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Takahashi, Shinya*; Inoue, Takanobu*; Tsushima, Koji*; Sakioka, Masamichi*; Matsunaga, Takeshi
Kankyo Kogaku Kenkyu Rombunshu, 46, p.565 - 572, 2009/00
This study analyzed the changes of water quality during rain events at Ijira river, a mountain stream in Gifu Prefecture, by measured the major ion concentration, pH, electric conductivity, discharge, and hydrograph separation using deuterium isotope ratio of the water. During rain events, where the discharge is increase, almost all of the major ion concentration, pH and electric conductivity were decreased. We also found that the correlation of the changes of pH and the changes of electric conductivity with precipitation were negative. The result of hydrograph separation shows that the ratio of surface runoff for discharge is increased with an increased of the precipitation, and also increased in the high precipitation. It was shown that the major factor of the changes of water quality in this study site is the contribution of surface runoff.
Takahashi, Manabu*; Tanaka, Kazuya*; Tamada, Masao; Aoi, Toru*
Kankyo Kogaku Kenkyu Rombunshu, Vol.41, p.229 - 235, 2004/11
Fibrous metal adsorbent having iminodiacetic acid was synthesized by radiation-induced grafting glycidyl methacrylate on nonwoven fabric and subsequent chemical treatment. The degree of grafting calculated by increasing weight after grafting reached 170 % for reaction time of 2h at 40 C. The adsorption characteristics of ferric and manganese ions were evaluated by using the resulting adsorbent with 2.1 mmol/g-adsorbent function group of iminodiacetic acid. Each distribution coefficient of ferric and manganese ion deceased with increase of another coexist ion. Both ferric and manganese ions were completely removed by the adsorbent column at the space velocity of 1000h. Adsorption capacities of both ions were reduced to 80% after 5 times reputation of adsorption and desorption.