均质滤料微絮凝过滤处理微污染水源水的试验研究

【作者】 高欣；

【导师】 张莉平；

【作者基本信息】 长安大学 ， 环境工程， 2006， 硕士

【摘要】 过滤作为常规给水处理控制水质的关键环节而备受人们的关注。为了缩小与世界发达国家水质指标的差距，其出水水质必须符合新的饮用水水质指标，这就要求我们不仅使水的嗅、色、浊度、细菌总数达标，而且要大大降低水中的有机物。《2010年发展规划》提出“对现有工艺进行必要的合理的技术改造，充分发挥常规处理效果”的规划目标。可以预见，在今后一段时期内，对现有水厂进行工艺挖潜与技术改造将是我国供水行业的重要工作内容和研究课题。 本文针对目前均质滤料微絮凝过滤研究热点，从西安曲江水厂滤料和西安田家湾水厂滤料中筛选出三种不同级配[d=（0.6～0.9mm，0.9～1.43mm，1.43～2.0mm）]的均质石英砂滤料，结合四种常用水处理絮凝剂（PAC、PAFC、Al₂（SO4）₃、FeCl₃）对微污染黄河泥沙配置原水进行过滤得出： 1) 处理效果细砂大于中砂，粗砂最差。 2) 细砂滤料（d=0.6～0.9mm）采用PAC微絮凝过滤效果相比其他组合要好，尤其是在水温18℃时，滤柱运行稳定后出水浊度0.2NTU，甚至达到0.1NTU，对COD_Mn的去除率也可以达到35％以上。低温时（10℃左右）出水浊度约0.4NTU，对有机物的去除率20％左右。同时得出PAC的最佳投药量为：1.0mg／L（水温18℃）；1.5mg／L（水温10℃）。 3) 使用PAC微絮凝过滤水温在18℃时使UV₂₅₄平均降低40％左右。低温10℃时能使UV₂₅₄平均降低20％左右。与COD_Mn的去除有一定的线性关系。 4) 不管使用那种滤料，都对硝酸盐氮几乎没有去除效果，相反到了过滤后期有出水硝酸盐氮大于进水的现象。可能是消化细菌将氨氮转化的结果。另外采用PAC微絮凝过滤可以使亚硝酸盐氮的去除达到50％左右。 5) 本次试验微絮凝过滤的反冲洗强度和时间都较常规过滤的反冲洗强度（15L／m²·s）大和冲洗时间（5～7min）长。 6) 采用PAC微絮凝过滤相对其它絮凝剂有良好的絮凝性能和较好的经济效益，且易于运输、使用和储存。 当原水COD_Mn超过5mg／L时，不管采用何种絮凝剂都不能使有机物达标。尤其是低温条件下去除率仅有20％左右，故此采用高锰酸钾预氧化。当原水更多还原

【Abstract】 Filtration, as one of a key method of water treatment which can meet people’s water quality requirements, is more and more concerned by people. In order to minish the difference from the developed country. Effluent quality must measure up the new standard of drinkable water. Except for the smell, chroma and turbidity, we must get rid of the organic substance greatly. The programming goal was come out in "development program of 2010": present process must be altered reasonably and the effect of traditional disposal should be full exerted. It is evident that overhauling present water plant and technique improving in a future time will be an important content and research task of water supply field in our country.This paper aimed at the research hotspot of micro-coagulated filtration by uniform gravel medium. We Selected three different series uniform mediums {d= （0.6⁰.9mm,0.9¹.43mm,1.43².0mm）} from Qujiang plant and Tian jia wan plant in Xi’an and combinated four types of flocculate dispels which was used in treating micro-polluted surface water confected from yellow river. The compared results are below:1) Small diameter quartzite （d=0.6-0.9mm） is the best while the wide diameter quartzite is the worst.2) Small diameter quartzite （d=0.6⁰.9mm） had got a better effect using PAC to micro-coagulate filtration than the other combinations. Especially at the 18 degree of water temperature, turbidity of effluence from column-filter could reach 0.2 NTU, even 0.1NTU when the system arrived at tranquilization. The removal rate for COD_Mn could also reach over 35 percent; the best dosage of PAC was 1.0mg per liter of the moment. While at the temperature of 10 degree, the turbidity of effluence was average to 0.4NTU and the removal rate for COD_Mn reduced to 20 percent, at the moment the best dosage for PAC was 1.5mg/L.3) At the temperature of 18 degree. The removal rate for UV₂₅₄ average reduced to 40% while at 10 degree this rate average reduced to 20 percent. It showed a good linearity -correlation with the removal rate to更多还原