Research articles
ScienceAsia (): 293-298 |doi:
10.2306/scienceasia1513-1874...293
Removal of haloacetic acids by ozone and biologically active carbon
Chalatip Ratasuka,*, Charnwit Kositanontb, Chavalit Ratanatamskulc
ABSTRACT: Haloacetic acids are recognized as carcinogens. They are naturally formed on the surface of water or as disinfection by-products of drinking water during the chlorination process. The efficiency of an integrated treatment system combining ozonation and biological activated carbon (BAC) was examined for the removal of five regulated haloacetic acids, namely, chloroacetic, dichloroacetic, trichloroacetic, bromoacetic, and dibromoacetic acid (known collectively as HAA5), in synthetic water. The effects of ozone dosage, contact time during the ozonation process, and the empty bed contact time (EBCT) of the BAC column were also evaluated. The results demonstrate that the ozonation process is not an effective approach to remove HAA5 since less than 20% of HAA5 at the concentration levels found in the water supply system was removed. The majority of HAA5 in the tested solutions were subsequently removed by the BAC column inoculated with bacteria readily available in surface water. More than 90% of the remaining HAA5 was eliminated after having been passed through the BAC column with an EBCT of at least 20 minutes. Indigenous microorganism communities inoculated in the BAC column were able to degrade individual HAA5 species without preference.
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a |
National Research Center for Environmental and Hazardous Waste Management, Chulalongkorn University,
Bangkok 10330, Thailand |
b |
Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand |
c |
Department of Environmental Engineering, Faculty of Engineer, Chulalongkorn University, Bangkok, 10330,
Thailand |
* Corresponding author, E-mail: chratasuk@yahoo.com
Received 14 May 2007, Accepted 20 May 2008
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