Wastewater Systems Research Articles

Marine Biodegradation Behavior of Wool and Other Textile Fibers

Microplastic pollution is a growing concern for the earth’s terrestrial and marine environments. Synthetic fibers from textiles are one source of microplastic pollution as fibers may be released from garments during use and especially during laundering, whereby they may enter the aquatic environment via wastewater systems. Wool is a natural fiber, but it is often given treatments to enhance its performance, such as to make it resistant to shrinkage caused by machine washing. Treatments of this type might influence the fiber’s inherent biodegradability. We sought to understand the aquatic biodegradation behavior of wool (in its unmodified form, and chlorine-Hercosett shrink-resist treated) and a range of synthetic fibers that are used in similar clothing applications. The biodegradation test was carried out in a simulated marine environment using a natural seawater inoculant according to the ASTM D6691 method with some modifications. Biodegraded wool residues were characterized by Fourier transform infrared and energy dispersive X-ray spectroscopies. The extent of fiber damage was observed by scanning electron microscopy. Both types of wool biodegraded readily under these conditions and machine-washable wool biodegraded to a greater extent than untreated wool. Regenerated cellulosic fiber (viscose rayon) also degraded readily, but all three synthetic fibers (polyester, nylon and polypropylene) showed virtually no biodegradation. Analysis of solid and liquid residues generated by the biodegraded wool showed no evidence that the chlorine-Hercosett-treated wool generated any non-degraded residues. Based on these findings we believe that, unlike synthetics, wool fibers are very unlikely to lead to microplastic pollution in the aquatic environment.

The effect of graphene oxide content on the photocatalytic activity of (ZnCdS/MnFe2O4/GO) nanocomposite

Novel ternary Zinc cadmium sulfate/Manganese ferrite/Graphene oxide (ZnCdS/MnFe2O4/GO) nanocomposites were synthesized via a hydrothermal process in this study, with a focus on optimizing the graphene oxide (GO) content. Characterization techniques such as X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), UV–visible spectroscopy, photoluminescence (PL) spectroscopy, and N2 physisorption were employed. The investigation revealed that nanocomposites with 3 wt% GO content exhibited superior adsorption capacity and visible-light photocatalytic activity for the removal of Methylene blue (MB) from wastewater. The ZnCdS/MnFe2O4/GO 3 % composite demonstrated exceptional stability and efficiency, achieving nearly 96 % MB removal within 220 min. Moreover, the ZnCdS/MnFe2O4/GO 3 % nanocomposites displayed promising reusability with sustained photocatalytic activity over multiple degradation-regeneration cycles. These findings highlight the potential of ternary GO/ZnCdS/MnFe2O4 nanocomposites as effective photocatalysts for the practical remediation of organic pollutants in wastewater systems.

UTILIZATION OF BIM TECHNOLOGIES FOR ENHANCING THE EFFICIENCY OF WATER SUPPLY AND WASTEWATER SYSTEMS DESIGN

Problem statement. The need for the formation and development of human resources in the construction industry of Ukraine to create a competitive sphere that complies with high standards of quality and efficiency, operating based on modern financial, economic, technical, and organizational mechanisms. One method to achieve the goals of innovative development is the modernization of architectural and construction design and engineering networks, particularly through the implementation of Building Information Modeling (BIM) technologies. These technologies enable effective decision-making at all stages of the life cycle of buildings and structures − from the initial idea to the stage of operation and even the dismantling of water supply and wastewater system engineering networks. The purpose of the article − to explore the utilization of BIM technologies to enhance the efficiency and accuracy of designing water supply and wastewater systems Conclusions. The application of BIM technologies in the design of water supply and wastewater systems significantly improves work efficiency. Creating digital models facilitates the interaction of all participants in the construction process and minimizes errors and conflicts during the design phase. The success of modernizing the construction industry became possible through active collaboration of all stakeholders. Public advocacy and participation in addressing industry issues provided a broader perspective on problem-solving. The implementation of BIM technologies allows for the development and improvement of water supply and wastewater system projects, contributing to work optimization and project planning enhancement.

