【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， 2012， 博士

【摘要】 在微污染饮用水处理中，臭氧氧化技术已越来越多地被选择应用到饮用水处理过程中。含溴水在臭氧氧化时会生成2B级致癌物溴酸盐，溴酸盐浓度的控制是确保水质安全的重要问题。目前，相关研究主要集中于应用各种外加方法去除水中的溴酸盐，忽略了常规水处理工艺环节的自身作用，未见溴酸盐在常规工艺中是否可以得到去除的相关研究。在现有水处理的工艺中解决溴酸盐的污染问题，是最切合实际，最易应用、最经济合理的方法。针对整套饮用水处理工艺流程，论文研究了水中溴酸盐的生成特性，常规处理对溴酸盐及其前驱物溴离子的控制，臭氧-活性炭工艺中的溴酸盐控制，紫外辐射处理对水中溴酸盐的控制，含溴饮用水处理工艺的构建与优化等内容。通过水中溴酸盐的生成特性的研究，明确了在水中常见的0～500μg/L的初始溴离子浓度范围内溴酸根和中间产物的数量关系，从而探明了0～4mg/L的臭氧投量下溴酸盐生成量较低的原因。臭氧剂量及水中初始溴离子浓度直接关系到水中溴酸盐生成量。水中氨氮存在形式对pH值和溴酸盐生成量有影响，与不含氨氮的水样相比，pH值接近的含氨氮的水样的溴酸盐的生成量相对较低。在同一氨氮含量下，提高pH值，溴酸盐的生成量有小幅升高，氨氮对溴酸盐的生成量的影响要大于pH值的影响。水样投加铵盐和投加氨水的实验表明，对于含有铵根离子的水样，由于其pH较低，所以对溴酸盐生成的抑制作用更大。通过对含溴水进行氯化实验，探明了饮用水氯化消毒处理对溴离子及溴酸盐的影响。含溴水样加氯后，溴酸盐的生成总量很小，加氯量5mg/L时，溴离子向溴酸根的转化率不足1.3%。次氯酸钠长时间与溴离子接触后，溴酸根的生成量只有小幅增加。在有机物浓度较高的水中，氯化不会导致溴酸盐产生。含溴原水氯化时，加氯量1mg/L和3mg/L都未检出溴酸盐，加氯量达到5mg/L时，原水中只是检出了非常少量的溴酸盐。在饮用水余氯浓度为0.11～0.26mg/L，TOC为1.4～1.8mg/L条件下，均未检出溴酸根，说明饮用水中较低浓度的余氯不会将溴离子氧化为溴酸根，不存在使溴酸盐超标的风险。通过以聚合氯化铝和三氯化铁作混凝剂的实验，明确了混凝沉淀对溴酸盐和溴离子有一定的控制作用，其效果受到混凝剂投量、pH、水样浊度、水温等条件的影响。三氯化铁比聚合氯化铝混凝沉淀对溴酸盐及溴离子的控制效果更好，70mg/L三氯化铁投量下，对原水中溴酸盐的平均去除率为58.5%。研制了具有除浊和控制溴酸盐双重功能的硅酸改性聚合亚铁混凝剂，通过红外光谱表征，证明改性聚合亚铁混凝剂的制备效果可靠。改性聚合亚铁混凝剂的除浊性能强于普通铁盐和亚铁盐，改性聚合亚铁混凝去除溴酸盐和溴离子的效果很好。硅铁比1:2的改性聚合亚铁控制溴酸盐的效果最佳，其投量为16.8mg/L时，溴酸盐的平均去除率为83.8%，说明改性聚合亚铁可作为控制水中溴酸盐的有效混凝剂。明确了过滤对溴酸盐和溴离子的控制作用有限，在水样初始浊度为40NTU， pH=6.86， T=23℃条件下，滤层深度1.2m时，溴酸盐去除率为14.4%。溴离子去除率为13.6%。滤层厚度对溴酸盐和溴离子浓度影响最大，其次是水样的浊度，而在50～200μg/L范围内，溴酸根和溴离子初始浓度的影响可以忽略。在中试的基础上，确定了优化臭氧-活性炭工艺参数控制溴酸盐的方法。一方面，通过控制臭氧氧化工艺参数限制溴酸盐的生成量不超标。另一方面，若溴酸盐生成量已经超标，通过控制活性炭运行参数使得出水溴酸盐的量不超标。水中初始溴离子浓度、臭氧投量和接触时间是控制溴酸盐生成量的关键因素。在臭氧处理单元，建立了控制溴酸盐生成量数学模型。在活性炭处理单元，炭柱接触时间和进水溴酸盐浓度是控制溴酸盐去除的关键因素，建立了控制溴酸盐去除率数学模型。考察了12个月连续运行的活性炭表面微生物的情况及生物量的变化。证明了生物活性炭对水中溴酸盐的去除效能强于活性炭，探明了生物活性炭对水中溴酸盐的作用机理，明确了微生物在活性炭表面的作用。通过紫外辐射含溴酸盐水样的研究，确定了短波紫外线UVC辐射可以作为去除饮用水中溴酸盐的有效手段，但辐射的剂量要求较大。长波紫外线UVA是紫外还原溴酸盐的一个干扰因素，应当减少其辐射剂量以确保水中溴酸盐的还原效果。本文揭示了溴酸盐及溴离子在水处理过程中的变化规律，构建了全流程协同溴控制酸盐的方法体系，探明了各个处理单元中控制溴酸盐风险的工艺参数。优化了针对溴酸盐控制的工艺运行条件，为溴酸盐控制技术在饮用水处理中的实际工程应用提供了理论与技术指导。更多还原

【Abstract】 In the micro-polluted drinking water treatment, ozone oxidation technologyhas been increasingly applied to drinking water treatment process. Containingbromide water in the ozone oxidation can generate bromate, which belongs to2Blevel carcinogen，and the bromate concentration control is important to ensure thewater quality security. At present, the relevant studies were mainly on Applicationof various applied methods in the removal of bromate, which ignoring theconventional water treatment process itself. It has not been reported that thebromate in the conventional process could be removed in the recent related research.In the existing water treatment technology, to solve the pollution problem ofbromate is the most practical and easily applied and the most economical method.For the whole system of drinking water treatment, this paper investigatedwater bromate formation characteristics, conventional treatment on bromate andcontrolling its precursor bromide ion, controlling bromate in ozone-activatedcarbon process, ultraviolet radiation treatment on the control of bromate in water,construction and optimization of bromine containing drinking water treatmenttechnology.Through the research on the characteristics of bromate formation in water, weascertained the quantitative relation between BrO3-and intermediate within theconventional range of0~500μg/L initial concentration of bromide ions in water, soas to find out the reason for low bromate production with0~4mg/L ozone dosage.Ozone dosage and the initial concentration of bromide ion in water are directlyrelated to the formation of bromate in water quantity. Ammonia nitrogen forms haveinfluence on pH and formation amount of BrO3-. Compared with water sampleswhich contained no ammonia nitrogen, the formation amount of BrO3-was relativelylowe in pH value close to the ammonia water samples. In the same ammonianitrogen content, when improved pH value, the formation amount of BrO3-wasslightly elevated. It means that the influence of the ammonia nitrogen on theformation amount of BrO3-was more than pH value. The experiment of addingammonium salt and adding ammonia to water respectively showed that theinfluence of ammonium group on bromide ion converting to bromate ion in water is more than that of free ammonia due to its low pH.Based on the experiment with bromine chloride, we ascertained the effect ofchloridizing disinfection of drinking water on bromine and bromate. Water addingchlorine within360min, the formation amount of bromate was