Sewer System Research Articles

Determination of the cover coefficient for soil surfaces of the runoff of residential areas

Due to the constant increase in tariffs in the field of public utilities, the problem of the need for accurate calculation of the volume of surface runoff is becoming more acute, which must take into account not only the landscape features of the area, but also the water-absorbing properties of the soil and coatings. The purpose of this work is to determine the coefficient of coverage zi for the most characteristic types of natural and artificial surfaces. The scientific novelty lies in the refinement of the existing methodology set out in the “Recommendations of the State Scientific Research Center of the Russian Federation FSUE Scientific Research Institute VODGEO”, in particular, the establishment of a mathematical dependence of the value of the coefficient of cover zi on the fractional composition of the soil to determine the coefficient of surface runoff Ψ, on which commercial calculations for the drainage of rain and meltwater into the storm sewer system are based.

Evaluation of the effect of disposal of landfill leachate in a sewage treatment plant composed of stabilization ponds

This study aimed to evaluate the combined treatment system of domestic sewage and leachate by serial stabilization ponds in a Wastewater Treatment Plant (WWTP). The WWTP had two parallel pond modules, one receiving (module II—pond M10) and the other not receiving leachate (module I—pond M5). Physical, chemical, and biological monitoring parameters collected from January 2017 to December 2021 were evaluated. High reducing efficiency for ammonium nitrogen was found, with an average of 95.7 ± 2.5%. BOD5 and COD can be considered statistically different for a 95% confidence level in the two pond modules. The phytoplankton community was composed of 46 taxa distributed in four taxonomic classes: 6 belonging to the Cyanobacteria group (13%), 22 to the Green Algae group (48%), 4 to the Diatoms group (9%), and 14 to the Phytoflagellate group (30%). No ecotoxicity was detected for the evaluated pond effluent samples. Thus, although the insertion of leachate impacted the quality of the final effluent of the ponds and the organic matter, it may not have affected the effluents’ ecotoxicity. This research helps to understand the impacts of long-term leachate insertion in a real treatment system using stabilization ponds for combined treatment. In addition to the usual efficiency evaluation parameters, ecotoxicological tests and phytoplankton are also evaluated.

Surface water quality in Costa Rica: new initiatives and challenges

ABSTRACT Despite Costa Rica's reputation for being a leader in environmental policy and its thriving nature-based tourism industry, the nation has had poor surface water quality. Reasons for poor water quality include the lack of sewerage treatment, overuse of septic tanks, and the application of large quantities of agrichemicals. Although Costa Rica has policies to maintain surface water quality, they have not been sufficiently implemented. Recent initiatives have addressed surface water quality, including an ambitious plan to expand treated sewerage systems in all urban areas. Current efforts to meet this goal have focused on the San Jose metropolitan area and coastal communities. This paper reviews the advances and challenges to Costa Rica's efforts to improve water quality.

Addressing Public Health Risks: Strategies to Combat Infectious Diseases After the August 2024 Floods in Bangladesh.

The August 2024 floods in Bangladesh have precipitated a major public health crisis, significantly elevating the risk of waterborne and vector-borne diseases and exacerbating existing health vulnerabilities. This disaster has impacted over 5 million people, causing widespread environmental disruption, population displacement, and strained healthcare resources. The flooding of latrines, sewage systems, and agricultural land has led to the contamination of drinking water sources, increasing the risk of cholera, enterotoxigenic Escherichia coli diarrhoea, shigellosis, and hepatitis. Additionally, stagnant floodwaters have created breeding grounds for mosquitoes, thereby increasing the threat of malaria and dengue fever. The disruption of healthcare services has further compounded the crisis, delaying emergency responses and impeding access to care. The psychological impact on affected communities is profound, with mental health issues such as anxiety, depression, and post-traumatic stress disorder emerging as significant concerns. This perspective provides an analysis of these public health threats, supported by data on the impact of floods and a discussion of the underlying risk factors. This underscores the need for immediate and long-term public health interventions, including restoring clean water access, enhancing disease surveillance, repairing healthcare infrastructure, and addressing mental health needs. The response to this disaster must be rapid and comprehensive, with lessons learned to inform preparedness efforts to better manage similar events in the future.

