Water Environment Research最新文献

This study examines the spatiotemporal dynamics and determinants of waterborne diseases (WBDs) in Algeria between 2000 and 2023, using annual epidemiological reports from the National Institute of Public Health. Five major diseases are analyzed: foodborne disease outbreaks (FBDOs), hepatitis A, dysentery, typhoid fever, and cholera. Descriptive statistics, temporal trend analysis, and age-stratified profiling are applied to identify epidemiological patterns and underlying determinants. Results indicate a significant epidemiological transition: Typhoid fever and dysentery declined by nearly 98%, reflecting progress in access to safe water and sanitation. In contrast, FBDOs and hepatitis A account for more than 80% of the total burden, with distinct seasonal peaks: hepatitis A in winter and FBDOs in summer. Cholera remains sporadic but re-emerged in 2018, highlighting persistent outbreak risks. Age-stratified analysis reveals differential vulnerabilities: Children and adolescents are most affected by hepatitis A and dysentery, young adults by typhoid fever and FBDOs, and older adults by cholera. Spatial disparities are evident, driven by climatic variability, unequal access to safe water, and weaknesses in the food supply chain. These findings underscore the need for an integrated public health approach that combines strengthened epidemiological surveillance, sustainable improvements in water and sanitation systems, enhanced food safety regulation, targeted vaccination, and climate-sensitive health policies. The Algerian experience offers insights relevant to other North African and Mediterranean contexts facing similar environmental and socio-demographic challenges.

This study assessed the long-term performance of sequencing batch reactor (SBR) technology for municipal wastewater treatment in Erbil, Kurdistan Region, Iraq, over the period 2021-2024. Four sampling stations (S1-S4) were monitored for key physicochemical parameters, including TSS, BOD₅, COD, turbidity, nitrate, and phosphate, before and after treatment. The reduction efficiency index (REI), contamination factor (CF), and pollution load index (PLI) were applied to evaluate system effectiveness and contamination trends. Results showed consistently high removal efficiencies (70%-90%) for TSS, BOD₅, COD, turbidity, nitrate, and phosphate. However, a gradual decline in performance was observed from 2022 to 2024, particularly for TSS, COD, and turbidity, indicating possible operational or load-related variations. Among all stations, S1 exhibited the most stable treatment efficiency, with PLI decreasing from 0.892 in 2021 to 0.517 in 2024, signifying improved water quality and sustained reactor performance. Overall, the findings confirm the reliability of SBR systems for municipal wastewater treatment under semiarid urban conditions, while emphasizing the need for continuous monitoring and operational optimization to maintain long-term efficiency.

This review summarizes scientific studies from 1963 to 2024 on how chemical and biological surfactants affect oxygen transfer at the air-water interface. Surfactants, which often enter water from human activities, can alter water surfaces and involve the transfer of oxygen, an important aspect of water quality and treatment. We reviewed 54 peer-reviewed studies and sorted them by surfactant type, water type, and experimental scale. A lot of research has been done on chemical surfactants, but less on biosurfactants. Most of the experiments were conducted in labs, indicating that more field research is needed. There are still more than 92.22% of possible combinations of surfactants and water that have not been tested. Surfactants usually make it harder for oxygen to move through water, but the extent to which they do depends on their chemistry, the amount present, and the water's cleanliness. Research is segregated into distinct disciplines, exhibiting minimal collaboration. This review highlights areas where further research is needed, especially on biosurfactants and their behavior in real-world water. It also offers ideas for improving wastewater treatment. Our findings support green chemistry and give a framework for better managing oxygen transfer and surfactant pollution in water systems.

Groundwater circulation well (GCW) technology and electro-Fenton (EF) technology offer promising prospects for groundwater remediation due to their high efficiency in removing volatile organic compounds and their advantage of causing no secondary pollution. In this study, chemical oxygen demand (COD) was selected as the target contaminant to investigate the remediation performance of the EF coupled with GCW technology. The results indicate that the optimal COD removal was achieved at an applied voltage of 30 V, as higher voltages facilitate the accelerated generation of ·OH radicals, thereby enhancing the degradation rate of pollutants. However, excessively high voltages may lead to increased current, elevated energy consumption, and potential anode damage; thus, considering both treatment efficiency and economic cost, 20 V was identified as the optimal voltage. In the coupled EF-GCW system, the optimal aeration rate was determined to be 1.3 L/min. Increasing the aeration rate beyond this value did not significantly improve the removal performance and instead reduced EF efficiency due to decreased dissolved oxygen residence time. Furthermore, the current GCW hydraulic design presents flow blind zones, which limit remediation efficiency in certain regions. This study defines the optimal operational window for the EF-GCW system and provides insights into overcoming hydraulic circulation blind spots, offering valuable process parameters for the optimization and practical application of groundwater remediation technologies.

