淨水場 前鹽素處理에 의한 鐵, 망간 殘留濃度에 關한 硏究
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This study, in order to investigate the cause of the color and turbidity in a small-scale water purification plant which uses lakes water as water supply source, we measured the number of water sources, aqueducts per depth of the lakes water, and the concentration of Iron, manganese and others according to the progress of the work. In a testing well as a beginning, in order to decide the optimum input concentration for the coagulant, oxidizer and others, we performed Jar-Test, and after dropping CaOCl investigated the change of the residual concentration of Iron and manganese ion in water according to the progress of the work. The results produced from this study are as follows: 1.The concentration of Iron ion was 0.13mg/ℓ and manganese ion was 0.08mg/ℓ on the surface water of the water source, but at a depth of 15m, concentration of Iron ion was 1.93mg/ℓ, and manganese ion was 0.433mg/ℓ. The concentration of dissolved oxygen was 11.2mg/ℓ on the surface and supersaturating, and at a depth of 5m it was 8.5mg/ℓ, and at a depth of over 10m decreased abruptly to 0.7~2.2mg/ℓ. 2.The water samples which were taken at the three sludge & mud-discharging holes located in the middle of the aqueduct were also similar to the deep water in view of the study of water-purity (temperature, dissolved oxygen, pH). Because the quality of the material of the aqueduct was steel tube, the concentration of iron in the points which were farther from the water purification plant (the nearest point from the water purification plant) increased to 5.35mg/ℓ. color also increased to 85 degrees the longer it stay in the aqueduct. 3.The best input concentration of Poly Aluminum Chloride (PAC) and Liquid Aluminum Sulfate (LAS) for determining the conditions of the color and turbidity, and removal of Iron ion, manganese ion, and aluminum ion are 17.5mg/ℓ and 35mg/ℓ each. 4.Under the condition which fixes the input concentration of Poly Aluminum Chloride (PAC) to 17.5mg/ℓ, Liquid Aluminum Sulfate (LAS) to 35mg/ℓ, if After the CaCOl used as a chlorination agent in clear well is injected into raw water at 10mg/ℓ, and then raw water is passed coagulation, sedimentation, rapid sand filtration, chlorination process. After all process, then the residual concentration of Iron ion decreased from 0.26mg/ℓ to 0.07mg/ℓ, and concentration of manganese ion from 0.25mg/ℓ to 0.137mg/ℓ. color also more decreased from 5 degrees to 4 degrees, and turbidity decreased from 0.7 NTU to 0.46 NTU.