Water Sources Research Articles

Long-term pilot study on advanced treatment of lake water by ultrafiltration / nanofiltration

Advanced water treatment technologies, including ozone biologically activated carbon adsorption (O3-BAC), ultrafiltration (UF), and nanofiltration (NF), are essential for enhancing drinking water quality. O3-BAC and UF excel in pathogen, virus, and by-product removal, while NF promises enhanced contaminant elimination for high-quality water. However, the implementation of combined UF/NF dual-membrane treatment processes in large-scale water treatment facilities using surface water sources like lakes remains relatively novel. The lack of long-term operational data is the main reason for the limited widespread adoption. To address this, two pilot systems were established: one comprising ‘O3-BAC + pressure-driven UF(I) + NF(I) (Route 1 at 6.4m3/h)’, and the other ‘immersed UF(II) + NF(II) (Route 2 at 3.2m3/h)’, undergoing a year-long evaluation. The trials showed that the dual-membrane systems were effective and resistant to interference. Notably, they achieved removal efficiencies exceeding 98 % for turbidity, UV254 absorbance, fluorescence substances, and algae, alongside significant reductions in odor (80 %) and total dissolved solids (TDS) by 30 %. Both membrane systems display promising performance and O3-BAC is recommended as a pretreatment process. Analysis revealed that the primary constituents of membrane fouling on the NF membranes are aluminum silicate, SiO2, CaCO3 particles, and organic pollutants, which are typically formed through interactions between calcium ions and dissolved organic matter (DOM). The most effective cleaning protocol involves acidic-alkaline treatments. This study provides valuable operational insights into advanced treatment processes using dual-membrane combinations for water treatment plants that rely on lake water sources.

Occurrence, analysis and removal processes of emerging pharmaceuticals from waters for the protection and preservation of a sustainable environment: a review

Pharmaceuticals are a group of man-made commercial and synthetic products and an important mainstay of modern society. However, their presence in aquatic environments is identified as a potential risk, causing harm to living things even at low concentrations ranging from ng L-1 to μg L-1. Due to their pseudo-persistence, bio-accumulation, and low elimination rate by conventional treatments, the majority of these xenobiotic contaminants and their metabolites are routinely released into the environment by sewage treatment plants and last longer in an aquatic environment. This review aims to provide an extensive report and a current state of knowledge concerning various classes of pharmaceutical compounds (PCs). It also discusses the occurrence, the analytical methods for the determination of PC micro-pollutants, and the remediation methods noted in recent literature focusing on the most recent advances. In this context, this review highlights the statistical data regarding the status of PCs in detection, analysis, and removal methods in aqueous media. In addition, this review provides an overview of the conventional and advanced technologies for the removal of PCs from water sources, offering critical comments, and discussing the challenges related to improving existing technologies for sustainable and eco-friendly management of water resources. It likewise emphasizes the importance of the combination of different treatment methods to reach up to 100% PC removal.Finally, gaps in the literature were found, and recommendations for further research were also cited in accordance with this paper. To the best of our knowledge, this review paper is among the rare works that deal with both: i) the analysis of large varieties of PCs in different water matrices, ii) the removal and identification of target analytes and their by-products generated during the elimination processes, and iii) the possible degradation pathways proposed by different studies.

Examining the Radiological Health Risks Associated with Water Sourced from the Ogwashi-Uku Earth Dam in Ogwashi-Uku, Delta State, Nigeria

Given the increased human activities and population growth in Ogwashi-Uku, there is a possibility of potential contamination of the water in the dam with elevated levels of alpha and beta radiation. Therefore, this study aimed to assess the radiological health risks associated with water obtained from the Ogwashi-Uku Earth dam by analyzing the concentrations of gross alpha and gross beta activity in the water. The results indicate that the measured activity concentrations of gross alpha and gross beta in the water samples are below the permissible limits of 0.1 Bq/l and 1.0 Bq/l respectively. Additionally, the average annual effective dose equivalent calculated for all the water samples is lower than the recommended dose limit of 0.1 mSv for radionuclides in water. These findings suggest that the assessed life cancer risk associated with the water consumption is low, indicating that the water from the Ogwashi-Uku Earth dam is safe for consumption.

