Characterization treatment and removal of trihalomethane precursors in Bangkok source water / Bunyarit Panyapinyopol = การจำแนกลักษณะการบำบัดและกำจัดสารไตรฮาโลมีเทนพรีเคอเซอร์ในแหล่งน้ำดิบของกรุงเทพมหานคร / บุณยฤทธิ์ ปัญญาภิญโญผล
Resin adsorption technique using three types of resin; DAX-8, AG-MP-50, and WA-10 was employed to characterize the raw water from the Bangkhen water treatment plant, Bangkok Thailand. The dissolved organic carbon (DOC) mass distribution sequences of the six organic fractions in the raw water from high to low were hydrophilic neutral (HPIN), hydrophilic base (HPIB), and hydrophobic base (HPOB). HPIN and HPOA were the two main precursors of THMFP in this water source, whereas HPOB and HPIB were the most active precursors. A linear dependency between each organic fraction concentration and THMFP indicated that the reactions of each organic fraction with chlorine were first-order. The fractionation led to a deviation of bromide concentration in each organic fraction from the original concentration, and this affected the formation of brominated THM species. However, this effect was demonstrated to be within an acceptable range. The chlorination of an individual organic fraction resulted in a higher level of THMFP than that of the raw water and mixed fractions. This indicated that there existed an inhibitory effect between the organic species. Coagulation by using alum was proven to be able to remove THMFP but not as effectively as that with alum combined with polymers. DADMAC was found to be the most effective polymer for the removal of THMFP, where the next most effectives were EpiDMA, CatPAM, and AnPAM, respectively. Each polymer showed different preferences in the removal of each organic fraction, i.e. CatPAM for HPON, DADMAC for HPOB, EpiDMA for HPIN, and alum alone for HPOA and HPIA.