3:30 PM - 4:45 PM
[AHW16-P10] Transportation mechanism of trace elements from river to the inside of paddy rice in river water system
Keywords:toxic trace element, rice, river, colloid, Mt. Yatsugatake, Mt. Asama
From the correlation between major elements and toxic trace elements, it is inferred that Fe-colloid works as an attracter due to sorption to trace elements in a river. In paddy field, some trace elements are likely to precipitate with Fe-colloid, and other trace elements in water-soluble state can infiltrate into soil. The following conclusions are obtained: 1) The toxic trace elements in river waters are with compatible major attracter elements; (a) Fe-colloid for (Cr, Cu, Ga, La, Zn, Cs, U) and (Ti, Al, Mn) in Mt. Yatsugatake area, (b) Fe-colloid for (Cr, Cu, Zn) and (Al) in Mt. Asama area, 2) (a) No attractor for (Se, Rb, Sr) in river water in Mt. Yatsugatake area, (b) No attractor for (Se, V, Ga, Ge, Sr, Y, Cs, Ba, La, U) and (Mn, Ti) in river water in Mt. Asama area. And 3) (As, Cd, Mn, Ni, Sb, Sr, Zn) are transported with Fe from root to shoot in paddy rice, while (As, Co, Mn, Sr, Zn) are transported with Fe from shoot to grain in paddy rice, and (Sr, Zn) are transported with Fe from shoot to leaf in paddy rice. Especially, we conclude that As is transported with Fe from root to grain through root in paddy rice.
From the described above, it is modeled that first, Fe-colloid works as an attractor of trace elements, transporting them to paddy fields, second, Fe works as a transporter of trace elements from root to shoot, however, from shoot to leaf, and from shoot to grain, some trace elements are transported and deposited in separating from Fe.