Novel hybrid coating material with triple distinct healing bond for fat oil and grease deposition control in the sewer system

Hybrid materials with distinct self-healing bonds are a prominent category of materials, demanding in various modern applications. Developing self-healable hybrid materials with desired self-healing properties at ambient conditions is highly desirable and challenging. Herein, we developed a novel zinc (II)–dimethylglyoxime–urethane-complex-based polyurethane elastomer (Zn-polyurethane hybrid material) with synergetic triple dynamic bonds, which exhibits spontaneous self-healing properties at 30 °C. Moreover, this material shows excellent thermal stability up to approximately 850 °C and is highly stable in water systems. This hybrid material has potential applications in water systems; in this study, we characterized it for fat, oil and grease (FOG) deposition management in sewer systems by applying it as a coating on concrete blocks. The findings indicate that following a 30-day leaching test conducted under controlled pH conditions on uncoated and Zn-polyurethane-coated concrete blocks, a reduction of over 80 % in calcium release was observed in the coated block compared to the uncoated concrete block. Additionally, in FOG deposit formation tests conducted on uncoated and coated concrete blocks for 30 days, a reduction of over 30 % in FOG deposit formation was noted in the coated sample.

Significant effects of Rural Wastewater Treatment Plants in Reducing Microplastic Pollution: A Perspective from China's Southwest Area

Sewage systems are a major source for microplastics in riverine exports to oceans. Urban areas are generally considered hotspots for microplastic discharge, whereas emissions from rural areas remain largely understudied. Hence, this study investigated the abundance, characteristics, and polymer types of microplastics in rural wastewater treatment plants (WWTPs) in Guiyang and estimated the annual microplastic emissions of China based on sewage discharge. The influent abundance of microplastics was 3.8-8.2 items/L, the effluent abundance was 3.1-5.9 items/L, with a lower removal rate of 14.4%-54.6%, which might be influenced by lower operating loads and influent concentrations. Raman spectroscopy analysis revealed that polyvinyl alcohol (PVA) was the predominant polymer type. Rural WWTPs were more effective at removing large-sized particles (> 0.1mm) and films, resulting in higher removal effectiveness by weight (49.1%) compared to urban WWTPs (30.8%). Based on the abundance of microplastics in WWTPs within the study area and China's annual sewage discharge, this study estimated the microplastic emissions released through sewage in China in 2022. The annual microplastic emissions through sewage in China were estimated to be 2995.7 tons, with rural and urban areas contributing 25.1% and 74.9%, respectively. Approximately 724.8 tons and 1001.6 tons of microplastics were removed from rural and urban WWTPs, respectively. This work indicates the unignorable emissions of microplastics from rural sewage and highlights the crucial role of rural WWTPs in reducing microplastic pollution.

HISTORY OF WASTEWATER TERMS

In the article, comments are made about the expression and structural use of waste water and the lexical units related to it, which continue to be used to a certain extent in the lexical treasure of the Uzbek language or have completely gone out of use today. There are pipelines and structures that remove waste water from our houses, and they are expressed by different words, such as obrez, hanik, tazar, toshnov (dashnov). These words meant the name of a device or structure built in cities to collect and remove underground, rain and polluted water. These words used in the history of sewage and treatment system were taken and analyzed as an object of research.

First evidence of the suitability of hair for assessing wildlife exposure to anticoagulant rodenticides (ARs)

