Environmental Engineering Commons^™

Investigation Of Bench-Scale Packed Bioreactor For Perchlorate Reduction In The Presence Of Co-Contaminants And High Salinity, Julia Ribeiro Rabello

UNLV Theses, Dissertations, Professional Papers, and Capstones

Perchlorate (ClO4-), commonly found as a salt, is naturally occurring in nature and is found in natural nitrate deposits (such as the Chilean nitrate). Perchlorate anion is considered an inhibitor of iodine by the thyroid gland, reducing the production of thyroid hormones. The latest action by the USEPA was to not determine a national drinking water standard for perchlorate. However, the states still have their own regulations on perchlorate concentration in drinking water. Contaminated sites with high concentrations of perchlorate (ppm levels) are associated with historic perchlorate manufacture and use, while those with low concentrations (ppb levels) are found in …

Comparison Of Zero Valent Iron (Zvi) And Zvi+Sludge For The Removal Of High Levels Of Hexavalent Chromium And Chlorate From Waters, Kenneth R. Greenhalgh

UNLV Theses, Dissertations, Professional Papers, and Capstones

Remediation of contaminated groundwater is becoming increasingly more

important as much of the U.S. population relies on groundwater for their drinking water.

Contaminates such as Chromium, common pollutant at industrial waste sites, and

Hexavalent chromium which is toxic to humans, animals, and plants are major

concerns. Chlorate, another contaminate of concern, has been widely detected in

ground and surface water in the United States and even locally in Henderson Nevada at

the Nevada Environmental Response Trust (NERT) sites. To assist in mitigating this

issue, this research focuses on the removal of high levels of hexavalent chromium (ppm

range) (Cr(VI)) and …

Modeling Of Grace-Derived Groundwater Information In The Colorado River Basin, Md Mafuzur Rahaman, Balbhadra Thakur, Ajay Kalra, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Groundwater depletion has been one of the major challenges in recent years. Analysis of groundwater levels can be beneficial for groundwater management. The National Aeronautics and Space Administration’s twin satellite, Gravity Recovery and Climate Experiment (GRACE), serves in monitoring terrestrial water storage. Increasing freshwater demand amidst recent drought (2000–2014) posed a significant groundwater level decline within the Colorado River Basin (CRB). In the current study, a non-parametric technique was utilized to analyze historical groundwater variability. Additionally, a stochastic Autoregressive Integrated Moving Average (ARIMA) model was developed and tested to forecast the GRACE-derived groundwater anomalies within the CRB. The ARIMA model …

Evaluation Of Electron Donors For Perchlorate And Nitrate Biodegradation In Contaminated Groundwater Applications, Mayra Alejandra Sarria Cortes

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the United States, perchlorate contamination has been widely reported, including in Las Vegas, Nevada, where perchlorate has been detected at concentrations of 34.7 mg/kg in vadose zone soil and 0.18-3.7 g/L in groundwater. Once this groundwater reaches the Las Vegas Wash, there is potential for widespread contamination of drinking water sources throughout the Southwest, including in Nevada, Arizona, and California. This issue is becoming increasingly important because even at low perchlorate concentrations, sensitive populations such as infants and pregnant women can be potentially impacted due to perchlorate’s ability to hinder iodine uptake into the thyroid glands, which leads to …

Management Of Water Resources In Shanshan, China: A System Dynamic Approach, Chao Chen, Zhixia Xu, Ajay Kalra, Sajjad Ahmad

College of Engineering: Graduate Celebration Programs

Shanshan County, located in Xinjiang, China, has severe problems of water scarcity, overexploitation of groundwater. In need of efficient water resources management strategies, this study proposes a System Dynamics (SD) approach to simulate the water resource allocation, which can assist in providing a better understanding of the dynamic water supply and demand system and exploring different water resources management and allocation scenarios.