A Preliminary Study on N₂O Production through Nitrification in Lake Kizaki

Abstract

In the hypolimnion of Lake Kizaki, an increase of N₂O concentration was observed with time, concomitant with an increase of NO₃^- concentration and a decrease of oxygen concentration. In addition, the amount of apparent N₂O production (ΔN₂O) was found to be linearly correlated with that of apparent oxygen consumption (-ΔO₂). These facts suggest that N₂O was produced during the process of nitrification in the hypolimnion of Lake Kizaki. The mole fraction of ΔN₂O/-ΔO₂was found to be 2.7×10^-4, consistent with the value of 1.0×10^-4, obtained by YOSHINARI (1976) in the western North Atlantic Ocean.