Nitrate nitrogen denitrification substrate and its substrate

摘要

PROBLEM TO BE SOLVED: To simply start more rapid denitrification by allowing a flame- retardant material to coexist with the material comprising primarily of calcium and/or magnesium carbonate and sulfur and making them the granular material or the bulk material solidified bu using the sulfur as a binder. SOLUTION: The nitrate nitrogen denitrification substrate is constituted of the granular material or the bulk material obtained by allowing the flame- retardant material to coexist with the material comprising primarily of calcium and/or magnesium carbonate and sulfur and solidifying the mixture by usig the sulfur as the binder. However, when the carbon source concerned to denitrifying bacteria synthesis exists sufficiently in the water to be treated, a flame- retardant and alkaline material and the sulfur are used as principal components in spite of the calcium and/or magnesium carbonate. When the replenishment of iron in the water to be treated is required, iron and/or an iron compd. are allowed to coexist to form the same composition. The composition in which bacteria or microorganisms are used for the denitrification is obtained by applying rupture surface/cut surface/scratched surface, etc., to the composition.