUTHOR]

The current environmental problems urgently require researchers to seek an environmentally friendly, effective and easy to operate sewage treatment method. Graphite carbon nitride (g-C3N4), which has the advantages of simple preparation, safety, non-toxicity and chemical resistance, was expected to become a photocatalyst for solving environmental pollution. However, the performances of g-C3N4 still have some limitations that the electron hole recombination is fast and the powder is not easy to recover. In this study, zinc-doped graphite carbon nitride photocatalyst (Zn-g-C3N4) was mixed with polyacrylonitrile (PAN) to produce photocatalyst fibres by electrospinning. It not only solves the problem that the powder catalyst is difficult to recycle, but also effectively inhibits the recombination of photoelectron-hole pairs. Zn-g-C3N4/PAN has good photocatalytic activity for the simultaneous reduction of hexavalent chromium and degradation of pharmaceuticals. When organic pollutants are present, the reduction efficiency of hexavalent chromium was improved without affecting its own removal efficiency. The potential application value of Zn-g-C3N4/PAN catalytic fibre was further explored by simulating the complex actual water environment. The composite fibre can be easily reused and keep its superior photocatalytic performance. The mechanism of pharmaceuticals degradation was proposed, in which ∙ O 2 − is the most important active species, which leads to the oxidation of pharmaceuticals. Besides, the photoelectrons generated by the catalyst can reduce the toxic hexavalent chromium. The efficiency of Zn-g-C3N4 to remove pollutants is improved by PAN fibre as a carrier, which not only solves the problem of difficult recovery of powder catalysts, but also provides more active sites. [ABSTRACT FROM AUTHOR]

Down-flow hanging sponge (DHS) reactor that is sponge-based trickling filter was considered to be an alternative aerobic treatment system for low strength sewage treatment under tropical conditions. This study aims to determine the process performance of the DHS reactor combined with a pre-treatment sedimentation tank (SED) system installed at the municipality sewage treatment plant in Khon Kaen, Thailand over, 1,600 days. The DHS reactor was operated with three operational periods: low (0.2 kgBODm3 per day), high (0.5–1.3 kgBODm3 per day), and super rates (1.7–2.2. kgBODm3 per day). The results showed effective reductions in biochemical oxygen demand (BOD) and suspended solids by more than 74% and 78%, respectively, during the entire experimental period. Moreover, the final effluent met the Thailand discharge standard with an external short hydraulic retention time of 0.2 h. In addition, the combined system facilitates simultaneous nitrification and denitrification and effectively removed up to 43% of total nitrogen. The self-degradation of the organic compounds occurs owing to the retained sludge in the DHS reactor; this leads to undisputed clogging in sponge media. Therefore, the combined SED-DHS system could be an appropriate sewage treatment system for tropical conditions. [ABSTRACT FROM AUTHOR]

This research aimed the performance evaluation of a structured bed reactor with different cycles of Intermittent Aeration (IA)(SBRRIA) in the municipal sewage treatment and the verification of the effect of IA cycles on the total nitrogen (TN) removal and organic matter (COD). Three IA cycles were evaluated: phase I (4 h AE (aeration on) – 2 h NA (aeration off)); II (2 h AE–1 h NA) and III (2 h AE–2 h NA), with Hydraulic Retention Time of 16 h. The best nitrogen removal was obtained during phase II, with the lowest non-aeration time: efficiency of nitrification, denitrification, TN and COD removal of 80 ± 15%, 82 ± 12%, 67 ± 6% and 94 ± 7%, respectively. The mean cell residence time was 19, 26 and 33 d in phases I, II and III, respectively. The statistical analysis applied to the AE/NA profiles showed that the time of AE and NA in the cycles did not influence nitrogen and organic matter removal. Thus, this indicates the recirculation and the gradient formed in the support material facilitate the process of Simultaneous Nitrification and Denitrification. The lowest concentration of nitrifying and denitrifying microorganisms was obtained in effluent and sludge at the end of phase III. From the TP (Total Proteins)/TPS (Total Polysaccharides) ratio obtained (0.8 ± 0.1, 1.3 ± 0.1 e 1.5 ± 0.1 in phases I, II and III), it was possible to conclude that the biofilm in phase I was more porous, with a thin layer if compared to that in phase II and III. [ABSTRACT FROM AUTHOR]

The present study was conducted to assess the strain aptness, phycoremediation potential and lipid yield in microalgae Chloroccocum humicola and Oscillatoria sp. Results revealed that microalgae treated with different concentration of wastewater (25%, 50%, 75% and 100%) recovered nutrients (Nitrogen: 50.55–85.90%, Phosphorus: 69.98–93.72%) and removed heavy metals (24.17–88.10%) from wastewater. Microalgae C. humicola showed significant reduction in physico-chemical parameters of wastewater at 25% and 50% respectively with considerable increase in lipid production (1.61 folds) at 50% wastewater concentration. In order to counterbalance the wastewater induced toxicity, both microalgae exhibited stimulated antioxidants viz., proline (1.26–4.04 folds), ascorbic acid (1.01–9.21 folds), cysteine (1.44–4.92 folds), catalase (0.99–3.63 folds), superoxide dismutase (1.15–1.43 folds) and glutathione reductase (1.43–6.67 folds) at different wastewater concentrations. Further, Fourier transforms infrared spectroscopy spectral elucidation of Chloroccocum humicola at 50% reflected high lipid peak in the regions 3000–2800 cm−1 as compared to Oscillatoria sp. Thus, growth characteristics, biochemical responses and lipid yield presented the suitability of the Chloroccocum humicola to be used in phycoremedation, resource recovery as well as lipid production, which may be further utilized as potent feedstock for third generation energy demand. [ABSTRACT FROM AUTHOR]

