- Water Treatment and Disinfection
- Pharmaceutical and Antibiotic Environmental Impacts
- Per- and polyfluoroalkyl substances research
- Toxic Organic Pollutants Impact
- Wastewater Treatment and Nitrogen Removal
- Atmospheric chemistry and aerosols
- Water Quality Monitoring and Analysis
- Urban Stormwater Management Solutions
- Advanced oxidation water treatment
- Wastewater Treatment and Reuse
- Chemical Analysis and Environmental Impact
- Water Quality and Pollution Assessment
- Fecal contamination and water quality
- Water Quality Monitoring Technologies
- Odor and Emission Control Technologies
- Environmental Chemistry and Analysis
- Analytical chemistry methods development
- Groundwater flow and contamination studies
- Constructed Wetlands for Wastewater Treatment
- Environmental remediation with nanomaterials
- Fire effects on ecosystems
- Plant responses to elevated CO2
- Water Systems and Optimization
- Membrane Separation Technologies
- Recycling and Waste Management Techniques
Southern Nevada Water Authority
2015-2024
Quality Research
2013-2024
Las Vegas Institute
2019
Colorado School of Mines
2008-2017
Henderson Community College
2015-2017
Université de Poitiers
2008
Centre National de la Recherche Scientifique
2008
University of Colorado Boulder
2000
Lawrence Livermore National Laboratory
1996-1997
University of California, Davis
1996
A process based on electrical discharge plasma was tested for the transformation of perfluorooctanoic acid (PFOA). The plasma-based adapted two cases, high removal rate and efficiency. During a 30 min treatment, PFOA concentration in 1.4 L aqueous solutions reduced by 90% with (76.5 W input power) 25% efficiency (4.1 power). Both achieved remarkably defluorination efficiencies compared to leading alternative technologies. also used treat groundwater containing several cocontaminants...
This paper presents an up-to-date meta-analysis assessing per- and polyfluoroalkyl substance (PFAS) concentrations at wastewater treatment plants (WWTPs) as well changes over time. PFAS were compiled for WWTPs in the United States from peer-reviewed studies, technical reports, original data. Perfluorooctanoic acid (PFOA) increased by average of 6.0 ± 1.6 ng/L influents to effluents WWTPs, but perfluorosulfonic (PFOS) did not significantly change, indicating sorption sludge is offset...
Using reclaimed water to irrigate food crops presents an exposure pathway for persistent organic contaminants such as perfluoroalkyl acids (PFAAs) enter the human chain. This greenhouse study used augmented with varying concentrations (0.2–40 μg/L) of PFAAs, including perfluorocarboxylates (C3F7COO– C8F17COO–) and perfluorosulfonates (C4F9SO2O–, C6F13SO2O–, C8F17SO2O–), investigate potential uptake concentration–response trends in lettuce (Lactuca sativa) strawberry (Fragaria ananassa). In...
Microbial community structure in the ozone-biofiltration systems of two drinking water and wastewater treatment facilities was characterized using 16S rRNA gene sequencing. Collectively, these datasets enabled comparisons by facility, type (drinking water, wastewater), pre-oxidation (ozonation, chlorination), media (anthracite, activated carbon), depth, backwash dynamics. Proteobacteria most abundant phylum filters, whereas Bacteroidetes, Chloroflexi, Firmicutes, Planctomycetes were...
To determine the types of applications for which plasma-based water treatment (PWT) is best suited, treatability 23 environmental contaminants was assessed through in a gas discharge reactor with argon bubbling, termed enhanced-contact reactor. The were treated mixture to normalize reaction conditions and convective transport limitations. Treatability compared terms observed removal rate constant (k obs). characterize influence interfacial processes on k obs, model developed that accurately...
While it is known that resorcinol- and phenol-type aromatic structures within natural organic matter (NOM) react during drinking water chlorination to form trihalomethanes (THMs), limited studies have examined aliphatic-type as THM haloacetic acid (HAA) precursors. A suite of aliphatic model compounds were chlorinated brominated separately in controlled laboratory-scale batch experiments. Four two β-dicarbonyl found be important precursors for the formation THMs (chloroform bromoform (71–91%...
To respond to concerns associated with wastewater-derived contaminants water utilities are looking for new approaches monitoring trace organic chemicals in conventional and advanced treatment processes. This study examines the use of a combination surrogate parameters indicator compounds tailored monitor removal efficiency oxidation processes employed by plants engaged indirect potable reuse programs. Potential compounds, identified reviewing previous publications classified their structural...
A comparison of loadings N-nitrosamines and their precursors from different source water categories is needed to design effective blending strategies. Previous research using Formation Potential (FP) chloramination protocols (high dose prolonged contact times) raised concerns about precursor various categories, but differences in the employed rendered comparisons difficult. In this study, we applied Uniform Condition (UFC) ozonation mimicking typical disinfection practice compare ambient...
Sequencing batch reactors (SBRs) were operated for 36 days to simulate the potential wastewater treatment impacts as well fate and transport of per- polyfluoroalkyl substances (PFAS) that could be associated with a release alcohol resistant aqueous film forming foam (AR-AFFF) from on-site methanol fire suppression systems. The results this study indicate two exposure AFFF small reductions in mixed liquor solids content nitrification rates. No on denitrification or biological phosphorus...
Abstract Contaminants of emerging concern present in domestic waste streams include a highly diverse group potentially biologically active compounds that can be detected at trace levels wastewater. Concerns about potential uptake into crops arise when reclaimed water is used food crop production. The study investigated how 9 contaminants are taken up edible portions two crops. Two flame retardant chemicals, tris(1‐chloro‐2‐propyl) phosphate (TCPP) and tris(2‐chloroethyl) (TCEP) several polar...
The evolving demands of drinking water treatment necessitate processes capable removing a diverse suite contaminants. Biofiltration can employ biotransformation and sorption to remove various classes chemicals from water. Here, pilot-scale virgin anthracite-sand previously used biological activated carbon (BAC)-sand dual media filters were operated for ∼250 days assess removals 0.4 mg/L ammonia as nitrogen, 50-140 μg/L manganese, ∼100 ng/L each trace organic compounds (TOrCs) spiked into...