Municipal Wastewater Collection Research Articles

Methane Emissions from Municipal Wastewater Collection and Treatment Systems.

Municipal wastewater collection and treatment systems are critical infrastructures, and they are also identified as major sources of anthropogenic CH4 emissions that contribute to climate change. The actual CH4 emissions at the plant- or regional level vary greatly due to site-specific conditions as well as high seasonal and diurnal variations. Here, we conducted the first quantitative analysis of CH4 emissions from different types of sewers and water resource recovery facilities (WRRFs). We examined variations in CH4 emissions associated with methods applied in different monitoring campaigns, and identified main CH4 sources and sinks to facilitate carbon emission reduction efforts in the wastewater sector. We found plant-wide CH4 emissions vary by orders of magnitude, from 0.01 to 110 g CH4/m3 with high emissions associated with plants equipped with anaerobic digestion or stabilization ponds. Rising mains show higher dissolved CH4 concentrations than gravity sewers when transporting similar raw sewage under similar environmental conditions, but the latter dominates most collection systems around the world. Using the updated data sets, we estimated annual CH4 emission from the U.S. centralized, municipal wastewater treatment to be approximately 10.9 ± 7.0 MMT CO2-eq/year, which is about twice as the IPCC (2019) Tier 2 estimates (4.3-6.1 MMT CO2-eq/year). Given CH4 emission control will play a crucial role in achieving net zero carbon goals by the midcentury, more studies are needed to profile and mitigate CH4 emissions from the wastewater sector.

Batch correction methods for nontarget chemical analysis data: application to a municipal wastewater collection system

Nontarget chemical analysis using high-resolution mass spectrometry has increasingly been used to discern spatial patterns and temporal trends in anthropogenic chemical abundance in natural and engineered systems. A critical experimental design consideration in such applications, especially those monitoring complex matrices over long time periods, is a choice between analyzing samples in multiple batches as they are collected, or in one batch after all samples have been processed. While datasets acquired in multiple analytical batches can include the effects of instrumental variability over time, datasets acquired in a single batch risk compound degradation during sample storage. To assess the influence of batch effects on the analysis and interpretation of nontarget data, this study examined a set of 56 samples collected from a municipal wastewater system over 7 months. Each month’s samples included 6 from sites within the collection system, one combined influent, and one treated effluent sample. Samples were analyzed using liquid chromatography high-resolution mass spectrometry in positive electrospray ionization mode in multiple batches as the samples were collected and in a single batch at the conclusion of the study. Data were aligned and normalized using internal standard scaling and ComBat, an empirical Bayes method developed for estimating and removing batch effects in microarrays. As judged by multiple lines of evidence, including comparing principal variance component analysis between single and multi-batch datasets and through patterns in principal components and hierarchical clustering analyses, ComBat appeared to significantly reduce the influence of batch effects. For this reason, we recommend the use of more, small batches with an appropriate batch correction step rather than acquisition in one large batch.Graphical abstract

Numerical modeling of groundwater flow and nitrate transport using MODFLOW and MT3DMS in the Karaj alluvial aquifer, Iran.

Nitrate is one of the most dangerous pollutants in groundwater, being regarded as a severe environmental hazard and a global-scale problem. The present study aims to analyze the groundwater flow and nitrate contamination in the Karaj unconfined aquifer, Central Iran. Simulation of the quantitative and qualitative status was performed using MODFLOW and MT3DMS. Sampling was done to model groundwater flow for eight seasonal time periods and nitrate pollution transport for four time periods (a total of 420days), and calibration was carried out by trial-and-error method. Due to the predominance of advection term in the transport of nitrate pollution, the total variation diminishing method was used in transport modeling. The groundwater flow modeling showed a reservoir deficit of - 33 MCUM and 67cm decrease in the water year 2016-2017 and 173cm in the entire modeling period (2016-2018) in groundwater level. Also, the RMSE in the calibration and validation stages was obtained from 24.9 to 0.72 and 0.84, respectively. The nitrate contamination transport modeling indicated that there are three nitrate contamination concentration parts with more than safe concentration of nitrate (50mg/l). The most pollution is in the urban areas in the east of the aquifer. The nitrate pollution is primarily anthropogenic due to industrial and especially domestic wastewater and then fertilizers used in agricultural activities. It can be predicted that with the full implementation of a municipal wastewater collection network, the nitrate pollution concentration in urban areas would reduce significantly to the range of 20 to 25mg/l.

