EFFECT OF SUVA AND ENHANCED COAGULATION ON REMOVAL OF TOX PRECURSORS

摘要

This work examined the effect of raw water total organic carbon (TOC) concentration and alkalinity on the reduction of organic halide formation potential by enhanced coagulation. Enhanced coagulation is considered the best available technology for removal of disinfection by-product (DBP) precursors. Enhanced coagulation is also mandated by the Stage 1 Disinfectants/Disinfection Byproducts Rule, which prescribes specific TOC removal requirements for the control of unidentified halogenated DBPs of potential public health concern. In this research, 27 waters were obtained from different utilities across the United States; 3 waters were obtained for each element of the 3 x 3 enhanced coagulation matrix. Jar tests were performed on each water to determine the requisite alum dose for TOC removal in accordance with the enhanced coagulation guidance manual. Each water was then treated with the requisite alum dose for enhanced coagulation, and the resulting settled waters, along with each of the raw waters, were chlorinated under uniform formation conditions. The chlorinated waters were analyzed for total organic halides (TOX). The formation of TOX in the raw waters and the effectiveness of coagulation for the reduction of TOX formation potential were compared for each of the elements in the 3 x 3 enhanced coagulation matrix. Results demonstrated the ability of specific ultraviolet absorbance to reflect the reactivity of organics in water toward removal by coagulation and toward organic halide formation potential.