BIOLOGICAL DENITRIFICATION METHOD UTILIZING HYDROGEN GAS

摘要

PROBLEM TO BE SOLVED: To keep denitrifying capacity high even in the case of raw water having a high concn. of nitrate nitrogen or the like. SOLUTION: In a biological denitrifying method supplying hydrogen gas into raw water in a denitrification tank 12 when nitrate nitrogen or the like in raw water supplied into the denitrification tank 12 is biologically treated with denitrifying bacteria to be removed, the pH of raw water denitrified in the denitrification tank 12 is measured and, when the measured pH of treated water becomes a predetermined value or more, treated water is neutralized to be circulated to the denitrification tank 12.