Municipal Sewer Research Articles

P-117. Wastewater-Based Surveillance (WBS) of Shiga Toxin-Producing Escherichia coli (STEC) in Alberta, Canada

Abstract Background Shigatoxin-producing E. coli (STEC) are responsible for significant human morbidity, with the potential to cause severe food-borne illness and outbreaks. STEC incidence varies between communities and peaks in summer months (PMID 31652648). Leveraging a SARS-CoV-2 WBS program, we sought to explore genomic targets for STEC WBS.Figure 1.Prevalence of STEC differs across Alberta’s municipal sewer sheds Methods Composite-24h wastewater (WW) was collected from geographically disparate, and socioeconomically diverse Alberta communities (n=5) at the level of municipal WW treatment plants. From 04/2022-03/2024, monthly WW underwent pelleting and DNA extraction by Qiagen DNeasy PowerSoil Pro kit. WW extracts were assessed for four potential genomic STEC targets: Shiga Toxin 1 (stx1), Shiga Toxin 2 (stx2), Intimin (eae) and LPS O antigen gene specific for O157 (rfbEO157), by multiplex PCR. Each target was normalized by 16S rRNA-for total bacterial burden. WW STEC targets were assessed for correlation using Spearman’s and compared between communities and seasonality (July-Sept vs Jan-Mar) by Mann-Whitney U-test.Figure 2.STEC WBS demonstrates seasonal prevalence trends Results Of 111 WW samples assessed, 108 (97%) were positive for all targets, and individual targets were identified in 110 (99%) stx1; 110 (99%;) stx2; 111 (100%) eae, and 110 (99%) rfbEO157. Gene abundance for each STEC target exhibited strong correlations across sites (stx1 vs stx2, r=0.802, p< 0.0001; stx2 vs rfbEO157, r=0.634, p< 0.0001; eae vs rfbEO157, r =0.551, p< 0.0001; stx2 vs. eae r=0.542, p< 0.0001). WW measured STEC gene targets exhibited significant differences between municipalities (Figure 1) with strong seasonal trends (Figure 2). Conclusion WBS for STEC yielded patterns consistent with established patterns of disease (PMID 31652648). All four STEC genomic targets demonstrated significant correlation across sewersheds. STEC WBS may represent a novel tool to understand and monitor population-level activity and prevent disease. Disclosures All Authors: No reported disclosures

Efficient Treatment of Leachate from Municipal Solid Waste Transfer Stations via a Bioreactor–Nanofiltration System: A Pilot-Scale Study

The management of municipal solid waste leachate has emerged as a pivotal challenge in sustainable urban development. Currently, there is limited information on the practical engineering applications of bioreactors and nanofiltration systems on the pilot scale. This work employs a bioreactor–nanofiltration pilot system for the treatment of leachate in municipal solid waste transfer stations. The results demonstrate that the bioreactor–nanofiltration system exhibits excellent and stable efficiency in removing organic pollutants and heavy metal ions. The effluent qualities of COD, TN, and TP are 50, 28, and 2 mg/L, and the removal rates are 99.4%, 99.3%, and 96.1%, respectively. All types of heavy metal ions also comply with the standard limits specified in the “Wastewater quality standards for discharge to municipal sewers” (GB/T 31962-2015). More importantly, using waste materials such as mineralized waste and animal aggregates as bioreactor fillers increases the diversity of the microbial community in the system, and provides an engineering basis for the resource utilization of waste materials. The bioreactor–nanofiltration process is expected to become an ideal solution for the treatment of leachate in transfer stations.

Novel insights on biofilm development in sewers: Cross-kingdom exchange of quorum-sensing signaling molecules