Anticoagulant rodenticides (ARs) are potent pesticides acting as vitamin K epoxide reductase inhibitors causing haemorrhaging or external bleeding from orifices and/or skin lesions in intoxicated rodents. However, their non-selective mode of action makes them particularly harmful for non-target wildlife, which may be exposed to ARs via ingestion of AR-containing baits (primary exposure), feeding on AR-intoxicated rodents and carrions (secondary exposure), consuming AR-contaminated necrophagous species (tertiary exposure), and exposure to surface waters receiving baited sewer systems and ARs from outdoor-placed traps after heavy rain events. In the present study, we assessed the suitability of hairs as a non-invasive matrix for monitoring the possible exposure of mammals to ARs with a focus on the first-generation anticoagulant rodenticides (FGARs) warfarin, coumatetralyl, and chlorophacinone and the second-generation anticoagulant rodenticides (SGARs) brodifacoum, bromadiolone, difenacoum, flocoumafen, and difethialone. The Red fox (n = 24) was selected as the species representing the potentially exposed non-target wildlife in a littoral area of Northern Italy along the Adriatic coast (Cavallino-Treporti municipality). Half (n = 12) of the analysed hair samples were positive for at least one of the targeted ARs, with a higher prevalence of SGARs (n = 11; 46%) compared to FGARs (n = 1; 4%). The most frequently quantified ARs were brodifacoum (25%), difethialone (13%), and flocoumafen (13%), with concentrations ranging from 0.08 ng g−1 (difethialone) to 0.96 ng g−1 (brodifacoum). These data documented that a relevant part of the Red foxes living in the study area were exposed to ARs and, most importantly, provided the first evidence that hair residues can be used as a non-invasive matrix for assessing the possible exposure of mammals to ARs.

Different nitrogen conditions regulating extracellular polymeric substances and erosion resistance of sewer sediment: Mechanism of microbial metabolism and molecular response

Nitrogen biotransformation plays a vital role in the metabolism of microbial communities in sewers. Extracellular polymeric substances (EPS) secreted by microbial communities can form gel-like sewer sediments, causing clogging of the sewer. However, knowledge on the effects of varying nitrogen conditions on the erosion resistance of sewer sediments and EPS produced by sewer microorganisms is limited. In this study, two typical organic/inorganic nitrogen ratios of sewage were reproduced in simulated sewer reactors, i.e., 3/7 (R1 group) and 7/3 (R2 group). Higher organic nitrogen (ON) concentrations were found to increase the critical erosion shear stress by 26.43%; this was ascribed to increased particle diameter, weakened electrostatic repulsion of sediments and stimulated EPS secretion in the R2 group. The protein and polysaccharide contents of the R2 group were 48.84% and 34.25% higher than those of the R1 group, respectively, which was supported by increased gene abundances for aromatic amino acid synthesis, general secretory pathways of protein, and synthesis of precursors and polysaccharides. Tightly-bound EPS in R2 group exhibited increased contents of hydrophobic protein secondary structures and intermolecular hydrogen bonds, thereby promoting the formation of gel-like sediment structures with enhanced erosion resistance. However, the microbial diversity and the abundance of key genes involved in EPS generation and secretion (e.g., tyrB, yajC, secB, gumF, and gumH) obviously decreased in the R1 group. Moreover, high ON concentrations increased microbial diversity and enhanced microbial glycolysis, tricarboxylic acid cycle and ammonium assimilation. This study reveals the formation mechanisms of EPS in sewer sediments under different nitrogen conditions and their effects on sediment erosion resistance, which contributed to improved sewer system operation and sewer sediment control.

Application of a hybrid fuzzy-based algorithm to investigate the environmental impact of sewer overflow

PurposeThis study underscores the critical importance of well-functioning sewer systems in achieving smart and sustainable urban drainage within cities. It specifically targets the pressing issue of sewer overflows (SO), widely recognized for their detrimental impact on the environment and public health. The primary purpose of this research is to bridge significant research gaps by investigating the root causes of SO incidents and comprehending their broader ecological consequences.Design/methodology/approachTo fill research gaps, the study introduces the Multi-Phase Causal Inference Fuzzy-Based Framework (MCIF). MCIF integrates the fuzzy Delphi technique, fuzzy DEMATEL method, fuzzy TOPSIS technique and expert interviews. Drawing on expertise from developed countries, MCIF systematically identifies and prioritizes SO causes, explores causal interrelationships, prioritizes environmental impacts and compiles mitigation strategies.FindingsThe study's findings are multifaceted and substantially contribute to addressing SO challenges. Utilizing the MCIF, the research effectively identifies and prioritizes causal factors behind SO incidents, highlighting their relative significance. Additionally, it unravels intricate causal relationships among key factors such as blockages, flow velocity, infiltration and inflow, under-designed pipe diameter and pipe deformation, holes or collapse, providing a profound insight into the intricate web of influences leading to SO.Originality/valueThis study introduces originality by presenting the innovative MCIF tailored for SO mitigation. The combination of fuzzy techniques, expert input and holistic analysis enriches the existing knowledge. These findings pave the way for informed decision-making and proactive measures to achieve sustainable urban drainage systems.

