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This study explores the potential of food waste-recycling wastewater (FRW) for biogas production, emphasizing oil–water separation before anaerobic digestion. Three FRW samples were analyzed: non-treated (FRW), water–oil separated (FRW_sep), and mixed with domestic sewage (FRW_mix). Physicochemical characterization showed a 26% reduction in crude lipid content after oil–water separation. The biochemical methane potential (BMP) tests revealed similar methane yields for FRW_sep and FRW_mix compared to non-treated FRW. Microbial analysis identified Firmicutes and Methanoculleus as active populations. Energy balance suggests that combining biodiesel and biogas production can enhance net energy recovery. This research indicates that oil–water separation in FRW treatment can optimize anaerobic digestion, contributing to sustainable waste management and renewable energy generation. [ABSTRACT FROM AUTHOR]

Background and Objective: A high concentration of Hydrogen Sulfide in biogas is a major problem associated with anaerobic digestion of waste rich in sulfate. It disrupts the functional process and reduces the lifespan of biogas facilities. The micro-aerobic (MA) process is an alternative method for direct sulfurization. Materials and Methods: The effect of sulfate loading (200, 500 and 700 mg/L) on H2S in biogas were investigated. Subsequently, the effect of MA process (0.88, 1.04, 1.34 NL/day) on H2S reduction in biogas production was evaluated. Additionally, oxidationreduction potential (ORP) and pH were measured. Finally, under optimal conditions, the biogas volume and the content of CH4 and CO2 in biogas were determined. Results: The results indicated that there were no significant differences in biogas volume production between the reactor fed with 200 mg/L sulfate and the control. However, the biogas production in reactors with 500 and 700 mg/L sulfate decreased to 4103 and 3929 mL, respectively. The H2S levels in control and reactors with 200, 500, 700 mg/L sulfate were 0.35, 0.46, 2.4, and 1.8%, respectively. In reactors with MA at rates of 0, 0.88, 1.04, 1.34 NL/day, the H2S levels were 1.95%, 0.9%, 0.4% and 0.1% (V/V) in biogas, respectively. The pH in reactor varied between 2.7 and 4.7, and the ORP was measured between -281 and -291 mV. Statistical analysis shows that no significant difference was observed between the average daily production of biogas with MA process of 0.88 and 1.04 NL/day. However, MA with 1.34 NL/day resulted in a decrease in biogas production. Conclusion: The results indicated MA at a rate of 1.04 NL/day is a favorable option for the treatment of sulfate-rich urban wastewater sludge due to its efficiency in H2S removal. [ABSTRACT FROM AUTHOR]

To study the feasibility of using municipal sewage as a reserve water source for oilfield reinjection, the water sample treated by the municipal sewage treatment plant and the produced water of the Chang 2 reservoir were taken as the research objects. Through the analysis of water quality and compatibility, the optimal ratio of reinjection water samples was determined. At the same time, the clay swelling experiment and reservoir damage experiment were carried out. The experimental results show that the salinity of municipal sewage is low, and the content of scale ions is low. When the ratio of produced water to municipal sewage is 7:3, the scale formation amount can reach 42.5 mg.L-1, and when the scale inhibitor is added, the scale formation amount can be reduced to 10.4 mg.L-1. The mixed water sample will not cause clay expansion. Meanwhile, Chang 2 reservoir is moderately weak water sensitive and weak acid sensitive. The oil content, suspended solids content, and median particle size of the mixed water sample during reinjection should be controlled at 5 mg.L-1, 5 mg.L-1, and 5 µm to ensure that the reinjected water sample does not cause damage to the reservoir. [ABSTRACT FROM AUTHOR]

India, being a developing country, faces big challenges in ensuring water, sanitation, and hygiene (WASH) for all. This case study presents the performance evaluation of a large wastewater management and sanitation-related infrastructure in a metropolitan city in North India. "Dravyavati River Project" is the major sanitation program of the water-stressed Jaipur city based on the concept of river rejuvenation of the long-lost Dravyavati River which flows across the city. The project envisages integrated urban water management such that it aims at the collection and treatment of wastewater (sewage network and treatment plants), safe disposal, ensuring continuous unpolluted flow, geological and ecological integrity to strengthen public health, to reduce the impact of water stress on the total water cycle by promoting groundwater recharge, and improvement in biodiversity. The technical assessment is based on the primary and secondary data collection of field samples and laboratory analysis of influent and effluent samples collected from the five sewage treatment plants (STPs). The results suggest that the project has largely delivered the envisaged environment, public well-being, and ecological and socioeconomic benefits, but there are substantial gaps in the conceived outputs and actual performance. The challenge lies in bridging these gaps and overcoming operational inefficiencies to ensure the sustainability of the Dravyavati River rejuvenation. [ABSTRACT FROM AUTHOR]

The present study investigates the potential of locust bean gum (LBG), in accelerating the startup of a novel upflow anaerobic sludge blanket (UASB) reactor handling municipal sewage. Under identical conditions, two lab-scale UASB reactors were operated in parallel, to substantiate this idea. The novel reactor (RH) with an inner centric hybrid UASB module and an outer concentric downflow hanging sponge (DHS) unit started off with an LBG polymer as an additive. Its performance was compared with a conventional system (RC). RH outclassed with an accelerated startup in 40 days, with the highest COD removal of 89% by the UASB compartment and 95% by the entire system (UASB + DHS). RC took nearly 85 days to achieve the highest COD removal of 83%. The polymer also succeeded with a dense sludge bed fastening most of the anaerobes, read by the least sludge volume index (SVI) of 26 mL/g. Specific methanogenic activity (SMA) (RH – 0.715 ± 0.05 and RC – 0.670 ± 0.07 g CH4-COD/g VSS/ day) and extracellular polymer (ECP) concentration (0.30–0.32 g/g VSS) of biomass in both reactors were almost similar. This further confirmed that early granulation was induced solely by the polymer and it also had no deleterious impact on substrate transfer. HIGHLIGHTS Enhancement of anaerobic granulation by natural gum-based polymer – locust bean gum.; Polysaccharidic structure, self-gelling property, and good coagulating potential of the biopolymer, favored aggregation of microflora in the sludge bed.; The novel UASB reactor was designed to bear the resemblance of clariflocculator – inner centric UASB module and an outer concentric downflow hanging sponge unit;

This study explores the potential of food waste-recycling wastewater (FRW) for biogas production, emphasizing oil–water separation before anaerobic digestion. Three FRW samples were analyzed: non-treated (FRW), water–oil separated (FRW_sep), and mixed with domestic sewage (FRW_mix). Physicochemical characterization showed a 26% reduction in crude lipid content after oil–water separation. The biochemical methane potential (BMP) tests revealed similar methane yields for FRW_sep and FRW_mix compared to non-treated FRW. Microbial analysis identified Firmicutes and Methanoculleus as active populations. Energy balance suggests that combining biodiesel and biogas production can enhance net energy recovery. This research indicates that oil–water separation in FRW treatment can optimize anaerobic digestion, contributing to sustainable waste management and renewable energy generation.

