净水厂出厂水余铝的影响因素及控制研究

Study on influence factors and control of alumina in effluent of water purification plant

针对高温、高pH、低碱度原水,净水厂出厂水余铝含量较难达到0.1 mg/L的优质水控制要求。为解决这一问题,对影响余铝因素和控制进行相关试验。结果表明:水温、pH是影响余铝含量的主要因素,使用高盐基度聚合铝铁能明显降低余铝;在高温、高pH时期,采用三氯化铁调节pH值到7.7以下,投加盐基度90%以上的聚合铝铁,能保证余铝含量在0.1mg/L以下。在合肥某水厂进行的生产试验也表明,采用这一技术方案能使出厂水余铝达到控制要求。

For raw water with high temperature,high pH and low alkalinity,it is difficult to meet the high-quality water control requirement of 0.1 mg/L for the residual aluminum content of treated water.In order to solve this issue,the factors affecting residual aluminum and control were investigated.The results showed that water temperature and pH were the main factors affecting the residual aluminum,and the use of polymer ferroaluminium with high basicity could obviously reduce the residual aluminum.During high temperature and high pH period in the raw water,the residual aluminum content could be less than 0.1 mg/L by adjusting the pH to 7.7 below with ferric chloride and then dosing polymer ferroaluminium with basicity of more than 90%.The production test in a waterworks in Hefei City also showed that the technical scheme could make the residual aluminum of the treated water meet the control requirements.