Engineering Commons^™

Trihalomethanes In Water Supply System And Water Distribution Networks, Sornsiri Sriboonnak, Phacharapol Induvesa, Suraphong Wattanachira, Pharkphum Rakruam, Adisak Siyasukh, Chayakorn Pumas, Aunnop Wongrueng, Eakalak Khan

Civil and Environmental Engineering and Construction Faculty Research

The formation of trihalomethanes (THMs) in natural and treated water from water supply systems is an urgent research area due to the carcinogenic risk they pose. Seasonal effects and pH have captured interest as potential factors affecting THM formation in the water supply and distribution systems. We investigated THM occurrence in the water supply chain, including raw and treated water from water treatment plants (coagulation, sedimentation, sand filtration, ClO2-disinfection processes, and distribution pipelines) in the Chiang Mai municipality, particularly the educational institute area. The effects of two seasons, rainy (September–November 2019) and dry (December 2019–February 2020), acted as surrogates for …

Exploring Analytical Issues Associated With Oxidation Kinetics In Drinking Water, Shadi Haji Eghrari

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation contains two different section that pertain to two different subjects.

Section One (Haloamines): Disinfection with ozone and chlorine is critical in protecting the public and animals from pathogens in pools. Disinfection results in in the formation of haloamines from the unintended reactions of human and animal inputs and bromide/chloride with oxidants and disinfectants which cause health problems.

The purpose of this research was to examine the occurrence of haloamines during the chlorination of saltwaters. In this study, the effect of bromide concentration was observed to exert a significant effect on the stability of Haloamines, and with no bromide …

Evaluation Of Two Real Time Methods For Assessing Thm Precursor Concentrations, Griffin Moriarty

Environmental & Water Resources Engineering Masters Projects

Conventional drinking water treatment generally requires maintenance of a disinfectant residual, most commonly free or combined chlorine. Since the discovery of disinfection byproducts (DBPs), utilities have relied on a broad range of water quality parameters to help them achieve compliance with DBP regulations. Most notably, dissolved organic carbon (DOC) and ultraviolet absorbance at 254 nm (UV254) have been used to assess DBP precursor levels in near-real time. These are often compared to actual system DBP concentrations or to results from laboratory DBP precursor tests resulting in a site-specific precursor-DBP model. The DOC or UV254 models are often inaccurate, requiring re-calibration, …

Assessing Biofiltration Without Ozonation For Removal Of Trihalomethane Precursors In Drinking Water At The Beaver Water District Drinking Water Treatment Plant, Sana Ajaz

Graduate Theses and Dissertations

Biofiltration without pre-ozonation has the capability to remove natural organic matter (NOM) fractions that serve as precursors of disinfection byproducts (DBPs), which include the four regulated trihalomethanes (THMs) and dichloroacetonitrile (DCAN). Rapid small-scale column tests (RSSCTs) and Pilot Plant filters operated at empty-bed contact times (EBCTs) of 4, 8, and 16 minutes were used to evaluate the performance of nutrient-amended (free ammonia and phosphorus) biofiltration for THM and DCAN precursor removal, as measured using formation potential (FP) tests. NOM surrogates – which include dissolved organic carbon (DOC), specific ultraviolet absorbance (SUVA254) and fluorescence-PARAFAC components – were measured weekly throughout the …

Evaluating The Toxicity And Formation Of Halobenzoquinones In Point-Of-Use Chlorinated Drinking Water, Stephanie Hung

Masters Theses

Chlorine has effectively reduced the prevalence of waterborne diseases, however there are secondary consequences to this public health advancement. Disinfection byproducts (DBPs) are chemicals formed when chlorine reacts with natural organic matter (NOM) in water. A new class of DBPs, halobenzoquinones (HBQs), has recently been identified and data suggests it could be potentially carcinogenic and up to 1000 times more toxic than some regulated DBPs. So far, in vitro studies have assessed HBQ toxicity without taking into account its transformation in cell media into potentially less toxic compounds. This study evaluated the toxic effects of one HBQ, 2,6-DCBQ, and its …

Determination Of The Rate Constant For Reaction Of Ozone With 1-Hexene In Water, Pranav Mashankar

Environmental & Water Resources Engineering Masters Projects

Low molecular weight aldehydes such as formaldehyde may be formed as disinfection byproducts (DBPs) of ozonation when low molecular weight, aliphatic, alpha olefins are present as contaminants in water. Such alkenes form a small but significant part of crude oil, and would therefore be present in water contaminated with an oil spill. This project studied the kinetics of the reaction between ozone and 1-hexene in water as part of a study to predict the effects of an oil spill on the water quality in the Wachusett reservoir in Massachusetts. The data for the reaction rate constant for the aqueous ozonolysis …

