The Research On Removal Characteristic And Mechanism Of Manganese From Groundwater By Biotreatment

The residual manganese concentration of the groundwater treatment plants, which normally exceeds the limit of 0.1 mg/L. Based on the water sample of the laboratory of Hunan University and by the aid of model experiment, the time needed for the cultivation of the biological filter were discussed, so were its affecting factors. The effort of manganese removal was studied and the kinetics of manganese removal was tried to establish.The factors of dissolved oxygen concentration, Fe2+concentration, pH ,P concentration and closing of the filter were studied to evaluate their effort for biological manganese removal, and the correlation of residual manganese and oxidation-reduction potential was also discussed.As the iron content of water was high, experiment results showed that the reaction was zero order, as the iron content of water was low, the reaction was first order. The time needed for the cultivation of biological manganese removal was 60～70 days. The filter operated at the filtration rate of 8～10m/h, silica sand of effective size 0.95～1.25mm filled the filter to a depth of 1200mm. Under this operation conditions, manganese can be efficiently removed. When the dissolved oxygen content of biological manganese removal filter was up to 1.0 mg/L, its content didn't affect biological manganese removal. When pH was in the range of 5.0 to 8.5, filter can operate efficiently, but below this range, the reaction of biological manganese removal was restrained, the removal effect decreased; at the condition of neutral pH, oxidation-reduction potential(ORP) of the filtrate ascended to 540～700mV.