Optimal Design of Municipal Wastewater Collection Networks with Long-Term Performance Improvement Approach

Optimal Design of Municipal Wastewater Collection Networks with Long-Term Performance Improvement Approach

Investigating SARS-CoV-2 RNA in five municipal wastewater treatment plants, hospital wastewater and wastewater collection networks during the COVID-19 pandemic in Ardabil Province, Iran

Since 2019, the outbreak of coronavirus with acute respiratory symptoms has caused an epidemic worldwide. Transmission of the disease through respiratory droplets was announced as the main mode of transmission in 2020. But in this study, we discussed the method of indirect transmission of the virus through sewage. In this study, effluents related to urban and hospital wastewater treatment plants in 5 regions of Ardabil Province (northwest of Iran) were investigated. In this research, 120 samples were kept in pre-test conditions (temperature -20 degrees Celsius). To identify the viral genome, special primer and chain reaction probe targeting ORF1ab and N (nucleoprotein gene) genes were used. Out of a total of 120 samples, a total of 3 samples were positive. Wastewater epidemiology (WBE) can be considered as a cost-effective method in the diagnosis and prediction of pathogenic agents. And be considered an effective method for decision-making in order to protect the health of citizens.

Method of cost-effectiveness-based total maximum allocated load index and measures of nitrogen and phosphorus pollutants on jurisdictions in Jiangsu coast, China

Cost-effective total maximum allocated load (TMAL) management of land-based pollutants is required to promote sustainable and healthy development of coastal areas. For the high concentrations of nitrogen and phosphorus pollutants and the deterioration in water quality in the coastal waters of Jiangsu Province, China, the TMALs of total nitrogen (TN) and total phosphorus (TP) pollutants within jurisdictions were calculated using a cost-efficiency optimization calculation method with a 3D hydrodynamic water quality model. This method is suitable for collaborative pollution prevention and land–sea integration management in coastal areas. Our calculation results showed that the emission TMALs of TN and TP in 43 jurisdictions near the coast of Jiangsu Province were approximately 8.6 × 104 and 0.8 × 104 ton/a, respectively, and the source TMALs were 55.8 × 104 and 14.9 × 104 ton/a, respectively. The high concentrations of nitrogen and phosphorus in these waters were caused mainly by Yancheng, Suqian and Lianyungang City. The average responsibility sharing rates (the responsibility sharing of land-based over-pressured administrative areas to marine pollution areas) of these three cities were 48.3%, 23.4%, and 12.2%, respectively. Regarding over-pressured administrative areas (the administrative regions where the discharge exceeds the allocation capacity), we suggest pollution prevention and technical control measures based on the cost-effectiveness optimization method. First, source control should be strengthened, including the control of industrial point source and agricultural nonpoint source pollution, which account for approximately 77.3% of total reduction. Second, it is necessary to strengthen the construction of the municipal wastewater collection and treatment system, which accounts for approximately 16.3% of total reduction. Further, it is necessary to perform wetland ecological restoration and implement capacity-increasing measures, which account for approximately 6.4% of total reduction. The cost-effectiveness optimization calculation method for the technical indicators of collaborative prevention and control of coastal pollution provides a scientific quantitative basis suitable for global coastal pollution control.

SARS-CoV-2 in municipal wastewater treatment plant, collection network, and hospital wastewater.

