| With the speeding up of urbanization and the development of urban sewage treatment,urban sludge production increases dramatically. Because of lack of reasonable andeffective management methods and the disposal technology, a lot of city sludge can onlybe temporary piled up, the resulting secondary pollution to the environment having broughtgreat harm. Produced in the process of mining, tail ore mostly be piled up everywhere. Itnot only takes up a lot of land, the long-term piling up may also result in pollution of theenvironment. What’s more, existing research shows that polycyclic aromatic hydrocarbons(PAHs) pollution from urban sewage sludge is not solved so that may lead to dangerous.Based on this, consider the comprehensive utilization of sludge and tail mineral sand andphytoremediation, in order to solve the waste and the problem of pollution. However,related studies are rarely reported. Based on this, for the comprehensive utilization ofsludge and tail mineral sand, use plants to repair the existing sludge and tail ore miningarea of PAHs pollution, to guide the mining area ecological environment recovery andprovide scientific theoretical basis to reduce sludge pollution of polycyclic aromatichydrocarbons, which has important practical application value.Choosing Awnless Brome and Alfalfa, carrying out pot experiment in greenhouse,applying gas chromatography-mass spectrometry(GC-MS) and Polymerase ChainReaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) techniques, the studystudied the resistance and tolerance of plants for PAHs in sewage sludge, plant rhizosphereenzymes activity, bacterial species diversity, and repairing effect of PAHs in the sludge,after different ratio combination with the tail ore.The main results are shown as fo11ows:1. The resistance and tolerance of plants for sludge PAHs in different treatments.With the increase of sludge PAHs, biomass and plant height of Awnless Bromeincreased gradually. And Alfalfa in high concentration of polycyclic aromatichydrocarbons(PAHs) was significantly inhibited. Awnless Brome had better resistance andtolerance for sludge polycyclic aromatic hydrocarbons (PAHs).2. Effect of removal and bioaccumulation sludge PAHs with Awnless Brome and Alfalfa In sludge treatments with Awnless Brome, the removal efficiency of total PAHs wasin the range of64.6%~84.3%. The biggest was84.3%, and the accumulated contributionrate of plants accounted for only1.68%. BaA、Flu and Pyr had higher removal rates thanothers in almost all treatments. In sludge treatments with Alfalfa, the removal efficiency oftotal PAHs was in the range of21.76%~77.21%. The biggest was77.2%, and theaccumulated contribution rate of plants accounted for2.13%. DbA had highest removalrates than others in all treatments, which was in the range of91.20%~97.72%. Thenbioaccumulation factor(BCF), the biggest BCF with Awnless Brome was12.95, while thebiggest BCF with Alfalfa was3.77.The best combination for Awnless Brome was100%sludge with no tail sand while itwas50%sludge with50%sand for Alfalfa.3. The study of influence mechanism for sludge PAHs in different treatments.For Awnless Brome and Alfalfa, single and total PAHs was significantly positivelyrelated with root zone enzyme activity basically. Different monomer PAHs in root zoneshowed different degrees of antagonistic or synergistic effects to enzyme activity.For Awnless Brome, the root zone microbial flora was the most with1822μg/kgsludge PAHs. While,it was most with1372μg/kg sludge PAHs for Alfalfa. There werespecific microorganisms of high sludge PAHs treatments both with Awnless Brome andAlfalfa. |
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