Applied Research and Development Center

Las Vegas, NV, United States

Applied Research and Development Center

Las Vegas, NV, United States

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Gerrity D.,University of Nevada, Las Vegas | Gerrity D.,CA Technologies | Gamage S.,Applied Research and Development Center | Jones D.,University of Arizona | And 9 more authors.
Water Research | Year: 2012

The performance of ozonation in wastewater depends on water quality and the ability to form hydroxyl radicals (OH) to meet disinfection or contaminant transformation objectives. Since there are no on-line methods to assess ozone and OH exposure in wastewater, many agencies are now embracing indicator frameworks and surrogate monitoring for regulatory compliance. Two of the most promising surrogate parameters for ozone-based treatment of secondary and tertiary wastewater effluents are differential UV254 absorbance (ΔUV254) and total fluorescence (ΔTF). In the current study, empirical correlations for ΔUV254 and ΔTF were developed for the oxidation of 18 trace organic contaminants (TOrCs), including 1,4-dioxane, atenolol, atrazine, bisphenol A, carbamazepine, diclofenac, gemfibrozil, ibuprofen, meprobamate, naproxen, N,N-diethyl-meta-toluamide (DEET), para-chlorobenzoic acid (pCBA), phenytoin, primidone, sulfamethoxazole, triclosan, trimethoprim, and tris-(2-chloroethyl)-phosphate (TCEP) (R2 = 0.50-0.83) and the inactivation of three microbial surrogates, including Escherichia coli, MS2, and Bacillus subtilis spores (R2 = 0.46-0.78). Nine wastewaters were tested in laboratory systems, and eight wastewaters were evaluated at pilot- and full-scale. A predictive model for OH exposure based on ΔUV254 or ΔTF was also proposed. © 2012 Elsevier Ltd.


Makris K.C.,Cyprus University of Technology | Snyder S.A.,Applied Research and Development Center
Water Science and Technology | Year: 2010

Cyprus is currently the leading country in antibiotic consumption among all European Union member countries and is likely to have a high consumption of pharmaceuticals overall. This reconnaissance type of project sought to investigate the occurrence of 16 pharmaceuticals,six known or suspected endocrine disrupting compounds (EDCs), two flame retardants, one insect repellant, and one fragrance for the first time in water supplies of Cyprus. Groundwater samples from sites that were located beneath farms scattered around Cyprus, wastewater influent and tertiary-treated effluent, raw and finished surface water, and household potable water samples were analyzed using liquid chromatography and tandem mass spectrometry. Most of the tested compounds were , minimum reporting limit, except for ibuprofen(mean of 1.4 ng L-1) and bisphenol A (mean of 50 ng L-1), which were detected in more than one out of the five groundwater sampling sites. Certain compounds were found in large concentrations in the wastewater influent (caffeine 82,000 ng L -1, sulfamethoxazole 240 ng L-1, ibuprofen 4,300 ng L -1, and triclosan 480 ng L-1). However, several pharmaceuticals and EDCs were detected in the tertiary-treated effluent (recycled water). For the raw and finished surface water, and potable water samples, ibuprofen was detected, whereas, bisphenol-A was measured in only potable water. Overall, with a few notable exceptions, source, finished and potable water had rare detection or low concentration of target compounds, but further research is needed to elucidate the temporal and spatial distribution of the detected emerging contaminants along with the characterization of the related public health risk © IWA Publishing 2010.


Snyder S.A.,Applied Research and Development Center | Benotti M.J.,Applied Research and Development Center
Water Science and Technology | Year: 2010

The presence of pharmaceuticals and endocrine disrupting compounds (EDCs) in the environment raises many questions about risk to the environment and risk to human health. Researchers have attributed adverse ecological effect effects to the presence of these compounds, particularly EDCs, though there is no consensus on what risk, if any, these compounds pose to human health. The scientific community is in the process of developing a better understanding of the occurrence, fate, and transport of pharmaceuticals and EDCs in the environment, including a better characterization of human exposure via drinking water. This paper provides a brief review of pharmaceuticals and EDCs in drinking water, as well as uses examples from Lake Mead, Nevada, USA, to highlight the issues associated with their fate and transport. Lastly, the effects of natural or anthropogenically driven processes, like natural seasonal flow or climatechange/prolonged drought are discussed as they are factors which can drastically alter environmental concentrations of these compounds. Without question, the propensity for the contamination of fresh water will rise as (1) human population continues to grow or (2) patterns of natural surface water slow and wastewater becomes a larger fraction of flow further highlighting the need for a more comprehensive understanding of their environmental behavior. © IWA Publishing 2010.


