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ความรู้ทั่วไปเกี่ยวกับสิ่งเป็นพิษความรู้ทั่วไปที่นักวิชาการควรทราบพิษวิทยาคลีนิคก้าวทันโลกข้อมูลบริการแหล่งข้อมูลที่เกี่ยวข้อง
 
   
REDUCTION OF TOXIC TRIHALOMETHANE FORMATION IN TAP WATER PRODUCTION BY REOZONATION

ORAPIN THAPSINGKAEW1, WERAWAN RUANGYUTTIKARN1
AND VILILUCK KIJJANAPANICH2

1Division of Toxicology, Department of Forensic Medicine, Faculty of Medicine, 2Department of Environmental Engineering, Faculty of Engineering, Chiang Mai University, Thailand.
E-mail : k_orpin@hotmail.com

      Chlorine is a normal disinfectant used in conventional water treatment, which can react with natural organic matter in raw water to form trihalomethanes (THMs). The THMs consist of chloroform, dichlorobromomethane, dibromochloromethane and bromoform. They are classified as carcinogenic substances. The US.EPA promulgates the maximum contaminant level (MCL) of THMs at 80 mg/L in drinking water. Using ozone to replace chlorine in order to mitigate the THMs by-product formation was our goal for this study. The level of THMs in water samples treated conventionally was measured from raw, pre-, intermediate- and post-chlorination water samples from Mae-Kuang water treatment plant in Chiang Mai. An ozonation pilot plant, from which pre and post treated water samples were taken, was operated at an oxidation-reduction potential (ORP) of 500, 600 and 700 mV. THMs were analyzed by gas chromatography with an electron capture detector. The results showed that THMs in raw water were not detected, whereas, the average value of THMs in water samples from ozonation was lower than that of the THMs in the chlorination process. There was no correlation of ORP variation in the reduction of the THMs formation. In conclusion, using ozone could reduce the formation of THMs. The concentration of THMs in water samples from chlorination and ozonation processes is slightly lower than the MCL.


ที่มา ABSTRACT นำเสนอที่ การประชุมวิชาการสมาคมพิษวิทยาแห่งประเทศไทย ประจำปี 2547 อาหารกับความปลอดภัย วันศุกร์ที่ 17 ธันวาคม 2547 โรงแรมมิราเคิลแกรนด์ กรุงเทพฯ