Treatment of Raw Water in Yangtze Chenhang Reservoir by Diatomaceous Earth Precoat Filtration

Taking the raw water of Yangtze Chenhang Reservoir as the research object, the characterization of diatomaceous earth, and the removal efficiency of CODMn, turbidity by precoat filtration process were investigated by pilot experiment in this paper. The results showed that diatomaceous earth patterns having porous structure and the pure silica peak at 2θ angles 21.980, 36.080, 31.460 and 28.430 in XRD analysis. Precoat filtration has a good stability to remove solid suspended particle, effluent turbidity was remained about 0.05NTU. Precoat filtration had no effect on removing CODMn. The pressure of 50KPa could be defined as a critical point in this experiment. Beyond the critical point, the devices should be stop and backwash, to resume operation pressure. Overall, precoat filtration can be defined as a filtration technique for relatively low turbidity raw waters.