In sewers, biofilms are generated due to long-distance sewage transportation. However, the metabolism and reproduction of bacteria and fungi in biofilms and the mechanism of cross-kingdom exchanges mediated by quorum-sensing signaling molecules remain unclear. In this study, the distributions of bacteria and fungi communities in biofilms were investigated using high-throughput sequencing. The mechanism by which signaling molecules participate in biofilm development was explored through statistical analysis. The ecosystem operation mode featured by pollutant conversion, bacteria–fungi interaction (BFI), and cross-kingdom exchange of key signaling molecules in municipal sewers was clarified. The result showed that variations in C, N, and S pollutants in the sewer were related to BFI. Lactivibrio and Candida, key species generating signaling molecules in bacteria and fungi, significantly accelerated pollutant biodegradation and biofilm development. Additionally, a quantitative detection system was established for the signaling molecules. The average concentrations of C4-HSL, C10-HSL, and 3-oxo-C12-HSL (bacteria) were 0.25, 1.41, and 0.98 μg/L, respectively. Average concentrations of farnesol, tyrosol, and farnesoic acid signaling molecules were 10.04, 126.29, and 94.79 ng/L, respectively. Moreover, thickness and extracellular polymeric substances in different stages of biofilm development were explored. The results showed that acyl homoserine lactones dominated biofilm development, whereas signaling molecules of C. albicans had limited influences. The interaction of Pseudomonas aeruginosa and C. albicans dominated the cross-kingdom exchange between bacteria and fungi mediated by signaling molecules. This study reveals the characteristics of the interaction and metabolism of bacteria and fungi in sewers. It also provides theoretical references for social behaviors and the regulation of microbes in biofilms in sewers.

Cigarette butt littering as a potential source of water pollution and human health risk

Smoked cigarette butts (CBs) serve as reservoirs for harmful contaminants. The objective of the current study is to assess the CB littering in Aizawl city and estimate its potential contribution to water pollution in downstream surface water sources, along with the associated human health risks. The spatial-temporal distribution of CB littering density (CBD) across the city, spanning various land-use patterns, was analyzed through a visual-oriented littering survey. With an annual average CBD of 0.438 ± 0.669 CBs/m2, commercial areas were identified as the littering hotspots. Further, the water pollution potential index (WPPI) was formulated considering leached concentrations of different contaminants from CBs into the water and their standard permissible limits. WPPI was calculated as 5.22 × 10−02, which represented water pollution potential from a single CB/L of water. This corresponded to a cumulative WPPI of (59.97 ± 6.68) × 10−06 from CB littering to surface water pollution through municipal sewerage system. The health risk assessment associated with CB littering was analyzed through the potential chronic daily intake (CDI) of leached contaminants, non-cancer risk (NCR), and cancer risk (CR). Heavy metals (lifetime exposure of 1125.9 mg from 1 CB/L) were found to be the most significant contributor to the cumulative CR (3.847 × 10−06) and hazard index (HI) (1.785 × 10−02). Further, it was estimated that the potential CR associated with 242 CBs/L in water is equivalent to smoking 1 cigarette per day for a lifetime. The WPPI, CR, and HI suggested that littered CBs can significantly contribute to water pollution.

Carbon flow allocation patterns of CH4, CO2, and biomass production vary with sewage and sediment microbial and biochemical factors in the anaerobic sewer environment.

Understanding the carbon (C) fate in municipal sewers is imperative for optimizing current sewer-C-degradation control and treatment efficiency, aligning with China's C-neutrality strategy in determining the exact C budget of the wastewater system. This study used laboratory batch tests mimicking the anaerobic sewer environment and sewage-sediment stratification to evaluate C flow allocation (CFA) patterns in response to biotic and abiotic variables. We quantified the C equivalent mass (CEM) and used absolute quantitative 16S rRNA gene amplicon sequencing to characterize the microbiome. The substantial methane production (CH4, 17.2%-18.8%) required both activated sediment and exogenous C, while biomass production (BP, 63.1%-74.9%) formed C sink predominated as the main CFA direction under the stratified state. This was supported by the high diversity, interspecific interactions, and metabolic capacity of the sediment microbiome. However, CH4 and BP patterns demonstrated non-synchronicity and opposite dynamic characteristics. Carbon dioxide (CO2, 64.0%-81.3%) production dominated the sewage CFA. The absolute abundance of the sediment microbiome, which was 5.6 times higher than that of the sewage, exhibited a strong increase in magnitude across the phases. It was primarily associated with biomass growth and N metabolism, whereas sewage showed differentiated and competing communities and appeared to act mainly as the exogenous C sources. We constructed a binary quadratic linear model revealing the non-linear relationship between ACK activity, DOC degradation rate, and CEMCH4 rate; the former maintained low CH4 production when the available substrate was insufficient. The influence of N and S factors on the CFA is complex and multi-faceted. These findings highlight the importance of further investigations into the process-based framework of the sewer C budget, focusing on the C source-emission-sink functions and mass balance.