small. Whenchlorine dosage was5mg/L, the conversion rate of bromine ion to bromate wasless than1.3%. After long time for Sodium hypochlorite contacted with bromideions, the formation amount of BrO3-was slightly elevated. In the water with higherconcentration of organic matter, chlorination did not lead to bromate. Whenchloridizing bromine water, bromate were not detected with chlorine dosage of1mg/L and3mg/L. With chlorine dosage up to5mg/L, bromate was detected byvery small amount in raw water. When chlorine residual level was0.11～0.26mg/Land TOC was1.4~1.8mg/L, BrO3-were not detected in drinking water. Thatmeant the existence of low concentration of residual chlorine could not oxidize thebromide ions to bromate, let alone bromate exceed standard.By experiment of PAC and FeCl3as coagulant, the article made clear thatcoagulation and sedimentation have certain control effect on bromate and bromideions, and its effect by coagulant dosage, pH, turbidity, water temperature and otherconditions. The control effect of FeCl3on bromate and bromide ions was better thanthat of PAC coagulation sedimentation. With the dosage of FeCl3of70mg/L, theaverage removal rate of bromate was58.5%in the raw water.A silicic acid modified polymerized ferrous coagulant was developed, whichhad turbidity removal and control of bromate in the dual function. characterized byinfrared spectroscopy, we found that the modified polymerized ferrous coagulantpreparation effect was reliable. The operty of turbidity removal of modifiedpolymerized ferrous coagulant was stronger than common salt and ferrous salt. Theeffect of polymer modified ferric coagulation on removal of bromate and bromideions was very good. Modified polymerized ferrous with ferrosilicon ratio1:2hadbest effect on control of bromate.When the dosage of16.8mg/L, bromate averageremoval rate was83.8%, that meant modified polymerized iron could be used asefficient coagulant for the control of bromate in water.The Control Action of filtration on bromate and bromide ion was limited.When the initial turbidity water was40NTU, pH=6.86, T=23℃, filter depth1.2m,bromate removal rate was14.4%, bromide ion removal rate was13.6%. The filterlayer thickness had most important influence on bromate and bromide ions concentration. Next came the water turbidity, in the range of50~200g/L, the initialconcentration of bromate and bromide ion effect can be ignored.Based on the pilot experiment，we determined the method which controlledbromate by ozone-activated carbon process with the optimal parameter. On onehand, by controlling the ozone oxidation process parameter limits the bromateformation amount to not exceed the standard. On the other hand, if the bromateproduction had already exceed the standard, by controlling the operating parametersof the active carbon water bromate amount to not exceed the standard. The initialconcentration of bromide ion in water, ozone dosage and contact time were thecontrol of bromate production key elements. In the ozone processing unit,established the mathematical model of controlling bromate production. In theactivated carbon processing unit, an activated charcoal column contact time andwater bromate concentration were the key factors of controlling bromate removal,established control of bromate removal rate mathematical model. We Studied12months of continuous operation of the activated carbon surface microorganismsand biomass change,and proved that the biological activated carbon for waterbromate removal efficiency was better than activated carbon, It was ascertained thatthe mechanism of action of biological activated carbon on bromate in water, andthe effect of microorganisms on activated carbon surface.Ultraviolet radiation containing bromate in water was researched, thendetermined the shortwave ultraviolet UVC radiation can be used as effective meansin the removal of bromate in drinking water, but the radiation dose required larger.UVA was a disturbance factor for reducing bromate, so we should reduce theradiation dose to ensure water bromate reduction effect.This paper revealed the change law of bromate and bromide ions in watertreatment process, and built the control technology system of bromate, proved theparameters combination in bromate processing unit for safety. We optimizedprocess operating conditions for bromate control, provided theoretical and technicalguidance for bromate control technology in drinking water treatment in the actualproject application.更多还原