Study On Removal Of Iron And Manganese In Micro - Polluted Raw Water By O₃-Biological Zeolite

On the basis of Review of relevant literature in full and experimental results, for our water plant source water quality decline and conventional drinking water treatment process is difficult to guarantee the requirements of safety and health In the new status of the water pollution situation ,studying technology of slightly polluted raw water is important and urgent; Carrying out research removal of iron and manganese in micro-polluted raw water and deepen understanding removal of iron and manganese by biological technology is necessary. This paper studied removal of iron and manganese in micro-polluted raw water by natural zeolite, bio-zeolite, and ozone - biological zeolite respectively, and explored the related factors on the impact of removing iron and manganese. Law and the role of factors were discussed; under the condition of the optimum process parameters, effect of the overall operation was examined finally. The main conclusions are:Static adsorption test: the adsorption of zeolite has a "rapid absorption, slow balance" feature; the presence of iron or manganese can make the adsorption capacity of the other one by zeolite decreased, there is competitive adsorption; other factors have some impact;Biological Zeolite Test: the biomembrance of this test is inoculated biomembrance, after 22 days of operation, the removal rate of CODMn basically stable at 25%, while there is a good biological stability on surface of zeolite by microscopic examination, thus believe that the biomembrance is successful; the removal rate of iron and manganese is about 40%; hydraulic loading on the impact of iron is large than manganese; the temperature range of the high removal rate of iron and manganese is 10~15℃; ferrous ions had a role in the removal reaction of manganese, but not with growth of concentration of ferrous ions, the removal of manganese increased, the concentration of ferrous ions exists a critical value. Backwash cycle: 4 days. Backwash time was 10min, rinse strength: 10L/ (s.m~2). The removal of iron mainly happened in the filter layer above the range of 30cm, while the manganese was removed step by step along the filter layer.Ozone-Biological Zeolite test: the optimal dosage of ozone was 2.04mg / L, the best contact time of ozone is 10min; under the condition of the optimum process parameters, the maximum removal of iron rate by Ozone-Biological Zeolite increased by 26% than Biological Zeolite.The maximum removal rate of manganese increased by 30%. After the backwashing, the recovery of removal ability is fast, and there is strong resistance to changes in influent concentration.