Microscopic and molecular epidemiology of gastrointestinal nematodes in dairy and beef cattle in Pak Chong district, Nakhon Ratchasima province, Thailand

Background and Aim: Gastrointestinal (GI) nematode infection remains an important problem in livestock, particularly cattle. The infection may lead to serious health complications and affect animal products. The objective of this study was to investigate GI nematode infection and its associated risk factors in dairy and beef cattle farmed in Pak Chong District of Nakhon Ratchasima Province, northeast Thailand. Materials and Methods: Fecal specimens were collected from 101 dairy cattle and 100 beef cattle. Formalin-ethyl acetate concentration techniques were used to process the samples and the samples were observed under a light microscope. Samples were subjected to molecular identification of specific genera using conventional polymerase chain reaction and DNA sequencing. Results: The overall prevalence of GI nematode infection was 33.3%. The strongyle nematode was the most significant GI nematode in this area with a prevalence of 28.4%. The prevalence of strongyle nematodes was 58.0% in beef cattle and only 7.9% in dairy cattle. Trichuris spp. was another nematode found in both types of cattle with an overall prevalence of 5.0% with 9.0% in beef cattle and 1.0% in dairy cattle. The results of the epidemiological study indicate that the age of cattle, food, water sources, farming system, and housing floor are the most important risk factors. Among the strongyle nematodes, Ostertagia spp. was the most prevalent (82.0%), followed by Haemonchus spp. (62.3%) and Trichostrongylus spp. (8.2%), respectively. Conclusion: Infection with GI nematodes still exists in this area, particularly in beef cattle. Our reported data may benefit local parasitic control policies in the future. Keywords: beef cattle, dairy cattle, gastrointestinal nematode, strongyle nematodes.

Farmer's climate smart livestock production adoption and determinant factors in Hidebu Abote District, Central Ethiopia.

This study aimed to identify the status, determining factors, and challenges in adopting climate smart livestock production practices by farmers. Three-staged sampling techniques were used to select the research sites and 233 sample farmer household respondents. Data were collected mainly using a pre-tested structured questionnaire. Key informant interviews and focus group discussions were also conducted to complement the household survey data. Descriptive statistics and an ordered logistic regression model were applied to analyze the quantitative data. The result revealed that the most adopted practices were composting (85.41%) and manure management (70.39%) while the least adopted technologies were biogas generation (3.86%) and rotation grazing (22.32%). The adoption status of the sampled farmers was also categorized into low (19.74%), medium (67.81%), and high adopter (12.45%). The high cost of improved breed, use of manure for fuel, free grazing, lack of information and awareness were the major constraints to adopting the climate smart livestock production technologies. The result also revealed that education, grazing land, total livestock holding, and extension agent contact contributed significantly and positively to the adoption of smart livestock production technology, while the distance from the water source had an insignificant and negative effect on the adoption status of climate smart livestock production practices. The study suggests the relevance of the cooperation of stakeholders and strengthening extension services for the maximum benefits of climate smart livestock production.

Hybrid machine learning models for groundwater level prediction in a snow‐dominated region: An evaluation of EEMD, VMD and EWT decomposition techniques

Hybrid machine learning models for groundwater level prediction in a <scp>snow‐dominated</scp> region: An evaluation of <scp>EEMD</scp>, <scp>VMD</scp> and <scp>EWT</scp> decomposition techniques

Higher water content observed in smaller size fraction of Chang’e-5 lunar regolith samples

