PRODUCTION AND EMISSION OF NITROUS OXIDE FROM RIVERS IN URBAN AND AGRICULTURAL AREAS

Abstract

Nitrous oxide (N₂O) fluxes and concentrations were measured in the rivers placed in urban and agricultural areas in Kanto and influencing factors were determined. The highest concentration of N₂O (20.3 μgN/L) was detected in the river where high concentration of nitrate, around 20mgN/L, was found. The 8 years ago survey at the same river indicated that high organic materials influenced on N₂O production. However, nitrate becomes current influencing factor due to improvement of water quality after river reconstruction. The batch experiments using water and sediment of the river also indicated that organic materials and nitrate are important factors influencing on nitrous oxide production.