| 摘要 |
PROBLEM TO BE SOLVED: To easily reduce the concentration of nitrite ions in wastewater.SOLUTION: A metal oxide, which can convert nitrite ions in an aqueous solution into nitrate ions, is brought into contact with an aqueous solution containing at least nitrite ions. The metal oxide preferably is one or more kinds of metallic oxides selected from molybdenum, tungsten, nickel, silicon and aluminum. In addition, zeolite or molybdenum oxide can be suitably used as the metal oxide. The ratio of silica to aluminum contained in zeolite preferably is in the range of 10 to 1000 and cations contained in zeolite preferably are protons.SELECTED DRAWING: Figure 1 |
