The Study Of Correlation Between Mercury Speciation And Their Bioavailability In Soil

Mercury is one of the global environmental pollutants, due to its high toxicity and bioaccumulation, become one of the difficulties in heavy metal pollutants treatment in the environment. Mercury in soil environment, variety of different of formation, the environment of soil changed may cause the change of Hg migration, and release to the environment in different degree, environmental organisms in the absorption and accumulation of mercury in the body, and can transfer through the food chain, causing the amplification of toxicity. So the bioavailability of mercury in soil is particularly important for the control of environment mercury pollution, and to study the form of mercury in the soil and the form of mercury release rules, which in turn determine the influence of the occurrence form of bioavailability of mercury is the key.This paper aimed to mercury contaminated soil in region of tang yang ge in Quanzhou city of Fujian province caused by gold mining, screening different pollution level area, by using Tessier continuous extraction experiment to analysis the different form of Hg, and investigate the factors that effects of mercury form distribution in soil, the results showed:when NTSH dosage is0%～0.5%, valid mercury in soils fixed best, the proportion of ions mercury in soil decline largest, soil the average fixed-efficiency of valid mercury in soil reached88.3%, the average fixed efficiency for the four forms of mercury is26.1%. After different plants planting, organic bounds to soil and residue Hg increased of a certain degree, and less of the original ionic state ratio.Based on the results of mercury speciation analysis data, conducted indoor pot experiment and field pot experiment, indoor pot experiment choose three different kinds of plants:rape, wheat, and water spinach potted plant experiment, explore relationship between the different forms of mercury in soil and mercury content in the plants. The results show that plants uptake content and ionic mercury soil content in most relevant for oilseed rape and water spinach, and give the multiple linear regression equations between plant uptake and ions states, for wheat, due to the its special nature of rhizosphere, the root exudates activated residual and other difficult to use form, so there have a significant correlation between the residual mercury content and its uptake; Outdoor potted experiment, choosing water spinach, after NTSH added in soil water spinach uptake content of Hg decreased about15%, further evidence of the close correlation between the plants uptake and the valid state amount of mercury in soil. In addition, simulated various forms of mercury in soil, and after a certain time of aging, spinach pot experiment results show that the amount Hg uptake by water spinach related to content of the of activity form mercury in the soil, uptake of mercury in sulfide combine soil is the weakest, uptake of mercury in calcium carbonate combined is the most obvious.