WASTEWATER TREATMENT APPARATUS

摘要

PROBLEM TO BE SOLVED: To enable precise anaerobic treatment in which granular anaerobic bacteria are not broken in a methane fermentation tank even when wastewater has a high DO concentration. SOLUTION: The apparatus is provided with a pH adjustment tank 1 in which wastewater is introduced, having a DO stripping part 4 and a methane fermentation reactor 3 connected with the pH adjustment tank 1. Biogas introducing piping 7 for sending biogas in the methane fermentation reactor 3 to the DO stripping parts 4 is connected between the upper part of the reactor 3 and the stripping part 4. The piping 7 is connected with a nitrogen gas supply source 6.