Phytoremediation Of Heavy Metal Polluted Urban Sewage River Sediment

Six kinds of plant were selected, they are Zea mays varrugosa Bomaf, Brassica juncea L, Lolium multiflorum Lam, Festuca arundinacea, Brassica juncea and Scher Medicogo sativa. Pot experiment was conducted to study phytoremediation efficiency of heavy metal contaminated sewage river sediment by three designed different treatment levels. They were plant, plant-indigenous bacteria and plant- AMF epiphyte. In order to determine the best combination of repair method and repaired conditions, the number of different periods of soil microorganisms, enzyme activity, and heavy metals concentration were monitored during the growth of the plants. PCR-DGGE was also used to analyse the diversity of bacteria and fungi in rhizosphere sediments.Phytoremediation makes the total heavy metals in sediments and major forms changes a lot. Total heavy metals decreased more. Zea mays varrugosa Bomaf and Brassica juncea, Lolium multiflorum Lam and Festuca arundinacea were two kinds of interaction that have the higher efficiency of 15% for heavy metals accumulation. In these two kinds of interaction the repaird effect of treatments by plants and indigenous bacteria or AMF epiphyte is better than the blank control, so they are the most suitable plants for the inoculation of sediment restoration. The experimental results indicated that Zea mays varrugosa Bomaf interacted wiht AMF or bacteria are the best repair combination.After the phytoremediationby different plant and different treatments concentration of heavy metals in sediments decreased and evident changes have took place in the amount of bioavanability form of heavy metal. The change of rhizosphere environment and concentration of heavy metals have great impact on populations of rhizosphere microorganisms such as bacteria and fungi increasing nearly 100 times.compared with environment bacteria and fungi. The significant change in the rhizosphere is the fungus. The activity of urease, polyphone oxidizes and dehydrogenises can reflect the pollution degree of and the repaired effect heavy metal in sediments. Urease activity has the fastest restore speed during the phytoremediation process. Dehydrogenises can reflect plants healthy quickly.PCR-DGGE was used to analyzed the diversity of bacteria and fungi in rhizosphere sediments. Specific bands were rebacked, sequenced and analyzed in NCBI. Evolutionary trees of the sequencing bands were establishedin order to reveal the taxonomic status of each band. It can be seen that most of the bands have high comparability with non-cultured strains.