Long-Term Comparison of Disinfection By-Product Formation Potential in a Full Scale Treatment Plant Utilizing a Multi-Coagulant Drinking Water Treatment Scheme

Abstract

A comparative study of two coagulants, aluminum sulfate (Alum) and aluminum chlorohydrate (ACH), used in parallel in a full scale water treatment plant (WTP) in Ohio from October 2009 to December 2012, was conducted to determine disinfection by-product (DBP) formation potential removal based on both dissolved organic matter (DOM) and fluorescence-derived metrics. Water quality parameters and fluorescence intensity of water samples collected before and after coagulation were measured three times per week and fluorescence matrices were analyzed using parallel factor (PARAFAC) analysis, while DBP formation potential was measured in a weekly basis in pre-and post-coagulation water samples. This study revealed that Alum consistently removed more trihalomethane (THM) formation potential per mg/L of dissolved organic carbon (DOC) than ACH. ACH treated waters averaged approximately 33% more THM formation potential when normalized to DOC. Similarly, haloacetic acid (HAA) formation potential averaged 10% higher in ACH treated waters. From the fluorescence analysis, PARAFAC components C1 and C2 (humic-like fluorophores groups) removal were 23% and 16% higher, respectively, with Alum when compared to ACH. Monte Carlo simulations, based on neural network models developed from the field data, were performed to compare DBP formation across a wide range of conditions. At similar pH, the model results showed that ACH coagulated water had 13% and 20% higher THM and HAA formation potential, respectively, when compared with Alum. The observations from this study reveal that a coagulant's preferential removal of DBP precursors has an impact on DBP formation despite similar DOC removal.

Fuzzy Comprehensive Assessment Method Based on the Entropy Weight Method and Its Application in the Water Environmental Safety Evaluation of the Heshangshan Drinking Water Source Area, Three Gorges Reservoir Area, China

“…The reservoirs of drinking water are important areas for the people who depend on them. Therefore, ensuring that drinking water areas remain clean is an important issue in the field of water environmental management, ecological protection, and economic and social growth [3][4][5]. Water environmental safety evaluation is a scientific and effective approach to identifying potential risks, assessing the safety level, and determining the water supply capacity of drinking water source areas [6,7].…”

Comparative Analysis of Different Disinfection Techniques Performances in Drinking Water Treatment Plant Using a Process Simulation Software Hayder Mohammed Issa

“…Kim et al 2003). The DBPs are produced mainly by reactions occur between dissolved organic carbons in treated water with used chlorine for disinfection (Skeriotis et al 2016). Commonly, organic carbon in the water supply is resulting from discharged sewerage and over natural remains (LeChevallier et al 1991).…”