실용적인 이취미 측정법을 이용한 상수원수 내 이취미 모니터링

Monitoring of Taste and Odor Compounds in Drinking Water Supplies Using Practical Taste and Odor Methods

In order to investigate the occurrence characteristics of taste and odor(T&O) In drinking water supplies, water quality data of the Songchon water treatment plant (WTP) copes with T&O episode were used. Three kinds of water, such as raw and filtered water of the Songchon WTP, and tap water of consumer's house, were monitored by using three sensory methods, including TON, 2-out-of 5 odor test, and attribute difference test for the presence or absence of geosmin. The population densities of algae species were high correlate with Chlorophyll-a during T&O episode. At that time, dominant genus of algae were blue-green algae which were Microcystis, Oscillatoria, Apbanieomenon, and Anabaena. TON values of raw water increased about 40 since July, but decreased below 10 after July due probably to the heavy rain lasted for a long time. TON values of filtered water were maintained less than 5, because of added PAC (powdered activated carbon) in raw water of the Song chon WTP. For identifying geosmin and 2-MlB in raw and Filtered water of the Songchon WTP were measured by Daejeon University and Philadelphia Suburban Water Company(PSWCO). PSWCO showed some difference in absolute values, there might be somewhat clear relationship between CLSA data and TON values. The maximum geosmin was about 45 ng/l on July 14. Comparing the results of 2-out-of 5 odor test and TON, it seems that 2-out-of 5 odor test is more sensitive than TON for the samples with TON below 5. Like 2-out-of 5 odor test, it was found that the attribute difference test might be more sensitive and appropriate than TON when the odor intensity of sample is low.