The current outbreak of coronavirus disease (COVID-19) has led to creating a public health emergency conditions since 2019. COVID-19, which is caused by SARS-CoV-2, is spread via human-to-human transmission by direct contact or droplets. Through conducting this study, we were looking for detecting SARS-CoV-2 in wastewater produced in Iran country (Ardabil, Nir, Khalkhal, and Kowsar) (wastewater collection network, wastewater treatment plant, and hospital wastewater). In this research, samples (n=76) were collected from influent and effluent of municipal and hospital wastewater treatment plants, and some samples were also collected from Ardabil municipal wastewater manholes. The sampling duration included the white (lower risk of COVID-19) and red (high risk of COVID-19) conditions. Samples were stored at −20 °C for further diagnostic tests. The specific primer and probe real-time reverse transcriptase-polymerase chain reaction (real-time PCR) targeting ORF1ab and N genes (nucleoprotein gene) were applied to detect viral genomes of the SARS-CoV-2 virus in the wastewater samples. Out of 76 samples, a total of 15 samples (19.73%) collected from wastewater in Ardabil province (Ardabil, Nir, Khalkhal, and Kowsar), were positive in terms of SARS-CoV-2. Wastewater epidemiology can facilitate detection of the incidence of pathogens through metropolises, measurement of population prevalence without direct testing, and provision of information to the public health system about the efficiency of intervening efforts. Graphical abstract

Understanding the occurrence and distribution of emerging pollutants and endocrine disruptors in sensitive coastal South Florida Ecosystems

Environmental exposure risk to different xenobiotics, which can potentially alter the function of the endocrine system, remains a great health and safety concern for aquatic species and humans. Steroid hormones, pharmaceuticals and personal care products (PPCPs) have been identified as important aquatic contaminants due to their widespread occurrence in surface waters and their endocrine disrupting properties. Heavily populated areas in South Florida not served by municipal wastewater collection present an unexpected high risk of anthropogenic contaminants to nearby coastal systems through surface runoff and groundwater flow. Previous studies in South Florida have been largely concentrated on assessing the relevance of the fate and transport of inorganic nutrients, heavy metals and pesticides with regulatory criteria. Therefore, a significant gap exists in assessing occurrence, distribution and biological significance of the presence of human related organic contaminants in natural surface waters. In this study, we have developed a fast and sensitive online solid-phase extraction followed by liquid chromatography-high resolution mass spectrometry (SPE-LC-HRMS) method using a Q-Exactive system for the determination of the occurrence and distribution of selected wastewater tracers/indicators, recalcitrant PPCPs and steroid hormones in South Florida surface waters. Seasonal and spatial variations of these contaminants were monitored from 2017 to 2019. The presence of total coliforms and E. coli were also evaluated in order to further assess water quality. Correlations between hormones and anthropogenic tracers were explored to better elucidate the sources, pathways and exposure risks to these contaminants. Caffeine, sucralose, Diethyl-m-toluamide (DEET) and carbamazepine were frequently detected in the water samples, which is indicative of extensive wastewater intrusion impacting the surface water. Estrone (E1), 17-β-estradiol (E2), and 17-α-ethynylestradiol (EE2) levels found in surface water raises concern of potential endocrine disruption effects in the aquatic ecosystem. Hazard quotient has been calculated to identify areas with high ecological risks to aquatic organisms.

Influence of synthetic wastewater on entrapped air on the isotactic and atactic polypropylene microplastic surfaces.

The municipal wastewater collection system is recognized as an initial point of interaction between microplastics (MPs) and the urban wastewater matrix. The raw wastewater contains a wide variety of organic and inorganic substances including chemicals and heavy metals. However, the fate of MPs in urban sewer systems is not yet well understood. In this work two types of virgin polypropylene (PP) samples, isotactic (iPP) and atactic (aPP), were exposed to two synthetic wastewater solutions in order to study their effects on the physical properties of the hydrophobic polymer surfaces. Particular attention was paid to the pollution adhesion at the air-liquid-solid interfaces of the surface air pockets entrapped on the polymer surfaces. The first wastewater solution consists of mixed fat, oil and grease (FOG) - surfactant and another which is an exclusively contained wastewater surfactant. The interaction experiment over a period of 10min between the polymer's air pocket and solutions indicated that the size of the bubble in the mixed FOG-surfactant solution increased more pronouncedly for iPP (%152) in contrast to aPP (%31) and was also compared with the greater surface roughness of the polymers. The size variation of the spherical cap on the immersed polymer surfaces were measured between 17µm and 85µm using image processing techniques while the data was analyzed by the Young-Laplace equation. The corresponding technical surface roughness of the polymers, the surface tension of the liquids and their air/water contact angle on the flat polymer surfaces were also measured. The results of this study indicated that surface air pockets influence the adsorption capacity of MPs and thus their buoyancy and contamination potential.

