| Summary: | 碩士 === 國立成功大學 === 環境工程學系 === 87 === This research studied the efficiency of drinking water treatment techniques and operational condition for the removal of biodegradable dissolved organic carbon (BDOC) and trihalomethane formation potential (THMFP). The experimental procedures and objectives included：(1) to enhance conventional treatment processes; (2) to compare slow and fast sand filters; (3) to estimate advanced water treatment processes.
The results show that with either pre- or post chlorination, enhanced coagulation could removal 22~51% of NPDOC. Ferric chloride proved to be consistently more effective than alum in removing NPDOC. Enhanced coagulation could remove BDOC, which was not to be increased by postchlorination. However prechlorination could inhibited coagulation removal of BDOC. CHCl3 and CHBrCl2 were main species of THMFP, which could be reduced by enhanced coagulation. As enhanced coagulation could remove organic matter but not bromide ion, therefore the proportion of TTHM contributed by brominated species increased.
Biological activity in slow sand filters could remove BDOC and THM precursors, properly cleaning aging biofilms on the surface of slow sand filters and turning medium could increase hydraulic loading and the biological activity of filters.
Advanced drinking water treatment, including ozone and GAC, could remove BDOC and achieved the goal of biological stability in distribution system, and good control for disinfectation by-products. Preozonation could aid coagulation-sedmentation-filteration to remove UV254, NPDOC, BDOC, and THMFP, and promoted biological activity of the full process to achieve the goal of biologically stable water and reducing disinfectation by-products formation.
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