Water has been detected in lunar regolith, with multiple sources identified through the analysis of individual grains. However, the primary origin of water in the bulk lunar regolith remains uncertain. This study presents spectroscopic analyses of water content in sealed Chang’e-5 samples. These samples were sieved into various size fractions (bulk, <45 μm, 45-355 μm) inside a glovebox filled with high-purity nitrogen. Results indicate a higher water content in the fine fractions (∼87±11.9 ppm) than in bulk soil (∼37±4.8 ppm) and coarse fractions (∼11±1.5 ppm). This suggests that water is predominantly concentrated in the outermost rims of the regolith grains, and thus exhibits dependence on the surface volume ratio (also known as surface correlation), indicating solar wind is a primary source of lunar surface water. Laboratory, in-situ, and orbital results bridge sample analysis and remote sensing, offering a cohesive understanding of lunar surface water characteristics as represented by Chang’e-5. The discovery provides statistical evidence for the origin of water in lunar soil and can be considered representative of the lunar surface conditions. The water enrichment of the finest fraction suggests the feasibility of employing size sorting of lunar soils as a potential technological approach for water resource extraction in future lunar research stations.

Mapping of groundwater potential zones of Khordha District using GIS and AHP approaches

The most dependable source of fresh water is groundwater. Groundwater supplies are severely threatened by a number of factors, including urbanization, industrialization, and population growth. The amount, quality and variables affecting groundwater supplies are significantly impacted by climate variability. The fall in groundwater levels is often exacerbated by poor quality surface water resources and unreliable monsoons. Therefore, in order to supplement the groundwater supply, it is important to locate and define the groundwater potential zone (GPZ). The analysis is conducted for the Khordha district, where groundwater rather is a primary source for agricultural uses. In order to determine the possible groundwater zones, many factors, including geomorphology, geology, elevation, slope, precipitation, soil type, soil texture, drainage density (DD), lineament density (LD), Land use/Land cover (LULC), and lineament density (LD), are constructed as separate layers in the geographical information system (GIS) backdrop. The multi-criteria decision-making technique and the Analytic Hierarchy Process (AHP), which enable pairwise evaluation of criteria impacting the potential zone, were utilized to establish the weights for the different layers and after that, the weighted overlay analysis (WOA) tool in ArcGIS10.8 was used to produce the final groundwater potential map. The output map of specified region was delineated into five new classes-very good, good, moderate, poor, and very poor of which 12% (325.1745 km2) falls under ‘very low’, 22% (603.9765 km2) under ‘low’, 26% (700.7715 km2) under ‘moderate’, 26% (694.2591 km2) under ‘high’, 14% (376.7553 km2) under ‘very high’. Approximately 1395 km2 area concerning 52% of study region, falls under ‘high’ and ‘very high’ categories of GPZ. Validation of the generated GPWZ map was done with data acquired from Central groundwater board. The accuracy assessment was done by kappa coefficient error matrix, and based on overall accuracy, the obtained map was 81.538% accurate to field value. As dependable results were produced with the proposed methodology, future management plans incorporating natural and artificial recharge practices can be created in these locations with effectiveness.

Transformation of existing inefficient buildings into nearly zero-emission buildings – A case study of a residential building from the Czech Republic

This article presents a case study focusing on the conversion of an existing typical residential building in the Czech Republic into a near-zero emission building. Five parameters were compared in the study: average heat transfer, coefficient of the building envelope, non-renewable primary energy, energy requirements for heating, total energy supplied, and carbon dioxide emissions. A total of five energy-saving options were developed for the building, covering the building envelope and building services. The study was conducted considering two separate heat sources for heating and domestic hot water. The evaluation was carried out for a scenario involving a heat pump, and a district heating system

Characterization and recognition of three-dimensional excitation-emission matrix spectra of wastewater from six typical categories

