某水厂微污染原水处理工程设计及运行分析

Design and Operation Analysis of Micro-Polluted Raw Water Treatment Project of a WTP

江苏某水厂原水中氨氮、高锰酸盐指数、铁等指标长期超标,达不到《地表水环境质量标准》(GB 3838—2002)Ⅲ类水标准,为微污染原水。针对原水水质特点,改造后的水厂净水工艺采用“预处理工艺+常规处理工艺+深度处理”的全流程净水工艺,其中预处理采用生物预处理工艺,常规处理采用“混凝沉淀+过滤”工艺,深度处理采用“臭氧-生物活性炭”工艺。改造后工艺运行稳定,对原水中的浑浊度、氨氮、高锰酸盐指数、铁、色度等均有较好的去除效果,出厂水水质指标稳定达到《生活饮用水卫生标准》(GB 5749—2006),其中出厂水浑浊度、氨氮、高锰酸盐指数、铁、色度分别稳定在0.5 NTU、0.5 mg/L、3.0 mg/L、0.05 mg/L、5度以下,平均去除率分别为99.6%、88.8%、73.3%、96.9%、82.9%。

Ammonia nitrogen,permanganate index,iron and other indicators in raw water of a water treatment plant(WTP)in Jiangsu exceeded the standard for a long time,and could not reach the classⅢwater standard of Environmental Quality Standards for Surface Water(GB 3838—2002),so it was micro-polluted raw water.According to the characteristics of raw water quality,the modified water purification process of the WTP adopted the whole process of pretreatment process+conventional treatment process+advanced treatment,in which the pretreatment adopted biological pretreatment process,the conventional treatment adopted coagulation precipitation+filtration process,and the advanced treatment adopted ozone-biological activated carbon process.The modified process ran stably and had a good removal effect on turbidity,ammonia nitrogen,permanganate index,iron,chroma,etc.,in raw water,the finished water quality parameters reached Standards for Drinking Water Quality(GB 5749—2006).Among them,the finished water turbidity,ammonia nitrogen,permanganate index,iron and chroma were stabilized below 0.5 NTU,0.5 mg/L,3.0 mg/L,0.05 mg/L and 5 degrees,respectively,and the average removal rate was 99.6%,88.8%,73.3%,96.9%and 82.9%,respectively.