A 7-month pilot investigation of the biological treatment performance of the membrane tank within a membrane bioreactor (MBR) system was conducted in Tacoma, WA. The study compared performance with and without the presence of an aeration basin upstream of the membrane tank to determine if biological reactions in the membrane tank play a significant role in the treatment process to determine if the aerated volume of the biological reactor could be further reduced. Performance of the two operating schemes was evaluated for treatment efficiency of biochemical oxygen demand (BOD), carbonaceous BOD (cBOD), and ammonia removal, while denitrification and biological phosphorus removal were also monitored. Effluent concentrations of BOD, sCOD, and ammonia were similar with and without the aeration basin, suggesting that designers of MBR facilities should account for biological processes occurring within the membrane tank when sizing MBR systems.

Pharmaceutical industrial effluent consisting of a complex cocktail of toxic chemicals poses a significant impact on the aquatic environment. Conventional methods for treating pharmaceutical effluent are often inefficient due to high cost, environmental concerns and sludge production. In contrast, vermifiltration offers a cost-effective and environmentally sustainable alternative especially suitable for developing countries. Consequently, the current analysis explored the toxicological influence of pharmaceutical wastewater, both untreated and vermifiltration treated, in the brain tissue of Channa punctata through oxidative stress markers, DNA damage, histopathological, and ATR-FTIR analysis. The experiment comprised three groups (control, untreated, and vermifiltration treated) with three replicates and was conducted under controlled laboratory conditions. Significant (p ≤ 0.05) alterations in oxidative stress markers, for instance, malondialdehyde (MDA) content, superoxide dismutase, catalase, glutathione-S-transferase, and acetylcholinesterase activities, were observed in the group exposed to untreated effluent. A 2.91-, 3.02-, and 3.77-fold rise in MDA content was observed after 15, 30, and 45 days in the untreated effluent-exposed group compared to the control group. The comet assay results demonstrated a substantial increase in all the comet parameters in the untreated effluent group compared to the control group. Further severe histopathological and biomolecular anomalies were observed in the untreated effluent group. Conversely, the vermifiltration-treated group exhibited fewer alterations in enzyme activities, DNA damage, histopathological and biomolecular deviations compared to the untreated group. This reveals the less toxic nature of treated effluent. In light of the findings, we can say that vermifiltration technology has the potential to reduce environmental pollution and emerge as an environmentally friendly solution. Its ecological sustainability makes it particularly suitable for developing countries.

Quantifying how sedimentary architecture governs groundwater quality remains a critical research challenge in hydrogeology. This challenge spans from hydrochemical evolution to public health impacts. To address this knowledge gap, we developed an integrated quantitative framework to analyze the complete "geological-to-health" pathway in the northwestern Tangshan piedmont alluvial plain. We conducted a systematic analysis of 42 groundwater samples using three complementary approaches: hydrochemical characterization, absolute principal component score-multiple linear regression (APCS-MLR) receptor modeling, and health risk assessment. This multi-method investigation demonstrates the fundamental control of sedimentary architecture over groundwater systems. This study establishes that groundwater in the study area is predominantly of the weakly alkaline HCO₃-Ca·Mg type. Ion correlation analysis indicates that mineral dissolution (mainly carbonates and evaporites) governs groundwater chemistry and enhances NO₂ ^- migration through increased ionic strength. Gibbs diagrams, ion ratios, and saturation index (SI) collectively demonstrate that sedimentary architecture exerts fundamental control over hydrogeochemical processes. The chemical evolution is primarily governed by coupled carbonate precipitation and evaporite dissolution. High-permeability zones within this architectural framework facilitate anthropogenic contamination. APCS-MLR receptor modeling quantifies the anthropogenic contribution at 20.7%, while also revealing that all contaminant sources are constrained by architectural heterogeneity. Health risk assessment identifies F^- as posing the most significant noncarcinogenic risk. Hazard indices for infants (3.318) and children (2.903) substantially exceed those for adults (1.288). These findings establish a mechanistic framework linking subsurface architectural heterogeneity to public health outcomes. This framework provides a transferable paradigm for predictive groundwater quality management.