Exploring transitions of sewer wastewater infrastructure towards decentralisation using the modular model TURN-Sewers

We present a new modular model called TURN-Sewers for exploring different adaptations of centralised wastewater infrastructure towards more decentralised wastewater systems under different urban development scenarios. The modular model is flexible and computationally efficient in exploring transitions at the city scale, allowing for the comparison of different policies and management strategies for sanitary wastewater infrastructure. TURN-Sewers includes independent modules that simulate the generation, dimensioning, deterioration, management, and calculation of performance indicators for different wastewater systems. This model can use readily available spatial information to support infrastructure planners and other stakeholders in exploring different transition pathways from centralised to decentralised wastewater infrastructure. An illustrative example demonstrates how TURN-Sewers can generate multiple future alternatives, define different infrastructure management strategies regarding system expansion, rehabilitation and transition, and assess the economic, hydraulic and structural impacts.

Optimizing carbon sources regulation in the biochemical treatment systems for coal chemical wastewater: Aromatic compounds biodegradation and microbial response strategies

The complex composition of coal chemical wastewater (CCW), marked by numerous highly toxic aromatic compounds, induces the destabilization of the biochemical treatment system, leading to suboptimal treatment efficacy. In this study, a biochemical treatment system was established to efficiently degrade aromatic compounds by quantitatively regulating the dosage of co-metabolized substrates (specifically, the chemical oxygen demand (COD) Glucose: COD Sodium acetate = 3:1, 1:3, and 1:1). The findings demonstrated that the system achieved optimal performance under the condition that the ratio of COD Glucose to COD Sodium acetate was 3:1. When the co-metabolized substrate was added to the system at an optimal ratio, examination of pollutant removal and cumulative effects revealed that the removal efficiencies for COD and total organic carbon (TOC) reached 94.61 % and 86.40 %, respectively. The removal rates of benzene series, nitrogen heterocyclic compounds, polycyclic aromatic hydrocarbons, and phenols were 100 %, 100 %, 63.58 %, and 94.12 %, respectively. Research on the physiological response of microbial cells showed that, under optimal ratio regulation, co-metabolic substrates led to a substantial rise in microbial extracellular polymeric substances (EPS) secretion, particularly extracellular proteins. When the system reached the end of its operation, the contents of loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS) for proteins in the optimal group were 7.12 mg/g-SS and 152.28 mg/g-SS, respectively. Meanwhile, the ratio of α-Helix / (β-Sheet + Random coil) and the proportion of intermolecular interaction forces were also increased in the optimal group. At system completion, the ratio of α-Helix / (β-Sheet + Random coil) reached 0.717 (LB-EPS) and 0.618 (TB-EPS), respectively. Additionally, the proportion of intermolecular interaction forces reached 74.83 % (LB-EPS) and 55.03 % (TB-EPS). An in-depth analysis of the metabolic regulation of microorganisms indicated that the introduction of optimal ratios of co-metabolic substrates contributed to a noteworthy upregulation in the expression of Catechol 2,3-dioxygenase (C23O) and Dehydrogenase (DHA). The expression levels of C23O and DHA were measured at 0.029 U/mg Pro·g MLSS and 75.25 mg TF·(g MLSS·h)−1 (peak value), respectively. Correspondingly, enrichment of aromatic compound-degrading bacteria, including Thauera, Saccharimonadales, and Candidatus_Competibacter, occurred, along with the upregulation of associated functional genes such as Catechol 1,2-dioxygenase, Catechol 2,3-dioxygenase, Protocatechuate 3,4-dioxygenase, and Protocatechuate 4,5-dioxygenase. Considering the intricate system of multiple coexisting aromatic compounds in real CCW, this study not only obtained an optimal ratio for carbon source addition but also enhanced the efficient utilization of carbon sources and improved the capability of the system to effectively degrade aromatic compounds. Additionally, this paper established a theoretical foundation for metabolic regulation and harmless treatment within the biochemical treatment of intricate systems, exemplified by real CCW.

Phthalates Boost Natural Transformation of Extracellular Antibiotic Resistance Genes through Enhancing Bacterial Motility and DNA Environmental Persistence.

