報文
天野川の塩基性化が微量金属の溶存状態に及ぼす影響
2016 年 50 巻 3 号 p. 227-241
詳細
2016 年 50 巻 3 号 p. 227-241
High pH values of 9.65 and 10.1 were observed in the Amano River, Osaka Prefecture in 2013 and 2015. On the other hand, the high pH values were not recorded in 2014. This basification was observed under conditions of high water temperature and high dissolved oxygen concentration. From the results of pH, dissolved oxygen, nitrate+nitrite, phosphate and total alkalinity, we confirmed that this basification might be due to decrease of carbon dioxide by photosynthesis in the Amano River. The changes of pH value in the river water might be affect the speciation of trace metals. Concentrations of dissolved species of aluminum, chromium and copper were increased with increase of pH value, while those of dissolved species of nickel and zinc were decreased with increase of pH value. From the positive correlation between the relative fluorescent intensity of dissolved organic matter and the concentrations of nickel and zinc we confirmed that these elements might be dissolved as metal-fulvic acid complex within the observed pH range.