As the problem of eutrophication of water bodies and nitrate pollution of surface and groundwater is becoming more and more prominent, deep denitrification of wastewater can effectively reduce the amount of nitrate nitrogen (NO3−-N) discharged into natural water bodies. To solve this problem, in this research, the autotrophic denitrifying bacteria were incorporated in an autotrophic denitrification simulator equipped with magnetic pyrite to remove NO3−-N and total nitrogen (TN) from wastewater. The purified strains were inoculated into municipal sewage. When the ratio of magnetic pyrite to quartz sand was 1:1 and the particle size of the filler was 0.5–1 mm, the removal rate of NO3−-N and TN was optimized, at 93.52% and 83.22%, respectively. Sulphate (SO42−) concentrations will level off during stable system operation, and SO42− concentrations show a positive correlation with NO3−-N and TN removal. The 16s rDNA sequencing analysis of the screened sludge showed that the main phyla in the screened and purified sludge were Epsilonbacteraeota and Proteobacteria, with an abundance of 65.83% and 26.88%, and the final enriched products were dominated by Sulfurimonas and Thiobacillus, with an abundance of 64.91% and 9.32%, respectively. The results showed that autotrophic denitrifying bacteria could be screened and purified using thiosulfate as a substrate, and that the use of magneto pyrite as an electron donor reduced most of the NO3−-N to N2, while reducing the TN content. [ABSTRACT FROM AUTHOR]

Treatment of Municipal wastewater by Electrocoagulation (EC) process using punched aluminium and zinc electrodes was studied in a batch EC cell reactor. Response surface methodology (RSM) based on Central Composite Design (CCD) was utilized to optimize the operating parameters for the removal of % Total Suspended Solids (TSS) and % Chemical Oxygen Demand (COD) from Municipal Sewage. Effect of operating parameters such as Electrode Distance (x1), Electrolysis Time (x2) and Voltage (x3) has been optimized for the removal of TSS and COD. The prediction of removal percentage of TSS and COD in various Operational circumstances is done by using Quadratic model. The significance of each operating parameter was computed by Analysis of variance (ANOVA). To achieve the maximum removal of % TSS and % COD, the optimum conditions were Electrode distance(x1)—3 cm, Electrolysis Time (x2)—70.299 minute and Voltage (x3)—6.5V. It was observed that the performance of electrocoagulation process increased up to 61.45% for COD removal, and 73.73% for TSS removal using punched electrode compared to plane electrodes. [ABSTRACT FROM AUTHOR]

Background and Objectives: he occurrence and characteristics of Extended Spectrum- and AmpC-ß-lactamase producing Enterobacterales (ESBL-PE and AmpC-PE) in an urban wastewater treatment plant (WWTP) were investigated. Materials and Methods: A total of 30 wastewater samples were collected from all sections of WWTP. Enterobacterales were isolated and identified using standard microbiological tests. The antibiotic resistance profile was determined by the Kirby-Bauer disk diffusion method. Phenotypic screening for ESBL-PE and AmpC-PE isolates was performed by double-disk synergy and boronic acid disk potentiation tests, respectively. The isolates were examined for AmpC- and ESBL-encoding genes by PCR and sequencing methods. Results: Among 146 Enterobacterales isolates, 8.9% (n=13) [ESBL-only; 5.48% (n=8) and ESBL + AmpC; 3.42% (n=5)] were ESBL-producers and 15.75% (n=23) [AmpC-only; 12.33% (n=18) and ESBL + AmpC; 3.42% (n=5)] AmpC-producers. Hafnia spp. with 33.33% (n=1/3) and E. coli with 20.58% (n=7/34) [ESBL-only; 17.64% (n=6/34) and ESBL + AmpC; 2.94% (n=1/34)] were the most common ESBL-producing bacteria. Enterobacter spp. with 37.50% (n=6/16) of isolates were the most common AmpC-producing organisms. ESBL- and/or AmpC-producing isolates were identified in all parts of the WWTP including 80% (n=8/10) of samples taken from effluent. Among ESBL-producing isolates, blaCTX-M TEM, and blaSHV ESBL-encoding genes were found in 61.5% (n=8), 15.3% (n=2), and 7.7% (n=1) of isolates, respectively. All CTX-Mtype enzymes belonged to the CTX-M-1 group and CTX-M-15 subgroup. blaTEM and blaSHV type genes belonged to blaTEM-20 and blaHSV-12 subtypes, respectively. bla with 73.9% (n=17/23), and blaCIT and bla with 30.4% (n=7/23) each, were the most common AmpC-encoding genes among AmpC-producing isolates. Overall, 75% of ESBL-producing and 55.5% of AmpC-producing isolates exhibited multi-drug resistance phenotypes. The organisms were most resistant against ampicillin (82.2%) nalidixic acid (43.8%) and cephalexin (41.1%). Conclusion: ESBL- and AmpC-producing Enterobacterales spp. with diverse genetic resistance backgrounds in WWTP effluent poses a significant risk to public health. [ABSTRACT FROM AUTHOR]

Use of wastewater for irrigation remains a disagreement among policymakers and researchers. However, it is fact that wastewater may contains many contaminants including heavy metals that can negatively impact ecosystem health. The present study is an attempt to assess the impact of wastewater use on soil, crop, and water and associated health risks based on exposure risk model where wastewater irrigation is more prominent in Hyderabad city, South India by analyzing physical (pH, EC, turbidity, oil and grease, TSS), chemical (Zn, Cr, Pb, Mn, Cu and Ni) and biological (BOD, COD, DO) parameters. The results indicated that biological contamination and the presence of heavy metals with the rising groundwater salinity. Low to moderate cancer risks are also inferred if humans are exposed to these waters for a long time. However, the study suggests continuous monitoring of the water and soil quality in wastewater irrigated areas to take remedial actions for sustainable agriculture development and protect ecosystems.