The environmental dissemination of extracellular antibiotic resistance genes (eARGs) in wastewater and natural water bodies has aroused growing ecological concerns. The coexisting chemical pollutants in water are known to markedly affect the eARGs transfer behaviors of the environmental microbial community, but the detailed interactions and specific impacts remain elusive so far. Here, we revealed a concentration-dependent impact of dimethyl phthalate (DMP) and several other types of phthalate esters (common water pollutants released from plastics) on the natural transformation of eARGs. The DMP exposure at an environmentally relevant concentration (10 μg/L) resulted in a 4.8-times raised transformation frequency of Acinetobacter baylyi but severely suppressed the transformation at a high concentration (1000 μg/L). The promotion by low-concentration DMP was attributed to multiple mechanisms, including increased bacterial mobility and membrane permeability to facilitate eARGs uptake and improved resistance of the DMP-bounded eARGs (via noncovalent interaction) to enzymatic degradation (with suppressed DNase activity). Similar promoting effects of DMP on the eARGs transformation were also found in real wastewater and biofilm systems. In contrast, higher-concentration DMP suppressed the eARGs transformation by disrupting the DNA structure. Our findings highlight a potentially underestimated eARGs spreading in aquatic environments due to the impacts of coexisting chemical pollutants and deepen our understanding of the risks of biological-chemical combined pollution in wastewater and environmental water bodies.

Microplastics and the Water Industry

Key TakeawaysFound in freshwater and ocean environments, microplastics may pose hazards through chemical transfer if they are made of harmful chemicals or they can adsorb pollutants.Microplastics pollution sources include clothes washing, wastewater systems, biosolids, tire and road wear, and atmospheric particles that affect wildlife and humans.Nanofiltration and reverse osmosis should more effectively remove microplastics than microfiltration and ultrafiltration, even if the membrane barriers are also made of plastics.Analytical method progress on microplastics includes quantification (enumeration and mass concentration), size characterization, and minimum thresholds for detection (size and mass).

Monitoring SARS-CoV-2 RNA in wastewater from a shared septic system and sub-sewershed sites to expand COVID-19 disease surveillance

ABSTRACT Wastewater-based epidemiology has expanded as a tool for collecting COVID-19 surveillance data, but there is limited information on the feasibility of this form of surveillance within decentralized wastewater systems (e.g., septic systems). This study assessed SARS-CoV-2 RNA concentrations in wastewater samples from a septic system servicing a mobile home park (66 households) and from two pumping stations serving a similarly sized (71 households) and a larger (1,000 households) neighborhood within a nearby sewershed over 35 weeks in 2020. Also, raw wastewater from a hospital in the same sewershed was sampled. The mobile home park samples had the highest detection frequency (39/39 days) and mean concentration of SARS-CoV-2 RNA (2.7 × 107 gene copies/person/day for the N1) among the four sampling sites. N1 gene and N2 gene copies were highly correlated across mobile home park samples (Pearson's r = 0.93, p < 0.0001). In the larger neighborhood, new COVID-19 cases were reported every week during the sampling period; however, we detected SARS-CoV-2 RNA in 12% of the corresponding wastewater samples. The results of this study suggest that sampling from decentralized wastewater infrastructure can be used for continuous monitoring of SARS-CoV-2 infections.

Associations between wastewater gut microbiome and community obesity rates: Potential microbial biomarkers for surveillance

