No.5（2002）23.Removal of nitrogen in wastewater by UV radiation and agent addition method

Yukio KOSAKA, Shigeru NAGASHIMA, Akira HASEGAWA and Kunihiko HIGASHI

The focus of the study was the removal of nitrate-ion and nitrite-ion in industrial wastewater by UV irradiation and the reagent addition method. The UV irradiation of the wastewater reduced the nitrate-ion to nitrite-ion. The reduction rate was higher where the pH is high. At pH 12, more than 95% of nitrate ion was reduced. Addition of amide sulfuric acid eliminated the nitrite-ion from the wastewater as nitrogen. More than 95% nitrite-ion was removed at a pH7 or less. Within a temperature rage of 15 to 30℃, the removal rate was the same. The process of treating wastewater is as follows. First, the pH of the wastewater is adjusted to pH12, Then UV rays are irradiated. Finally, the amide sulfuric acid is added, its pH having been adjusted to pH7 or below.

Keywords
Wastewater, Removal, Nitrogen, UV irradiation, Amide sulfuric acid

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