Submerged membrane bioreactors (SMBRs) are a promising technology for municipal sewage treatment, but membrane fouling has limited their development. In this study, biochar (BC), which has a certain adsorption capacity, was added to an SMBR to investigate its potential in treating municipal sewage and alleviating membrane fouling. The results showed that the average removal rates of ammonia nitrogen (NH4+-N), total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (COD) were 94.38%, 59.01%, 44.15% and 83.70%, respectively. After BC was added and operation was stable, the ratio of mixed liquor volatile suspended solids to mixed liquor suspended solids (MLVSS/MLSS) was maintained between 0.78 and 0.81. The concentrations of soluble microbial products (SMPs) and extracellular polymeric substances (EPSs) were stabilized between 63.05 ± 8.49 mg/L and 67.12 ± 1.54 mg/L. Trans-membrane pressure (TMP) and scanning electron microscopy (SEM) analyses showed that BC reduced the TMP by reducing the thickness and compactness of the cake layer on the membrane surface. The high-throughput sequencing results showed that the microorganisms associated with biofilm formation (proteobacteria, γ-proteobacteria and α-proteobacteria) were significantly reduced in the BC-enhanced SMBR system. BC promoted the enrichment of functional microorganisms such as Chloroflexi, Acidobacteriota, Anaerolineae and Planctomycetes. Compared with traditional anti-fouling methods, the results of this study may provide a low-cost membrane fouling mitigation method for industrial applications of SMBRs. [ABSTRACT FROM AUTHOR]

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BACKGROUND: With the rapid development of modern industry and agriculture, large amounts of sewage of various types are being discharged into water bodies every year, causing huge environmental pressure and posing a threat to organisms. Amongst different solutions to this problem, microalgae can remove pollutants including pesticides and antibiotics from water. In this work, an algal strain designated as Scenedesmus sp. TXH. was isolated from the Tangxun Lake Sewage Treatment Plant (Wuhan, China) and used to remove imidacloprid (IMI) from sewage. The removal efficiency, degradation products, removal of conventional contaminants [total dissolved nitrogen (TDN) ammonia nitrogen (NH4+‐N), total dissolved phosphorus (TDP)], the biochemical response of the microalgae, and the effects of environmental factors such as light intensity and temperature were investigated. RESULTS: The results showed that: (i) the highest IMI removal efficiency of ≈60% was achieved under 80 μmol m−2 s−1 at 25 °C; (ii) the removal of NH4+‐N, TDP and TDN in the sewage reached 90%, 90% and 65%, respectively; (iii) there was a significant linear relationship between the concentration of total chlorophyll and the removal of IMI in the sewage; and (iv) finally, based on the analysis of degradation products by mass spectrometer, three potential IMI degradation pathways were proposed. CONCLUSION: In summary, our results showed that Scenedesmus sp. TXH can remove IMI and conventional nutrients efficiently from sewage, implying a potential application in sewage treatment in the near future. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Copyright of Energy Chemical Industry is the property of Energy Chemical Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background and Objectives: he occurrence and characteristics of Extended Spectrum- and AmpC-β-lactamase producing Enterobacterales (ESBL-PE and AmpC-PE) in an urban wastewater treatment plant (WWTP) were investigated. Materials and Methods: A total of 30 wastewater samples were collected from all sections of WWTP. Enterobacterales were isolated and identified using standard microbiological tests. The antibiotic resistance profile was determined by the Kirby–Bauer disk diffusion method. Phenotypic screening for ESBL-PE and AmpC-PE isolates was performed by double-disk synergy and boronic acid disk potentiation tests, respectively. The isolates were examined for AmpC- and ESBL-encoding genes by PCR and sequencing methods. Results: Among 146 Enterobacterales isolates, 8.9% (n=13) [ESBL-only; 5.48% (n=8) and ESBL + AmpC; 3.42% (n=5)] were ESBL-producers and 15.75% (n=23) [AmpC-only; 12.33% (n=18) and ESBL + AmpC; 3.42% (n=5)] AmpC-producers. Hafnia spp. with 33.33% (n=1/3) and E. coli with 20.58% (n=7/34) [ESBL-only; 17.64% (n=6/34) and ESBL + AmpC; 2.94% (n=1/34)] were the most common ESBL-producing bacteria. Enterobacter spp. with 37.50% (n=6/16) of isolates were the most common AmpC-producing organisms. ESBL- and/or AmpC-producing isolates were identified in all parts of the WWTP including 80% (n=8/10) of samples taken from effluent. Among ESBL-producing isolates, blaCTX-M, blaTEM, and blaSHV ESBL-encoding genes were found in 61.5% (n=8), 15.3% (n=2), and 7.7% (n=1) of isolates, respectively. All CTX-M-type enzymes belonged to the CTX-M-1 group and CTX-M-15 subgroup. blaTEM and blaSHV type genes belonged to blaTEM-20 and blaHSV-12 subtypes, respectively. blaDHA with 73.9% (n=17/23), and blaCIT and blaFOX with 30.4% (n=7/23) each, were the most common AmpC-encoding genes among AmpC-producing isolates. Overall, 75% of ESBL-producing and 55.5% of AmpC-producing isolates exhibited multi-drug resistance phenotypes. The organisms were most resistant against ampicillin (82.2%) nalidixic acid (43.8%) and cephalexin (41.1%). Conclusion: ESBL- and AmpC-producing Enterobacterales spp. with diverse genetic resistance backgrounds in WWTP effluent poses a significant risk to public health.