Optimize Stormwater Management for Green Roofs Based on IoT Technology and Sensor Networks

The intensification of global climate change and the significant increase of extreme rainfall events have made traditional urban drainage systems face great adjustments. As a key component of green infrastructure to avoid urban flood risk, green roofs are receiving increasing attention due to their unique capabilities in stormwater management. This paper explores the potential of Internet of Things (IoT) technology and sensor networks to enhance green roof stormwater management. Integrated real-time monitoring of key environmental parameters, including soil moisture, temperature and rainfall, enables the system to dynamically adjust roof drainage and irrigation strategies. This greatly improves the rainwater retention capacity and reduces the pressure on the municipal sewage system. The results show that the combination of IoT technology and sensor networks not only improves the efficiency of green roof management in combating climate change, but also promotes the efficient use of water resources and enhances the adaptability and sustainability of the system. This research provides the necessary technical support for the wider adoption of green roofs in urban environments and offers viable solutions to future challenges posed by climate change.

Attitude of Romanian students and their families concerning waste management

Abstract Waste recovery, recycling included, is an important step in waste management, preceding final disposal. In 2018, according to Eurostat, the recycling rate of municipal waste was 47% in the European Union and only 11.1% in Romania. Thus governmental institutions have implemented new measures in order to reduce environmental pollution by ineffective waste management. In 2022, 535 students aged 22-24.5 years, males and females, studying in Craiova (one of the six largest academic cities of Romania), were asked to answer an 18-item questionnaire regarding their and their families’ attitude towards waste recycling. Most of the students (60.7%) were residents in the university city, while the others - in smaller cities or in villages of the region. Only 38.3% of the subjects (N = 205) declare their families recycle waste; the most common excuse for no-recycling (37.8%) is the lack of recycle bins in the house proximity. Only 20 families (3.7%), all of them living in Craiova, take the fried oil to collecting points in supermarkets; most of the others eliminate it in the sewerage system, especially those from outside the city (p < 0.01). Seventy-five students (14%) are not able to mention any recent measure taken by the government in order to reduce plastics environmental pollution; the others discuss about the increased number of recycle bins around the city (53.2%), recycling of single-use plastics (34.5%) or use of biodegradable bags (25.2%). No-recycling (42%), using daily his/her own car (18.7%, p < 0.01 males vs. females), using too much plastics (11.2%) are the most frequent self-reported students’ disregards for the environment. Most of the subjects consider environmental health of essential importance (88.7%) and would like to participate in environment protection actions (92.5%). Romanian students seem to have a positive attitude and like to be involved in the environment protection, without a significant influence regarding the gender and the residence place. Key messages • Education and information are essential tools to make people ecologically aware. • Recycling is one of the best ways to have a positive impact on both natural and community environment.

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.

Sewer system sampling for wastewater-based disease surveillance: Is the work worth it?

ABSTRACT Wastewater treatment plant (WWTP) influent sampling is commonly used in wastewater-based disease surveillance to assess the circulation of pathogens in the population aggregated in a catchment area. However, the signal can be lost within the sewer network due to adsorption, degradation, and dilution processes. The present work aimed to investigate the dynamics of SARS-CoV-2 concentration in three sub-catchments of the sewer system in the city of Hildesheim, Germany, characterised by different levels of urbanisation and presence/absence of industry, and to evaluate the benefit of sub-catchment sampling compared to WWTP influent sampling. Our study shows that sampling and analysis of virus concentrations in sub-catchments with particular settlement structures allows the identification of high concentrations of the virus at a local level in the wastewater, which are lower in samples collected at the inlet of the treatment plant covering the whole catchment. Higher virus concentrations per inhabitant were found in the sub-catchments in comparison to the inlet of the WWTP. Additionally, sewer sampling provides spatially resolved concentrations of SARS-CoV-2 in the catchment area, which is important for detecting local high incidences of COVID-19.