Gut microbes are crucial for human health, which are usually accumulated in urban wastewater systems. Seven wastewater treatment plants in Australia with distinct population obesity rates between 18% and 33% were selected for wastewater sampling and analysis. Human gut microbiome were detected using metagenomic sequencing to investigate their associations with the community obesity rate. To unravel this complex relationship, a range of algorithm models, including linear discriminant analysis effect size (LEfSe), similarity percentage analysis (SIMPER), statistical analysis of metagenomic profiles (STAMP), linear models for microarray and RNA-Seq data analysis (LIMMA), Relief, ratio approach for identifying differential abundance (RAIDA), least absolute shrinkage and selection operator (LASSO), support vector machine (SVM), Boruta, DESeq2 and analysis of compositions of microbiomes with bias correction (ANCOM-BC), were used to identify potential bacterial biomarkers for obesity in the wastewater microbiome. Among these algorithm models, LEfSe, LIMMA, SIMPER and SVM are effective in identifying multiple microbial biomarkers. Specific human gut microbes, including Ruminococcus_E, Agathobacter, Fusicatenibacter, Anaerobutyricum, Blautia_A and Neisseria, were identified as potential consensus microbial biomarkers for obesity in the population. A high obesity rate is mainly characterized by a high abundance of pathogenic bacteria and microorganisms associated with xenobiotic biodegradation and metabolism, endocrine and metabolic diseases, and transcription pathways. This study underscores the innovative potential of leveraging human gut microbes in wastewater as biomarkers for monitoring obesity levels across communities, offering a novel, cost-effective, and indirect approach to public health surveillance.

Enhanced adsorption of phenolic compounds using biomass-derived high surface area activated carbon: Isotherms, kinetics and thermodynamics.

The progress of industrial and agricultural pursuits, along with the release of inadequately treated effluents especially phenolic pollutant, has amplified the pollution load on environment. These organic compounds pose considerable challenges in both drinking water and wastewater systems, given their toxicity, demanding high oxygen and limited biodegradability. Thus, developing an eco-friendly, low-cost and highly efficient adsorbent to treat the organic pollutants has become an important task. The present investigation highlights development of a novel adsorbent (CFPAC) by activation of Cassia fistula pod shell for the purpose of removing phenol and 2,4-dichlorophnenol (2,4-DCP). The significant operational factors (dosage, pH, concentration, temperature, speed) were also investigated. The factors such as pH = 2 and T = 20°C were found to be significant at 1.6g/L and 0.6g/L dosage for phenol and 2,4-DCPrespectively. Batch experiments were further conducted to study isotherms, kinetic and thermodynamics studies for the removal of phenol and 2,4-DCP. The activated carbon was characterised as mesoporous (specific surface area 1146 m2/g, pore volume = 0.8628cc/g), amorphous and pHPZC =6.4. At optimum conditions, the maximum sorption capacity for phenol and 2,4-DCP were 183.79mg/g and 374.4mg/g respectively. The adsorption isotherm was better conformed to Redlich Peterson isotherm (phenol) and Langmuir isotherm (2,4-DCP). The kinetic study obeyed pseudo-second-order type behaviour for both the pollutants with R2 > 0.999. The thermodynamic studies and the value of isosteric heat of adsorption for both the pollutants suggested that the adsorption reaction was dominated by physical adsorption (ΔHx < 80kJ/mol). Further, the whole process was feasible, exothermic and spontaneous in nature. The overall studies suggested that the activated carbon synthesised from Cassia fistula pods can be a promising adsorbent for phenolic compounds.

A review on agrowaste based activated carbons for pollutant removal in wastewater systems

Environmental pollution from chemicals utilized in manufacturing, pharmaceuticals, and chemical process industries is of serious concern nowadays due to the contamination that ensues when these chemicals are discharged into water bodies. Activated carbon adsorption provides an efficient and economically viable means for mitigation of toxic chemicals (i.e., heavy metals, dyes, pharmaceutics, and antibiotics). However, the exorbitant cost of commercial activated carbons has resulted in the search for low-cost alternatives for the treatment of contaminated effluents. An exhaustive literature survey in this area is necessary to know the extent of work done in this area and seek out the gaps that future research will provide answers to. In this review, various works on activated carbon utilization, batch adsorption, fixed-bed adsorption (experimental and numerical studies) are summarized. This review elucidates the different kinetic and isotherm models of agrowastes-derived activated carbon materials in context with pollutants (dyes, heavy metals, pharmaceuticals, miscellaneous adsorbates) removal through batch and column methods. In addition, fixed-bed column adsorption/regeneration methods using various activated carbons derived from agrowastes are discussed. Among these methods, heavy metal adsorption from aqueous solutions by the activated carbons is the most efficient. The deployment of mathematical and machine learning approaches (ANN and novel GMDH algorithms) in optimization of batch and continuous adsorption processes are also highlighted. Numerical simulation of fixed-column adsorption systems for more improved industrial-scale column designs is described. Conclusions and future challenges of chemicals removal from polluted wastewater utilizing agrowaste-derived activated carbons are also presented.

