Kakishima Hayato, Kagamu Ayaka, Ebie Yoshitaka, Yamazaki Hiroshi
Course of Architecture Civil and Environmental System Design, Toyo University, 2100, Kujirai, Kawagoe-shi, Saitama 350-8585, Japan.
NJS Co., Ltd, 1-1-1, Shibaura, Minato-ku, Tokyo 105-0023, Japan.
Water Sci Technol. 2025 May;91(9):1022-1031. doi: 10.2166/wst.2025.055. Epub 2025 Apr 22.
Treated sewage water flowing into rivers contains nitrogen (N) compounds, producing nitrous oxide (NO) through nitrification and denitrification reactions. In Japan, environmental reference values have been set for water quality for various locations within waterways, and these are classified into six different categories based on the level of water quality. This study aimed to refine the NO emission factor originating from treated sewage water by conducting year-round research on the production of dissolved NO in rivers with varying concentrations of organic matter, N, and dissolved oxygen. There were differences in the NO emission factor derived from the nitrification reaction of ammonium (NH)-N due to the impact of N pollution load caused by the inflow of treated sewage water into rivers with different water qualities. The calculated NO emission factor for rivers with relatively high water quality concentrations was 0.0028 kgNO-N kgNH-N, and the calculated average NO emission factor originating from treated sewage water in rivers was 0.0026 kgNO-N kgNH-N.
流入河流的经处理污水含有氮（N）化合物，通过硝化和反硝化反应产生一氧化二氮（NO）。在日本，已针对水道内不同地点设定了水质环境参考值，这些参考值根据水质水平分为六个不同类别。本研究旨在通过对不同有机物、氮和溶解氧浓度的河流中溶解态NO的产生进行全年研究，来完善源自经处理污水的NO排放因子。由于不同水质的河流中流入经处理污水导致的氮污染负荷影响，源自铵（NH）-N硝化反应的NO排放因子存在差异。水质浓度相对较高的河流计算得出的NO排放因子为0.0028 kgNO-N/kgNH-N，河流中源自经处理污水的计算得出的平均NO排放因子为0.0026 kgNO-N/kgNH-N。