Novel hydrogen-bonded organic frameworks-based coating for fat oil and grease deposition control in the sewer system

Hydrogen-bonded organic frameworks (HOFs) represent an emerging class of porous materials characterized by crystalline frame structures, self-assembled from organic molecules through hydrogen bonding. This study demonstrates that HOFs fragment into small particles while preserving their original structure when dispersed in a polymeric epoxy solution. The intermolecular hydrogen bond structural and electronic properties of the LH4-HOF complex as well as the mechanism of HOF incorporated epoxy were extensively studied using density functional theory. LH4-HOF has a high Langmuir surface area of 2758.3 m2/g and nonlocal density functional theory pore size distributions of 3 A°. This unique solution processability enables the fabrication of coatings with high stability in aqueous systems. Results from a 30-day leaching test under controlled conditions (pH 7, temperature 20 ± 2 °C) indicate that LH4-HOF incorporated epoxy-coated concrete samples exhibited an over 85 % reduction in calcium release compared to uncoated samples, with epoxy-coated samples alone showing a 60 % reduction in calcium leaching. Additionally, the LH4-HOF-incorporated epoxy coating reduced the formation of fats, oils and grease deposits by more than 73 % on the concrete samples. Thus, this novel coating approach offers a sustainable solution with significant potential applications in sewer management.

Application of time series and multivariate statistical models for water quality assessment and pollution source apportionment in an Urban River, New Jersey, USA

Water quality monitoring reveals changing trends in the environmental condition of aquatic systems, elucidates the prevailing factors impacting a water body, and facilitates science-backed policymaking. A 2020 hiatus in water quality data tracking in the Lower Passaic River (LPR), New Jersey, has created a 5-year information gap. To gain insight into the LPR water quality status during this lag period and ahead, water quality indices computed with 16-year historical data available for 12 physical, chemical, nutrient, and microbiological parameters were used to predict water quality between 2020 and 2025 using seasonal autoregressive moving average (ARIMA) models. Average water quality ranged from good to very poor (34 ≤ µWQI ≤ 95), with noticeable spatial and seasonal variations detected in the historical and predicted data. Pollution source tracking with the positive matrix factorization (PMF) model yielded significant R2 values (0.9 < R2 ≤ 1) for the input parameters and revealed four major LPR pollution factors, i.e., combined sewer systems, surface runoff, tide-influenced sediment resuspension, and industrial wastewater with pollution contribution rates of 23–30.2% in the upstream and downstream study areas. Significant correlation of toxic metals, nutrients, and sewage indicators suggest similarities in their sources.Graphical

Urban Wastewater Management Using BIM Method

Building Information Modeling (BIM) is a method that emphasizes object-based data management, communication, and collaboration among all project participants throughout the entire lifecycle of a system. It is becoming an international standard for large-scale construction and infrastructure projects. Although BIM is gaining traction in the wastewater industry, the literature on its application in this field is still limited. This research, through expert interviews and literature review, explores the extent to which BIM has been introduced in the sewage industry and the associated opportunities and challenges. Initial projects in wastewater management using BIM include the construction and development of sewage treatment plants and special structures. Planning offices are leading the way in adopting BIM, supported by catalogs of industry-specific objects, clear definitions of responsibilities, and the potential for enhanced operation of sewage systems. Some users have already recognized the benefits of BIM and adjusted their processes accordingly. BIM’s object-oriented modeling improves the visualization of construction projects and processes, offering significant advantages in model-based plan derivation and mass determination. It also focuses on the collection, exchange, and storage of relevant data, which can benefit the entire wastewater industry. The research confirms that BIM adds value to wastewater management, especially since infrastructure is often difficult to access post-construction and knowledge about the systems is typically limited to those involved in the construction phase. However, to fully and effectively utilize BIM, further improvements are necessary. This requires intensive collaboration among project participants, software producers, and customers. The integration of BIM in wastewater management holds promise, but its successful implementation depends on overcoming current challenges and enhancing the method through collective effort. DOI: https://doi.org/10.52783/pst.928