This study aims to isolate and characterize efficient biohydrogen generating facultative anaerobic bacteria from various samples, viz., biogas plant (BGP), municipal sewage (MS), and dairy industry treatment plant (DTP). The physicochemical properties of various untreated anaerobic sludge samples reflect the anoxic state and appropriateness of the substrate for separating biohydrogen generating bacteria. The biohydrogen producing bacterial strains were separated from methanogens using the heat-treatment method. The facultative anaerobic bacterial load of heat-treated test samples was determined viz., 27.2±0.57×106 (BGP), 21.8±0.43×106 (MS), and 18.6±0.92×106 (DTP) CFU mL-1 (Colony forming unit), which decreased from the total anaerobic bacterial load of untreated anaerobic sludge viz., 32.1±0.28×106 (BGP), 42.2±0.16×106 (MS), and 34.7±0.12×106 (DTP) CFU mL-1. The 28 predominant bacterial isolates strains were isolated from the heat-treated test samples. All 28 bacterial strains were identified using microscopic and biochemical techniques. Biohydrogen producing potential bacterial strains were screened using the Hungate technique with glucose as a carbon source. Among them, 12 strains were capable of producing biohydrogen, among these 5 strains being excellent biohydrogen producers. Based on the16s rRNA molecular sequencing, the 5 selected biohydrogen generating organisms were authenticated as viz., Salmonella bongori (MZ636759), Escherichia coli (MZ636716), Staphylococcus hominis (MZ636713), Yersinia enterocolitica (OM009292), and Shewanella oneidensis (MZ636800). The gas composition study by GC-TCD in a fermentative medium shows that Shewanella oneidensis (MZ636800) could produce the best biohydrogen (111.4±8.3 mLH2/L), followed by Salmonella bongori (MZ636759) with 98.1±2.9 mL H2/L and Escherichia coli (MZ636716) with 86.7±6.2 mLH2/L.

Water scarcity is a worldwide problem. Recycled municipal wastewater is considered a useful alternative to the conventional types of water resources. In this study, a shallow constructed wetland (SCW) with porous filter material and Rotala rotundifolia was used for advanced municipal sewage treatment. The wetland without plant was set as the control (SCW-C). The pollutant removal performance of the system at different hydraulic retention times (HRTs) was investigated. The diversity of the microbial community was analyzed, and the fate of nutrients, mainly N and P, in the system was discussed. Results showed that SCW was efficient in pollutant removal. Effluent concentrations of chemical oxygen demand (COD), total phosphorus (TP), and ammonium nitrogen (NH4+-N) were 15.0–23.6, 0.19–0.28, and 0.83–1.16 mg/L, separately, with average removal efficiencies of 61.2%, 46.3%, and 88.1% at HRT 18 h, which met the requirements of type IV water set by the environmental quality standards for surface water in China. The richness and evenness of the bacterial community were significantly higher in the plant-rooted SCW. They increased along with the system. The dominant genera in the system were phosphate-solubilizing bacteria, nitrifying bacteria, and denitrifying bacteria. The P in the influent mainly flowed to the substrate and plant. At the same time, most N was removed by nitrification and denitrification. These findings suggested that the SCW could remove pollutants from the municipal sewage effluent and meet the standard requirement at low HRT. [ABSTRACT FROM AUTHOR]

Cultivation of high-lipid microalgae using municipal sewage can both treat polluted water and gain biodiesel. Rapid cultivation of microalgae is crucial for the entire process. In this study, four stimulants (phytohormone 2,4-d; Fe3+; photosynthetic bacteria—Rhodopseudomonas palustris; CO2) were firstly chosen to investigate their effects on microalgae Chlorella pyrenoidosa cultivation in municipal sewage. Meanwhile, orthogonal experiments were designed to compare the enhancing effects on the growth of microalgae C. pyrenoidosa and lipid accumulation by different combinations of stimulants, which were also conducted for outdoor culture. The optimum stimulant combination was 1.0 mg/L 2,4-d; 10−7 mol/L Fe3+; 4.5 mL (109 cells/mL) photosynthetic bacteria; and 8% CO2. Among the four kinds of stimulants, phytohormone 2,4-d and photosynthetic bacteria played more important roles on the microalgae growth and lipid accumulation. The optimum combination of stimulants could also promote the microalgae biomass and lipid yield during outdoor cultivation. The maximum OD681 of microalgae was 37.9% higher than that of the control group without addition of stimulants. The obtained microalgae dry weight and lipid production were 0.3 and 0.13 g /L, which were 80.0% and 85.7% higher than that of the control group, respectively. The promotion of microalgae photosynthetic rate was the main reason for the stimulant-enhanced microalgae cultivation. This study exerts positive effects on the development of microalgae biodiesel. [ABSTRACT FROM AUTHOR]

The anaerobic ammonia oxidation (anammox) process is a pivotal nitrogen removal technique, playing a significant role in the field of wastewater treatment. The paper commences by delineating the merits of the anammox process in comparison to conventional nitrification-denitrification techniques. Subsequently, it delves into the characteristics of different sludge morphologies process of the behavior of anammox bacteria and their reactions to environmental factors. Revising the issues associated with managing urban sewage in mainstream areas., it discusses the issues faced by the anammox process under reduced nitrogen loads, such as restricted activity due to decreased the levels of ammonia nitrogen and nitrite concentrations, as well as the impact of environmental factors like low temperature, organic matter, and sulfur ions. Following this, a comprehensive review of various types of coupled anammox processes is provided, highlighting the advantages and characteristics of partial nitrification (PN), partial denitrification (PD), methane-dependent nitrite/nitrate reduction (DAMO), sulfur-driven autotrophic denitrification (SAD), iron ammonia oxidation (feammox) and algae photoautotrophy coupling techniques, emphasizing their significance in system stability and resource utilization efficiency. Future research directions include exploring the applicability of the anammox process under various temperature conditions and addressing NO 3 −-N issues in effluent. The findings from these studies will offer valuable insights for further enhancing the optimization of the anammox process in mainstream urban wastewater treatment. [Display omitted] • The mainstream anammox treatment of municipal sewage can reduce sludge discharge and energy consumption. • The mainstream anammox activity is limited by the low load of municipal sewage. • The control conditions applied in the mainstream of urban sewage are more complex. • Some new coupling processes of anammox deserve attention in the mainstream anammox process. [ABSTRACT FROM AUTHOR]

[Display omitted] • PD/A-A2O process was started up rapidly by inoculating PD/A biofilm in 30 days. • NRE improved by 23.8% contrasted to traditional A2O process. • The contribution of anammox to TN loss was maintained at 37.9 %∼55.7 %. • Reducing HRT would simultaneously improve denitrification and anammox activity. • Cooperation of DNB, GAO and AnAOB resulted in enhanced nitrogen removal. This study investigated the rapid start-up of mainstream partial denitrification coupled with anammox (PD/A) and nitrogen removal performance by inoculating precultured PD/A biofilm. The results showed mainstream PD/A in the anaerobic-anoxic-aerobic (A2O) process was rapidly established within 30 days. Nitrogen removal efficiency (NRE) improved by 23.8 % contrasted to the traditional A2O process. The mass balance showed that anammox contribution to total nitrogen (TN) removal were maintained at 37.9 %∼55.7 %, and reducing hydraulic retention time (HRT) strengthened simultaneously denitrification and anammox activity. The microbial community showed that the dominant bacteria such as denitrifying bacteria (DNBs) and glycogen accumulating organisms (GAOs) both in biofilm and flocculent sludge (floc), integrating with anammox bacteria (AnAOB) in biofilm might lead to enhanced nitrogen removal. Overall, this study offered a fast start-up strategy of mainstream PD/A with enhanced nitrogen removal, which are valuable for upgradation and renovation of existed municipal wastewater treatment plants (WWTPs). [ABSTRACT FROM AUTHOR]

