Study On Phytoremediation Technology Of DDT-contaminated Soil

In this dissertation, DDT-contaminated soil is taken as the research object, which is treated by phytoremediation technology. Better prothetic plants and appropriate adjustment measures that can be used to promote the plants removing DDT in the soil are selected through the results of this study. Finally the best combination of plant and adjustment measures has been carried out through in-situ remediation. The results could be summarized as follows:1. The remediation abilities of Lolium perenne L, Festuca arundinace and Medicago sativa L are studied. The results show that: Lolium perenne L has the best removal rate that ranges from 53.19% to 65.04%. Festuca arundinace is the second one, which has the removal rate ranging from 39.03% to 60.55%. And Medicago sativa L is the last one with the removal rate ranging from 30.47% to 58.71%. Lolium perenne L is supposed to be the best remediation plant because of its high removal capacity, vigorous growth and tremendous biomass.2. The results of the study on adjustment measures show that compound fertilizer has better effect than Plant growth promoting rhizobacteria on promoting plant biomass. Compound fertilizer can be used as an adjustment measure to take into the next study. Staphylococcus pasteuri is better than Agrobacterium tumefaciens in promoting plant removal rate. Staphylococcus pasteuri can be used as an adjustment measure to take into the next study.3. The best combination of plant and adjustment measures is Lolium perenne L+Compound fertilizer+Staphylococcus pasteuri, and the removal rate of the best combination could reach up to 69.60%. DDT-degrading microbe could promote Phytoremediation. Because of the high removal capacity, the vigorous growth, the tremendous biomass and the nethermore residual quantity, Lolium perenne L+Compound fertilizer+Staphylococcus pasteuri can be used as the best combination.4. The best combination of plant and adjustment measures are taken to remediation of DDT-contaminated soil in situ. And DDT degrading-microbe could be as a strengthening measure to remediation. The results show that the removal rate of the treatment of Lolium perenne L+Compound fertilizer+DDT degrading-microbe+Staphylococcus pasteuri could reach up to 66.24%. In a certain extent, the research of this experiment could support the theories and dates for remediation DDT-contaminated soil.