Breaking the chains of discrimination: an assessment of India’s legal framework and rehabilitation initiatives for manual scavengers

ABSTRACT Tragically, between March and April of 2023, during a period lasting just one month, eight individuals perished while undertaking one of society’s most hazardous jobs: cleaning sewers. These fatalities have resurrected anxieties regarding the persisting deaths among manual scavengers despite explicit legal prohibitions against such practices nationwide. Despite legal efforts against it, news reports reveal that this harmful practice continues across India. The dangers are real for those who work in septic tanks or sewage systems, with incidents frequently cited where death results from accidental asphyxiation. Through a comprehensive analysis of social and legal factors at play for manual scavengers, this research looks into how far the laws and government schemes have successfully improved the condition of manual scavengers. It explores recent court cases alongside legal developments to determine efficacy while highlighting challenges faced in the implementation stages of relevant laws. By considering cultural perspectives and these factors, it becomes clear that pervasive stigmatization has severe psychological consequences for those working as manual scavengers within India’s caste system today. This research highlights how this scenario affects those who scavenge as they deal with being socially excluded while enduring economic exploitation and denying their fundamental human rights and dignity. Furthermore, it examines current rehabilitation plans by analyzing their efficacy and what hinders implementation through social empowerment initiatives for these individuals who manually scavenge human waste.

Modeling transient mixed flows in sewer systems with data fusion via physics-informed machine learning

Transitions between free-surface and pressurized flows, known as transient mixed flows, have posed significant challenges in urban drainage systems (UDS), e.g., pipe bursts, road collapses, and geysers. However, traditional mechanistic modeling for mixed flows is challenged by the difficult integration of multi-source data, complex equation forms for the discovery of dynamic processes, and high computational demands. In response, we proposed a data-driven model, TMF-PINN, which utilizes a Physics-Informed Neural Network (PINN) to simulate and invert Transient Mixed Flow (TMF) in sewer networks. This model integrates experimental data, simulation results and Partial Differential Equations (PDEs) into its loss function, leveraging the extensive data available in smart urban water systems. A status factor (α) has been introduced to seamlessly link open channel and pressurized flow dynamics, facilitating rapid adjustments in wave speed. On this basis, Fourier feature extraction and quadratic neural networks have been employed to capture complex dynamic processes featuring high-frequency. Validation through three classical cases using the Storm Water Management Model (SWMM) and comparisons with finite volume Harten-Lax-van Leer (HLL) solver reveal that the proposed model circumvents the constraints of spatiotemporal resolution, yielding accurate flow field predictions.

Health and environmental impacts of Gaza conflict (2023-2024): A review

The war in Gaza, which erupted on October 7, 2023, unleashed unprecedented assaults from the air, sea, and land, affecting the densely populated area of 360 square kilometers housing 2.3 million people. The conflict claimed over 36 000 Palestinian lives, with women and children making up 70% of the casualties, and resulted in more than 80 000 injuries. The devastation was extensive, with over 70% of homes destroyed, along with six universities, numerous hospitals, communication networks, sewage systems, water desalination plants, roads, wells, and other essential infrastructure. Over a million people were displaced from the northern regions to the southern coastal area of Al-Mawasi, which constitutes less than 3% of Gaza's total area, facing dire shortages of water, healthcare, food, and medicine. The collapse of sewage networks and garbage accumulation led to an increase in flies, mosquitoes, insects, and rodents, contributing to the spread of infectious and non-communicable diseases among the displaced population. This research aimed to study the health and environmental impacts of the war in Gaza through data collection, field visits, and photographic documentation. The findings revealed catastrophic conditions, with the destruction of all infrastructure, including buildings, hospitals, universities, mosques, churches, sanitation, water networks, and communications, and the spread of diseases such as intestinal, respiratory infections, and skin infections due to the complete lack of basic life necessities.