Journal: ACS ES&T Water

Abbreviation

ACS EST Water

Publisher

American Chemical Society

Journal Volumes

ISSN

2690-0637

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Filters

2021 - 20245
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Publications 1 - 5 of 5
  • Seasonal Preferences and Alternatives for Domestic Water Sources: A Prospective Cohort Study in Malawi
    Item type: Journal Article
    Cassivi, Alexandra; Tilley, Elizabeth; Waygood, Owen; et al. (2021)
    ACS ES&T Water
    Access to a sufficient quantity of safe water is widely recognized as fundamental to ensure health and prevent water- and excreta-related diseases. The objective of this study is to analyze seasonal variations in household preferences and alternatives in accessing domestic water, including for drinking, and to identify predictors for the use of multiple water sources. A prospective cohort study was conducted in Malawi, and data were collected using structured household questionnaires and water quality testing. Results showed that households fetching water were more likely to rely on multiple water sources during the rainy season, compared to the dry season. When access to a single water source is insufficient, and/or the main water source is broken or not functional, households use additional water sources that are more likely to be contaminated or distant as a coping strategy. Water source reliability (i.e., functionality and availability) and proximity to water sources (i.e., time to collect water, waiting time) were found to be the most important factors influencing households’ preferences. Ensuring reliable and continuous access, throughout the seasons, to at least a single water source that is located in proximity to the household is a key intervention to reduce the fetching burden.
  • Methodological Advances to Study Contaminant Biotransformation: New Prospects for Understanding and Reducing Environmental Persistence?
    Item type: Journal Article
    Fenner, Kathrin; Elsner, Martin; Lueders, Tillmann; et al. (2021)
    ACS ES&T Water
    Complex microbial communities in environmental systems play a key role in the detoxification of chemical contaminants by transforming them into less active metabolites or by complete mineralization. Biotransformation, i.e., transformation by microbes, is well understood for a number of priority pollutants, but a similar level of understanding is lacking for many emerging contaminants encountered at low concentrations and in complex mixtures across natural and engineered systems. Any advanced approaches aiming to reduce environmental exposure to such contaminants (e.g., novel engineered biological water treatment systems, design of readily degradable chemicals, or improved regulatory assessment strategies to determine contaminant persistence a priori) will depend on understanding the causal links among contaminant removal, the key driving agents of biotransformation at low concentrations (i.e., relevant microbes and their metabolic activities), and how their presence and activity depend on environmental conditions. In this Perspective, we present the current understanding and recent methodological advances that can help to identify such links, even in complex environmental microbiomes and for contaminants present at low concentrations in complex chemical mixtures. We discuss the ensuing insights into contaminant biotransformation across varying environments and conditions and ask how much closer we have come to designing improved approaches to reducing environmental exposure to contaminants.
  • Reactive Transport with Fluid–Solid Interactions in Dual-Porosity Media
    Item type: Journal Article
    Nissan, Alon; Alcolombri, Uria; de Schaetzen, Frédéric; et al. (2021)
    ACS ES&T Water
    We study pore-scale dynamics of reactive transport in heterogeneous, dual-porosity media, wherein a reactant in the invading fluid interacts chemically with the surface of the permeable grains, leading to the irreversible reaction Aaq + Bs → Caq. A microfluidic porous medium was synthesized, consisting of a single layer of hydrogel pillars (grains), chemically modified to contain immobilized enzymes on the grain surfaces. Fluorescence microscopy was used to monitor the spatiotemporal evolution of the reaction product Caq at different flow rates (Péclet values) and to characterize the impact on its transport. The experimental setup enables delineation of three key features of the temporal evolution of the reaction product within the domain: (i) the characteristic time until the rate of Caq production reaches steady state, (ii) the magnitude of the reaction rate at steady state, and (iii) the rate at which Caq is flushed from the system. These features, individually, are found to be sensitive to the value of the Péclet number, because of the relative impact of diffusion (vs advection) on the production and spatiotemporal evolution of Caq within the system. As the Péclet number increases, the production of Caq is reduced and the transport becomes more localized within the vicinity of the grains. The dual-porosity feature causes the residence time of the transported species to increase, by forming stagnant zones and diffusive-dominant regions within the flow field, thus enhancing the reaction potential of the system. Using complementary numerical simulations, we explore these effects for a wider range of Péclet and Damköhler numbers and propose nonlinear scaling laws for the key features of the temporal evolution of Caq.
  • Time-Integrated Bioavailability Proxy for Actinides in a Contaminated Estuary
    Item type: Journal Article
    Chaplin, Joshua D.; Christl, Marcus; Cundy, Andrew B.; et al. (2022)
    ACS ES&T Water
    Actinides accumulate within aquatic biota in concentrations several orders of magnitude higher than in the seawater [the concentration factor (CF)], presenting an elevated radiological and biotoxicological risk to human consumers. CFs currently vary widely for the same radionuclide and species, which limits the accuracy of the modeled radiation dose to the public through seafood consumption. We propose that CFs will show less dispersion if calculated using a time-integrated measure of the labile (bioavailable) fraction instead of a specific spot sample of bulk water. Herein, we assess recently developed configurations of the diffusive gradients in thin films (DGT) sampling technique to provide a more accurate predictor for the bioaccumulation of uranium, plutonium, and americium within the biota of the Sellafield-impacted Esk Estuary (UK). We complement DGT data with the cross-flow ultrafiltration of bulk seawater to assess the DGT-labile fraction versus the bulk concentration. Sequential elution of Fucus vesiculosis reveals preferential internalization and strong intracellular binding of less particle-reactive uranium. We find significant variations between CF values in biota calculated using a spot sample versus using DGT, which suggest an underestimation of the CF by spot sampling in some cases. We therefore recommend a revision of CF values using time-integrated bioavailability proxies.
  • Copper Decontamination Using Feather Keratin Amyloid-Carbon Hybrid Membranes
    Item type: Journal Article
    Soon, Wei Long; Peydayesh, Mohammad; Bui, My Hanh; et al. (2024)
    ACS ES&T Water
    Copper is an essential metal used in many manufacturing processes across several important industries. This commonly results in copper-containing acidic industrial effluents that require neutralization before treatment and recovery. This generates additional secondary waste sludge that must be further treated before disposal. The valorization of industrial proteinaceous byproducts is a promising approach toward sustainable heavy metal water treatment. Here, we demonstrate the utilization of feather keratin amyloid fibrils for the removal of copper from contaminated water. Keratin amyloid fibril/carbon hybrid membranes feature high adsorption capacities of copper even at a low pH with high reusability without significant energy consumption.
Publications 1 - 5 of 5