ACS ES&T water最新文献

Russia’s invasion of Ukraine continues to have a devastating effect on the well-being of Ukrainians and their environment. We evaluated a major environmental hazard caused by the war: the potential for groundwater contamination in proximity to the Zaporizhzhia Nuclear Power Plant (NPP). We quantified groundwater vulnerability with the DRASTIC index, which was originally developed by the United States Environmental Protection Agency and has been used at various locations worldwide to assess relative pollution potential. We found that there are two major gradients of groundwater vulnerability in the region: (1) broadly higher risk to the northeast of the NPP and lower risk to the southeast driven by a regional gradient in water availability and water table depth; and (2) higher risk in proximity to the channels and floodplains of the Dnipro River and tributaries, which host coarser-textured soils and sedimentary deposits. We also found that the DRASTIC vulnerability index can be used to identify and prioritize groundwater well-network monitoring. These and more detailed assessments will be necessary to prioritize monitoring and remediation strategies across Ukraine in the event of a nuclear accident, and more broadly demonstrate the utility of the DRASTIC approach for prognostic contamination risk assessment.

We mapped groundwater contamination vulnerability near Ukraine’s Zaporizhzhia nuclear power plant, a facility located in an active war zone.

Russia's invasion of Ukraine continues to have a devastating effect on the well-being of Ukrainians and their environment. We evaluated a major environmental hazard caused by the war: the potential for groundwater contamination in proximity to the Zaporizhzhia Nuclear Power Plant (NPP). We quantified groundwater vulnerability with the DRASTIC index, which was originally developed by the United States Environmental Protection Agency and has been used at various locations worldwide to assess relative pollution potential. We found that there are two major gradients of groundwater vulnerability in the region: (1) broadly higher risk to the northeast of the NPP and lower risk to the southeast driven by a regional gradient in water availability and water table depth; and (2) higher risk in proximity to the channels and floodplains of the Dnipro River and tributaries, which host coarser-textured soils and sedimentary deposits. We also found that the DRASTIC vulnerability index can be used to identify and prioritize groundwater well-network monitoring. These and more detailed assessments will be necessary to prioritize monitoring and remediation strategies across Ukraine in the event of a nuclear accident, and more broadly demonstrate the utility of the DRASTIC approach for prognostic contamination risk assessment.

The main drivers of mercury (Hg) compound distribution in seawater are poorly understood, calling for novel spatial and seasonal observations of potential transformations. However, scientific progress is hindered by a lack of intercomparability among incubation studies and the infrequent inclusion of dissolved gaseous mercury species (DGM = elemental Hg (Hg(0)) + dimethyl Hg (DMHg)) despite their importance in the biogeochemical cycle of Hg. We perform a comprehensive quality assessment on our proposed incubation protocol at near ambient concentrations (∼10 × ambient background) including the formation of DGM on three distinct coastal seawaters and discuss intercomparability with previous experimental approaches. We establish an excellent mass balance for tracer isotopes both excluding DGM (¹⁹⁹Hg = 99.5% and ²⁰¹Hg = 100.4%, median) and including DGM (¹⁹⁹Hg = 100.3% and ²⁰¹Hg = 101.7%, median). We find a good median relative standard deviation for experimental triplicates (¹⁹⁹Hg(II) ∼ 1.7%, MM²⁰¹Hg ∼ 1.5%, ¹⁹⁹DGM ∼ 10%, ²⁰¹Hg(II) ∼ 13%, and ²⁰¹DGM ∼ 22%), enabling the accurate determination of methylation, demethylation, and reduction rate constants at femtomolar concentration levels. We observed Hg(0) formation from MMHg, potentially indicating reductive demethylation. This study highlights the practicability and importance of incorporating DGM species (here, Hg(0), eventually DMHg) in future incubation studies.

Metals are ubiquitous in Earth’s Critical Zone and play key roles in ecosystem function, human health, and water security. They are essential nutrients at low concentrations, yet some metals are toxic at a high dose. Permafrost thaw substantially alters all the physical and chemical processes governing metal mobility, including water movement and solute transport and (bio)geochemical interactions involving water, organic matter, minerals, and microbes. The outcomes of these interconnected changes are nonintuitive yet hold global implications for water resources and ecosystem health. This Perspective outlines the primary factors affecting metal mobility in thawing permafrost and underscores the urgent need and priorities for interdisciplinary research to better understand this emerging issue.

