Study On The Influence Factors And Control Measures Of Aluminum In Water Supply System

Aluminum has detrimental effect on human health, how can it be removed in potable water? The residual aluminum in drinking water has been studied and discussed in thesis on the basis of the lab-scale and pilot researches.The article first investigation and study the current situation of aluminum in raw water and finished water in Shenzhen. The possible causes of aluminum over-standard in drinking water are analysised as the following aspects: the quantity of aluminum in raw water is too high, the coagulants dosages are too big, the operating conditions during coagulation are insufficiency, and the turbidity of finished water is too high.The influence and control measures of coagulation sedimentation process on the residual aluminum are studied. Coagulant, coagulant aid, turbidity, pH, the process parameters of coagulation sedimentation affect the quantity of the residual aluminum in drinking water, as well as its formation in water. According to the experiments, the disciplinarian that each factor abides by to influence the residual aluminum and the corresponding control measures have been found.The influence and control measures of filtration process on the residual aluminum are studied. Through changing the value of parameter such as the rate of filtration, the depth of filter bed, the composition of filtering media in filtration process, the analysises that filtration process influences the residual aluminum are made systematically and deeply in thesis. In accordance with the residual aluminum in drinking water, we have got the fit value of important parameters in filtration.Finally, on the basis of pilot-scale test, the influence of the dosage of coagulant, pH and turbidity on the residual aluminum is further analysised. Make multiple factors quadrature experiment, the result indicate that: The important order of the four factors that effect the quantity of the residual aluminum in drinking water is the dosage of PAC, pH, the rate of filtration, the dosage of activated silicic acid; The important order of the four factors that effect the turbidity in drinking water is the dosage of PAC, the rate of filtration, the dosage of activated silicic acid, pH. The optimum conditions of control the residual aluminum is: the dosage of PAC is 2.0mg/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. The result has good reference to reduce the residual aluminum in drinking water.