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Full-Text Articles in Engineering
Microbial Community Shifts Caused By Changes In The Primary Oxidant At A Drinking Water Treatment Plant, Connie Marie Moloney
Microbial Community Shifts Caused By Changes In The Primary Oxidant At A Drinking Water Treatment Plant, Connie Marie Moloney
Graduate Theses and Dissertations
Microbial communities resistant to common oxidants can cause concerns for water treatment plants (WTPs). If a bacterium is not fully oxidized during disinfection, these species can impede upon filtration processes or seed biofilms in the distribution system. In an effort to minimize disinfection by-products (DBP's) that result from the reaction of chlorine (Cl2) with natural organic matter, water treatment plants have the option to change their primary oxidant to chlorine dioxide (ClO2). The following study examines the change in microbial communities during the sedimentation process under differing oxidation regimes, specifically chlorine (Cl2) and ClO2 at the local water treatment plant …
Assessment Of Nitrifying Bacteria In Massard Plant Using Molecular Tools, Jennifer Puanani Holmes-Smith
Assessment Of Nitrifying Bacteria In Massard Plant Using Molecular Tools, Jennifer Puanani Holmes-Smith
Civil Engineering Undergraduate Honors Theses
The discharge of nutrients (such as nitrogen and phosphorus) from wastewater treatment plants (WWTP) has become an increasingly important issue in the United States. Ammonia (NH3) is a common contaminant found in domestic wastewater and agricultural runoff. It can cause toxicity in fish if left untreated. The United States Environmental Protection Agency (EPA) recommends low national criteria for ammonia limits in freshwater. With these greater restrictions, ammonia-nitrogen limit compliance (5 mg/L) has become an issue at the Massard WWTP in Fort Smith, Arkansas. The purpose of this research is to assess the ammonia removal in the Massard WWTP in order …
Lab-Scale Experiment For Assessing The Effect Of Resuspension And Oxygenation On Sediment Oxygen Demand, Grace Richardson
Lab-Scale Experiment For Assessing The Effect Of Resuspension And Oxygenation On Sediment Oxygen Demand, Grace Richardson
Graduate Theses and Dissertations
This study examined the effects of resuspending lake sediment for different time periods in a lab-scale tank under both oxic and anoxic conditions on sediment oxygen demand (SOD) and other related sediment properties. This lab-scale study was conducted as a first step to determine if a proposed method for reducing SOD by treating sediments in lakes and reservoirs is feasible. SOD is a critical process responsible for the formation of anoxic hypolimnia in lakes and reservoirs. A reduction in SOD may delay or eliminate the onset of anoxia in the hypolimnia, preventing adverse ecosystem effects and improving water quality and …
Comparing Ferrous Chloride And Ferrous Sulfate As Secondary Coagulants At The Beaver Water District Drinking Water Treatment Plant, Jenny Doyle
Graduate Theses and Dissertations
In November 2012, the Beaver Water District (BWD) switched primary oxidants from free chlorine to chlorine dioxide (ClO2) to curb formation of trihalomethanes, a regulated group of organic disinfection byproducts (DBPs). Because ClO2 is reduced to chlorite (ClO2-), a regulated inorganic DBP, BWD incorporated ferrous salt into their coagulation regime to quench chlorite to chloride. In this study, two ferrous salts - ferrous chloride (FC) and ferrous sulfate (FS) - were compared as secondary coagulants in combination with alum, the primary coagulant. Ferrous salts were dosed stoichiometrically to reduce chlorite and alum was dosed at percentages (0-100%) relative to a …