Hybrid green infrastructure for reducing demands on urban water and energy systems: a New York City hypothetical case study

Green infrastructure shows promise as a “best management practice” for controlling stormwater runoff, particularly in older cities with combined sewer systems. Green infrastructure systems have been used to both mitigate pollutant loading to adjacent waterways as well as to reduce burdens on municipal wastewater and stormwater collection and treatment systems during storm events. Although the electric and water/wastewater networks are closely linked, wastewater, water supply, and energy systems have been typically studied in isolation. Here, we present a hypothetical case study for applying a modular hybrid green infrastructure approach to manage stormwater in the Newtown Creek sewershed in New York City. We provide background information on current and projected stormwater flows to the Newtown Creek Wastewater Treatment Plant (WWTP) and evaluate how interception and storage rainwater in the Newtown Creek sewershed could offset inflows to the WWTP and how this offset of stormwater inflows might result in reduced electric grid burdens and cost savings for the city. Our assessment indicates that a 0.66 % conversion of impervious sewershed surface area to modular hybrid green infrastructure could reduce stormwater inflow volumes (i.e., for an annual median storm) to the Newtown Creek WWTP by 10 %. We estimate that this would result in a 14-MWh reduction in energy required for wastewater treatment per storm event. Collectively, our results suggest that implementation of modular hybrid green infrastructure can significantly reduce burdens on urban water and energy systems, thereby helping to mitigate water-energy nexus challenges associated with climate change and population growth.

Identifying and Controlling Odor in the Municipal Wastewater Environment Phase 1: Literature Search and Review

A general review of literature published from 1990 to 2000 and unpublished literature on odors associated with municipal wastewater collection sysytems and treatment facilities, including biosolids handling. The literature review focused on several areas including odor characterization technology, odor sampling, analysis, measurement technology and odor mitigation (control) technology. Odor literature from the agricultural industry and the industrial wastewtaer arena was also reviewed for technology transfer feasibility. Public perception of odors was also reviewed. Five databases searched yielded 5,155 abstracts of which 669 articles were retrieved. Gray literature (155 articles) was received by soliciting WEF, AMSA and A&WMA memberships. All literature was reviewed to determine knowledge gaps and identify the most needy and promising areas for field research in Phase 2. The top priority research agenda selected for field research in Phase 2 was “Impacts of In-Plant Operational Parameters on Biosolids Odor Quality” This title belongs to WERF Research Report Series ISBN: 9781780404103 (eBook) ISBN: 9781843396475 (Print)

A Survey on the Removal Efficiency of Fat, Oil and Grease in Shiraz Municipal Wastewater Treatment Plant

Background:Fat, oil and grease (FOG) in municipal wastewater treatment plant (MWWTP) caused many problems. Objectives: This study aimed to determine the removal efficiency of FOG in Shiraz MWWTP. Materials and Methods: The removal efficiencies of FOG in the MWWTP were studied from June 2011 to September 2011 in Shiraz (Iran). The influent and effluent wastewater samples were collected in a volume of one liter (4 samples per week) and analyzed according to the standard methods. Samples are transferred to the laboratory immediately. The concentration of FOG was determined using the solvent extraction and separating funnel and then compared with the effluent standards. To analyze the data, SPSS (version 11.5), Chi-square test and t test were used. Results: The results showed that the FOG amount in input raw sewage in the MWWTP from June 2011 to September 2011 was around 25.5 mg/L and the amount in treated wastewater was about 8.1 mg/L. The FOG removal efficiency in this refinery was about 70% and met the environmental standards for the discharge (less than 10 mg/L) (P < 0.05). Conclusions: The effluent can be discharged to surface waters or used for irrigation. In order to the FOG concentration met the effluent standards, it is very crucial to control the entrance of industrial wastewater to the municipal wastewater collection networks. Otherwise, the MWWTP should be upgraded and the special techniques used to reduce FOG.

