摘要 |
PROBLEM TO BE SOLVED: To provide a processing method of selenium-containing effluent, which enables reduction of equipment cost and operation cost by making it possible to remove COD components and selenium in one tank.SOLUTION: The processing method of selenium-containing effluent removes selenium and COD components concurrently. In a reaction tank 1 are installed a contact reaction zone 9 provided with a contact reduction material 8 and a circulation path 4a for circulating selenium containing effluent by returning selenium containing effluent which passed through the contact reaction zone 9 again to the contact reaction zone 9. The pH in the reaction tank 1 is controlled in a range of 4 to 6. At an inflow part 4b where the effluent which passed through the contact reaction zone of the circulation path 4a flows in, an oxidizing agent is placed in order to oxidize the COD components. By doing so, redox potential is controlled within 0 to 200 mV at an outflow part 4c where effluent is discharged to the contact reaction zone 9 of the circulation path 4a, and the redox potential at the inflow part 4b is controlled within 200 to 300 mV. |