Treatment of Drinking Water and Control of Disinfection By-products Using Ozone and Biological Fluidized-Bed Processes.

• Main Authors: Ming-Tsung Wu, 吳明宗
• Other Authors: Dong-Chir Hwang
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/637633

碩士 === 逢甲大學 === 環境工程與科學所 === 90 === The highly demand of drinking water quality has accelerated the innovation of modern technology of water treatment. Thus, remarkable attention has been paid on the water increasingly polluted by human activities due to the presence of numerous contaminants, mainly humic and nonhumic substances and inorganic species. The formation of halogenated organic contaminants arising from the reaction of chlorinated disinfectants with biogenic organic matter has been widely found in drinking water supplies. Therefore, this research is directed towards the use of combined processes of using ozonation and biological-fluidized-bed treatment to eliminate the natural and synthetic organic matters and control the formation of disinfectant by-products (DBPs). In this research, the tested raw water was withdrawn from Feng-Shan reservoir and Shan-Shuan water treatment plant, respectively. The water quality in Feng-Shan reservoir is typically known to be eutrophic and higher ammonia concentration. Raw water in Shan-Shuan water treatment plant has higher concentration of bromide ions and organic substances. Three phases have been conducted in this work. In the first phase, raw water was oxidized at different ozone dosages to evaluate the effects on the organic matters. In the second phase, the ozonation process followed by the biological fluidized-bed treatment (FBT) was utilized to control the precursors of DBPs and to evaluate the formation of ozonated by-products, such as aldehydes and bromate. In the third phase, a complete treatment train that combined the conventional drinking water treatment processes and our proposed ozonation/FBT processes was conducted to compare their efficacy on the water quality. Result indicates that less than 5 mg ozone/mg DOC dosage should be adopted for better decreasing NPDOC and controlling the precursors of THM and HAA if combining with FBT process to treat the raw water of Feng-Shan reservoir. When adding external organic substances from the supernatant of swine manure to simulate an extreme situation with high organic polluted raw water, the HAAFP decreases significantly after ozonation, whereas THMFP increases. It is thought to be the intermediate products formed by ozonation have higher affinity to react with chlorine to produce THMs rather than HAAs. On controlling the formation of DBPs for Shan-Shuan raw water, 4 mg O3/mg NPDOC and 2.7 hour detention time in FBT processes are recommended as a treatment strategy. In our integrated evaluation for THMFP control of Feng-Shan raw water, FBT plus traditional processes would be the best one, then pre-ozonation, FBT, plus traditional processes, and the traditional process alone is the least.