WASTE WATER TREATMENT EQUIPMENT FOR RECYCLING WATER IN SURFACE TREATMENT USING TRIVALENT CHROMATE, AND WASTE WATER TREATMENT METHOD FOR RECYCLING WATER

摘要

PROBLEM TO BE SOLVED: To solve a problem that a structure having a galvanized material coated with the hexavalent chromate and a trivalent chromate is generally adopted in a method of using a hexavalent chromate in plating treatment for vehicle parts, but there is the case in which the hexavalent chromate dissolves in relation to temperature and humidity, which requires an urgent measure, and there are issues of a health hazard to a human body and the deterioration of parts, for instance.;SOLUTION: This waste water treatment method is a method for recycling water in the surface treatment which includes subjecting an article to a plating pretreatment of alkaline degreasing pretreatment and galvanizing pretreatment and finishing the resultant article by trivalent chromate post-treatment. A pH balancing tank, a flocculation tank, a filter device, a neutralizing tank and the like are arranged for the alkaline degreasing pretreatment. A pH balancing tank, a flocculation tank, a precipitation device/a filter device, a neutralizing tank and a storage tank for a returned liquid are arranged for the galvanizing pretreatment. The method of treating the waste water in the trivalent chromate post-treatment includes: the first step of passing the waste water through a washing and storage tank for the trivalent chromate and a concentrating device, and the second step of passing the waste water through a washing and storage tank for the trivalent chromate, a cartridge filter/an RO device and an ion exchange tower, according to the concentration of the waste water.;COPYRIGHT: (C)2010,JPO&INPIT