In this study, we analyzed the characteristics of three-dimensional excitation-emission matrix spectra (EEMs) of 150 samples from five industrial wastewater types and domestic sewage to track water pollution sources effectively. We then developed a recognition model for wastewater EEMs by establishing a feature dataset containing fluorescence peak values and parameters derived from EEMs, integrated with machine learning techniques. This model enables the rapid and precise identification of pollution sources. Our findings suggest that although the EEMs of the six wastewater categories are distinct, visual differentiation is challenging. This was confirmed by cosine similarity assessments, showing some samples with low within-group (< 0.8) and high between-group (> 0.95) similarities. Despite significant variations in EEMs features across wastewater categories, identifying specific pollutants remains difficult, especially for pulp mills and leather effluents. Among the tested classification algorithms, Support Vector Machine (SVM) achieved the highest performance with 91.7 % accuracy, 94 % precision, 91 % recall, and 92 % F1-score, outperforming K-Nearest Neighbors and Partial Least Squares Discriminant Analysis. The SVM significantly improved identification accuracy for pulp mill and leather processing wastewaters compared to other models. To enhance identification accuracy, further exploration of EEMs features and expanding the training dataset are recommended. Combining EEMs features with machine learning presents a promising method for improving water pollution supervision and source tracing in environmental management practices.

Quaternary tectonic and climatic forcing on the spatio-temporal evolution of the Meuse fluvial terrace staircase

The Quaternary is characterized by pronounced alterations between cold and warm climatic states, with the Mid-Pleistocene Transition marking a strong increase in the intensity of cold-climate conditions. River systems are sensitive to environmental perturbation (e.g., climate, tectonics, base level) and are expected to respond to such profound changes. This study uses a combination of terrace mapping and analysis of a dense borehole database to investigate the Meuse terrace staircase (and its deposits), and gain insight on how it reflects climatic and tectonic perturbations during the Quaternary. The lower reaches of the Meuse river, which has both its main water and sediment source in the Ardennes displays a well-developed terrace staircase that was sculpted mainly throughout the Quaternary. The staircase is located near the cities of Maastricht (southern Netherlands) and Liège (northwestern Belgium). About 30 terrace levels reflect signals of environmental perturbations in the lithological composition, gradients, thicknesses, and spatial distribution. The terraces are organized in groups, based on their morphological position, from old to young; these are the East Meuse terrace group and West Meuse High-, Middle- and Low terrace groups. Our findings show a consistent increase in the gravel content from older to younger terraces. The sandier composition of the deposits of the oldest terraces (Early Pleistocene) is closely related to the supply of the Miocene-Pliocene weathered material from the Ardennes. Younger terraces (Middle and Late Pleistocene) are much richer in gravel, evidencing sediment input from fresh or partially weathered bedrock. These changes point to a downstream migration of the gravel front throughout the Quaternary. The mean thickness of the terrace groups shows a slight increase, even though the same trend is not clear when each terrace is analyzed on an individual basis. The anomalous thickness of the Caberg 1 terrace suggests increased sediment input during the cold climatic conditions of the Elsterian (MIS 12), the first Quaternary glacial during which an ice sheet extended into the northern Netherlands. Reconstruction of terrace gradients reveals that older East Meuse terraces show a (reversed) gradient opposite to reconstructed palaeo flow directions, which is attributed to a combination of low gradients during terrace formation and footwall back-tilting of the Feldbiss Fault Zone. In our analysis we do not see clear evidence for the imprint of the Mid-Pleistocene Transition, which suggests that due to its gradual nature, its signal is either buffered or assimilated by the overall climatic signal of the Quaternary. This study offers a first complete temporal analysis of the Meuse terrace staircase, providing an important basis for better understanding the effects of Quaternary climatic change and tectonics, and their resulting effects in other river systems worldwide.

Menstrual hygiene behaviour among the tribal married women aged 15 to 49 years: A cross-sectional study in a community development block of Paschim Bardhaman District, West Bengal

