| Summary: | 碩士 === 國立中山大學 === 環境工程研究所 === 104 === This study is focused to investigate the relations between operation conditions of chloramine and monitoring items of water quality, and could be used for increasing the efficiency of disinfection on water reusing. The major points of design on water reusing are to consider the optimal operation in membrane systems. The effects of chloramine of biological block on operation of membrane systems are found primarily considered in designing.
In this study the jar tests were used in all tests. The relations between formation of chloramine and pH were observed by using high and low concentrations of ammonia solution reacted with NaOCl solutions added by us under pH = 6, 7, 8 respectively. The levels of pH were adjusted with H2SO4 and HCl in this work. Final step was conducted to study the variations of residual chlorine curves using pH and ORP. This step could obtain the control conditions of chloramine in all tests. The experimental results showed the formatting concentrations of chloramine was the highest in weight ratio 3.9:1 of Cl2/N (molar ratio was 0.76:1) when concentrations of ammonia nitrogen were high or low and pH were set on 6, 7, and 8. The concentrations of free chlorine were started to format in reaction when weight ratio 6.4:1 of Cl2/N (molar ratio was 1.27:1) was set in reaction. The reaction of ammonia nitrogen was finished when weight ratio 7.7:1 of Cl2/N (molar ratio was 1.52:1) conducted in reaction. In this study for considering chloramine formatting and avoiding free chlorine formatting, thus made the alarming point of chloramine was set on weight ratio 5.5 :1 of Cl2/N (molar ratio was 1:1) for avoiding free chlorine formatting, and made the optimal point of chloramine was set on weight ratio 3.95 :1 of Cl2/N (molar ratio was 0.76:1). It was no significant effects on formatting concentrations of chloramine under different pH by adjusting with H2SO4 and HCl in this work. Therefore, H2SO4 was primarily selected to adjust pH of raw water in influent of RO systems. For this way could raise the treatment efficiency of ammonia nitrogen in RO systems. The limited conditions of application were suggested the times for stopping added chemicals in RO systems when two controlling conditions were observed: (1) when low concentrations of ammonia nitrogen in raw water, pH were lower than 6.8 and ORP were larger than 603.7mV; (2) when high concentrations of ammonia nitrogen in raw water, pH were lower than 6.73 and ORP were larger than 625.8mV.
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