DOMESTICATION AND MULTIPLICATION OF SULFUR OXIDIZING BACTERIA BY ADDITION OF INORGANIC COAGULANT AND BIOLOGICAL TREATMENT OF WASTE WATER CONTAINING REDUCING SULFUR COMPOUND

摘要

PURPOSE:To effect the domestication and multiplication of sulfur oxidizing bacteria for oxidizing a reducing sulfur compound and a highly efficient biological treatment of the waste water contg. the reducing sulfur compound. CONSTITUTION:An active sludge for treating sewage and industrial waste water is introduced into an aeration tank. The domestication and multiplication of sulfur oxidizing bacteria is accelerated by supplying the waste water contg. a reducing sulfur compound and an inorg. coagulating agent into the aeration tank, with the aeration tank kept in the pH range of 4.0-7.5 and while adjusting ORP to the value obtained by calculation from the free energy variation DELTAG0 taking place when the reducing sulfur compound is chemically oxidized into a sulfuric acid compound. The waste water contg. the reducing sulfur compound is thereafter treated with the sulfur oxidizing bacteria. The aforesaid methods effect the domestication and multiplication of the sulfur oxidizing bacteria in a short period of time and obviate the need for a complicated treatment such as pH adjustment of the waste water and for the provisions of acid resistance to the waste water treating equipment, leading to a considerable reduction in the construction costs of the waste water treating facilitates and in the treating costs.