【作者】 张凤；

【导师】 顾平；

【作者基本信息】 天津大学 ， 环境工程， 2007， 硕士

【摘要】 随着水源水质的恶化和人们生活水平的提高,饮用水常规处理工艺已不能与现有的水源水质和水质标准相适应。混凝-微滤工艺制备饮用水是非常有前景的水处理技术。从工艺流程上看,混凝-微滤工艺简单,运行管理方便。试验以滦河水为水源水,采用混凝-微滤工艺制备饮用水。两套中试规模的反应器在天津市杨柳青自来水厂已稳定运行,该装置为浸没式膜处理系统,分别采用帘式膜组件和柱式膜组件。试验监测了两套处理系统的出水水质;采用超滤分离的方式对原水和两种膜分离出水的有机物进行分离,考察各分子量区间的DOC、UV254、THMFP等指标;研究了THMs的生成特性。试验结果表明,两套处理系统的出水水质均满足《生活饮用水卫生标准》(GB 5749-2006)的要求。原水中的TOC和CODMn的去除率分别在26%和35%左右;出水浊度低于0.10 NTU以下的占90%左右;菌落总数低于15 CFU/mL,总大肠菌群数未检出;在与氯接触30 min后出水游离氯不低于0.3 mg/L的情况下,出水中三卤甲烷各组分均满足标准的要求。总体分析,由于混凝剂投加量不同和膜公称孔径的差别,帘式膜系统出水的CODMn、TOC、UV254、氨氮、菌落总数等指标稍差于柱式膜系统;在高藻期期间,柱式膜系统增加了预氯化处理方式,有效氯投量约为2 mg/L,这段时间内出水水质明显优于未预加氯的出水水质。超滤试验结果显示,原水中的溶解性有机物以小分子为主,该部分有机物是产生THMs的主要物质,其中分子量介于3k-1k Da之间的有机物THMs的生成能力最强;膜分离出水中大分子有机物的含量具有较大幅度的降低,而小分子物质去除效果较差,甚至出现负增长的现象;比较不同有机物指标的去除效果,在各个分子量区间,UV254的去除率高于DOC;两套处理系统对THMFP的去除率在40%左右。将Rodriguez对THMs的预测模型应用于膜处理系统的原水和出水,通过统计分析发现,取显著性水平α=0.05,预测值与实测值之间有较好的相关性(R=0.945);t检验结果表明,两组数据的差异性并不显著(p=0.182>0.05)。对于滦河水Rodriguez模型具有一定的适用性。更多还原

【Abstract】 As water source quality gets worse and people’s living standard becomes better, conventional treatment process is not suitable to the water source and the quality of drinking water. Coagulation-microfiltration process for drinking water production is promising, which has some advantages, such as simpler process and more convenient operation.Water from the Luan River was used as raw water for drinking water production by coagulation-microfiltration process. Two pilot-scale reactors have been operated stably in Yangliuqing Water Treatment Plant in Tianjin. Curtain-type membrane and cylinder-type membrane were used separately. Quality of the treated water was monitored. The organic matters in the raw water and the treated water were separated according to different molecular weight (MW) by ultrafiltration. DOC, UV254 and trihalomethanes formation precursor (THMFP) were compared in various MW fractions. The character of trihalomethanes (THMs) formation was studied.The results show that, the quality of the treated water can meet the requirements of Standards for Drinking Water Quality (GB 5749-2006). DOC and CODMn removal efficiencies are 26% and 35% separately. Ninety percent of the turbidity of the treated water is lower than 0.10 NTU. The total count of bacteria is below 15 CFU/mL while the total coliform is not detected. All species of THMs in the treated water comply with the water quality standards, when the concentration of free residual chlorine is no less than 0.3 mg/L after contacting with the disinfectant for 30 min. On the whole, the treated water form cylinder-type system shows some superior quality than that from curtain-type system. Sodium hypochlorite was added into the raw water along with coagulant when the concentration of algae was very high in the beginning of autumn. As a result, a superior water quality is gotten.The results of ultrafiltration test show that the organic matters with low MW are the major THMs precursors and the organic matters with MW between 3k-1k Da have the greatest THMFP in raw water. The organic matters with high MW are removed efficiently, and that with low MW even have minus-increase reversely. UV254 has a better removal than DOC in various MW fractions. THMFP removal efficiency of the two systems is nearly 40%.The mathematical predictive model for THMs formation rectified by Rodriguez was used in the raw water and the treated water. The results of statistic calculation show that, predicted values and measured values have a correlation coefficient of 0.945 when the level is 0.05. The two group of datas do not have significant difference (p=0.182>0.05). The model is applicable for the Luan River water.更多还原