The present study evaluated the performance of a full-scale gravity-driven membrane filtration system with passive hydraulic fouling control (PGDMF) for drinking water treatment in a small community over a 3-year period. The PGDMF system consistently met the design flow and regulated water quality/performance parameters (i.e., total coliform, Escherichia coli, turbidity, and membrane integrity). The instantaneous temperature-corrected permeability (TCP) varied seasonally, being greater during the winter months. The overall TCP decreased slowly to ∼60% of the initial value by the end of 3 years, a TCP that is much greater than would have been expected without passive hydraulic fouling control. Although it was not possible to directly link the observed seasonal changes in TCP to potential seasonal changes in the biofilm microbiome, the analysis did suggest that the lower TCP during summer months was due to a greater microorganism richness in the feed and presence of filamentous, stalked, and biofilm-forming bacteria in the biofilm. Operation with higher trans-membrane pressure (i.e., ∼30 vs ∼20 mbar) and more frequent passive hydraulic fouling control (i.e., every 12 vs 24 h) enabled a greater flow to be sustained. The study demonstrated the long-term robustness and performance of GDMF with passive hydraulic fouling control for drinking water treatment.

The present study evaluated the performance of a full-scale gravity-driven membrane filtration system with passive hydraulic fouling control (PGDMF) for drinking water treatment in a small community over a 3-year period. The PGDMF system consistently met the design flow and regulated water quality/performance parameters (i.e., total coliform, Escherichia coli, turbidity, and membrane integrity). The instantaneous temperature-corrected permeability (TCP) varied seasonally, being greater during the winter months. The overall TCP decreased slowly to ∼60% of the initial value by the end of 3 years, a TCP that is much greater than would have been expected without passive hydraulic fouling control. Although it was not possible to directly link the observed seasonal changes in TCP to potential seasonal changes in the biofilm microbiome, the analysis did suggest that the lower TCP during summer months was due to a greater microorganism richness in the feed and presence of filamentous, stalked, and biofilm-forming bacteria in the biofilm. Operation with higher trans-membrane pressure (i.e., ∼30 vs ∼20 mbar) and more frequent passive hydraulic fouling control (i.e., every 12 vs 24 h) enabled a greater flow to be sustained. The study demonstrated the long-term robustness and performance of GDMF with passive hydraulic fouling control for drinking water treatment.

Gravity-driven membrane filtration with passive hydraulic cleaning offers simple and effective drinking water treatment. This study showcases a successful full-scale application for a small community for over 3 years.

Metals are ubiquitous in Earth's Critical Zone and play key roles in ecosystem function, human health, and water security. They are essential nutrients at low concentrations, yet some metals are toxic at a high dose. Permafrost thaw substantially alters all the physical and chemical processes governing metal mobility, including water movement and solute transport and (bio)geochemical interactions involving water, organic matter, minerals, and microbes. The outcomes of these interconnected changes are nonintuitive yet hold global implications for water resources and ecosystem health. This Perspective outlines the primary factors affecting metal mobility in thawing permafrost and underscores the urgent need and priorities for interdisciplinary research to better understand this emerging issue.

The standard methods for detecting per- and polyfluoroalkyl substances (PFAS) are precise and sensitive, but their operational complexity and high costs hinder the regular monitoring. Raman spectroscopy offers a promising complementary approach due to its fingerprinting ability for trace analysis, low operational cost, and fitness for field-deployable applications. However, the effective use of Raman spectroscopy requires a well-established Raman library, which is currently lacking. This study proposes a simple drop-coating deposition Raman (DCDR) spectroscopy method to concentrate PFAS and establish a library. We prepared DCDR samples of thirteen linear PFAS with carboxyl or sulfonic groups and seven nonfluorinated alkyl acids with similar chemical structures. Raman maps were collected using a 532 nm laser and a confocal Raman spectrometer. All tested PFAS shared common Raman bands at approximately 300, 380, and 725 cm^–1, with varying band-to-band intensity ratios depending on their chain lengths, head groups, and extents of telomerization. Principal component analysis was performed on wavenumbers 200–1,000 and 1,100–1,600 cm^–1 to differentiate PFAS with nonfluorinated alkyl acids and PFAS with various functional groups. To our knowledge, this research created a novel experiment-based reproducible Raman spectral library for PFAS, laying a foundation for efficient PFAS screening using Raman spectroscopy.

Flux declines seriously affect gravity-driven membrane (GDM) separation modules’ production efficiency and service life. Here, permeation and nuclear magnetic resonance (NMR) experiments were conducted to disentangle the relationship between the volume ratio of the adsorbed water layer to the pore volume (VATP) and the flux of the GDM for predicting flux. The results indicate that all permeation flux patterns follow a similar decreasing trend over time, eventually reaching a stable flux. The subtle variation of the number and area of NMR T₂ peaks in the permeation process indicates a substantial influence of VATP on the permeation flux. Specifically, a higher VATP corresponds to a higher flux decline rate. Furthermore, upon incrementing the pressure from 20 to 100 mbar, the value of VATP exhibits a reduction in the range of 20–10%. An improved stable permeation flux prediction model was constructed by using the Hagen–Poiseuille permeability equation and fractal theory with parameters (VATP, operating pressure, and material characteristics). The predicted permeation flux exhibits good agreement with the experimental results of stable flux (R² = 0.92). These findings confirm that the transition from free water to adsorbed water within GDM pores is the mechanism by which the permeability decreases to a stable low level in porous media.