Constructed wetlands (CWs) have great potential as low-cost natural wastewater treatment in developing countries. The present study appraises the performance of the vertical flow constructed wetland for domestic wastewater treatment. More specifically, the potential of Canna Indica in the removal of carbon, nitrogen, and phosphorus (CNP) from wastewater under tropical conditions. CW cell was fabricated with a vegetative layer of Canna Indica and tested with domestic wastewater. Based on the test results, Canna Indica shows a high Removal Efficiency (RE) of Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD5) on the order of 87% and 91%, respectively. Similarly, nutrients removal efficiency for total nitrogen (TN), total phosphorus (TP) was found to be 97% and 98%, respectively. The investigation also revealed that there is considerable removal of sulfates with efficiency equal to 78.4%. Overall, the Canna Indica based CWs were found to be suitable for wastewater treatment in the tropical regions, provided a viable medium for treating the wastewater in peri-urban and rural areas of developing countries. This study investigates the performance of Canna indica based vertical flow wetlands for greywater treatment. The study investigates the results at different hydraulic retention times and loading rates. There are no much studies reporting the performance of this variety of plant species under a tropical humid climate. The results from the study can encourage adoption of this plant variety, indigenous to this part of the country, for wastewater treatment It could emphasize the importance of familiarity with constructed wetlands to comprehend the RE of various climatic zones. It is possible to highlight the Canna-based CW's efficiency in removing organics and nutrients from domestic wastewater. The possibility for field-scale Canna-based CW to remove pollution in tropical climates was investigated, and Decentralization of wastewater treatment at the household level to apply CWs that will improve wastewater quality. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate long-term phosphorus (P) retention in a pilot-scale system made of four horizontal subsurface flow (HSSF) constructed wetlands for wastewater treatment. Each wetland had an area of 4.5 m2 and was operated for nearly 8 years (2833 days). Two wetlands with Schoenoplectus californicus (HSSF-Sch) and the other two with Phragmites australis (HSSF-Phr) were planted. The P removal efficiency was 18% for both types of HSSF wetlands. The primary factors that correlated with long-term P retention efficiency in HSSF were phosphorus loading rate (PLR), hydraulic loading rate (HLR) and dissolved oxygen (DO). Average biomass production of HSSF-Phr and HSSF-Sch was 4.8 and 12.1 kg dry weight (DW)/m2, respectively. The P uptake by the plant increased over the years of operation from 1.8 gP/m2 to 7.1 gP/m2 for Phragmites and from 3.2 to 7.4 gP/m2 for Schoenoplectus over the same periods. Moreover, the warm season (S/Sm) was more efficient reaching 14% P uptake than the cold season (F/W) with 9%. These results suggest that both plants' P retention capacity in HSSF systems represents a sustainable treatment in the long term. Novelty statement Long-term (8 years) phosphorus uptake by Schoenoplectus californicus and Phragmites australis and retention in pilot-scale constructed wetlands are evaluated. Schoenoplectus californicus is an uncommon species that has been less studied for phosphorus uptake compared to Phragmites australis, a globally known species in constructed wetlands. Moreover, some studies evaluating the performance of constructed wetland systems for domestic wastewater treatment are usually limited in time (1–3 years). Therefore, this long-term study demonstrates that the plant plays an important role in phosphorus retention, especially the species Schoenoplectus californicus. So, the phosphorus uptake by plants can contribute between 9 and 14% of the phosphorus load of constructed wetland systems in early years of operation. [ABSTRACT FROM AUTHOR]

Although highway runoff has historically been extensively studied, the increasing complexity of stormwater management means that there are still significant gaps regarding the reduction of soluble metals. The work reported in this paper addresses these challenges by analysing the presence and behaviour of iron, copper and zinc in runoff from junction 24 of the M1 motorway in the UK (peak traffic flow: 30,000 vehicles per hour) and comparing it with other urban sources of metals found in the same catchment (a local brook and sewage treatment works). The sampling site included an interceptor and a treatment lagoon and the event monitoring indicated a trend by which the metals did not change their concentration or particulate soluble proportion immediately, hence showing that pre- and post-storm conditions are important factors when analysing the solubility of metals and their behaviour. The data provided further evidence of the important influence of storm characteristics on metal concentrations in highway runoff, in particular the effects of an antecedent dry weather period (ADWP). In addition, this study also helped us to better understand how the release of sodium the application of de-icer for road maintenance in winter affects the availability of zinc. [ABSTRACT FROM AUTHOR]