ABSTRACT Background: Menstrual hygiene management is integrally associated with reproductive health of women. Menstrual health and hygiene needs, particularly of tribal women still remain unmet for many reasons. Inappropriate menstrual behaviour leads to adverse health consequences. Objectives: This study aimed to ascertain the menstrual hygiene behaviour of tribal married women aged 15 to 49 years and its correlates. Methods: A descriptive cross-sectional study was conducted from May 2019 to April 2020 in the Barabani block of Paschim Bardhaman district, West Bengal. A calculated sample of 530 women was selected randomly from 10 tribal villages of the study area; they were interviewed through a pre-designed schedule for socio-demographic and menstrual hygiene behaviour characteristics. Menstrual hygiene management score was derived based on five essential components- hygienic absorbents, hygienic disposal of absorbents, frequency of changing of absorbents, cleaning of external genitalia and source of water for cleaning; menstrual hygiene behaviour was categorised as favourable and unfavourable. Bivariate and multivariable logistic regression was performed using SPSS v. 20. Results: All 530 women were Hindu and belonged to Santhal ethnicity; 53.4% were illiterate. Sanitary pads were used by 43.8% of women; 63% practised indiscriminate throwing for disposal of absorbents; 86% practised appropriate changing of absorbents. Overall, 63% had favourable menstrual hygiene management behaviour, and the literacy status of women was found to be a significant predictor. Conclusion: Unfavourable menstrual practices are still widely prevalent among tribal women, mainly attributable to lack of knowledge. Awareness generation should be focused on improving those practices, which would also result in the improvement of general health conditions.

Tissue distribution, migration pathways and dietary risk assessment of fungicides in pomelo orchards in South China

Fungicides are used to protect vegetables and fruits from fungal diseases. Their ubiquitous utilization has resulted in water source contamination and human health concerns. However, the occurrence of fungicides in fruits and the potential implications for human health remain unclear. In this study, ninety-five fungicides were measured in pomelo and corresponding soil and leaf samples from two pomelo orchards in South China. The mean concentration of target fungicides (∑fungicides) in pulp (honey pomelo: 0.23±0.24ng/g; shatian pomelo: 0.23±0.11ng/g) were much lower than those in surface soil (0.53±0.57ng/g; 1.41±1.85ng/g) and leaf (6.97±3.20ng/g; 28.5±11.1ng/g). Triazole fungicides emerged as the predominant fungicides. Varied fungicides exhibit distinct tissue distribution in fruits, demonstrating diverse migration behaviors. The distribution of all fungicides followed the order: exocarp > mesocarp > endocarp > seed > pulp. No significant associations between fungicides in both soil and pulp suggest that the primary origin of fungicides in pulp may involve external exposure. Although the dietary risks of the target fungicides in pomelo were far lower than 1, it was not negligible. Our study provides novel insights into the residues and behavior of fungicides, offering foundational data for the dietary risk assessment of pomelo consumption.

A regulatory framework for bottled water quality monitoring: A case of Emfuleni local municipality

BackgroundThe quality of drinking water has recently become of utmost concern to consumers worldwide, especially in areas where Water Service Authorities (WSAs) failed to provide safe water. To combat this challenge, government entities regulate water to ensure that safe water is provided. The Emfuleni Local Municipality (ELM) has experienced cases of water contamination by human excretion, whereby communities were affected. As a result, there was a sharp increase in bottled water (BW) use, which however gave rise to unregulated and counterfeit versions of popular brands. This situation poses threats to public health. AimThis study sought to determine the regulation of drinking water and to assess whether environmental health practitioners (EHPs) monitor the quality of water sources (BW and tap water) in ELM as outlined by the National Environmental Health Norms and Standards (NEHNS). SettingsThe study was conducted in the Emfuleni Local Municipality in South Africa. MethodsA quantitative cross-sectional study design was employed in this research. Fifteen online questionnaires using a Google Forms survey were distributed amongst all EHPs servicing ELM. Secondary data that included the Integrated Development Plan (IDP) and Service Delivery Budget Implentation Plan (SDBIP) for the 2017–2020 financial years were also evaluated, specifically for water quality monitoring (tap and bottled water). The dataset was analysed using the Statistical Package for the Social Sciences (SPSS) version 29. ResultsDue to complexity in the legislation and NEHNS in relation to Municipal Health Services (MHS), bottled water was not sampled at all. A number of EHPs were also not conversant with the regulations governing BW. Moreover, NEHNS consider bottled water as food, which does not fall under the MHS. ConclusionThere should be clarity in the legislation to ensure that bottled water monitoring is intensified to protect public health within the WSAs. ContributionThe findings of this study could assist policy-makers to make informed decisions on water quality monitoring, as well as clarify legislative issues on bottled water.