A Review of Sanitation Options and Programming in Ghana, West Africa

This review examines Ghana’s progress in sanitation. These efforts include the containment, transport, treatment, and disposal or reuse of human waste. This research specifically examined the current sanitation processes and programming efforts within Ghana, West Africa. Some reports indicate that Ghana is the second dirtiest country in Africa and the seventh dirtiest country in the world. A review of the current water, sanitation, and hygiene (WASH) options within the country indicates that significant efforts need to be undertaken. There are multiple toilet options and current practices within the country for the disposal of excrement. Unfortunately, the municipal sewer systems and wastewater treatment facilities within the country are either broken down or severely inadequate compared to their surrounding population. Current WASH programming, extension efforts, and key factors affecting the uptake of sanitation investment are reviewed. The price point where consumers would utilize sanitation products and services was analyzed, as well as the cost-to-benefit ratio of specific technologies for community members. This review demonstrated that initiatives should be undertaken to provide more sanitation professionals, renovate and expand urban municipal sewerage systems, and provide basic access to rural community areas. It was recommended that future programming, extension, and policy efforts be intentional and include relevant stakeholders and community members to provide a greater opportunity for establishing successful and substantial efforts.

A Conceptual Site Model for Per‐ and Polyfluoroalkyl Substance Water Supply Impacts in a Residential Community

ABSTRACTAt a Class 4 State Superfund site located in a densely developed residential/commercial area in a suburb of New York City, emerging contaminant sampling for PFAS was performed as part of a statewide data‐gathering project. Two per‐ and polyfluoroalkyl substances (PFAS), perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), were detected at concentrations in excess of drinking water standards in bedrock and overburden monitoring wells at the State Superfund site. A bedrock private water supply well sampling program and a PFAS source investigation, consisting of overburden investigations near potential sources (i.e., sites with a history of known or suspected use, storage, or discharge of PFAS), were undertaken to assess exposures and identify and potentially eliminate sources of PFAS contaminants in the bedrock drinking water supply.Relative ratios of PFAS (i.e., PFAS signatures) were plotted geospatially to facilitate comparison of the characteristics of overburden groundwater sampling results to that of nearby bedrock private water supply sampling results. In addition, total PFAS concentrations in overburden groundwater and bedrock private water supply samples were compared to identify potential sources of bedrock groundwater impacts. The PFAS signature analysis revealed that (1) PFAS signatures of overburden groundwater samples were generally consistent with nearby bedrock private water supply samples; (2) total PFAS concentrations detected in overburden groundwater samples were marginally higher than concentrations detected in nearby bedrock private water supplies; (3) there was generally low variability in PFAS signatures throughout the study area (Assessment Area); and (4) overburden groundwater and bedrock private water supply PFAS signatures were similar to that of the nearby wastewater treatment plant effluent discharge, which represents a composite average PFAS signature for domestic wastewater from the area. Finally, septic system tracers were also detected in bedrock private water supply and overburden groundwater samples. Based on the results of the investigation, multiple lines of evidence support the Conceptual Site Model, which is likely applicable to many PFAS‐contaminated drinking water supplies with conditions similar to the Assessment Area: consumer product use and discharge to domestic septic systems in a densely developed residential area, lacking area‐wide municipal water and sewer, with shallow groundwater and bedrock, and a vertical downward groundwater gradient, have resulted in the widespread presence of PFAS in private water supply wells.

A comparative study of the potentials of Oman and UAE in condensate water recovery

