【作者】 朱琦；

【导师】 崔福义；

【作者基本信息】 哈尔滨工业大学 ， 城市水资源， 2008， 硕士

【摘要】 臭氧氧化是O₃—BAC工艺重要环节, O₃—BAC是饮用水深度处理的一种方法。臭氧氧化的效能因原水、滤后水水质的不同而不同。臭氧氧化过程中可能产生致癌性副产物—溴酸盐,溴酸盐生成量的控制是保证饮用水安全的重要问题。研究了饮用水臭氧氧化效能、溴酸盐生成的影响因素、臭氧氧化绍和净水厂滤后水的溴酸盐形成及控制方法,为研发溴酸盐控制技术寻找规律。小试试验表明:臭氧氧化对绍和净水厂滤后水没有明显的降浊效果。向绍和净水厂滤后水投加2mg/L O₃和3mg/L O₃时,臭氧氧化后出水UV254平均去除率分别为18.87%和22.23%,滤后水TOC的去除率分别为4.67%和6.01%。投加2mg/L O₃和4mg/L O₃氧化后CODMn分别下降了21.42%和24.74%,氨氮含量分别增高了21.57%和23.74%。当Br^-浓度在50μg/L～1000μg/L范围内变化时,BrO₃^-生成量与Br^-初始浓度显示了良好的线性关系。臭氧投加量为1～4mg/L时,BrO₃^-生成量有逐渐增加的趋势,臭氧投加量越大,BrO₃^-的生成量越大,但BrO₃^-的生成量增加的速度比较缓慢。当[Br^-]=100μg/L,T=5℃,pH=7.24,t=10min,臭氧投加量为4mg/L时,在超纯水中只有19%的Br^-转化为BrO₃^-。当Ct值在0～40mg·L^-1min时,超纯水中BrO₃^-的生成量随Ct值增加而增加。当pH值在6.5～8.5变化时, BrO₃^-的生成量随pH值增加而增加。加氨可有效控制溴酸盐的生成。氨氮浓度越大则控制效果越好,当氨氮浓度大于0.65mg/L后溴酸盐的生成量基本恒定。中试试验表明:对于Br^-浓度为100μg/L和200μg/L左右的绍和净水厂滤后水,柱内接触反应时间在12min和10min以内可以控制BrO₃^-的生成量不超过国标规定的10μg/L。在绍和净水厂滤后水中增加Br^-浓度会使BrO₃^-的生成量增加。当反应时间在10min,Br^-浓度﹤200μg/L时,臭氧氧化后的BrO₃^-的生成量可以控制在10μg/L以下。当哈尔滨绍和净水厂滤后水的Ct值﹤30mg·L-1min时,可将BrO₃^-的生成量控制在10μg/L以下。滤后水的BrO₃^-超标的原因可能是pH值较高,TOC和UV254含量较低。当臭氧投量为4mg/L,Br^-含量为0.11～0.21 mg/L, pH值为7.0～7.8,氨氮为1mg/L左右,TOC为3.0～3.1mg/L时,生成BrO₃^-的含量不会超过国家规定的标准。当臭氧投量为4mg/L,Br^-含量为﹥0.21 mg/L, pH值﹥7.8,氨氮为1mg/L左右,TOC﹥3.1mg/L时,生成BrO₃^-的含量会超过10μg/L的标准。更多还原

【Abstract】 Ozonation is one of important step in O₃—BAC process, which is one of advanced treatment method in drinking water. The efficiency of ozonation is different because of water quality of source water and filtered water. A carcinogenic by-product—bromate may be produced during the ozonation, and the control of the bromate production is a difficult problem in guaranteeing the safety of drinking water.This article did research on the efficiency of ozonation, the influence factor of bromate formation, bromate formation and control method in filtered water in Shaohe water treatment plant after ozonation, to find rules for developing bromate control technology.The pilot test showed that: ozonation did not have obvious effect on reducing turbidity of filtered water in Shaohe water treatment plant. When adding 2mg/L O₃ and 3mg/L O₃ to the filtered water in Shaohe water treatment plant, the average removal rate under UV254 of effluent after ozonation were 18.87% and 22.23% respectively, the removal rate of TOC in filtered water were 4.67% and 6.01% respectively. When adding 2mg/L O₃ and 4mg/L O₃ to the filtered water, the CODMn decreased respectively by 21.57% and 23.74%.When the concentration of Br were changed from 50μg/L to 1000μg/L, formation amount of BrO₃^- and the initial concentration of Br^- showed a good linear relationship. When the dosing quantity of O₃ were changed from 1 mg/L to 4mg/L, the formation amount of BrO₃^- showed crescent current, that meant the more dosing quantity of O₃ was, the more formation amount of BrO₃^- was. But the speed of formation amount of BrO₃^- was slow.When [Br^-]=100μg/L,T=5℃,pH=7.24,t=10min, the dosing quantity of O₃ was 4mg/L, only 19% Br^- transform to BrO₃^- in ultrapure water. When Ct value changed between 0 and 40mg·L-1min, the formation amount of BrO₃^- were increased by increasing Ct value. When pH value changed between 6.5 and 8.5, the formation amount of BrO₃^- were increased by increasing pH value. Ammonification could control the formation amount of bromate effectively. The big concentration of NH3-N was, the better control effect was. When [NH₃-N]﹥0.65mg/L, the formation amount of bromate was nearly constant.The pilot scale test showed that:when the concentration of Br^- were 100μg/L and 200μg/L in filtered water in Shaohe water treatment plant , contact reaction time in ozone column were within 12min和10min,that can control the formation amount of BrO₃^- was less than 10μg/L which was stipulated by national standard.It found that increasing the concentration of Br^- could increasing the formation amount of BrO₃^-. when the reaction time 10min, [Br^-]﹤200μg/L, the formation amount of BrO₃^- after ozonation could be controlled under 10μg/L. When Ct value of filtered water in Shaohe water treatment plant was less than 30mg·L-1min, the formation amount of BrO₃^- could be controlled under 10μg/L. The reason of the over standard of BrO₃^- in filtered water may be the high pH and the lower content of TOC and UV254. When the dosing quantity of O₃ 4mg/L, the Br^- content 0.11⁰.21mg/L, pH7.0⁷.8, [NH3-N]1mg/L, TOC 3.0³.1mg/L, the formation amount of BrO₃^- was less than standard stipulated by Chinese Ministry of Health. When the dosing quantity of O₃ was 4mg/L, the Br^- content was more than 0.21 mg/L, pH>7.8, [NH3-N]1mg/L, TOC>3.1mg/L, the formation amount of BrO₃^- could be more than 10μg/L stipulated by national standard.更多还原