Research On Removal Of Aluminum In Drinking Water

The new national standard of aluminum for drinking water is 0.2mg/L, Shenzhen would occasionally fail to meet this demand according to a survey. Aluminum is injurious to the health. How can it be removed efficiently in water supply system? The residual aluminum in drinking water has been studied and discussed in thesis on the basis of the lab-scale and pilot researches. The treatise mostly contains several parts of contents as following:First, the situation of aluminum of drinking water in Shenzhen was analyzed, the reason why aluminum content sometimes did not comply with the national standard was discussed. Two, how the raw water quality and coagulants affect the content of residual aluminum was studied, the optimal operation situation of these factors was found. Three, how to control aluminum in drinking water through changing and optimizing the value of parameter in regular water treatment processes.The result of research shows that the main reason of high aluminum content in drinking water was the high residual aluminum of effluent, there exist the possibility that the pipe may increase the aluminum level of drinking water. The kind and dosage of coagulant, coagulant aid, turbidity, pH affect the quantity of the residual aluminum in drinking water, as well as the value of parameters in flocculation, coagulation, and filtration. The result indicate that: the importance order of the four factors affecting the content of the residual aluminum in drinking water is the dosage of PAC, pH, the rate of filtration, the dosage of activated silicic acid. The optimum conditions of controlling the residual aluminum is as follows: the dosage of PAC is 2.0 mg/L, pH in solution is 7.5, the dosage of activated silicic acid is 1.0mg/L, and the rate of filtration is 8m/h.In addition, the connection between the residual aluminum and turbidity in clarified effluent or filtrated effluent, is osmosed through whole thesis, in order that we could discover the consistency how to remove the aluminum and turbidity in drinking water, so the purpose for reducing the residual aluminum in potable water may be achieved through controlling turbidity strictly.The result is expected to have some meaning on the design and performance of water plants.