<p class="MsoNormal" style="text-align: justify; text-justify: inter-ideograph; line-height: 120%; mso-pagination: none; layout-grid-mode: char; mso-layout-grid-align: none; text-autospace: none; margin: 12.0pt 0cm 6.0pt 147.4pt;"><span lang="EN-US" style="font-size: 10.0pt; line-height: 120%; font-family: 'Times New Roman',serif;">Freshwater is essential for everyday activities including drinking, irrigation, farming and many industrial processes. However, freshwater is less than 1% of the total water resources in the planet and, therefore, it is considered a very valuable commodity. Limited resources and growing needs for freshwater triggered global exploration for alternatives to produce enough freshwater for human needs. Today’s most widely used methods to produce freshwater is desalination. However, critical appraisal of the desalination procedures raised the alarm about </span><span lang="EN-GB" style="font-size: 10.0pt; line-height: 120%; font-family: 'Times New Roman',serif; mso-fareast-font-family: 宋体; mso-font-width: 105%; mso-font-kerning: 0pt; mso-ligatures: none; mso-ansi-language: EN-GB;">sustainability</span><span lang="EN-US" style="font-size: 10.0pt; line-height: 120%; font-family: 'Times New Roman',serif;"> of desalination and indicated that significant research is needed to develop alternative green resources of freshwater. Countries in the Gulf area such as Oman and UAE experience hot and humid climates and use air-conditioning units to achieve acceptable comfort levels and create a </span><span lang="EN-GB" style="font-size: 10.0pt; line-height: 120%; font-family: 'Times New Roman',serif; mso-fareast-font-family: 宋体; mso-font-width: 105%; mso-font-kerning: 0pt; mso-ligatures: none; mso-ansi-language: EN-GB;">healthier</span><span lang="EN-US" style="font-size: 10.0pt; line-height: 120%; font-family: 'Times New Roman',serif;"> indoor environment. The cooling process release a large amount of condensate water through cooling coils. This amount of water is usually considered as a problem rather than opportunity and, thus, is wasted into municipal sewerage systems via a system of drainage pipes. This alternative source can be utilized in various drainage, irrigation, and cooling applications to reduce the use of considerable amount of municipal potable water. This source not only takes part in controlling the water scarcity, but also in saving energy and to reducing the carbon footprint. This paper focus on highlighting the opportunities for Oman and UAE to utilize the condensate water from air-conditioning process, as a viable alternative source of green </span><span lang="EN-GB" style="font-size: 10.0pt; line-height: 120%; font-family: 'Times New Roman',serif; mso-fareast-font-family: 宋体; mso-font-width: 105%; mso-font-kerning: 0pt; mso-ligatures: none; mso-ansi-language: EN-GB;">fresh</span><span lang="EN-US" style="font-size: 10.0pt; line-height: 120%; font-family: 'Times New Roman',serif;"> water. It provides a comparison of the potentials of both countries to collect condensate water, based on meteorological data, location and climate. It was concluded that both countries have great potentials and opportunities to utilize this wasted resource. </span></p>

Biotemplated Fe/La-co-doped TiO2 for photocatalytic depth treatment of compressed leachate from refuse transfer station.

Compressed leachate is a contaminated liquid containing various organic and inorganic pollutants produced in municipal refuse transfer stations, which pollute soil and groundwater, posing serious risks to the environment and human health. The Environmental Technology Co., Ltd. (Shenzhen, Guangdong Province, South China) treated compressed leachate obtained from a refuse transfer station. The chemical oxygen demand (COD) (641.2mg/L) of treated compressed leachate did not meet the wastewater quality standards in China for discharge into municipal sewers (COD ≤ 500mg/L) and the company's design discharge requirements (COD ≤ 400mg/L). Therefore, their further in-depth treatment is necessary. To this end, waste tobacco leaves were used as the biotemplate herein, and Fe/La-co-doped TiO2 (xFe,yLa)-TTiO2(g) was synthesized using a solvothermal-assisted biotemplating method. The photocatalytic depth treatment of compressed leachate was performed under simulated solar light using the prepared catalysts. After (3Fe,3La)-TTiO2(g) treatment, the COD of the leachate decreased from 641.2 to 280.1mg/L, and the COD removal rate was 1.2, 1.1, and 1.6 times higher than that of pure Fe-doped, La-doped and non-biological template TiO2, respectively. Characterization confirmed that the biological template endowed the catalyst with a unique morphology and high specific surface area. Its rich activity sites are conducive to enhancing the adsorption capacity of pollutants and providing an ideal place for photocatalytic reactions. Co-doping with iron and lanthanum ions altered the band structure of TiO2 and promoted the interconversion of Fe3+/Fe2+ and La3+/La2+ during photocatalysis. First-principles density functional theory simulations demonstrated that co-doping Fe and La in TiO2 created impurity levels that facilitated the transfer of photogenerated electrons. This study provides a new purification pathway for the depth treatment of compressed leachate.

Quantitative fecal source characterization of urban municipal storm sewer system outfall ‘wet’ and ‘dry’ weather discharges