The present study investigates the potential of a novel upflow anaerobic sludge blanket (UASB) reactor with a built-in polishing facility for the treatment of municipal sewage. A laboratory-scale reactor, which combined an inner-centric hybrid UASB module and an outer concentric downflow hanging sponge (DHS) unit, was designed and fabricated as a part of this research work. The reactor had been continuously operated for 210 days under ambient conditions. With anaerobically digested sewage sludge (seed sludge blended with Locust bean gum polymer) as inoculum, the reactor attained a successful startup in 40 days. Ensuring startup, the reactor was employed under varying organic loading rates (OLR) from 0.87 to 5.09 kg COD/m3/d, with corresponding hydraulic retention times (HRT) of 24–4 h. The novel UASB reactor made its mark with a high COD and TSS removal of 93.2% and 93%, respectively, under the optimum conditions of 6-h HRT. In addition, biogas rich in methane content (68%), with a maximum specific yield of 0.42± 0.02 m3 biogas /kg COD destroyed, was generated. The VSS/TSS ratio observed a steady rise (0.51 to 0.75) with increasing sludge age, bearing witness to the active growth of biomass. Hence, in brief, the novel UASB reactor can be coined as an energy economic system with improved effluent quality. [ABSTRACT FROM AUTHOR]

The research covered two lakes: Karczemne and Domowe Małe, which served as receivers for rainwater and municipal or industrial sewage. The sediment cores were obtained using a Kajak tube sampler. Analyses of HM, PAH and PCB were done by the AAS, ICP-AES and GC MS methods. OM, SiO2, TH, Ca, Mg, CO2, Fe, Al, Mn, TN and TP were measured. The research showed that the sediments of Lake Karczemne, into which the untreated municipal sewage was discharged, are characterized by a high content of P. It was found that the sediments accumulate toxins, OM and pollutants characteristic for various industries. Karczemne Lake which collected municipal and industrial wastewater, contained a high content of Pb, Cu and PAH in the sediments, and Domowe Małe Lake, receiving stormwater, contained high concentrations of PAH. Research has shown that one of the most important tools for selecting an appropriate method of lake restoration is the analysis of the spatial distribution of pollutants in the bottom sediments. Thanks to such an analysis of the composition of the bottom sediments and the correlation between the components of the sediments and their sorption properties, the restoration of the Karczemne Lake using the Ripl method was planned and the possibility of restoration of the Domowe Małe Lake in this way was eliminated.

This study aims to isolate and characterize efficient biohydrogen generating facultative anaerobic bacteria from various samples, viz., biogas plant (BGP), municipal sewage (MS), and dairy industry treatment plant (DTP). The physiochemical properties of various untreated anaerobic sludge samples reflect the anoxic state and appropriateness of the substrate for separating biohydrogen generating bacteria. The biohydrogen producing bacterial strains were separated from methanogens using the heat-treatment method. The facultative anaerobic bacterial load of heat-treated test samples was determined viz., 27.2±0.57×106 (BGP), 21.8±0.43×106 (MS), and 18.6±0.92×106 (DTP) CFU mL-1 (Colony forming unit), which decreased from the total anaerobic bacterial load of untreated anaerobic sludge viz., 32.1±0.28×106 (BGP), 42.2±0.16×106 (MS), and 34.7±0.12×106 (DTP) CFU mL-1. The 28 predominant bacterial isolates strains were isolated from the heat-treated test samples. All 28 bacterial strains were identified using microscopic and biochemical techniques. Biohydrogen producing potential bacterial strains were screened using the Hungate technique with glucose as a carbon source. Among them, 12 strains were capable of producing biohydrogen, among these 5 strains being excellent biohydrogen producers. Based on the16s rRNA molecular sequencing, the 5 selected biohydrogen generating organisms were authenticated as viz., Salmonella bongori (MZ636759), Escherichia coli (MZ636716), Staphylococcus hominis (MZ636713), Yersinia enterocolitica (OM009292), and Shewanella oneidensis (MZ636800). The gas composition study by GC-TCD in a fermentative medium shows that Shewanella oneidensis (MZ636800) could produce the best biohydrogen (111.4±8.3 mLH 2/L), followed by Salmonella bongori (MZ636759) with 98.1±2.9 mL H2/L and Escherichia coli (MZ636716) with 86.7±6.2 mLH 2/L. [ABSTRACT FROM AUTHOR]

• A continuous self-circulating up-flow granular sludge bed process was introduced. • Accurate self-circulating multiple times and O 2 supply were driven only by aeration. • High up-flow velocity of 7–16 m/h contributed to particle formation and stability. • HRT of 10 h and DO of 0–0.3 mg/L were optimized for higher OLR and energy savings. • Self-circulation driven by aeration is key factor regulating nitrogen removal. Aerobic granular sludge (AGS) capable of nitrogen and phosphorus removal is mainly limited to the applications in sequencing batch reactors. This study introduced an innovative continuous self-circulating up-flow fluidized bed process (Zier process) using separate aeration. The process was composed of an anoxic column (Zier-A), aeration column (Zier-OO) and aerobic column (Zier-O), and was used to treat actual municipal sewage continuously for 170 days. The process achieved self-circulation of 20–32 times and an up-flow velocity within the reactor of 7–16 m/h which were accurately controlled with only separate aeration. The larger proportion of self-circulating multiple times contributed to particle formation and stability, providing hydraulic shear conditions, and screened the precipitation performance of the granular sludge (GS). Meanwhile, the dissolved oxygen (DO) of Zier-O was controlled at 0.1–0.3 mg/L, and the DO of Zier-A input water was zero. The accurate oxygen supply enhanced simultaneous nitrification and denitrification (SND) as well as short-cut nitrification and denitrification in Zier-O and improved the COD utilization rate and the nitrogen removal rate in Zier-A. The COD treatment capacity reached 2.46 kg-COD/(m³·d). With a hydraulic retention time of 10 h, the process consistently ensured that the average concentrations of ammonia nitrogen and total nitrogen in the effluent were maintained below 5 and 15 mg/L, respectively. Moreover, the process maintained the shape and stability of GS, the median diameter of GS ranged between 300–1210 μm, the percentage of mass with particle size distribution < 200 μm at a height of 150 cm within Zier-A and Zier-O accounted for as low as 0.04%–0.05%, and showed good settling performance. The suspended solids in effluent can be maintained at 50–80 mg/L. Overall, the unique structural setting and control method of the Zier process provide another approach for the application of continuous AGS treatment for municipal sewage. [Display omitted] [ABSTRACT FROM AUTHOR]

