Phytoremediation In Soil Co-contaminated With Organic And Heavy Metals Pollutants

With the economic development, numerous soil sites are contaminated with high concentrations of heavy metals and organic pollutants, which affect normal agricultural practices. Remediation of sites co-contaminated with organic and metal pollutants is a complex problem. A potential strategy to remediate these soils is the use of plants to remove pollutants from the habitat or to render them harmless. Successful applications of plants for remediation of contaminated soils not only depend on the phenotype and genotype of plants, but are also of great importance. In this paper, phytoremediation efficiency of different plants to soils co-contaminated with organic pollutants and heavy metals and effect of different surfactants on efficiency of phytoremediation were discussed.(1)Remediation efficiency of different plants to organic pollutants and heavy metals was different. Sequence of prominent plants affecting the degradation of PCP were proved to be : sweet photo > rye grass > radish > ripe. However ,the four plants had high efficiency of remediation to pyrene. After 3 month's growth, the decrease's efficiency of pyrene was more than 90%. The extraction efficiency of Cu was low by maize, but the Elsholtzia splendens and Vetiveria zizanioides could highly distill the Cu.(2)When Cu existed with organic pollutants together, the decrease's efficiency of PCP or Pyrene was correlation with different plants and concentration of organic pollutans. The degradation of PCP could be inhibited by Cu(150,300mg/kg) in high concentration of PCP (100mg/kg) when the polluted soil was planted with rye grass and radish , but in low concentration the degradation could be induced. Sweet photo and ripe could not effect the degradation of PCP. The pyrene's degradation was similar to the PCP's in effect of Cu.(3) Organic pollutants affected on the extraction of plant to Cu. As the pyrene existed, the ability of extraction to Cu was weakened by maize. The phenanthrene inhibited Cu's extraction of maize more than pyrene. When the DCP, PCP and Cu compiled in Fuyang soil, the concentration of Cu in overground part of rye grass increased ,but the efficiency of extraction to Cu by maize decreased.(4) Extraction ability of chemical surfactants to heavy metal in polluted soil was studied.Distribution of Cu after extraction of "a" and "b"(chemical surfactants) was different. "A" and "b" could improve uptake and translocation of plant to Cu, but the "a" was adapt comparable with "b". Effect of different chemical surfactants on decreasing of pyrene in soil polluted with Cu and pyrene was experimented. Water solubility enhancements of Pyrene or PCP in solutions of single-surfactant and mixed-surfactant were studied. The results indicated that pyrene's dissolve by TritonX100 and SDS was enhance strongly, and low concentration of "a" to water solubility enhancements of pyrene was obvious. Low concentration of SDS, TritonX-100 ,a and b could disciplinary enhance water solubility enhancements of PCP. Mixed-surfactant SDS-Tritonx-100 positively appeared to be enhancement to pyrene. In the soil polluted by pyrene and Cu, the SDS and "a"(chemical surfactants) enhanced the extractable concentration of Pyrene., in which the effect of SDS on residual concentration of pyrene was more than "a". However, the extractable concentration of PCP was different from Pyrene when the chemical surfactants were induced the soils. Different type of soil affected the enhancement solubility of chemical surfactants. In the soil co-contaminated with organic and heavy metals , the extractable concentration of Cu was lower than in single-Cu polluted soil, and the chemical surfactants indistinctively affect on bioavailable concentration of Cu.