Advances and Challenges of Sensing in Water Using CRISPR-Cas Technology.

The groundbreaking gene-editing mechanism, CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats), paired with the protein Cas9, has significantly advanced the realms of biology, medicine, and agriculture. Through its precision in modifying genetic sequences, CRISPR holds the potential to alter the trajectory of genetic disorders and accelerate advancements in agriculture. While its therapeutic potential is profound, the technology also invites ethical debates centered on responsible use and equity in access. Parallelly, in the environmental monitoring sphere and sensing in water, especially biosensors have been instrumental in evaluating natural water sources' quality. These biosensors, integrating biological components with detection techniques, have the potential to revolutionize healthcare by providing rapid and minimally invasive diagnostic methods. However, the design and application of these sensors bring forth challenges, especially in ensuring sensitivity, selectivity, and ethical data handling. This article delves into the prospective use of CRISPR-Cas technology for sensing in water, exploring its capabilities in detecting diverse biomarkers, hazardous substances, and varied reactions in water and wastewater systems.

Exogenous compound bacteria enhance the nutrient removal efficiency of integrated bioremediation systems: Functional genes and microorganisms play key roles

With the continuous development of intensive mariculture, the application of the integrated bioremediation system of aquaculture wastewater (IBSAW) is increasingly promoted. However, the process and nutrients removal performance of the IBSAW need to be further optimized due to its immature technologies. In this study, exogenous compound bacteria (ECB) were added to IBSAW to investigate its pollutants removal efficiency and the relevant mechanisms. High-throughput sequencing and Geochip gene array were used to analyze the correlation between nutrients and bacteria, and the abundance of N and P cycling genes were quantified. Multivariable statistics, dimensionality reduction analysis, and network analysis were applied to explore the mechanisms of IBSAW operation. The results showed that the nutrients decreased significantly after adding ECB, with the brush treatment group significantly outperforming the ceramsite in removing NO3− and PO43−. Ceramsite has an advantage in removing NO2−-N. The addition of ECB and different substrates significantly affected the composition of bacterial communities. The contents of nosZ and nirKS related to denitrification in the treatment groups were significantly higher than those in the control group, and the contents in the brush treatment group were significantly higher than that of ceramsite. The biomarkers Psychroserpens and Ruegeria on the biofilm of the brush treatment group were positively correlated with nirKS, while Mycobacterium, Erythrobacter and Paracoccus, Pseudohaliea in the ceramsite group were positively correlated with nirS and nirK, respectively. Therefore, it is speculated that the ECB significantly promoted the increase of denitrification bacteria by affecting the composition of bacterial communities, and the ECB combined with functional genera improved the efficiency of nutrients removal in the system. This study provided a reference for understanding the process and mechanism of nutrients removal, optimizing the wastewater purification technology of the IBSAW and improving the performance of the system.

Enhancing the treatment efficiency of three-dimensional electro-Fenton system for organic wastewater: An analysis from the comprehensive perspective of H2O2 generation

For optimizing H2O2 generation in three-dimensional electro-Fenton (3D-EF) to enhance efficacy in treating organic wastewater, a comprehensive analysis from various perspectives of H2O2 generation was provided. By quantifying the generation of H2O2 within the reaction system and comparing it with the changing trends in organic wastewater treatment efficiency, a close correlation between H2O2 generation and organic wastewater treatment was revealed. A reliable and accurate kinetic model for H2O2 generation was formulated by building upon the reactions of H2O2 with electrodes and coexisting substances. The mathematical formulation of the kinetic model pinpointed pivotal factors influencing H2O2 generation, including current density, dissolved oxygen concentration, and the Fe catalytic activity substance. The experimental data and fitted results under various conditions indicated that the model could reasonably and accurately describe the relationship between pivotal factors and the quantity of generated H2O2. Crucial strategies were proposed to enhance H2O2 generation in the 3D-EF system by drawing from the impact rules of pivotal factors on H2O2 generation. These strategies primarily focused on improving electrode performance, optimizing reactor conditions, and refining particle electrode preparation processes.