Municipal wastewater treatment in Poland – efficiency, costs and returns to scale

This paper reports the costs of municipal wastewater collection and treatment in Poland. Our study provides detailed cost estimates for the collection and treatment of municipal wastewater, based on an empirical sample of 1,400 operators, who jointly collect and treat over 80% of wastewater in Poland. The unit costs of collection and treatment, and the nitrogen and phosphorus treatment efficiency were investigated, and the effects of plant capacity on unit costs (scale effects) were explored. Primary, secondary and tertiary treatment cost functions were analysed econometrically using the Box-Cox regression model, indicating high non-linearity and significant scale effects. We found that wastewater treatment costs were increasing with technology efficiency (moving from the primary, through the secondary, to the tertiary treatment), and decreasing with higher wastewater treatment plant capacity. Our results provide a comprehensive picture of municipal wastewater treatment in Poland but potentially, as the technology is fairly generic, they can also be used for applications in other countries, after accounting for capital and labour cost differences. The paper thus provides a valuable input into cost-benefit analyses of nutrient loading reduction achieved by extending or intensifying municipal wastewater treatment.

Indicators for Valorisation of Municipal Solid Waste and Special Waste

Indicators are important tools that assist decision-makers in formulating and implementing plans for the management of waste at local, national and international levels. An indicator is an elementary datum or a simple combination of data capable of measuring an observed phenomenon. Indicators are there to enhance communication about the environment and to serve as a tool for policy-making. Indicators can be used to track progress over time, or to compare characteristics between one or more communities, companies, agencies, departments, products or processes. By examining these indicators over time or between different regions, communities, etc., improvements or setbacks in resource use and waste generation can be identified. In addition, these indicators can be used to illustrate the shift in industrial strategy away from end-of-pipe processes towards waste recycling, cleaner production and integrated lifecycle analysis. Different sets of environmental indicators that convey information about waste valorisation at the regional level have been developed. Indicators of reuse, recycling and other recovery like energetic valorisation related to different kinds of waste are presented. In this paper two groups of indicators are defined; the first one evaluates the valorisation of different components of municipal solid waste: treatment of municipal solid waste, recycling of glass packaging, recycling of paper and cardboard, valorisation of light packaging and energy produced from municipal solid waste. The second one evaluates the valorisation of different kinds of special waste with other kinds of treatments applied to this special waste: treatment of construction and demolition waste, used tyres management, production and disposal of municipal wastewater sewage sludge, and collection and management of waste electrical and electronic equipment. The obtained indicators of the defined methodology are applied to the region of Cantabria (Spain) presenting that the waste management in this region is good. The information of the indicators can serve as a reference for decision-making and implementing useful tools for enhancing the valorisation of waste at the regional level.

Characterization of Natural Ventilation in Municipal Wastewater Collection Systems

Characterization of Natural Ventilation in Municipal Wastewater Collection Systems

DEVELOPING A GIS-BASED INFORMATION MANAGEMENT SYSTEM FOR ON-SITE WASTEWATER TREATMENT FACILITIES

On-site wastewater treatment facilities (WWTFs) collect, treat, and dispose wastewater from dwellings that are not connected to municipal wastewater collection and treatment systems. They serve about 25% of the total population in the United States from an estimated 26 million homes, businesses, and recreational facilities nationwide. There is currently no adequate coordinated information management system for on-site WWTFs. Given the increasing concern about environmental contamination and its effect on public health, it is necessary to provide a more adequate management tool for on-site WWTFs information. This paper presents the development of an integrated, GIS-based, on-site wastewater information management system, which includes three components: (1) a mobile GIS for field data collection; (2) a World Wide Web (WWW) interface for electronic submission of individual WWTF information to a centralized GIS database in a state department of public health or state environmental protection agency; and (3) a GIS for the display and management of on-site WWTFs information, along with other spatial information such as land use, soil types, streams, and topography. It is anticipated that this GIS-based on-site wastewater information management system will provide environmental protection agencies and public health organizations with a spatial framework for managing on-site WWTFs and assessing the risks related to surface discharges.

