A5079663690- Water Treatment and Disinfection
- Water Systems and Optimization
- Fecal contamination and water quality
- Legionella and Acanthamoeba research
- Wastewater Treatment and Reuse
- Fluorine in Organic Chemistry
- Groundwater and Isotope Geochemistry
- Arsenic contamination and mitigation
- Environmental Chemistry and Analysis
- Per- and polyfluoroalkyl substances research
- Wastewater Treatment and Nitrogen Removal
- Fluoride Effects and Removal
- Geochemistry and Geologic Mapping
- Water resources management and optimization
- Agriculture and Biological Studies
- Child Nutrition and Water Access
- Urban Stormwater Management Solutions
- Groundwater and Watershed Analysis
- Water Quality and Pollution Assessment
- Engineering and Materials Science Studies
- Chemical Analysis and Environmental Impact
George Mason University
2021-2025
Virginia Tech
2025
Waters (United States)
2025
Stanford University
2018-2022
The implementation of chlorine disinfection in low-income countries reduces the risk waterborne illness but initiates exposure to byproducts (DBPs). Like high-income countries, typically are adopting regulations focusing on trihalomethanes (THM4) as an indicator overall DBP exposure. However, use impaired water sources can decouple formation THM4 from other classes that more potent toxins. documentation species than is rare where may be degraded by inadequate sanitation infrastructure and...
Drinking water regulations often use indicators to represent risk associated with broader contaminant groups. To evaluate the efficacy of indicators, a quantitative approach is needed that aligns regulatory framework, in which benchmark value represents an unacceptably high level or class. This policy microsimulation study develops such context potential revisions address brominated HAAs, class disinfection byproducts. Likely scenarios include limit on sum nine and chlorinated HAAs (HAA9),...
Epidemiologists have used trihalomethanes (THMs) as a surrogate for overall disinfection byproduct (DBP) exposure based on the assumption that THM concentrations are proportional to of other DBP classes. Toxicological evidence indicates THMs less potent toxins than unregulated classes like haloacetonitriles (HANs). If not DBPs driving toxicity, use measure may introduce non-trivial misclassification bias in epidemiologic studies. This study developed statistical models evaluate covariance...
N-Nitrosodimethylamine (NDMA), an important contaminant for potable reuse of municipal wastewater, forms from reactions dichloramine and amine precursors. Injection concentrated free chlorine stock solutions into wastewaters containing low levels ammonia can promote NDMA formation because the high chlorine:ammonia ratio at point injection fosters during mixing. This study combined chemical kinetic modeling, laboratory mixing studies using deionized water authentic wastewater effluents, a...
Watersheds with relatively higher concentrations of disinfection by-product (DBP) precursors are concern for public water systems (PWSs) seeking to control DBP exposure risk. In this study, the occurrence bromide and total organic carbon (TOC), which important precursors, was evaluated in PWS source waters on a watershed basis at hydrologic unit code 2 (HUC2) level. Variations were examined across type (e.g., surface or groundwater) watershed, temporally based seasonality as well differences...
Intermittently operated distribution systems serve over one billion people and may be impacted by the intrusion of contaminated waters carrying disinfection byproduct (DBP) precursors. The impact on formation 19 DBPs was evaluated in an intermittent water system supplied deep aquifers Dhaka, Bangladesh. Untreated piped samples were collected from residential taps chlorinated under controlled conditions. Chloride, dissolved organic carbon, artificial sweetener sucralose measured as indicators...
Per-and polyfluoroalkyl substances (PFAS) are a class of toxic manufactured chemicals in commercial and consumer products. They resistant to environmental degradation mobile soil, air, water. This study used the introduced bivalve Corbiculafluminea as passive biomonitor at sampling locations primary drinking water source Virginia, USA. Many potential PFAS sources were identified region. Perfluorohexane sulfonate (PFHxS) 6:2 fluorotelomer sulfonic acids (6:2 FTS) levels highest downstream an...