|WANG Chun, LIU Jun, XIE Xin-miao, BAI Song, XING Xue-ke.Research on the Distribution of Dissolved Oxygen and Causes of Low Oxygen in the Surface Water of Nanjing：A Case Study of Qiqiaoweng in Waiqinhuai River[J].Environmental Monitoring and Forewarning,2022,14(3):63-69
|关键词: 溶解氧 时空分布 影响因素 低氧
|Research on the Distribution of Dissolved Oxygen and Causes of Low Oxygen in the Surface Water of Nanjing：A Case Study of Qiqiaoweng in Waiqinhuai River
WANG Chun, LIU Jun, XIE Xin-miao, BAI Song, XING Xue-ke
Nanjing Environmental Monitoring Center of Jiangsu Province, Nanjing, Jiangsu 210013, China
|A water quality survey was conducted on Nanjing and a National Surface Water Assessment Section Qiqiaoweng from 2018 to 2021, and the variation characteristics of dissolved oxygen (DO) were analyzed. By using the combined assessment of water quality and quantity as well as the Pearson correlation analysis and relevant hydrologic and meteorologic information, the causes of low DO in Qiqiaoweng section were analyzed in detail. The findings showed that the lowest DO in the surface water of Nanjing was observed in the summer, with a low concentration of DO in central downtown and its neighboring areas. The content of DO in Qiqiaoweng section ranged from 2.25 to 11.07 mg/L, with an exceeding fluctuation in the period from May to September. As the concentration of DO in the day was higher than that at night.Dissolved oxygen was positively correlated with pH, and negatively correlated with water temperature, permanganate index, ammonia nitrogen and total phosphorus. Water temperature and oxygen consuming pollutants brought by upstream water were the main causes for low DO in Qiqiaoweng. It is worth noting that the concentration of DO is most significantly correlated to water temperature. The research conclusion can provide a solid foundation for stably reaching the standard in Qiqiaoweng section, a technical basis for precise pollution control in Qinhuai River Basin, and a possible solution to the governance of simultaneous disposal of multi source water environment in Nanjing.
|Key words: Dissolved oxygen Spatial and temporal distribution Influencing factors Low oxygen