Development of a new class of precast concrete pipes - an experimental evaluation

Concrete pipes represent the backbone of the municipal storm and wastewater collection systems of Ontario, Canada. Industry and academia partnered on a research effort that aimed at developing new precast-concrete pipe products that provide added value to the final user in comparison with existing products. This paper describes a full-scale experimental evaluation of the design, manufacturing, and performance aspects of a "cellular" concrete pipe, a precast concrete pipe in which multiple continuous conduits were incorporated within its wall. Two fully-instrumented prototype segments of the proposed cellular concrete pipe were manufactured using standard dry-cast manufacturing procedures. The pipe segments were subjected to a D-load test to evaluate their structural performance. The observed structural performance was found to be comparable to solid-wall specimens, particularly when a four-conduit configuration was used. Of the six materials used as conduits, PVC and aluminum were found to perform the best. The presence of the conduits appears to delay the on-set of major cracks, thus increasing the D-load value. Key words: precast, concrete, pipe, experimental, conduit system, trenchless construction methods.

Modeling Ventilation Phenomenon in Sanitary Sewer Systems: A System Theoretic Approach

Municipal wastewater collection systems, due to the nature of their functions, carry varying concentrations of odorous gases. The production rate and transport of these gases within and out of sewer systems depend on air flow rate in the system piping. However, municipal sewers are generally designed to only transport sewage flow without giving consideration to the air flow field. As a consequence, the movement of air into, along, and out of collection systems is for the most part uncontrolled. The purpose of this paper therefore is to provide a new design protocol based on system theoretic techniques to be used by municipal engineers and environmentalists involved in odor control and sewer foul air transport studies. The modeling formulation accounts for combined wastewater drag and pressure-induced air flows, and manhole pressurization. The developed framework is applied to both hypothetical and real sewer systems to only illustrate the applicability of the modeling formulation.

Securing Your Wastewater System

Securing Your Wastewater SystemThis is a timely topic on Wastewater System Security, which will be facing the Nation's municipal wastewater collection and treatment systems in 2004 and beyond. Congress passed the Bio-Terrorism Act of 2002, which addressed the security of our Nation's Drinking Water Utilities serving populations over 3,300. Congress has been working throughout 2003 on similar legislation that will apply to the...Author(s)Bryon O. ElwellSourceProceedings of the Water Environment FederationSubjectSession 90: SecurityDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2004ISSN1938-6478SICI1938-6478(20040101)2004:8L.726;1-DOI10.2175/193864704784136883Volume / Issue2004 / 8Content sourceWEFTECFirst / last page(s)726 - 734Copyright2004Word count568

The Aquatic Environment and Textile Mill Effluents — An Ecological Risk Assessment

Textile mill effluents (TMEs) are wastewater discharges from textile mills that are involved in wet processes such as scouring, neutralizing, desizing, mercerizing, carbonizing, fulling, bleaching, dyeing, printing and other wet finishing activities. TMEs are complex mixtures containing a wide variety of chemicals which have a range of pH, temperature, colour and oxygen demand characteristics. Most wet processing mills in Canada discharge to municipal wastewater collection systems where those effluents receive some form of wastewater treatment. This paper reports the results of a tiered assessment approach that was used to determine the impacts on the aquatic environment of whole effluents discharged by wet processing textile mills in Canada. A conservative assessment indicated that no substantial threat to the aquatic environment was associated with TMEs receiving secondary or tertiary treatment, on- site or at a municipal wastewater treatment plant, prior to discharge to receiving waters. In the case of TMEs receiving only primary treatment or no treatment prior to discharge, a weight-of-evidence risk assessment supported the conclusion that those effluents could produce significant environmental harm in aquatic environments.