Reverse osmosis (RO) and nanofiltration (NF) processes are considered "best available technologies" by the US Environmental Protection Agency for perfluoroalkyl and polyfluoroalkyl substance (PFAS) remediation from water. While these processes are industry standard for applications such as desalination, commercial membranes are typically tailored to said applications, so different membrane products may show differing PFAS rejection behavior based on proprietary manufacturing methods or surface modifications. Additionally, there are limited studies reporting rejection trends of ultrashort-chain (USC) compared to short-chain (SC) and long-chain (LC) PFAS. This work benchmarks a total of 13 commercial RO or NF membranes for eight PFAS, spanning all size classes, under standardized conditions for rejection performance. A comparison of overall PFAS rejection across the membranes showed statistically significant differences in performance, indicating that membranes do not uniformly reject PFAS equally and highlighting the role of membrane chemistry on performance. A strong positive correlation between measured salt rejection and overall PFAS rejection was found. Lastly, USC and SC species were found to have similar rejection while LC species showed significantly higher rejection. These findings emphasize the importance of membrane selection when designing a system for PFAS remediation and provide new insight into PFAS rejection behavior relative to other species and salts.

This study aimed to identify the primary drivers of spatial and temporal variations in chlorophyll-a (Chl-a) concentrations and to improve the prediction accuracy of Chl-a concentrations at two adjacent weirs-Seungchon Weir (SC Weir) and Juksan Weir (JS Weir)-in the Yeongsan River, Korea. Utilizing over a decade of high-frequency monitoring data combined with a gradient boosting (GB) regression model, we investigated the conditions leading to high Chl-a concentrations, which are indicative of algal blooms. The results indicate that JS Weir frequently experiences extreme Chl-a concentrations (> 100 μg/L) under low discharge conditions (< 20 m³/s). Seasonal analysis revealed that diatoms dominated algal blooms at JS Weir during the colder months, which contradicts the conventional expectation of more intense summer blooms given the typically low temperatures and light availability in winter. Discharge rate and water temperature exhibited inverse relationships with Chl-a concentrations, and the GB model revealed a lagged multiday discharge effect. Water temperature and total organic carbon at JS Weir were identified as the most influential predictors of Chl-a concentrations. Parameters from SC Weir also showed high importance, confirming upstream-to-downstream connectivity along the 22-km reach between SC Weir and JS Weir. Integrating upstream data enhanced predictive accuracy for downstream bloom conditions. This research provides a foundation for coordinated weir operation-optimizing sluice gate control and upstream nutrient management-to mitigate algal blooms in regulated river systems. These management strategies can improve water quality and protect ecosystem health.

This study aimed to analyze evidence on the physical, chemical, and microbiological risks associated with dental wastewater (DWW) and its impact on the environment and human health. As part of a scoping review, we searched the PubMed, Scopus, and Web of Science databases for studies that described DWW management, characterization, filtration, and associated risks. The search was limited to studies published in English, including experimental, laboratory, observational studies, and reviews. We extracted the study design, country of origin, sample location, components, objectives, and results. Using VOSviewer software, an analysis of author coauthorship and keyword co-occurrence was conducted. Environmental and human risks were examined, and strategies to minimize damage were discussed. The search initially yielded 1967 articles until June 2024. After removing duplicates and applying exclusion criteria, 29 articles were selected for inclusion. Most studies (55.1%) were experimental, with heavy metals being the most frequently studied pollutants (60%), particularly mercury (Hg). Microbiological analyses appeared in six studies (20.6%), and bisphenol A in two studies (6.9%). The environmental pollutant potential of DWW was reported in 22 studies (75.8%), while only five studies (17.2%) documented risks to humans. In conclusion, DWW poses significant environmental hazards due to its toxic composition and pollutant potential. Although evidence on human health risks is still limited and fragmented, preliminary findings suggest possible concerns that warrant attention. These results highlight the urgent need for more comprehensive studies and support the implementation of regulatory and management strategies to mitigate environmental and potential human health impacts.