Inyang M.,Applied Research and Development Center | Dickenson E.,Applied Research and Development Center
Chemosphere | Year: 2015

In this work, the potential benefits, economics, and challenges of applying biochar in water treatment operations to remove organic and microbial contaminants was reviewed. Minimizing the use of relatively more expensive traditional sorbents in water treatment is a motivating aspect of biochar production, e.g., $246/ton non-activated biochar to $1500/ton activated carbon. Biochar can remove organic contaminants in water, such as some pesticides (0.02-23mgg-1), pharmaceutical and personal care products (0.001-59mgg-1), dyes (2-104mgg-1), humic acid (60mgg-1), perfluorooctane sulfonate (164mgg-1), and N-nitrosomodimethylamine (3mgg-1). Including adsorption/filtration applications, biochar can potentially be used to inactivate Escherichia coli via disinfection, and transform 95% of 2-chlorobiphenyl via advanced oxidation processes. However, more sorption data using biochar especially at demonstration-scale, for treating potable and reuse water in adsorption/filtration applications will help establish the potential of biochars to serve as surrogates for activated carbons. © 2015 Elsevier Ltd.


Gerrity D.,Applied Research and Development Center | Stanford B.D.,Applied Research and Development Center | Trenholm R.A.,Applied Research and Development Center | Snyder S.A.,Applied Research and Development Center
Water Research | Year: 2010

This study evaluated a pilot-scale nonthermal plasma (NTP) advanced oxidation process (AOP) for the degradation of trace organic compounds such as pharmaceuticals and potential endocrine disrupting compounds (EDCs). The degradation of seven indicator compounds was monitored in tertiary-treated wastewater and spiked surface water to evaluate the effects of differing water qualities on process efficiency. The tests were also conducted in batch and single-pass modes to examine contaminant degradation rates and the remediation capabilities of the technology, respectively. Values for electrical energy per order (EEO) of magnitude degradation ranged from <0.3 kWh/m3-log for easily degraded compounds (e.g., carbamazepine) in surface water to 14 kWh/m3-log for more recalcitrant compounds (e.g., meprobamate) in wastewater. Changes in the bulk organic matter based on UV254 absorbance and excitation-emission matrices (EEM) were also monitored and correlated to contaminant degradation. These results indicate that NTP may be a viable alternative to more common AOPs due to its comparable energy requirements for contaminant degradation and its ability to operate without any additional feed chemicals. © 2009 Elsevier Ltd. All rights reserved.


Gerrity D.,Applied Research and Development Center | Gamage S.,Applied Research and Development Center | Holady J.C.,Applied Research and Development Center | Mawhinney D.B.,Applied Research and Development Center | And 3 more authors.
Water Research | Year: 2011

In an effort to validate the use of ozone for contaminant oxidation and disinfection in water reclamation, extensive pilot testing was performed with ozone/H2O2 and biological activated carbon (BAC) at the Reno-Stead Water Reclamation Facility in Reno, Nevada. Three sets of samples were collected over a five-month period of continuous operation, and these samples were analyzed for a suite of trace organic contaminants (TOrCs), total estrogenicity, and several microbial surrogates, including the bacteriophage MS2, total and fecal coliforms, and Bacillus spores. Based on the high degree of microbial inactivation and contaminant destruction, this treatment train appears to be a viable alternative to the standard indirect potable reuse (IPR) configuration (i.e., membrane filtration, reverse osmosis, UV/H2O2, and aquifer injection), particularly for inland applications where brine disposal is an issue. Several issues, including regrowth of coliform bacteria in the BAC process, must be addressed prior to full-scale implementation. © 2011 Elsevier Ltd.


Gerrity D.,CA Technologies | Trenholm R.A.,Applied Research and Development Center | Snyder S.A.,Applied Research and Development Center | Snyder S.A.,University of Arizona
Water Research | Year: 2011

Diurnal variations in wastewater flows are common phenomena related to peak water use periods. However, few studies have examined high-resolution temporal variability in trace organic contaminant (TOrC) concentrations and loadings. Even fewer have assessed the impacts of a special event or holiday. This study characterizes the temporal variability associated with a major sporting event using flow data and corresponding mass loadings of a suite of prescription pharmaceuticals, potential endocrine disrupting compounds (EDCs), and illicit drugs. Wastewater influent and finished effluent samples were collected during the National Football League's Super Bowl, which is a significant weekend for tourism in the study area. Data from a baseline weekend is also provided to illustrate flows and TOrC loadings during " normal" operational conditions. Some compounds exhibited interesting temporal variations (e.g., atenolol), and several compounds demonstrated different loading profiles during the Super Bowl and baseline weekends (e.g., the primary cocaine metabolite benzoylecgonine). Interestingly, the influent mass loadings of prescription pharmaceuticals were generally similar in magnitude to those of the illicit drugs and their metabolites. However, conventional wastewater treatment was more effective in removing the illicit drugs and their metabolites. Total influent and effluent mass loadings are also provided to summarize treatment efficacy and environmental discharges. © 2011 Elsevier Ltd.


