Date of Award
Spring 2019
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Civil Engineering
First Advisor
Zitomer, Daniel H.
Second Advisor
McNamara, Patrick J.
Third Advisor
Mayer, Brooke K.
Abstract
Billions of gallons of untreated water are discharged into lakes and rivers every year due to combined and sanitary sewer overflows during high-intensity precipitation events. Combined sewer overflows (CSOs) and sanitary sewer overflows (SSOs) pose both environmental and public health risks due to potential human contact with contaminated water. To address the overflow issue, a novel, advanced, high-rate wet weather treatment process was investigated. The high-rate treatment process combined chemically enhanced primary treatment (CEPT) with an advanced oxidation process (AOP) using ozone to rapidly remove total suspended solids (TSS) and chemical oxygen demand (COD), inactive E. coli, and oxidize the micropollutants triclosan (TCS) and triclocarban (TCC) in synthetic SSO waters. Results demonstrated that the preferred chemicals for CEPT were ferric chloride with an anionic polymer coagulant aid, which achieved 95% turbidity removal in <5 min. For AOP treatment, ozone (O3), ultraviolet light (UV) with hydrogen peroxide (H2O2), UV with O3, and O3 with H2O2 were investigated. Ozone alone was selected for further study. Initial research results also demonstrated >99% TSS removal, 90% COD removal, and at least 6-log E. coli inactivation. The micropollutant oxidation results were inconclusive. The detention time for 90% COD removal was relatively long (6 h), suggesting necessary future work to reduce this detention time (<30 min) for applicability during high-intensity precipitation events.