Diatomaceous Earth Precoat Filtration For Drinking Water Treatment

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. Diatomaceous earth patterns having porous structure and the diatoms range in size from under 5 to more than 100 micrometers. Precoat filtration has a good stability to remove solid suspended particle, effluent turbidity was remained about 0.05 NTU. The running time is linear with the operating pressure, R-2 = 0.942, which indicate a good correlation. The precoat layer has little effect on operating pressure. The operating pressure (total head loss) is proportional to square of filtration rate. Precoat filtration can be defined as a filtration technique for relatively low turbidity raw waters.