TREATMENT METHOD OF FACILITY WASTEWATER FROM HOT-DIP GALVANIZED STEEL SHEET MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To provide a treatment method of facility wastewater from hot-dip galvanized steel sheet manufacture which can reduce the amount of acid necessary to neutralize an alkaline wastewater and achieve the cost reduction and the space saving of the treatment facility. SOLUTION: Thick system acid wastewater, thin system acid wastewater and thin system alkaline wastewater are processed through the process of introducing thick system acid wastewater, thin system acid wastewater and thin system alkaline wastewater into a raw water tank 1; a first neutralization process of adjusting the wastewater from the raw water tank 1 to acid water of pH2.5-3; the second neutralization process of generate an insoluble material by adjusting the acid water from the first neutralization process to pH6-11; the flocculating process to flocculate the insoluble material which was generated in the second neutralization process; the solid-liquid separation process of separating the flocculated matter from the treated water as sludge in the flocculating process; and the alkaline sludge return process of adding the alkali to a part of the sludge separated in the solid-liquid separation process and return it to the second neutralization process. COPYRIGHT: (C)2009,JPO&INPIT