蔣本基臺灣大學：環境工程學研究所李易書Li, I-ShuI-ShuLi2007-11-292018-06-282007-11-292018-06-282005http://ntur.lib.ntu.edu.tw//handle/246246/62794The objective in this investigation is intended to evaluate the effect of ozonation of low molecular weight precursors on DBP formation. In conventional water treatment process, high molecule weight compounds such as humic substances could be removed significantly by the enhanced coagulation. However, other low molecule weight compounds, i.e., resorcinol, phloroglucinol, and p-hydroxybenzoic acid, couldn’t be removed and exhibit high DBP formation potential (DBPFP). Therefore, the introduction of ozonation / chlorination processes to water treatment plant introduced to investigate the effect of DBP formation. The results of the investigation reveal that destruction of organic precursors by hydroxyl radical exhibits higher DBP formation. In the O3/UV process, the greater amount of hydroxyl radical exposure results in more reduction of DBP. Furthermore, the other harmful by-products such as aldehyde formation also focused on the investigation because of its carcinogenic character. In the comparison of risk assessment between ozonation and coagulation, the ozonation/chlorination processes decrease the carcinogenic risk of finished water. A new model proposed by Chang can fit the chlorine decay and DBP formation data quite well. Adding parameters of pH and alkalinity to the Chang model can predict the chlorine decay and DBP formation data more accurately.Contents Acknowledgement I Abstract II Contents III List of Figures VII List of Tables XII Chapter 1 Introduction 1-1 Background 1-1 1-2 Objectives 1-3 1-3 Major Tasks 1-4 Chapter 2 Literature Review 2-1 Organic Precursors 2-1 2-2 Ozonation and DBP Formation 2-4 2-2-1 Ozonation 2-4 2-2-2 O3/ UV Process 2-17 2-2-3 Free Radicals Scavenger 2-18 2-2-4 Ozonation By-Products 2-20 2-3 Methods for Hydroxyl Radical Determination 2-23 2-4 Chlorination and DBP formation 2-25 2-4-1 Chlorination 2-25 2-4-2 Disinfection By-Products (DBP) Formation 2-26 2-5 Predictive Model of Chlorine Decay and DBP Formation 2-30 Chapter 3 Materials and Methods 3-1 Research flowchart 3-1 3-2 Materials 3-2 3-2-1 Apparatus 3-2 3-2-2 Organic Precursors 3-5 3-3 Methods 3-6 3-3-1 Experimental Design 3-6 3-3-2 Unit Process 3-11 3-3-3 Analytical Method for Traditional Method 3-15 3-3-4 Analytical Method for DBPs 3-16 3-3-5 Hydroxyl Free Radical 3-29 3-3-6 Residual ozone 3-31 3-3-7 Hydrogen peroxide 3-33 Chapter 4 Results and Discussion 4-1 Ozonation and O3/UV Process 4-1 4-1-1 Ozonation Process at Different pH Levels 4-1 4-1-2 Effect of Alkalinity in Ozonation 4-8 4-1-3 O3/UV Process 4-12 4-1-4 Ozonation of Organic Precursors in terms of TOC and UV254 4-15 4-1-5 Formation of Ozonation By-products 4-20 4-2 Chlorine Demand and Chlorine Decay Model 4-25 4-2-1 Chlorine Demand 4-25 4-2-2 Chlorine Decay Model 4-32 4-3 DBP Formation and Predictive Model 4-42 4-3-1 THM Formation 4-42 4-3-2 HAA Formation 4-48 4-3-3 DBP Formation 4-53 4-3-4 Predictive DBP Formation Model 4-60 4-4 Comparison of DBPs Formations via Coagulation, ozonation and O3/UV processes 4-70 4-4-1 Chlorine Consumption 4-71 4-4-2 Chlorination Disinfection By-Product Formation 4-74 4-4-3 Risk Assessment Between Ozonation and Coagulation 4-77 Chapter 5 Conclusions and Recommendations 5-1 5-1 Conclusions 5-1 5-2 Recommendations 5-3 Reference Appendix6926278 bytesapplication/pdfen-US小分子有機前質氫氧自由基消毒副產物生成潛勢臭氧化/氯化臭氧/紫外光Low molecular weight organic precursohydroxyl radicalDBPFPozonation/chlorinationO3/UV processthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/62794/1/ntu-94-R92541123-1.pdf