Optimizing removal of antiretroviral drugs from tertiary wastewater using chlorination and AI-based prediction with response surface methodology

Chemical and pharmaceutical chemicals found in water sources create substantial risks to human health and the environment. The presence of pharmaceutical contaminants in water can cause antibiotic resistance development, toxicity to aquatic organisms, and endocrine disruption. Hence, the elimination of chemicals and other contaminants from wastewater prior to its release is a burgeoning concern in the domains of engineering and science. The use of treatment technologies in wastewater treatment plants can remove pharmaceutical contaminants through the oxidation process. However, many traditional wastewater treatment plants lack the advanced monitoring tools required to detect low concentrations of pharmaceuticals. Without the ability to detect these compounds, it's challenging to treat them effectively. The goal of this study was to use Response Surface Methodology (RSM) and Artificial Neural Networks (ANN) algorithms to model and improve how Nevirapine and Efavirenz break down in different chlorination conditions. The RSM analysis revealed statistically significant models (F-values: Nevirapine, pH-t: 108.15, T-t: 76.55, ICC-t: 110.84), indicating a strong correlation between operational parameters (pH, temperature, and initial chlorine concentration) and degradation behavior. The ANN model accurately predicted the degradation of both Nevirapine and Efavirenz under various chlorination conditions, as confirmed by analyzing actual-predicted graphs, residual plots, and Mean Squared Error (MSE) values. The ANN model using ICC-t achieved the highest MOD value of 31.31 % for Nevirapine. The ANN model based on ICC-t yielded a maximum MOD value of 16.06 % for Efavirenz. These findings provide valuable insights into optimizing chlorination processes for better removal of these pharmaceutical contaminants from water.

Cellulose-MIL-88A photocatalytic membrane to treat effluents containing dyes and oil emulsions

One of the major problems in semi-arid regions is the water shortage that has been exacerbated by industrial pollution of water sources. Photocatalytic membranes are a promising solution for treating different industrial effluents for water reuse. In this work, cellulose-MIL-88A membranes were produced by a single-step facile deposition of MIL-88A for separating dyes and emulsions from water followed by cleaning regeneration. The optimized membrane achieved a permeation flux of 5850Lh-1 m-2 bar-1 and a rejection rate of 91-100% for RB5 textile reactive dye. After use, the clogged membrane was regenerated via photo-Fenton degradation using H2O2 and artificial solar light. After 30 cycles of filtration and regeneration, the membrane presented 98.1% RB5 rejection rate with 74% of the initial permeation flux. The membrane was able to separate oil-water emulsions containing diesel, soybean oil or n-hexane. In addition, it was possible to treat real industrial textile wastewater with an efficiency of 61%. The cellulose-MIL88A photocatalytic membrane is a promising low-cost technology for industrial wastewater treatment using cellulose-based green material.

Mixed-charged polyamide-4-sulfocalix [4] arene hollow fiber nanofiltration membranes for heavy metal removal under various pH

The presence of heavy metal ions in water sources poses significant risks to both human health and environments; hence, it is critical to develop effective and trustworthy removal techniques. This research aims to fabricate a novel hollow fiber membrane consisting of mixed-charged characteristics via the formation of a positively charged thin film composite (TFC), followed by the infiltration of 4-sulfocalix [4] arene (SCA4). The formation, architecture and separation performance of the mixed-charged nanofiltration (NF) membrane have been confirmed by various characterizations. The SCA4-0.03 NF hollow fiber membrane shows excellent rejection performance up to 99.2% for a variety of ion removals such as common arsenate, nickel (II), and lead (II) ions over a broad pH range. Additionally, the mixed-charged membrane exhibits higher performance stability over 48 h and fouling resistance in both basic and acidic conditions. Consequently, the mixed-charged membrane described in this work is promising to treat both cationic and anionic liquids, and eliminate a variety of ecologically harmful ion species in industries.

