DRAIN TREATING DEVICE

摘要

PROBLEM TO BE SOLVED: To effectively remove nitrogen in a drain containing calcium and nitrogen. SOLUTION: The drain containing calcium and nitrogen is admitted into a fixed bed nitrification tank 10 and is subjected to nitrification treatment. An alkal agent is injected to plural points from an alkaline agent tank 14. Places where the pH of packing materials 30 for holding the microorganisms rises are dispersed to prevent the formation of scale. Changing of the places, where the agent is injected, temporally is also adequate.