Development of a computational model to inform environmental surveillance sampling plans for Salmonella enterica serovar Typhi in wastewater.

Typhoid fever-an acute febrile disease caused by infection with the bacterium Salmonella enterica serotype Typhi (S. Typhi)-continues to be a leading cause of global morbidity and mortality, particularly in developing countries with limited access to safe drinking water and adequate sanitation. Environmental surveillance, the process of detecting and enumerating disease-causing agents in wastewater, is a useful tool to monitor the circulation of typhoid fever in endemic regions. The design of environmental surveillance sampling plans and the interpretation of sampling results is complicated by a high degree of uncertainty and variability in factors that affect the final measured pathogens in wastewater samples, such as pathogen travel time through a wastewater network, pathogen dilution, decay and degradation, and laboratory processing methods. Computational models can, to an extent, assist in the design of sampling plans and aid in the evaluation of how different contributing factors affect sampling results. This study presents a computational model combining dynamic and probabilistic modeling techniques to estimate-on a spatial and temporal scale-the approximate probability of detecting S. Typhi within a wastewater system. This model may be utilized to inform environmental surveillance sampling plans and may provide useful insight into selecting appropriate sampling locations and times and interpreting results. A simulated applied modeling scenario is presented to demonstrate the model's functionality for aiding an environmental surveillance study in a typhoid-endemic community.

Participatory Budgeting in Public Sphere, Governance, Transparency and Participation

Today's modern cities have many vital problems. Participatory budgeting (PB) plays an important role in solving these problems by ensuring the effective development of democracy. Participatory budgeting, which incorporates democratic elements such as ensuring citizen participation in budget decision-making, increasing accountability and transparency, attempts to solve the problems of the city by increasing communication between citizens and representatives at the local level and creating an organised society. In this way, it can be used as a tool to promote different types of sustainability in the political, economic and social spheres, from creating an organised society that will enable segments of the city with limited opportunities to become effective in the budget process, to social justice, from environmental problems to providing basic health services, clean water and wastewater systems, schools and kindergartens and living spaces for the poor, from the provision of better quality public services to the efficient use of resources due to accurately identified public services, and from corruption, bribery and nepotism to the solution of administrative failures. This study aims to present the concept, emergence, functioning and outcomes of participatory budgeting.

Treatment efficiency and microbial community analysis in the integrated bioremediation system of aquaculture wastewater with the ceramsite and compound bacteria

The integrated bioremediation systems (IBSs) are becoming increasingly widespread to treat aquaculture wastewater. However, there is still significant room for the improvement of technological processes of the IBS. In this study, exogenous compound bacteria (ECB) were added to the system and combined with ceramsite to treat wastewater. The changes in bacterial communities within the system were analyzed through high-throughput sequencing and multivariable statistics, and the dynamic changes in bacterial communities within the system was visualized. The results showed that ECB significantly increased the diversity and affected the assembly of the bacterial communities in the water and biofilm, forming three succession stages. The ECB promoted the increase of denitrifying bacteria which play a key role in the ecological function of the system. Sedimentitalea and Paracoccus were the biomarkers of the water and biofilms in the treatment group, and were significantly positively correlated with the denitrification process. The overall nutrients removal efficiency of the treatment group exceeded 80%. And the removal efficiency of TN, NH4+-N, NO3−-N, NO2−-N, and PO43--P in the treatment group were significantly higher than those in the control group, which indicated the ECB led to a significant improvement in purification effectiveness. The significant influence of the ECB on the IBS provided a preliminary theoretical basis for improving the system process, enhancing nutrient removal performance, and exploring system working mechanisms.

