| Mercury is one of the global environmental pollutants, which is highly toxic and can migrate in the environment, with greater environmental risk, and is one of the problems of global pollution. At present, China’s mercury pollution is very serious, it is essential to seek an effective treatment method.With the serious situation of mercury pollution in our country, this paper hopes to find a kind of mercury enrichment ability of plants. By sampling survey in Fujian Dehua abandoned gold mines, Beijing Shijingshan steel mills and Guizhou Wanshan abandoned mercury mine, found that the mercury concentrations in soil of Fujian Dehua abandoned gold mine was 117.01 mg·kg-1, Beijing Shijingshan steel mills was 2.85 mg·kg-1, Guizhou Wanshan abandoned mercury mine was 158.44-517.45 mg·kg-1, with a single factor index method to get three places were severe pollution. Mercury content in plants, transport coefficient (TF), the enrichment factor (BCF), biomass and other indicators as screening criteria mercury enrichment plants, and eventually from Guizhou Wanshan abandoned mercury mine screened a large number of survival, growing well, large biomass, high levels of mercury, transport coefficient, enrichment capability mercury enrichment plant-Dryopteridaceae Cyrtomium Rhizome.Mercury enrichment plants pot experiment with mercuric chloride infected soil under laboratory simulation conditions such as artificial climate chamber. Studies have shown that the resistance to mercury concentration range of 0～500 mg·kg-1, which is the optimum mercury concentration of 25～50 mg·kg-1. Mercury have some impact on the physiological characteristics of Cyrtomium Rhizome and reflects the strength of the anti-stress capability. Experiments found that superoxide dismutase (SOD) activity increased at low concentrations and decreased at high concentrations, with the extension of time, the superoxide dismutase (SOD) activity began to decline; glutathione (GSH) content increases with the increase of the mercury concentration and time; proline content increase after the first decrease with the increase in mercury concentrations and as time increases the content of proline increased; malondialdehyde (MDA) content with the increase of mercury concentration and time showed an increasing trend. Cyrtomium Rhizome can still normal growth, indicating a strong anti-stress capability.The soil after aging and planting carried out the Tessier five-step extraction method morphological analysis found mercury speciation in the soil after aging the order was the ion exchange fraction> carbonate fraction> Organic bound> residual> Fe-Mn oxide bound, it show added mercuric chloride is mainly converted to ion exchange and carbonate bound; after planting the soil ion exchange and carbonate-bound dropped very significantly, indicating Cyrtomium Rhizome main absorption ion exchange and carbonate bound. It was found weak acid and a small amount of organic matter content are conducive Cyrtomium Rhizome absorb mercury, Basic and excess organic matter content is hinder the absorption, the optimum pH range of 6.24～6.85, the optimum organic matter content range of 1.79%～2.81%. By L9(34)orthogonal experiments:(1) the impact of mercury enrichment biggest factor for mercury concentration, followed by pH, organic matter with minimal impact; (2) the optimal growth conditions for mercury concentration 45 mg·kg-1, pH value of 6.35, the organic matter content of 2.52%. Cyrtomium Rhizome has strong mercury enrichment capability and can be applied to engineering practice test. |
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