降低饮用水中残余铝的中试研究

Pilot-scale test of reducing residual aluminum in drinking water

研究了水处理过程中铝含量的影响因素和控制条件,结果表明:对水中铝含量的影响PAC投加量﹥pH﹥滤速﹥活化硅酸投加量。控制余铝的最佳条件是:PAC投加量2.0 mg/L,pH值7.5,活化硅酸投加量1.5 mg/L,滤速8.0 m/h。过滤阶段对铝的影响小于混凝阶段,水厂实际运行时应尽量采用低滤速。为控制出厂水铝含量,建议水厂将沉后水浊度控制在3 NTU以下、沉后水铝含量控制在0.3 mg/L以下,特别是当沉后水浊度较大时,应定期检测滤后水余铝。

The influencing factors and control conditions of aluminum in water treatment process were studied. The result indicated that the influencing factors on aluminum in water were dosage of PAC 〉 pH 〉 filtration rate 〉 dosage of activated silicic acid. The optimal conditions of residual aluminum control were dosage of PAC 2.0 mg/L, pH value 7.5, dosage of activated silicic acid 1.5 mg/L,filtration rate 8.0 m/h. Filtration had less influence on aluminum than in the period of coagulation, and low rate of filtration should be adopted in practical operation of waterworks. In order to control aluminum in treated water, it was suggested to control turbidity below 3 NTU and aluminum below 0.3 mg/L after sedimentation, and residual aluminum of filtered water should be detected regularly especially when turbidity after sedimentation was high.