| Budget Amount *help |
¥4,010,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥510,000)
Fiscal Year 2007: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
Fiscal Year 2006: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Research Abstract |
In order to investigate the behavior of the pollutants in wetlands, the concentrations of trace metallic elements (REEs, Th, U), polycyclic aromatic hydrocarbon (PAHs), and oxygen stable isotope ratios (i.e., δ^(18)O) etc. in environmental samples were measured. In this study, laboratory model experiments regarding the uptake or adsorption of pollutants were also carried out. Consequently, the following matters have been mainly clarified.
(1) The concentrations of REEs, Th, U in precipitation increased in spring and the quantity of PAHs deposition and concentration increased at mountains area in winter. In addition, δ^(18) O of precipitations was the smallest in rainy season. The atmospheric concentrations of PAHs generally decreased at urban region in spring, and increased at mountains area in winter.
(2)δ^(18) O of sample waters in Sakata lagoon was larger than that of other environmental waters in Niigata Prefecture, and was especially large in summer. It can be closely related to the biological process such as the activity of Crustacea plankton and to the recharge from surrounding groundwater as well as the effect of evaporation.
(3) The concentration of REEs in seaweed species were about 10^2-10^3 times higher than those in seawater and the enrichment factor of REEs was larger in heavy REE than light REE. The concentration of U was large in brown algae, especially highest in Undaria pinnatifida.
(4) Cr(VI) was reduced to Cr(III) by humic substances; moreover, the reduction ability of humic substances decreased with increasing pH. The complexation of Cr(III) proceeded faster than the reduction of Cr(VI) and reached a maximum at pH 5.
(5) The method of hydrogen isotope exchange reaction used in this work is useful for evaluating influence of T on environment, and the actual analysis of some materials can be possible using both the MOPAC and the A "-McKay plot methods.
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