Association between Combined Sewer Overflow Events and Gastrointestinal Illness in Massachusetts Municipalities with and without River-Sourced Drinking Water, 2014-2019.

Combined sewer overflow (CSO) events release untreated wastewater into surface waterbodies during heavy precipitation and snowmelt. Combined sewer systems serve people in the United States, primarily in urban and suburban municipalities in the Midwest and Northeast. Predicted increases in heavy precipitation events driven by climate change underscore the importance of quantifying potential health risks associated with CSO events. The aims of this study were to a) estimate the association between CSO events (2014-2019) and emergency department (ED) visits for acute gastrointestinal illness (AGI) among Massachusetts municipalities that border a CSO-impacted river, and b) determine whether associations differ by municipal drinking water source. A case time-series design was used to estimate the association between daily cumulative upstream CSO discharge and ED visits for AGI over lag periods of 4, 7, and 14 days, adjusting for temporal trends, temperature, and precipitation. Associations between CSO events and AGI were also compared by municipal drinking water source (CSO-impacted river vs. other sources). Extreme upstream CSO discharge events (th percentile by cumulative volume) were associated with a cumulative risk ratio (CRR) of AGI of 1.22 [95% confidence interval (CI): 1.05, 1.42] over the next 4 days for all municipalities, and the association was robust after adjusting for precipitation [1.17 (95% CI: 0.98, 1.39)], although the CI includes the null. In municipalities with CSO-impacted drinking water sources, the adjusted association was somewhat less pronounced following 95th percentile CSO events [ 1.05 (95% CI: 0.82, 1.33)]. The adjusted CRR of AGI was 1.62 in all municipalities following 99th percentile CSO events (95% CI: 1.04, 2.51) and not statistically different when stratified by drinking water source. In municipalities bordering a CSO-impacted river in Massachusetts, extreme CSO events are associated with higher risk of AGI within 4 days. The largest CSO events are associated with increased risk of AGI regardless of drinking water source. https://doi.org/10.1289/EHP14213.

Assessment of Heavy Metal and E. coli Contamination in Water Sources of the East and South Districts, Sikkim Himalaya, India

Assessment of Heavy Metal and E. coli Contamination in Water Sources of the East and South Districts, Sikkim Himalaya, India

Ammonia nitrogen removal from coal gasification wastewater using a falling-film dielectric barrier discharge reactor: Process optimization and toxicity analysis

The continuous use of coal gasification technology for green energy generation to supplement the dwindling energy reserves generates significant amounts of wastewater containing ammonia nitrogen, posing a significant risk to the finite drinking water sources and aquatic lives. Herein, two falling-film dielectric barrier discharge (DBD) reactors with copper and titanium high-voltage electrodes, respectively, were designed to remove ammonia nitrogen (NH3−N) and chemical oxygen demand (COD) simultaneously from coal gasification wastewater. The operational parameters were screened using the Plackett-Burman design, and the significant parameters were further optimized via the response surface methodology. The results showed that the power parameter significantly influenced NH3-N removal, and COD removal was influenced considerably by power and treatment time. Under the optimum conditions (treatment time = 20.32 min, pH = 3, airflow rate = 1 L/min, power = 116 W, and recirculating flow rate = 50.02 mL/min), a removal ratio of 62.33 % and 37.35 % was achieved for NH3-N and COD for the reactor with the copper electrode, and 67.66 % and 44.90 % for NH3-N, and COD for the reactor with the titanium electrode. Additionally, the concentrations of O3, ·OH, and H2O2 produced by the reactors were quantified, and their crucial roles in the removal process of NH3-N were evaluated. Although smaller concentrations of NO2− and NO3− were detected in the treated wastewater, over 97 % of N2 selectivity encompassed NH3-N removal. Finally, acute phytotoxicity tests were performed, and the results indicated that at 100 mL/L dosage, the treated wastewater from both reactors did not restrict Barbarea verna growth.