Dissertation/Thesis Abstract

Evaluation of N-Nitrosodimethylamine (NDMA) Formation at Varied pH and Conditions in Treated Wastewater
by Vasudeva, Chetna, M.S., California State University, Long Beach, 2018, 49; 10976764
Abstract (Summary)

N-nitrosodimethylamine is a carcinogenic disinfection byproduct which can be reformed after wastewater treatment if appropriate conditions are present. In this study various NDMA formation precursors over a range of conditions have been studied to attempt to quantify this NDMA reformation potential. Efforts were made in this study to demonstrate the effect of time, pH, and multiple different precursor chemicals on the reformation process. Dimethylamine (DMA) has been demonstrated to be a precursor chemical, and was chosen as a standard for initial experiments. The concentration of this precursor was kept constant at 100 ppt (parts per trillion) and solutions at three different pH’s were tested over a 24-hour time period to see if any significant NDMA formation occurred. The impacts of various treated wastewater constituent chemicals including H2O2, monochloramine, dimethylhydrazine, etc. were also performed in this study. Significant difficulties occurred for the analysis of these samples, with large background interferences occurring in the method of analysis. Based on the data obtained, it appears that the formation potential of NDMA with DMA as a precursor was found to be the most efficient compound at basic pH (pH 9) and very basic (pH 13). This is consistent with the last step in wastewater remediation, where quicklime is added to the water to regulate the pH and for protection of distribution system. In addition, preliminary experiments were conducted using Ranitidine as a NDMA reformation precursor.

Indexing (document details)
Advisor: Mezyk, Stephen
Commitee: Brazier, Christopher, Tian, Fangyuan
School: California State University, Long Beach
Department: Chemistry and Biochemistry
School Location: United States -- California
Source: MAI 58/03M(E), Masters Abstracts International
Subjects: Chemistry, Analytical chemistry
Keywords: Dimethylamine (DMA), Disinfection byproduct, N-nitrosodimethylamine (NDMA), pH
Publication Number: 10976764
ISBN: 978-0-438-75213-9
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