ACS ES&T water最新文献

The three inorganic chloramines play central roles in aqueous chloramination processes. Mechanisms involving these species are required to obey the principle of detailed balancing, but very few published examples meet this requirement. There are at least 77 publications with chloramine mechanisms that violate the principle of detailed balancing. In this work, the violations are summarized, a set of reaction equilibrium constants and rate constants is proposed that should facilitate the development of acceptable mechanisms, and solutions to the published errors are proposed.

Water-based recreational activities can impact freshwater systems, but the resulting anthropogenic alterations to the chemical and microbial composition of natural streams remain poorly understood. Utilizing state-of-the-art analytical approaches, including liquid chromatography-high-resolution mass spectrometry (LC-HRMS), inductively coupled plasma mass spectrometry (ICP-MS), and 16S rRNA gene sequencing, we investigated changes in stream chemistry and microbiology resulting from recreational activities in Clear Creek (Golden, Colorado). Spatial and temporal sampling was conducted for 3 days over a summer holiday weekend when a large influx of recreational float tubing activity occurred. Nontarget LC-HRMS analysis demonstrated substantial differences in the organic fingerprint on days and locations with high recreational use compared to that of low use. Similarly, increases in the total suspended solids were correlated with suspended particulate metal concentrations (Al, Cu, Ti, Pb, and Zn). Element ratios suggest recreation-induced resuspension of streambed sediments as the metal source rather than other anthropogenic inputs (e.g., Ti/Zn-containing sunscreens). Gene sequencing revealed significant shifts in the stream microbial community, supporting an input of human-associated enteric microbiota during high recreation periods. However, the overall results indicate that recreational activities have a short-lived effect on the stream. In this work, we established a first-of-its-kind holistic assessment of the impact of anthropogenic activity on a natural stream by simultaneously considering changes in the organic, inorganic, and microbial fingerprints.

Solar interface evaporation is considered an innovative and effective technology for combating global freshwater scarcity, with its effectiveness primarily hinging on the efficiency of photothermal materials. Here, we designed a solar evaporation device comprising a sponge layer for water collection and a polypyrrole (PPy) layer chemically deposited on a single-sided flannel (PPy@SSF) for sunlight absorption. The fiber array within PPy@SSF facilitates to absorb light energy, establishing a heating interface between the light absorption layer and the water. The sponge layer not only aids in water collection but also serves as a thermal insulation layer, preventing heat dispersion. The resulting device exhibits characteristics such as high water evaporation, robust stability, and resistance to salt. The daily water output reaches 8.12 kg m^–2 under direct sunlight. In desalinating simulated seawater, the ion concentrations in the condensed water were reduced by 4 orders. Furthermore, heavy metal ions in purified water from sewage were reduced by at least 3 orders of magnitude. Additionally, the properties of the device showed no attenuation after being used repeatedly 10 times under 1 sun. Our research provides a platform with high photothermal conversion efficiency for seawater and sewage purification.

This study investigates the optimized design of horizontal flow constructed wetlands (HFCWs) to enhance pollutant removal efficiency while minimizing surface area requirements, particularly in the Southeast Asian region. By refining the first-order removal rate coefficient (k) for organics and nutrients, the research aims to meet specific performance benchmarks across three scenarios, ensuring compliance with discharge or reuse standards. Utilizing a data set comprising 1680 entries, five machine learning models─multiple linear regression (MLR), eXtreme Gradient Boosting (XGBoost), random forest (RF), artificial neural network (ANN), and support vector regression (SVR)─were employed to predict k values. Pearson’s correlation, heat maps, and ANOVA analysis identified the most influential parameters affecting k-value predictions. The k values ranged from 0.01 to 0.52 per day using the P–k–C* method, essential for effective pollutant removal. The SVR model demonstrated the highest predictive accuracy, with R² values of 0.91 for k_BOD, 0.90 for k_TN, 0.82 for k_TKN, and 0.76 for k_TP. This optimization reduced standard deviations significantly, from 136.90% to 2.28%. Consequently, the required wetland area was reduced by up to 68% for biochemical oxygen demand (BOD), 60% for TN (total nitrogen), and 67% for TP (total phosphorus) in larger systems, supporting the tailored design of HFCWs to meet targeted discharge standards.

Nitrogen-removing biofilters (NRBs) are alternative on-site wastewater treatment systems that can remove some trace organic contaminants (TOrCs) from domestic wastewater, though the dominant removal mechanisms are uncertain. We conducted column experiments representative of the nitrifying sand layer of an NRB to evaluate the contribution of sorption to removal of 16 wastewater-relevant TOrCs. The contribution of sorption was >25% for eight of the 16 TOrCs in at least one experimental treatment and >50% for five TOrCs. Transformation appeared to account for 51–93% of TOrC removal in columns. Transformation product screening resulted in the tentative identification of three TOrC transformation products in column effluent. To compare the bench-scale experiment to realistic field conditions, we analyzed solid samples from a recently excavated full-scale NRB. Median concentrations of sorbed TOrCs ranged from 0.02 to 5.09 ng/g in column studies and 0.05–7.14 ng/g in the full-scale NRB. Overall, the majority of TOrC removal in our laboratory study was by transformation, though some hydrophobic TOrCs exhibited significant removal by sorption. The concentration of sorbed hydrophobic TOrCs in aged NRBs and release of transformation products of frequently detected TOrCs should be taken into consideration during future system design and optimization.

