Removal of iron and manganese in water treatment process

This diploma thesis is aimed at the evaluation of water treatment technology in Písty waterworks which treats raw water with high concentration of iron and manganese. The most common method of iron and manganese removal from raw water is based on oxidation to insoluble hydrated oxides followed by separation of formed aggregates. The plant technology consists of aeration, oxidation agent KMnO4 dosing and mixing, sedimentation, filtration and hygienic protection. Chemical analysis of treated water, evaluation of the aeration efficiency of iron and manganese oxidation, evaluation of the separation efficiency of the sedimentation tank and filters, assessment of distribution of iron and manganese in the filter, assessment of dirt holding capacity and optimization of KMnO4 dose were determined. Raw water pH fluctuated around 7,3 during measurements, whereas iron and manganese concentrations in raw water were 6,00 and 0,82 mg.l-1 , respectively. Oxidation of 97,2 % of dissolved iron and of 14,3 % of dissolved manganese was achieved after the aeration. The separation efficiency of the sedimentation tank was 82,9 % for iron and 46,5 % for manganese, however the separation efficiency of the second half of the sedimentation tank was low. Thus, the perforated baffles in the second half of the sedimentation..