Impacts Of Ozone Dose And Empty Bed Contact Time On Bulk Organic Removal And Disinfection Byproduct Mitigation In Ozone-Biofiltration Systems, Mayara Aquino

UNLV Theses, Dissertations, Professional Papers, and Capstones

In areas where water shortages have compromised water supplies, potable reuse is a promising solution. However, additional research is needed to identify and/or optimize cost-effective treatment technologies to demonstrate compliance with potable reuse regulations. Treatment trains employing reverse osmosis (RO) and advanced oxidation, a combination known as ‘full advanced treatment’ (FAT), are required by the California Division of Drinking Water (CDDW) for surface water augmentation and direct injection of recycled water into local aquifers. A maximum concentration of 0.5 mg/L of wastewater-derived total organic carbon (TOC) is also required by CDDW in all groundwater recharge applications. This appears to be …

The Stability Of Ferrate(Vi) In Water And Its Impacts On Disinfection Byproduct Precursors, Yanjun Jiang

Doctoral Dissertations

Ferrate has been proposed as an alternative pre-oxidant in drinking water treatment for many years. Despite extensive studies that examined ferrate oxidation of specific contaminants, little research has been done on the impacts of ferrate in raw waters that include natural organic matter (NOM) and bromide, and that are also treated with coagulants and chlorine. The future of ferrate as a potable water treatment chemical depends on its ability to achieve adequate disinfection while minimizing the formation of disinfection byproducts (DBPs) under these realistic scenarios. In this work, laboratory-scale treatment studies were conducted to (1) clarify the stability of ferrate …

The Use Of Sodium Persulfate In Hydraulic Fracturing Fluids: A Degradation Study Based On Furfural, Katherine Elizabeth Manz

Masters Theses

Hydraulic fracturing has allowed natural gas to become a viable energy source via extraction of unconventional shale reserves, but this process requires an enormous amount of water. To ensure a productive fracture, a proprietary blend of chemical additives is added to the water. In this research, a hydraulic fracturing chemical additive – an enzyme breaking agent – is analyzed for organic components using gas chromatography mass spectrometry. The chemical changes that occur over the course of a fracture are also investigated using one model chemical found in the additive, furfural, in order to help assess the environmental risk that hydraulic …

Operational And Water Quality Analysis For The City Of Akron's Water Treatment Plant And Distribution System, Chelsea James

Williams Honors College, Honors Research Projects

Chlorination is one of the most common methods of treating pathogens and ensuring microbial water quality in water treatment and distribution. As chlorinated water leaves the source and travels through the water distribution system, the chlorine reacts with both the organic compounds (dissolved organic carbon, DOC) in the source water and the corrosion or biofilm of the pipe walls. The chlorine concentration, or chlorine residuals, at any point in the water distribution system is a good measure of water quality. At the same time, chlorination produces disinfection byproducts as the chlorine also reacts with other naturally-occurring materials in the water. …

Effect Of Ph And Temperature On Halogenated Dbps, Sm Shamimur Rahman

Electronic Theses and Dissertations

Water scarcity is one of the most challenging issues in the world in the 21st century. It is estimated that there are more than one billion of people without adequate access to freshwater and facing water shortages and water deficits. People are forced to drink polluted water despite the risk of consuming pathogenic microorganisms in the water that transmit waterborne diseases such as bacterial infections, protozoal infections and viral infections. The water disinfection process is one of the most important environmental technological advances in the 20th century which inactivates microbial contaminants in drinking water. Disinfection byproducts (DBPs) are a group …

Assessing The Impact Of Chlorine Residual On Trihalomethane And Haloacetonitrile Formation Under Chlorination And Chloramination Disinfection Regimes, Thien Duc Do

Graduate Theses and Dissertations

A disinfection byproduct (DBP) formation potential (FP) test can be used to indirectly measure the concentration of DBP precursors in natural waters, permitting assessment of various DBP-related treatment processes and control strategies. While these tests require a 7-day chlorine residual (CR) between 3-5 mg L^-1 as Cl², it is not well known if this recommended residual corresponds to the true DBPFP (i.e., the maximum concentrations) for trihalomethanes (THMs) and haloacetonitriles (HANs). In this study, THMs and HANs were quantified as a function of CR under three common disinfection regimes: (1) free chlorine at pH 7.0 (FC7), (2) …