Urban areas are built environments containing substantial amounts of impervious surfaces (e.g., streets, sidewalks, roof tops). These areas often include elaborately engineered drainage networks designed to collect, transport, and discharge untreated stormwater into local surface waters. When left uncontrolled, these discharges may contain unsafe levels of fecal waste from sources such as sanitary sewage and wildlife even under dry weather conditions. This study evaluates paired measurements of host-associated genetic markers (log10 copies per reaction) indicative of human (HF183/BacR287 and HumM2), ruminant (Rum2Bac), canine (DG3), and avian (GFD) fecal sources, 12-hour cumulative precipitation (mm), four catchment land use metrics determined by global information system (GIS) mapping, and Escherichia coli (MPN/100 ml) from seven municipal separate storm sewer system outfall locations situated at the southern portion of the Anacostia River Watershed (District of Columbia, U.S.A.). A total of 231 discharge samples were collected twice per month (n = 24 sampling days) and after rain events (n = 9) over a 13-month period. Approximately 50 % of samples (n = 116) were impaired, exceeding the local E. coli single sample maximum of 2.613 log10 MPN/100 ml. Genetic quality controls indicated the absence of amplification inhibition in 97.8 % of samples, however 14.7 % (n = 34) samples showed bias in DNA recovery. Of eligible samples, quantifiable levels were observed for avian (84.1 %), human (57.4 % for HF183/BacR287 and 40 % for HumM2), canine (46.7 %), and ruminant (15.9 %) host-associated genetic markers. Potential links between paired measurements are explored with a recently developed Bayesian qPCR censored data analysis approach. Findings indicate that human, pet, and urban wildlife all contribute to storm outfall discharge water quality in the District of Columbia, but pollutant source contributions vary based on ‘wet’ and ‘dry’ conditions and catchment land use, demonstrating that genetic-based fecal source identification methods combined with GIS land use mapping can complement routine E. coli monitoring to improve stormwater management in urban areas.

Assigning strategic COD flow to enhance denitrification coupled with anaerobic digestion and anammox for systematic upgradation of advanced nitrogen removal from food waste digestate

Anammox is a low-carbon and efficient technology for treating high-strength ammonium in food waste digestate (FWD). However, achieving superior low-nitrogen effluent levels to meet strict discharge standards remains challenging. This study proposes an anammox-based process that integrates simultaneous denitrification and methanogenesis (SDM), partial nitrification (PN), and simultaneous anammox and denitrification (SAD) to realize advanced nitrogen removal from FWD by strategically utilizing influent organic matter. The SAD process achieved an inorganic nitrogen removal efficiency of 94.0 %, with the anammox reaction contributing 96.0 %. Residual nitrate in the SAD effluent was recirculated into SDM, maintaining a removal efficiency of 95 %–97 %. Profiling wastewater and material flows in the integrated process showed a 97.2 % nitrogen removal efficiency, with effluent nitrogen levels meeting discharge standards (<70 mg/L for municipal sewer systems). 3D-fluorescence analysis indicated that quasi-humic acid was effectively removed through SDM. Soluble microbial by-products of FWD served as carbon source for the denitrifying bacteria in SAD. Controlling influent bypass flow and effluent recirculation allowed for strategic allocation of chemical oxygen demand (COD) flow, achieving a total removal efficiency of 71.8 %. SDM removed 45.8 % COD, followed by PN at 13.4 % and SAD at 12.6 %. Compared with those of conventional nitrification and denitrification process, the economic cost, greenhouse gas emission, and total environmental impact of this integrated process were reduced by 85.8 %, 35.8 %, and 84.1 %, respectively. This study provides new insights into the application of anammox-based process for attaining advanced nitrogen removal while minimizing environmental impact.

Fiscal institutions and racial equity: Determining the price of water

AbstractMunicipal water utilities across the United States establish their own rate structures to cover operations, maintenance, depreciation, and outstanding debt repayment. Yet, little is known about how rates are determined to ensure equity and/or affordability. To identify sources of variation in residential drinking water rates, we examine municipalities in northeastern Illinois, 2015–2019. Controlling for water utility characteristics, billing structures, financial management, service quality, and demographic/socioeconomic factors, we find no statistically significant correlations between water rates and median household income or race when nonrevenue water from leaking infrastructure is considered, revealing relative racial equity in water pricing within these communities. A larger water distribution network, more water included in the base charge, and a greater number of months in the billing cycle are all associated with lower rates. Purchasing water through an individual or cooperative agreement, a greater proportion of nonrevenue water from leaking infrastructure, a higher minimum monthly base charge, and more revenue debt outstanding (while controlling for nonrevenue water) are all associated with higher rates. We also find a positive correlation between municipal sewer rates and drinking water rates that supports findings from prior research. Overall, our research aids in the development of public policy that ensures all households have access to affordable and safe drinking water to promote water equity and public health.