This work has focused on the potential of natural gum based polymers as additives, to enhance the startup of upflow anaerobic sludge blanket (UASB) reactors treating municipal sewage. A laboratory study was taken up to substantiate this novel idea. Under identical conditions 4 similar UASB reactors were operated in parallel. Reactors locust bean gum (LBG) and guar gum (GG) were injected with the novel bio-flocculants LBG and guar gum. For better insights their performance was compared with the well proven cationic polymer chitosan, in reactor (CH). Reactor (CT) without any additive served as control. Reactor with LBG as additive outclassed others with an accelerated startup in 40 d reaching a maximum chemical oxygen demand removal of 92.5%, followed by GG, CH and CT with 88%, 80% and 60% removal respectively at the end of study period. Both LBG and GG also succeeded with a dense sludge bed anchoring most of the anaerobes denoted by a least sludge volume index of 26.2 and 29 mL/g, followed by high volatile suspended solids/ total suspended solids ratio of 0.75 and 0.72, respectively. Specific methanogenic activity and ECP secretions of all 4 reactors were almost similar, indicating that early granulation was primarily induced by the polymers. Hence in a nut shell, polymer enhanced reactors visualized an accelerated startup along with better biomass retention than the control. [ABSTRACT FROM AUTHOR]

Pharmaceuticals compounds are the emerging contaminants known for their refractory and environmental persistence, which pose threat to flora and fauna. In the present study, the occurrence and possible contamination sources of four drugs, namely paracetamol, diclofenac, salbutamol and ceftriaxone in wastewater of Mysuru, India, were investigated. The said pharma compounds were analyzed in the effluent of select health care establishments and municipal wastewater treatment plant (MWWTP). The results revealed that diclofenac was omnipresent in all the samples with the peak concentration of 4.2 µg/mL, whereas salbutamol and ceftriaxone were in the range of 0.7–18.7 µg/mL and 1.25–29.15 µg/mL, respectively. In addition, paracetamol was detected only at the inlet of MWWTP with a concentration of 4.6 µg/mL. Surprisingly, the presence of relative amounts of these drugs in the treated water released from MWWTP was observed. Further, the 'risk quotient method' for ecological risk assessment was adopted to assess the magnitude of risk toward aquatic species. Next, the study employed the concept of citizen science to gather information on disposal and management methods of unused and expired medications at household and health care centers. This survey revealed that hospital discharges and community disposal of unused medicines contributed to incidence of pharmaceutical compounds in the local environment. Finally, a precise perspective and future challenge for the safe management of drugs are presented. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Environmental Protection is the property of Polish Academy of Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Flow rate is one of the important operating parameters for monitoring of municipal sewage treatment facilities. The phase difference detection accuracy of Coriolis flowmeter determines the flow measurement accuracy. In order to study the phase difference detection method of Coriolis flowmeter, an experimental model of single straight tube Coriolis flowmeter is designed. On this basis, the phase difference processing method is improved. The signal pre processing method is combined with FIR filter and SVD noise reduction, and then the Nuttall window discrete Fourier transform is used. Compared with other methods, the simulation results show that the phase difference is more accurate. Finally, the experimental results on Coriolis flowmeter model show that the phase difference detection method improves the phase difference detection ac curacy. [ABSTRACT FROM AUTHOR]

The aerobic granular sludge membrane bioreactor (AGS-MBR) has the potential for simultaneous carbon/nitrogen removal and membrane fouling mitigation. Most studies have focused on comparison of granular sludge MBR and flocculent sludge MBR in short-term tests using synthetic wastewater. In this study, two identical AGS-MBRs were developed, and the reactor performance and membrane fouling were examined systemically over 120 days for synthetic wastewater and municipal sewage treatment, respectively. Results showed that regular granules with good settling ability were developed and maintained throughout the experimental period. Regardless of the substrate type, AGS-MBR demonstrated a stable removal of carbon (85–95%) and nitrogen (50–55%) in long-term operation. In addition, the membrane fouling propensity is apparently lower in AGS-MBRs with no membrane cleaning for 4 months at a flux of 20 L m−2h−1. The filtration resistance analysis indicates that the main membrane resistance was caused by irreversible fouling in both of the reactors. Membrane foulant analysis indicates that proteins in extracellular polymeric substances are more prone to be attached by the membrane of AGS-MBRs because of their hydrophobic nature. This study shows that AGS-MBR is effective and stable for municipal sewage treatment and reuse during long-term operation.

Urban wastewater contains various detergents, pesticides, pharmaceutical medications, cosmetics, hygiene products, and heavy metals. Discharge of municipal sewage into surface water affects the health of aquatic organisms through altering biochemical markers and accumulating heavy metals in various tissues. The present study aimed to evaluate the toxic effects of municipal sewage on the biochemical markers and bioaccumulation of cadmium and lead in freshwater snail (Galba truncatula) during 14 days. Concentrations of toxic metals in the snails were determined using ICP-OES-PerkinElmer, and biochemical parameters were measured via UV-Vis spectroscopy. The results indicated significantly lower levels of glycogen and total antioxidant in the cells, as well as the significantly lower activities of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, acetylcholine esterase, catalase, and glucose-6-phosphate dehydrogenase in the Galba truncatula exposed to sewage compared to the control. However, the activities of lactate dehydrogenase ,glutathione peroxidase, and malondialdehyde were significantly higher in the snails exposed to sewage compared to the control. Moreover, bioaccumulation of cadmium and lead was observed to increase in the experimental groups exposed to sewage. Alterations in biochemical parameters in the G. truncatula exposed to sewage could be due to the toxic effects of various environmental pollutants in municipal wastewater. According to the findings, oxidative damage to the vital tissues of G. truncatula was associated with the bioaccumulation of cadmium and lead, depletion of total antioxidant levels, changes in biochemical parameters, and lipid peroxidation in soft tissues.

