利用高效溶磷菌钝化修复铅污染土壤效果及其影响因素研究

利用高效溶磷菌的溶磷特性对受铅污染土壤展开修复研究,研究了菌液添加量与土壤全磷含量对重度污染土壤修复效果的影响。通过测定有效磷含量、有效态铅含量、pH等指标变化,结合X射线衍射法(XRD)分析土壤物相变化,初步研究了溶磷菌的钝化机制。当目标溶磷菌发酵菌液的添加量达到150mL/kg时,目标菌可有效在土壤中存活;当土壤全磷含量达到1g/kg时,经过钝化培养可将土壤有效态铅含量降至4mg/kg、土壤中有效磷含量增加至19mg/kg。对钝化后土壤Pb形态分析表明,在目标溶磷菌作用下,土壤中Pb由可交换态、碳酸盐结合态向残渣态转变,XRD分析结果表明残渣态主要为氯磷酸铅盐化合物(Pb_5(PO_4)_3Cl),是Pb在土壤中最稳定的化合物之一。

The passivation effect and influencing factor of Pb contaminated soil by phosphorus solubilizing bacteria

Bioremediation research of Pb-contaminated soil was studied by the P-solubilizing characteristic of phosphate solubilizing bacteria, The effect of theSfermentation liquid added amount and total phosphorus content of soil on the soil bioremediation was studied, the mechanism of lead immobilization was studied preliminary by determining the content of olsen-p, NH4NO3 extractable Pb and pH, combined with the results of X ray diffraction analyses. When the added content of target bacterial fermentative solution reached 150ml/kg, the target bacteria can survive in the soil; when the soil total phosphorus reached 1g/kg, the content of NH4NO3 extractable Pb reduced to 4mg/kg and the content of olsen-p increased to 19mg/kg; the analysis of lead speciation indicated that a shift from the exchangeable fractions and carbonate bound lead to residual lead, the results the of XRD analysis showed that the pyromorphite (Pb5(PO4)3Cl) was the main product of residual lead, which is one of the most stable compounds of Pb in soil.