Benotti M.J.,Applied Research and Development Center | Stanford B.D.,Applied Research and Development Center | Snyder S.A.,Applied Research and Development Center
Journal of Environmental Quality | Year: 2010

The concentrations of selected wastewater contaminants, including conductivity, nitrate, and pharmaceuticals and endocrine disrupting compounds (EDCs), were monitored from 2003 to 2007 in Lake Mead, the raw (untreated) drinking water for southern Nevada. Monitoring was also conducted in two inflows to Lake Mead: the Colorado River and the wastewater-dominated Las Vegas Wash. There was a statistically significant increase in source water conductivity, nitrate, and pharmaceutical and EDC concentrations over this time period, concomitant with a statistically significant decline in the volume of Lake Mead. There was no statistically significant increase in conductivity and nitrate in the Colorado River or the Las Vegas Wash over this period, nor was there an increase in flow of the Las Vegas Wash or Colorado River. Thus, the deterioration of source drinking water quality is due to the decrease in the volume of Lake Mead which has been attributed to drought. This phenomenon may also be a harbinger of how water quality may be adversely affected by climate change as patterns of surface water flow shift and treated wastewater becomes a larger fraction of surface water flow in some areas. Copyright © 2010 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.


Mawhinney D.B.,Applied Research and Development Center | Vanderford B.J.,Applied Research and Development Center | Snyder S.A.,University of Arizona
Environmental Science and Technology | Year: 2012

Recent studies have shown that 1H-benzotriazole is a widespread contaminant of wastewater and surface water. Although disinfection by ozone has been shown to efficiently remove this compound, the transformation products have not been identified. To that end, the reaction of ozone with 1H-benzotriazole in aqueous solution has been studied in real time employing quadrupole time-of-flight mass spectrometry (Q-TOF MS) and negative electrospray ionization. The transformation products have been identified by calculating their empirical formulas using accurate mass measurements, and further confirmed by performing the reaction with stable isotope-labeled 1H-benzotriazole and measuring product ion spectra. Stable reaction products were distinguished from transient species by plotting their extracted mass profiles. The products that resulted from ozone and hydroxyl radicals in the reaction were qualitatively identified by modifying the conditions to either promote the formation of hydroxyl radicals, or to scavenge them. Based on experimental evidence, a mechanism for the direct reaction between ozone and 1H-benzotriazole is proposed that results in the formation of 1H-1,2,3-triazole-4,5-dicarbaldehyde, which has an empirical formula of C 4H3O2N3. Lastly, it was confirmed that the same transformation products formed in surface water and tertiary-treated wastewater, although they were observed to degrade at higher ozone doses. © 2012 American Chemical Society.


Gerrity D.,Applied Research and Development Center | Snyder S.,Applied Research and Development Center
Water Policy | Year: 2011

Water has been a passionately contested issue in the United States (US) over the past century. Some argue for growth restrictions in drought-susceptible regions, but based on economic production, it may be worthwhile implementing creative measures to ensure continued and sustainable growth. The following economic analysis correlates water withdrawals in the 32 most populous metropolitan areas in the US with several economic indicators, including gross metropolitan product (GMP), income, and employment. The ratio of GMP to water withdrawals (GMP/H 2O) ranged from (US)$58, 788 per million gallons in Tampa to $939, 555 per million gallons in San Jose ($15, 532 to $248, 231 per megaliter, respectively). Some drought-susceptible areas (e.g., Atlanta, Denver, Los Angeles, and Las Vegas) had relatively high GMP/H 2O values, while others (e.g., Phoenix and San Diego) had relatively low GMP/H 2O values. From a regional perspective, the Northwest had the strongest economy relative to its water withdrawals, and the Midwest had the weakest. These data indicate that the GMP/H 2O metric can be used to justify water use in certain metropolitan areas but that the metric is less applicable to regional analyses due to unique aspects of local economies and water resource portfolios. © IWA Publishing 2011.

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