Current study explored the effects of municipal sewage (MS) irrigation on heavy metal phyto-accretion, biochemical responses and human health risks of diverse wheat genotypes along with recycled municipal sewage (RMS). Mean concentrations of PO43-, NO3--N, chemical oxygen demand, biological oxygen demand, K, Co, Cu, Cd, Cr and Ni were found higher in MS than irrigation criteria. This led to significant increase in heavy metal contents in roots, stem and grains of MS irrigated wheat genotypes compared to RMS and control treatments. No adverse health risk effects for individual or multiple metals were recorded in RMS irrigated wheat genotypes on grounds of lowest heavy metal accumulation. Multivariate techniques i.e. principal component analyses (PCA) and hierarchical agglomerative cluster analyses (HACA) identified tolerant (inefficient metal accumulators) and sensitive (efficient metal accumulators) wheat genotypes in MS and RMS. Tolerant wheat genotypes showed lowest accumulation of heavy metals, efficient biochemical mechanisms to combat oxidative stress and lower health risks to adults/children. Cultivation of identified tolerant wheat genotypes is recommended in areas receiving municipal wastes to reduce human and environmental health risks. Moreover, genetic potential of identified tolerant wheat genotypes from MS and RMS can be utilized in breeding heavy metal tolerant wheat germplasm worldwide. [ABSTRACT FROM AUTHOR]

In this paper, a fine aggregate with reasonable gradation and particle size of 0~5 mm was manufactured by secondary crushing and screening of the sludge of the municipal sewage treatment plant after high-temperature incinerated. The physical properties, the contents of harmful substances and the pore structure of the fine aggregate were determined. Chemical analysis tests showed that the chemical composition, the heavy metal content and leaching amount, and the radioactivity of the fine aggregate meet the standard control requirements of building materials. Based on the comprehensive analysis of the test results, the sintered sludge is feasible used as the lightweight fine aggregate for buildings after the secondary processing. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The occurrence and fate of 14 widely used phthalic acid esters (PAEs) in a wastewater treatment plant (WWTP) located in Guangzhou, China were investigated for 1 y. Results showed that PAEs were widely detected but the levels of PAEs in effluent were below the international standard. Seasonal variation of PAEs levels in the influent was observed, with higher levels in winter and spring and lower levels in summer and autumn. The mean overall removal efficiency of PAEs was 70.9% in WWTP. Results also indicated that the PAE pollution in sewage sludge was more severe than a previous report in Guangzhou. The annual emission of PAEs from effluent and sludge was 1,110 and 238 kg/y, respectively. The ecological risk of PAEs was considered to be medium, which suggested the need for advanced treatment in current full-scale WWTPs to improve the removal of PAEs and consequently, to prevent the receiving water body from the impact of PAEs. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Beijing University of Technology is the property of Journal of Beijing University of Technology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Beijing University of Technology is the property of Journal of Beijing University of Technology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] • Efficient sewage treatment was developed in continuous flow anammox process. • EPS content plays a key role in the formation of microbial interactions. • The inhibitory effect of DNB to NOB can be induced by organic substances. • The DNB that uses slowly biodegradable organics promotes anammox under limited NH 4 +-N. Organic matter concentration is a critical factor influencing the adaptability of anaerobic ammonium oxidation (anammox) bacteria to low-strength sewage treatment. To address this challenge and achieve stable anammox activity, a micro-aeration partial nitrification-anammox process was developed for continuous-flow municipal sewage treatment. Under limited ammonium conditions, the effective utilization of organics in denitrification promoted the stable accumulation of nitrite and enhanced anammox activity. This, in turn, led to enhanced nitrogen removal efficiency, reaching approximately 87.7%. During the start-up phase, the protein content of extracellular polymeric substances (EPS) increased. This enhanced EPS intensified the inhibitory effect of denitrifying bacteria (DNB) on nitrite-oxidizing bacteria through competition for nitrite, thereby facilitating the proliferation of anammox bacteria (AnAOB). Additionally, several types of DNB capable of utilizing slowly biodegradable organics contributed to the adaptability of AnAOB. These findings provide valuable insights for ensuring efficient anammox performance and robust nitrogen removal in the treatment of low-strength sewage. [ABSTRACT FROM AUTHOR]

Background and Objectives: Antibiotics are among the most effective drugs used to treat humans. These materials enter in different ways into sewage and known as important biological contaminants in aquatic and agricultural environment. The availability of conditions for antibiotic resistance gene transfer to sewage bacteria, converted human environmental wastes to an important source of antibiotic resistant bacteria. Considering the spread of antibiotic resistant strains in treatment centers of Qom province, the aim of this study is to investigate the frequency and antibiotic resistance pattern in coliform bacteria isolated from wastewater treatment system of Qom city in different seasons. Methods: This study was carried out on 120 samples of municipal wastewater treatment plant (incoming and outgoing) in Qom. After sampling, transport of samples to the laboratory, isolation and phenotypic identification of bacteria, and Determination of antibiotic resistance pattern, were performed according to CLSI standards. The frequency of bacteria was determined using most probable number (MPN) method. Results: In this study, of 384 strains of bacteria (isolated in spring, summer, and winter), Escherichia coli (50%), Citrobacter (30%), Enterobacter (11%), Klebsiella (1%) and non-coliform bacteria (Proteus sp.) 8%, were identified. The most antibiotic resistance was observed in Citrobacter and Enterobacter bacteria (isolated in summer) to penicillin G with a frequency of 94%. Conclusion: Due to the high frequency of antibiotic resistance in Citrobacter and Enterobacter strains in the sewage treatment plant in Qom province, especially in the summer, this ecosystem can be reported as an important source of spread of antibiotic-resistant strains.

