Wang Qi-chao

Distribution of mercury in typical wetland plants in the Sanjiang plain

Total mercury concentration of typical wetland plants was analyzed in this paper. There were great differences of total mercury concentration among different plants: moss>hydrophyte>segde>herbage>shrub. Total mercury concentrations show an increasing trend from vascular plants to bryophytes, and from dry to wet lands. The mercury concentration of wetland plants was higher than that of crops. The wetland soil was the source of mercury in the air close to the ground, so it affected the concentration of mercury in the plant. In different parts of a plant, mercury concentration was in the order of: dead stand>root>leaf>stem. Mercury concentration increased at the initial stage and decreased in the end of the growing season. According to the mercury content and biomass, mercury stock of plants was 39.4µg/m2 above ground in Calamagrostis angustifolia wetland and 35.8µg/m2 and Carex lasiocarpa wetland.

ESTIMATION OF ATMOSPHERIC INPUT OF MERCURY TO SOUTH LAKE AND JINGYUE POOL

Taking South Lake and Jingyue Pool in Changchun as examples, we determined particulate Hg in ambient air and Hg concentration in precipitation. Results indicated that particulate Hg in air and Hg concentration in precipitation in both sites in nonheating period were lower than that in heating period, which is influenced by coal combustion. The annual particulate Hg concentrations of South Lake and Jingyue Pool were 0.254ng/m3 and 0. 109ng/m3. The yearly average Hg concentrations in precipitation were 0.268µg/L(South Lake) and 0.108µg/L(Jingyue Pool). The higher particulate Hg concentration in air and Hg concentration in precipitation in South Lake than that of Jingyue Pool indicated that mercury deposition was influenced by anthropogenic sources (especially from coas combustion). Hg concentration in precipitation is related with particulate Hg in the atmosphere. Dry deposition fluxes were estimated by using dry deposition model on the base of particulate Hg concentrations in the atmosphere, they were 35.5µg/(m2. a) for South lake and 15.3µg/(m2. a) for Jingyue Pool. Combined with precipitation amount, wet deposition fluxes were estimated in these two sites, 152.2µg/(m2. a) for South Lake and 6.1.2µg/(m2. a) for Jingyue Pool. Atmospheric Hg deposition fluxes were 160.2g/a for South Lake and 328.62g/a for Jingyue Pool.