Pharmaceutical removal in soil-based treatment is often attributed to sorptive processes without direct analysis. This study evaluates the contributions of sorption and biotransformation of contaminants in soil-based treatment.

The architectural configuration of an electrode material significantly impacts its capacitive deionization (CDI) performance, particularly due to the disparity in ion diffusion resistance between the surface and core. To mitigate this disparity, a hollowing methodology was employed to revamp conventional porous carbon spheres. Hierarchically porous hollow carbon spheres (HCSs) were synthesized by thermal annealing phenol formaldehyde resin-coated melamine formaldehyde resin spheres (MFSs) in an inert gas at 800 °C. The advantage of employing modified MFSs as templates lies in their complete degradation during thermal annealing, a feature not observed with commercial polystyrene microspheres. Unlike mesoporous SiO₂ microspheres which require additional hydrofluoric acid treatment, these do not. HCS-100 exhibited exceptional NaCl adsorption capacity, achieving a salt adsorption capacity of 25.20 mg g^–1 and a salt adsorption rate of 2.78 mg g^–1 min^–1 under a working voltage of 1.2 V. This performance was demonstrated with an initial NaCl solution concentration of 500 mg L^–1, and it maintained impressive stability over 70 cycles. The results demonstrate that the hollowing strategy is a direct yet powerful way to enhance the CDI performance of electrode materials. The utilization of the modified MFS template simplifies the fabrication process, contributing to the overall effectiveness of this approach.

Regular monitoring of drinking water quality is crucial for achieving Sustainable Development Goal 6, but conventional methods are costly and challenging to implement in low-resource settings. Community-based monitoring, facilitated by sensor technology and information and communication tools, offers a more efficient and affordable approach, yet data reliability is uncertain. This study investigated whether minimally trained nonexpert rural women could reliably monitor drinking water quality, household water treatment and safe storage practices in low-resource settings using an integrated water quality testing kit. The kit combined a mobile app with sensors for detecting chemical (hardness, pH, alkalinity, chlorine, total dissolved solids, conductivity, dissolved oxygen, oxidation–reduction potential, turbidity) and biological (Escherichia coli) contamination. The AquaGenX P/A kit was used to measured E. coli. We examined the interrater reliability and agreement between data collected by 27 rural women and our research team in 1673 rural households in Tanzania and two Indian states. Results showed robust, moderate to high levels of agreement and interrater reliability between the nonexperts and experts, suggesting the method delivers valuable water quality data. Rural women’s involvement also led to empowerment, accountability, and ownership through technology. Our results indicate community-based initiatives’ potential to improve water quality management in resource-constrained contexts.

Transforming water quality monitoring in low-income areas, the study validates a community-based tool by empowering rural women for sustainable improvements.

Japanese encephalitis virus (JEV) and the Murray Valley encephalitis virus (MVEV) are mosquito-borne pathogens capable of transmission from animals to humans, causing significant economic and public health impacts in affected countries. Pigs serve as amplifying hosts for JEV and potentially play a role in the natural ecology of MVEV. Reports of JEV viral shedding underscore the prospect of wastewater surveillance for early detection and intervention for animal and human health. To assess the feasibility of wastewater surveillance, the decay rates of JEV and MVEV RNA were determined under the simulated diurnal temperatures in summer and winter by seeding these viruses in piggery wastewater collected from three potential surveillance sites (shed, pit, and lagoon). During a 52-day experiment, a one log₁₀ reduction in RNA copies was found for JEV within 24.8–36.4 days, while MVEV experienced a 90% reduction ranging from 15.5 to 24.4 days, which was significantly faster than that of JEV. Seasonal temperature and site-specific differences significantly influenced the RNA decay rates of both viruses in piggery wastewater samples. These data indicated the sufficient persistence of JEV and MVEV under diurnal temperatures in summer and winter conditions, which would facilitate surveillance of viruses in piggery environments.

Building water systems are associated with variable water age and temperatures, causing water quality concerns. Legionella spp., nontuberculous mycobacteria (NTM), and Pseudomonas spp. are known to inhabit and grow in these systems for which building-level interventions are often required to reduce their concentrations and detections. Other contaminants such as metals and disinfection byproducts (DBPs) are also health concerns. Interventions are typically flushing, temperature manipulation, responsive facility-level interventions (e.g., chemical disinfection and heat shock), or point-of-use devices. A systematic literature review was conducted to summarize interventions targeting pathogen control, and subsequent meta-analysis quantified their respective log reduction values (LRVs). Across the studies (n = 45), Legionella spp. was the primary target (n = 45), and studies varied from laboratory benchtops/pipe racks to hospitals and residential or commercial buildings. Additional measurements and LRVs for heavy metals (e.g., copper, lead, and iron) and DBPs such as trihalomethanes (THMs) were evaluated. The findings pointed to the importance of contextual conditions and incoming water quality in playing a role in both pathogen occurrence and intervention effectiveness. Common interventions such as recommissioning flushing and increased temperature should be further examined for their impacts on pathogens besides Legionella spp. and their contribution to biofilm sloughing and pathogen regrowth. Trade-offs, such as increased metal leaching in parallel with pathogen inactivation, should be examined in context with intervention and building water quality conditions.