TREATING APPARATUS OF WASTE WATER CONTAINING HEAVY METAL UTILIZING ACTIVATED SLUDGE

摘要

PURPOSE:To insolubilize heavy metals and to perform treatment with high efficiency by providing an anaerobic tank for raising sulphate-reducers by introducing waste water from a reaction tnak for generating sulphide, and a circulation line for circulation H2S generated in the anaerobic tank. CONSTITUTION:Waste water is introduced into a raw water tank 17 where it is stirred with gaseous H2S fed from a gas dispersing pipe 17a. Heavy metals in the waste water react with H2S to form sulphide as insoluble deposit. A part of the waste water which has caused reaction in the raw water tank 17 is introduced into an anaerobic tank 18 through a connecting pipe 19 without performing solid/liquid separation, and is mixed with sulphate-reducers in the tank together with returned activated sludge returned from a returned sludge pipe 13a. Generated gas is liberated through a gas dispersing pipe 18a, and the waste water is treated anaerobically at ca. 30 deg.C and at ca. 7pH. Generated gaseous H2S is sent to the gas dispersing pipe 18a and utilized through a gas pipe 18b for stirring, and then, transported further to the raw water tank 17 through a gas pipe 18c and utilized for the reaction with heavy metals.