| Summary: | 碩士 === 輔英科技大學 === 環境工程與科學系碩士班 === 94 === In order to monitor the concentration of microcystin-LR in drinking water, HPLC (High performance Liquid Chromatography) was employed for detecting this toxin from water which released from various treatment units withinin the Chengching Lake Advanced Drinking Water Treatment Plant. The recovery rate was as high as 105.37% based on 10000 times concentration factor. The Sep-pak C18 cartridge were used when 75% methanol were used as extraction solvent. The detection limitation was as low as 0.005 μg/L in this study. The data revealed that this study could provide an effective approach to detect microcystin-LR practically since 1 μg/L was the suggested guideline in most countries/orgnizations. The concentration of microcystin-LR from preozonation unit was higher than that of raw water. This is could be due to the breakage of cyanobacteria cells thus releasing its toxins in the process. However, the microcystin-LR was mostly eradicated during the five units of pre-treatment including preozonation → rapid mix and coagulation → flocculation and sedimentation → crystallization and softening → rapid sand filtration. No microcystin-LR can be detected from the last tree treatment units, which are bio-active carbon (BAC), post-ozonation, and chlorination. Moreover, although 100% acetone nitrite can not be used as extraction solvent but it can eradicate pretty much organic components other than microcystin-LR from the cartage. Thus, this solvent could be used in the pretreatment process for purification of microcystin-LR and could be much cheaper than using pretreatment supercritical fluid extraction.
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