Relationship between Gu(II) sorption and active H+ sorption sites of soils

Abstract

Sorption characteristics of Cu(PI) were investigated using six soils coPBected in Korea (JUF9 SUM, and HHM) and in Japan (HNG, TWD, and ISM). The Cu(IH) sorption amount increased with increasing initial Cu(II) concentration. The maximnm sorption amount of @u(PI) increased in the order of KHM< ISK< JUM < JUF < TWD < KNG, and was related to the pH and BZSE of soils. The H+ release curves due to Cu(II) sorption apparently were characterized by a two or three step pattern. The amount of H+ released due do Cu(II) sorption increased with the increase in the Cu(II) sorption amount. The amount of protons released per Cu(II) sorbed onto soils with a larger Gu(II) sorption amount tended to be smaller compared with soils with a smaller Cu(HHQ sorption amount. The W+ sorption amount of the original soils and those with Cu(II) sorption at the PZSE, which was referred to as σP (Sakurai et al. 1988: Soil Sci. Plant Nutr., 34, 171–182; 1996: Jpn. J. Soil Sci. Plant Nutr., 67, 32–39), was determined by the STPT method proposed by Sakurai et al. (4988: Soil Sci. Plant Nutp., 34, 171–182). The active H+ sorption sites of soils were used for Cu(II) sorption and their amount decreased after Cu(II) sorption because they were covered with Cu(II). Soils with a larger amount of active H+ sorption sites exhibited a higher aEamity to Cu(II) khan those with a smaller amount of active H+ sorption sites. The Cu(II) sorption created a positive charge in soils, causing the decrease in the amount of active H+ sorption sites.