Enhancing pollutants removal in hospital wastewater: Comparative analysis of PAC coagulation vs. bio-contact oxidation, highlighting the impact of outdated treatment plants

While the effectiveness of Poly-Aluminum Chloride (PAC) coagulation for pollutant removal has been documented across various wastewater scenarios, its specific application in hospital wastewater (HWW) treatment to remove conventional pollutants and hazardous genetic pollutants has not been studied. The research compared three hospital wastewater treatment plants (HWTPs) to address a knowledge gap, including the PAC coagulation-sodium hypochlorite disinfection process (PAC-HWTP), the biological contact oxidation-precipitation-sodium hypochlorite process (BCO-HWTP), and a system using outdated equipment with PAC coagulation (ODE-PAC-HWTP). Effluent compliance with national discharge standards is assessed, with BCO-HWTP meeting standards for direct or indirect discharge into natural aquatic environments. ODE-PAC-HWTP exceeds pretreatment standards for COD and BOD5 concentrations. PAC-HWTP effluent largely adheres to national pretreatment standards, enabling release into municipal sewers for further treatment. Metagenomic analysis reveals that PAC-HWTP exhibits higher removal efficiencies for antibiotic resistance genes, metal resistance genes, mobile genetic elements, and pathogens compared to BCO-HWTP and ODE-PAC-HWTP, achieving average removal rates of 45.13%, 57.54%, 80.61%, and 72.17%, respectively. These results suggests that when discharging treated HWW into municipal sewers for further processing, the use of PAC coagulation process is more feasible and cost-effective compared to BCO technologies. The analysis emphasizes the urgent need to upgrade outdated equipment HWTPs.

Evaluating Sediment Removal Efficiency of Catch Basin Inserts as a Post-Construction Water Quality Tool on Roadways

Urban areas produce large amounts of stormwater runoff due to vast areas of impervious surfaces. Stormwater inlets, or catch basins, are commonly used for collecting and directing stormwater runoff away from streets and sidewalks. The conveyances used to direct flow to surface waters may be part of a municipal separate storm sewer systems (MS4s). Typically, MS4s redirect runoff without providing a means for removing harmful pollutants. These pollutants are then often discharged directly into local lakes, rivers, and streams, potentially harming native aquatic ecosystems. Post-construction stormwater practices are commonly used to treat runoff from urban areas by reducing the total runoff volume, lowering peak flow rates, and/or removing harmful pollutants from runoff. However, some post construction stormwater practices require large footprints, construction, and maintenance. Catch basin inserts (CBIs) are one type of post-construction best management practice that are installed within existing catch basins and require no additional land use while still providing a means for removing pollutants from stormwater runoff before entering the MS4. However, limited data is available to demonstrate the expected performance of various CBIs to ensure that these practices meet the pollutant removal standards set forth by the US Environmental Protection Agency (USEPA). The objective of this study was to evaluate the sediment removal capabilities of eight different proprietary CBI products for potential use as a post-construction stormwater practice for Department of Transportation projects. Results indicate that only two basket-type CBIs met the 80% sediment retention benchmark established for the study. While not surpassing the benchmark, three bag-type CBIs did achieve more than 70% sediment retention. The remaining three CBIs (one basket-type, one bag-type, and one cartridge type) fell notably short of the performance benchmark.

Electrocatalytic water treatment of per- and polyfluoroalkyl substances reduces adsorbable organofluorine and bioaccumulation potential.

Per- and polyfluoroalkyl substances (PFAS) are pervasive in industrial processes, eliciting public concern upon their release into municipal sewers or the environment. Removing PFAS from the environment has become an urgent need. However, because potential endpoints span from energy-intensive complete mineralization to partial PFAS transformation, understanding and developing metrics for evaluating PFAS treatment can be a challenge. The goal of this study was to evaluate and compare the effectiveness of electrocatalytic degradation of PFAS with boron-doped diamond (BDD) electrodes using four techniques: LC-MS/MS target analysis, fluoride ion (F-), adsorbable organofluorine (AOF), and bioaccumulation potential using lipid-bilayer partition (LBP) tests. After 3 hours of electrocatalysis, >99% perfluorooctanoic acid (PFOA) degradation was achieved and corresponded with 84% conversion to F-, which was substantial - though intentionally not complete - defluorination. For the same 3 hour treatment time, AOF and LBP coefficient were reduced by 95% and 83%, respectively. LBP's detection limit was 2 orders of magnitude higher than that of AOF, so the positive correlation observed between LBP and AOF (r = 0.86) suggests AOF's practical utility as a design metric for assessing bioaccumulation potential of various organofluorine transformation by-products.

Exploring the variability of PFAS in urban sewage: a comparison of emissions in commercial versus municipal urban areas.

