MENG Fanfei1, YANG Cheng1, PENG Yan1, GUO Yun1, LI Tingting1, YUAN Ju2, WANG Zhikang1
(1. College of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang 550025, China;
2. Guizhou Zhuxin Water Service＆Environmental Industry Co. Ltd., China Water Environment Group Co., Ltd, Guiyang 550007, China）
Abstract: Dissolved nitrogen and phosphorus, proportion of different dissolved nitrogen components, and the variation of NH4+-N, NO3--N, dissolved organic nitrogen (DON), dissolved total nitrogen (DTN), and dissolved total phosphorus (DTP) in waters along five inflow rivers of Aha reservoir in Guiyang city were studied systematically in dry season. The results showed that concentration of dissolved nitrogen and phosphorus in five inflow rivers varied greatly, with average of 1.71-9.74 mg/L and 0.03-0.52 mg/L for DTN and DTP, respectively. Caichong river, Lannigou river, and Jinzhong river were greatly influenced by human activities, and had higher DTN and DTP concentrations. The proportion of different dissolved nitrogen components varied significantly in rivers, and was dominated by DON in Youyu river and Baiyan river that less affected by human activities, and the DON/DTN ratio reached up to 94%. However, dissolved inorganic nitrogen (DIN) was the main form of dissolved nitrogen in Caichong river, Lannigou river, and Jinzhong river. The nitrogen and phosphorus concentration fluctuated remarkably from upstream to downstream in different rivers, and the loading from man-made sources was much higher than that of natural sources. The annual input of DTN and DTP from Jinzhong river to Aha Reservoir was 97.03 t/a and 46.64 t/a, respectively, which contribute the most DTN and DTP inputs among inflow rivers, with a contribution of 45% and 66% to total input, respectively.
Key Words: Aha reservoir; inflow rivers; dissolved total nitrogen; dissolved total phosphorus; karst area
EARTH AND ENVIRONMENT Vol.48, No.5, Tot No.337, 2020, Page 612-621
