METHOD AND APPARATUS FOR BIOLOGICAL DENITRIFICATION

摘要

PROBLEM TO BE SOLVED: To provide a biological denitrification method that permits a simple economical execution of supply control of reductant.SOLUTION: A method is intended for biologically reducing and denitrifying oxidation state nitrogen in liquid containing oxidation state nitrogen in a denitrification process of biofouling carrier filling type by injecting reductant into the liquid. The method includes measuring turbidity of the liquid after subjected to denitrification treatment, and adjusting the amount of injection of the reductant in the denitrification process on the basis of the measured value.