Per- and polyfluoroalkyl substances (PFAS) are recognized for their persistence and ubiquitous occurrence in different environmental compartments. Conventional wastewater treatment plants (WWTPs) cannot effectively remove PFAS from wastewater, and a better understanding of the occurrence and sources of PFAS in this medium would enable effective source abatement. We compared sewage from urban areas exhibiting differentiating characteristics with respect to activities in their catchments. These included a sewer that serves primarily a municipal area, with no commercial activities involving PFAS emissions being identified, another sewer with a strong influence of commercial activities potentially related to PFAS emissions, and the influent of the whole city sewage network. The year-long monitoring campaign consisted of flow-proportional, monthly composite samples and targeted analysis of 29 PFAS compounds. Principal component analysis was used to investigate the relationships between selected PFAS and standard water quality parameters such as ammonium, a known tracer of urine and thus of typical municipal wastewater. Notable findings were seen for PFOS and 6:2 FTS, whose concentrations were most negatively correlated with ammonium. Ammonium concentration data allowed for a normalized per-person median load calculation, which resulted in loads of the observed PFAS ranging from below 0.4 up to 4.7 μg per person per day. Both the commercial area sewer and the city influent exhibited significantly higher (p < 0.05) median loads (>0.9 μg per person per day) in the case of 6:2 FTS and PFOS, compared to the municipal sewer (<0.6 μg per person per day). No statistically significant difference was found for other compounds, such as PFBA, PFHxA, PFOA, and PFHxS. We argue that this approach demonstrates that PFAS can differ in speciation and quantity within an urban wastewater setting, and consideration of both municipal and commercial activities is needed for a proper understanding of sources and emission pathways within the urban environment.

High-throughput absolute quantification sequencing reveals the adaptive succession and assembly pattern of plastisphere communities in municipal sewer systems: Influence of environmental factors and microplastic polymer types

Municipal sewer systems have received increasing attention due to the magnitude of the microplastic stock and its potential ecological impacts. However, as a critical aspect of the adverse impacts, little is known about the plastisphere that forms in these engineered environments. Using high-throughput absolute quantification sequencing, we conducted a systemic study combining field survey and laboratory batch test to explain the general plastisphere pattern and the role of environmental and polymeric factors in driving plastisphere succession and assembly there. We demonstrated the capacity of microplastics to support high levels of microbial colonization, increasing by 8.7–56.0 and 1.26–5.62 times at field and laboratory scales, respectively, despite the less diverse communities hosted in the resulting plastisphere. Sediment communities exhibited higher diversity but greater loss of specific operational taxonomic units in their plastisphere than in the wastewater. The former plastisphere had primarily an enhanced methanogenesis-oriented metabolic network linked to hydrolysis fermentation, hydrogen-producing acetogenesis, and denitrification, while the latter had a pronounced niche partitioning and competitive interaction network. Exogenous substrate flux and composition were key in stimulating plastisphere community growth and succession. Furthermore, the high nitrogen baseline facilitated alternative niche formation for plastisphere nitrifiers and denitrifiers, and the plastisphere pathogens associated with denitrification and plastic biodegradation functions increased significantly. The aerobic state also promoted a 1.71 times higher colonizer load and a denser interaction pattern than the anaerobic state. Selective filtering by polymers was evident: polyethylene supported higher plastisphere diversity than polypropylene. This study provides new insights into the mechanisms driving colonizer loads and the adaptive succession and assembly of the plastisphere in such a typically hydrodynamic and highly contaminated environment. The results help to fill the knowledge gap in understanding the potential role of microplastics in shaping the microecology of sewers and increasing health risks and substrate loss during sewer transfer.