Role of public attitude, knowledge, and trust in shaping the acceptance of recycled wastewater for potable and non-potable uses

Abstract The acceptance of recycled wastewater plays a pivotal role in shaping the success of water management strategies. This study examines relation of public attitudes, knowledge, behaviors, and trust toward recycled wastewater systems, utilizing a survey of participants. The results reveal substantial knowledge deficits, with only 23.8% correctly defining recycled wastewater. In addition, 46.3% of respondents were knowledgeable about water scarcity, while 45.3% correctly identified the largest water uses. Attitudes were more reserved toward potable applications, with only 5% strongly agreeing to consume recycled water for drinking. Behavioral intentions favored non-potable uses, with 87% agreeing to use recycled wastewater for home gardening and flushing toilets, while 56% considered consuming food irrigated with recycled wastewater acceptable. Trust in water authorities emerged as a significant factor influencing acceptance. Lack of competence and not acting in public interest were identified as key factors eroding trust. The study also explored the influence of religion, revealing that non-contact applications were widely accepted across all religions, while direct-contact applications generated varied responses. The findings underscore the need for targeted educational campaigns, the cultivation of trust, and a nuanced approach considering cultural and religious diversity to promote wastewater recycling.

Operation Risk Simulation and Interaction Impact of Stormwater and Sewage Systems Based on Storm Water Management Model

With the increasing urbanization rate, higher demand is placed on drainage systems, necessitating analysis of their risk profiles. While many studies focus on the individual hydraulic modeling of stormwater and wastewater systems when considering operational risks, they often overlook the exacerbating effects of combined stormwater and wastewater flows on each other’s risks. In this study, we constructed a model of the combined stormwater and wastewater drainage system in Lijiao, Guangdong Province. We analyzed the operational risks of both stormwater and sewage networks in different scenarios, focusing on full-load pipes, overload pipes, node overflows, and minimum flow velocities. Furthermore, we compared the exacerbating effects of sewage and stormwater on each other’s network operational risks. Simulation results indicated that, for sewage networks with combined sewer sections, the lengths of full-load pipes and overload pipes increased by an average of 27.4% and 16.3%, respectively, during rainy weather scenarios compared to dry weather. After considering the inflow of sewage into combined sewer sections, the average length of full-load pipes increased by 3.8 km, overload pipe length increased by 1.1 km, and overflow volume increased by 2.26 × 104 m3. As the return period of rainfall events increases, these inter-system impacts gradually diminish. Therefore, when modeling drainage systems and assessing operational risks, particularly during low return period rainfall events, the inclusion of both stormwater and sewage in combined sewer networks should be comprehensively considered.

A Comparison of the Co-Treatment of Urban Wastewater and Acidic Water Using a Ternary Emergy Diagram

The Pasco region in Peru is an area that has historically been polluted by mining activity and population growth. As a result, there is an increased production of urban wastewater and acidic water that contaminate local lakes such as Quiulacocha and Patarcocha. The construction of a treatment plant that can treat the different types of wastewaters has not yet been studied, and its sustainability has not yet been evaluated. The objective of this research was to predict the sustainability of co-treatment systems in different scenarios between urban wastewater and acidic water, expressed in terms of a ternary emergy diagram. The design of the co-treatment plant was carried out at an inflow of 10 L/s. The first scenario (Treatment I) has a primary settler for the mixture of urban wastewater and acidic water, while the second scenario (Treatment II) involves a settler and a subsurface artificial wetland, and the third scenario (Treatment IIIa and IIb) presents a settler, an electrocoagulation system and a secondary settler; this scenario differentiates between the use of urban wastewater and eutrophicated water from Patarcocha Lake. The results of the ternary diagram show the contributions of the fractions of renewable resources from Treatment I (69%), from Treatment II (65.7%), from Treatment IIIa (61.6%), and from Treatment IIIb (21.8%); the fractions of non-renewable resources in Treatment I (26.13%), Treatment II (24.13%), Treatment IIIa (23.33%), and Treatment IIIb (9.50%); and the fractions of imported inputs in Treatment I (4.84%), Treatment II (9.37%), Treatment IIIa (15.04%), and Treatment IIIb (68.72%). It is concluded that the use of a co-treatment system for urban wastewater and acidic water is sustainable in the long term when using an electrocoagulator or an artificial wetland.