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University of Nevada, Las Vegas

2016

Wastewater

Articles 1 - 2 of 2

Full-Text Articles in Engineering

Occurrence And Proliferation Of Antibiotics And Antibiotic Resistance In Wastewater Treatment Plants, Majid Neyestani Dec 2016

Occurrence And Proliferation Of Antibiotics And Antibiotic Resistance In Wastewater Treatment Plants, Majid Neyestani

UNLV Theses, Dissertations, Professional Papers, and Capstones

Solids retention time (SRT) is one of the most important factors in designing and operating activated sludge systems for biological wastewater treatment. Longer SRTs have been shown to alter the structure and function of microbial communities, thereby leading to improved treatment efficacy with respect to bulk and trace organics, nutrient removal, and membrane fouling. However, research has also shown that longer SRTs lead to increased prevalence of antibiotic resistant bacteria, perhaps due to increased exposure to antibiotics present in influent wastewater. The purpose of this study was to characterize changes in microbial community structure in a laboratory-scale activated sludge system …


Ozonation In Water Reuse: Formation And Mitigation Of N-~Nitrosodimethylamine, Erica J. Marti May 2016

Ozonation In Water Reuse: Formation And Mitigation Of N-~Nitrosodimethylamine, Erica J. Marti

UNLV Theses, Dissertations, Professional Papers, and Capstones

Formation of N-nitrosodimethylamine (NDMA) is a substantial concern for drinking water and water reuse. NDMA, a probable human carcinogen, is formed when water is disinfected with chloramines and ozone. This research focused on three issues regarding NDMA formation and mitigation. The first issue involved understanding the compounds (i.e., precursors) present in water and wastewater that react with ozone to form NDMA. Model precursors were identified and molar yields for NDMA formation were determined. The model precursors form high amounts of NDMA with ozone, but form very little NDMA with chloramines, which means there are two distinct groups of NDMA precursors: …