The occurrence, seasonal variation and emission of nine widely used phosphorus flame retardants (PFRs) were investigated in a wastewater treatment plant (WWTP) located in Guangzhou, China, over 1 year. Results showed that PFRs were widely detected in wastewater and sewage sludge. Tris(2-chloroisopropyl) phosphate (TCIPP) was the most dominant PFRs in influent, effluent, and sludge. Significant seasonal variation of total PFRs in the influent was observed (p < 0.05). However, no significant seasonal variation found in chlorinated and alkyl PFRs. The emission of PFRs was comparable with the previously reported values of decabromodiphenyl ether in WWTPs. Risk quotient for PFRs showed low eco-toxicity risk in effluent for aquatic organisms. Since the removal efficiency of total PFRs was less than 30% and the use of PFRs had been increasing, continuous monitoring of the environmental impact on the receiving water is still needed. [ABSTRACT FROM AUTHOR]

Abstract Elimination of nitrogen pollution from wastewater containing high-strength nitrate (NO 3 −-N) is a significant issue to prevent deterioration of water quality and eutrophication of receiving water body. Traditional denitrification process faces several challenges including the huge organic carbon demand, intermediate products accumulation, and long acclimatization period. In this study, an efficient solution was given by a novel two-stage Partial Denitrification (PD)-Anammox process. High NO 3 −-N (1000 mg N/L) wastewater and municipal sewage (COD: 182.5 mg/L, ammonia (NH 4 +-N): 58.3 mg/L) were simultaneously introduced to the PD reactor for NO 3 −-N converting to NO 2 −-N. The NH 4 +-N and NO 2 −-N in effluent of PD were removed in subsequent anammox reactor. Results showed that a satisfactory nitrogen removal was achieved by optimizing the volume ratios of influent NO 3 −-N and municipal sewage, as well as the external organic matter dosage. The NO 3 −-N removal efficiency reached up to 95.8% without accommodation period, along with the NH 4 +-N removal achieving 92.8%. Anammox contributed to 78.9% of TN removal despite the high COD (76.5–98.6 mg/L) in PD effluent was introduced, indicating the significant stability of the integrated process. The microbial analysis suggested that the Candidatus Brocadia , identified as anammox bacteria, cooperated stable with denitrifying bacteria in 215-day operation. The PD-Anammox process offers an economically and technically attractive approach in the high NO 3 −-N wastewater treatment since it has great advantages of much low carbon demand, minimal sludge production, enabling simultaneous treatment of municipal sewage, and avoiding the common issues in traditional denitrification process. Graphical abstract Unlabelled Image Highlights • Simultaneous treatment of high-strength nitrate and municipal sewage was demonstrated. • Nitrate removal efficiency reached up to 95.8% at influent nitrate of 1000 mg/L. • Municipal sewage was treated with nitrogen removal efficiency of 92.8%. • Anammox and denitrifying bacteria cooperated for advanced nitrogen removal. • Partial-denitrification combining with anammox is an economic and efficient option. [ABSTRACT FROM AUTHOR]

Highlights • An influent COD load forecasting model is proposed for municipal WWTPs. • The proposed forecasting model is based on hybrid ARMA and VAR algorithms. • The model shows high accuracy and good reliability with 1.08% of the MAPE. Abstract Due to different sources and the water using habits, the influent COD of municipal sewage fluctuates sharply over time. To ensure the treatment quality of sewage, the wastewater treatment plants (WWTP) often over-aerate the air and over-add the chemicals. This results in a waste of energy consumption and increases the operation cost for WWTP. With the rapid expansion of industrialization and urbanization, the quantity of municipal sewage has increased by years. Energy saving and sustainable water management for municipal WWTP are becoming an urgent issue that needs to be solved. This paper proposes a COD load forecasting model for municipal WWTP using hybrid artificial intelligence algorithms. The auto-regressive moving average (ARMA) algorithm is used for sewage inflow forecasting, and the vector auto-regression (VAR) algorithm is used for COD forecasting. The real-time data from a municipal WWTP is collected for model verification. Besides the proposed ARMA + VAR model, the BPNN, LSSVM, and GA-BPNN based COD load forecasting models are also studied as the contrasting cases. The accuracy of the forecasting performance of the ARMA + VAR model is as high as nearly 99%, which reveals its superior to the other forecasting models for future application in the wastewater treatment plants. [ABSTRACT FROM AUTHOR]

Wide occurrence of mercury species, including the highly toxic and readily bioaccumulative methylmercury (MeHg), in municipal sewage (MS) and sewage sludge (SS) has been evidenced in recent studies. Considering that vast amounts of MS and SS are produced globally each year and the majority of MS is discharged into aqueous environments, i.e., the main sites for MeHg bioaccumulation, special attention should be paid on the source and environmental behaviors of sewage-borne and sludge-borne mercury species. This review aims to summarize the findings on the occurrence of mercury species in MS and SS, their transport and transformation in MS treatment plants, as well as their fate and environmental implications. [ABSTRACT FROM AUTHOR]

Abstract This study investigated the influences of cetyltrimethyl trimethyl ammonium chloride (CTAC), an emerging pollutant quaternary ammonium compound (QAC) in municipal effluents, on the transfer and uptake of NH 4 + by Chlorella vulgaris F1068 cells removed EPS artificially (EPS-R) and coated EPS naturally (EPS-C) under different scenarios (e.g., the presence or absence of CTAC, different photoperiod sequences (light 12 h: dark 12 h or dark 12 h: light 12 h)). The results showed that the removal of EPS increased the transfer and uptake of NH 4 + but the presence of EPS caged NH 4 + and effectively weakened the stress of CTAC (<0.5 mg/L) on NH 4 + uptake. The main mechanism was considered that CTAC in the concentration range from 0.1 to 0.5 mg/L induced an increased amount of polysaccharide and protein in EPS and thus protected algal normal physiological functions (including cell membrane permeability and glutamine synthetase activity) from the damage of CTAC (0.1 to 0.5 mg/L) regardless of the photoperiod sequences. Thereby, the findings of this study provided an insight into the role of algal EPS in transfer and uptake of nutrients under the coexisted toxics for the future algae-based sewage treatment application. Graphical abstract Unlabelled Image Highlights • CTAC decreased uptake of NH 4 + but EPS retarded the decline of NH 4 + uptake. • EPS of algae F1068 decreased the toxicity of CTAC (<0.5 mg/L). • CTAC (<0.5 mg/L) increased the contents of polysaccharide and protein in EPS. • EPS protected algal membrane permeability, fluidity and glutamine synthetase. • EPS removal increased influx and uptake of NH 4 + compared to the presence of EPS. [ABSTRACT FROM AUTHOR]