The Effect Of Biochar On The Morphology And Passivation Of Mercury Contaminated Soil

Now mercury is a global pollutant, mercury in environmental pollution problem cause the attention of the scholars from all over the world, hard to soil microbial degradation of heavy metals, can exist in soil for a long time, however, remove the heavy metals in the soil need to spend a lot of manpower and material resources and financial resources. Biomass carbon is biomass in the anaerobic or anoxia environment under the condition of slow pyrolysis of carbon-rich organic material, and due to the highly aromatic carbon components with bio logical chemical and thermal stability. And biomass carbon has great specific surface area and adsorption capacity and abundant oxygen functional groups on the surface of the ion exchange reaction can effectively fixed heavy metals in the soil, improve soil condition, reduce the absorption of heavy metals by plants, the application of it will be open for repairing heavy metal contaminated soil in situ fixed and a potential new way.In this paper, we study the biomass carbon of chernozem soil adsorption, ina ctivation of Hg pollution.(1)When the mercury contamination of soil biochar application, can significantly increase the soil p H, biochar dosage 7%, p H value of up to 8.17, and the control CK(6.79) compared to, improved 1.38 p H units, significantly higher than the other deal with.(2)Applied in mercury pollution of soil into biochar, the total amount of mercury in soil increased significantly, to add 6 mg/kg of Hg Cl2, for example, when adding 7% biochar, the total mercury content in soil compared with no added biochar, up 35%, biochar to mercury pollutants passivation in the soil and translated into the inert form of not easy to be absorbed by plants.(3)The results of this study show that, in various forms of mercury in the soil, and the residue of mercury> Fe-Mn oxides bound Hg> organic form of mercury> carbonate-bound mercury> water soluble mercury and exchange biochar as a soil conditioner with a new improve soil physical and chemical properties, to reduce mercury biological in soil availability characteristics of heavy metals Hg by higher absorbed easily plant use active water soluble to easily be absorbed by plants inert residual and strong organic transition for heavy metals contaminated soil remediation has important potential applications.(4)Biochar applied in how much influence the change of the methyl mercury content in soil, to add 6 mg/kg of Hg Cl2, for example, when adding 7% biochar methyl mercury content in the soil with no added biochar fell by 20.9%, compared with methyl mercury wil l biochar intake increase and decrease, and biochar applied into the ratio, the greater the methyl mercury in soil increased the proportion of the smaller the greater.(5)Biochar will affect the leaching solution of mercury. To add 6 mg/kg of Hg Cl2, for example, when adding 7% biochar soil leaching solution content compared with no added biochar fell by 46.1%, the leaching solution in the mercury will be decreased with increasing the amount of biochar applied into the, and increased with the percentage of s hi into biochar, the Hg content in leaching solution increased the proportion of the drop.(6)Selected vegetables heavy metal hg content in root is about 2.3 times that of the heavy metal content in the leaves, leaf and root of the mercury decrease with the increased amount of biochar plowing, biochar into the content, the more the greater the p roportion of mercury content in plants to reduce. Biochar fixed in the soil of membership form make it into the inert form of active, thereby reducing the uptake of mercury in soil by plants. To add 6 mg/kg of Hg Cl2, for example, adding 7% biochar, the total mercury content in the soil than not to add biochar content increased by 22.25%, the total mercury content in plants than do not add biochar content decreased by 9.5%, mercury content in leaching solution than not add biochar content decreased by 10%. Biochar applied into the mercury pollution in the soil after fixed easily absorbed in the soil chemical form, into the inert form is not easy to be absorbed so that the higher content of mercury in the soil, the leaching solution and reduce the content of m ercury in plants, that biochar mercury can be solidified in the soil, thus reducing its biological effectiveness, makes the plants absorb the small amount of mercury, reduce the toxicity of soil. That biochar application has the characteristics of restoration and improvement of Hg contaminated soil.