ANALYSIS OF METHODS FOR ASSESSING THE IMPACT OF A COKE PLANT ON THE ENVIRONMENT

This academic paper explores various assessment methods used to evaluate the environmental impact of industrial enterprises, specifically focusing on coke plants. The study emphasises the widespread use of a global risk-based approach for assessing the environmental risks posed by such enterprises to both the environment and public health. This approach involves predicting potential future environmental consequences under different scenarios, with the choice of a specific method dependent on the particular conditions, objectives, and available resources.The analysis of these assessment methods reveals the prevalence of an integrated approach, which comprehensively evaluates multiple aspects of an industrial enterprise’s environmental impact. Moreover, the research underscores the importance of adopting modern technologies and strategies to enhance water supply and wastewater management efficiency for environmental preservation.The assessment of the ‘Kharkiv Coke Plant’ indicates minimal impact on land inundation issues, with little effect on groundwater quality. However, the excessive consumption of freshwater remains a significant concern, necessitating improved efficiency in the operation of the plant’s wastewater recycling systems. To evaluate the enterprise’s influence on surface waters, notably the Lopan and Udy rivers, the paper calculates the volume and flow of wastewater originating from the facility’s premises.Additionally, environmental impact assessment is conducted using key environmental indicators, including the alarm index, hazard index, and priority index. In light of the identified environmental challenges at the investigated industrial facility, including wastewater discharge into the municipal sewerage system, high water consumption, and phenol emissions from the quenching tower, the paper proposes a solution. This solution entails enhancing the plant’s water recycling infrastructure through the implementation of a closed-loop water recycling system and improving the efficiency of the biochemical plant. This approach aims to mitigate the environmental impact of the enterprise while promoting sustainable water management practices. Keywords: environmental problems, water resources, degree of pollution, enterprises.

Industrial Wastewater Indirect Discharges in Integrated Pollution Prevention and Control Perspective: A Case Study of Prague

Wastewater discharge is one of the sources of environmental pollution. Wastewater pollution originates, inter alia, in industrial wastewater. After treatment, industrial wastewater can be discharged directly into the receiving water body or indirectly into a sewerage network terminated by the concluding stage of wastewater treatment. In the Czech Republic, indirect wastewater discharges are obeyed by the contractual relationship between the wastewater producer and the sewerage network operator. General limits for indirectly discharged wastewater are not set by any national legislation. The aim of this paper is a description of industrial wastewater discharged into the municipal sewerage system in Prague and possibilities of setting limits for installations undertaking the industrial activities listed in Annex I of the Integrated Prevention Act. The study showed that 72% of installations discharge industrial wastewater indirectly. The majority are energy plants that produce boiler blowdown wastewater. More than 80% of wastewater from studied installations is treated by one central wastewater treatment plant. The studied installations are equipped with a wastewater neutralization unit. However, despite the existence of the legislative framework to propose limits for studied installations, only two installations covered by BAT conclusions with relevant BAT-AELs for indirect discharges to the receiving water body were determined. Generally, a small percentage of installations can be limited by an integrated permit due to an inconsistent approach to the issue of indirect discharges from installations under the scope of the Integrated Prevention Act.

Changes in stoichiometric ratio of carbon and sulfate affect methanogenesis pathways in sulfate-rich sewers

Methane emissions from sewer systems have been a major concern in terms of posing safety risks and aggravating the greenhouse effect. Discharging a large amount of sulfate-rich wastewater produced by industrial manufacture into municipal sewers breaks the balance between organic matter and sulfate, and has a significant influence on methanogenesis. However, the direct impact of sulfate-rich wastewater on the interactions between methane and sulfate metabolism in sewers remains unclear. In this study, methane production, microbial community and functional genes of the sewers with different chemical oxygen demand/sulfate ratios (C/S) were studied by 33 sampling sites collected in full-scale field investigation. The concentrations of chemical oxygen demand in the sewers were 10.0–378.0 mg/L, while the concentrations of sulfate fluctuated in a wider range of 4.1–758.4 mg/L, which distinguished the sewers into different C/S of 0.3, 2.5 and 5.8. With the average sulfate concentrations of 37.9 mg/L, the methane-production capabilities of sewers were reduced as the decreased C/S from 5.8 to 2.5. In contrast, the sewers with low C/S of 0.3 and high sulfate concentration of 368.2 mg/L exhibited twice as much methane concentrations (1.2 mL/L) than the sewers (0.6 mL/L) with C/S of 2.5 and 5.8. Genera showing a positive correlation (Enterobacter, Prevotella_9 and Acinetobacter) and a negative correlation (Bacteroidetes vadinHA17_norank, Smithella and Thiobacillus) with methanogenesis contributed significant variations of methane in the sewers with different C/S. The results of functional gene prediction suggested that the main pathways of methanogenesis in sewers with C/S of 5.8 and 2.5 were acetoclastic (ACSS and ackA) and hydrogenotrophic methanogenesis (mtrA, mtrH and K00400), whereas methylotrophic methanogenesis (mttB) was dominant in sewers with C/S of 0.3. The genes expressed by methylotrophic methanogens in sewer with low C/S and higher sulfate concentration refrained from the competitive inhibition by SRB, which contributed to the superior methane-production of the sewers. These results bridge the knowledge gap of methanogenesis with different sulfate levels and improve the understanding of methane cycle driven by microorganisms, facilitating more accurate prediction and assessment of methane in sewers.