Effects Of Environment-friendly Surfactant Alkyl Polyglucoside (APG) On Phytoremediation Of Soils Contaminated With Lead (Pb) And Polycyclic Aromtic Hydrocarbon (PAHs)

Contaminated soil often contains many pollutants which can do harm to theenvironment. These pollutants can coexist and interact with each other, increasingthe difficulty in remediation. This issue has attracted attention and become a focus inthe field of environmental science. This study assessed the potential abilities ofScirpus triqueter for phytoremediation of soils contaminated with Pb-PAHs,amended with environment-friendly surfactant alkyl polyglucoside （APG）. The mainresults and findings were summarized as following:（1） PAHs are solubilized by surfactant APG solutions. The solubilization isrelative to the concentrations of surfactants and the properties of organic solutes.There is a favorable linear relationship between apparent solubilities of PAHs andsurfactant. The solubilization of PAHs was slightly enhanced when dosages ofsurfactants were below their respective critical micelle concentration （CMC）.However, the solubilization of anthracene was dramatically enhanced when dosagesof surfactants were over their respective CMC.（2） In the enhancing of Pb in soil treatment, APG was effective to mobilize soilPb into soil pore water. But At low concentration range (0²0mg L^-1), promotingeffect is not obvious. APG could significantly increase the amount of soluble Pb.The amount of soluble Pb in soil is increased with the growing concentration of APG,especially when40mg L^-1surfactant were applied. Increased with the concentrationcontinues to rise, growth began to slow, and tend to balance.（3） Surfactant APG promoted PAHs biodegradation. With the surfactantconcentration increased, the biodegradation rate increased at first and then decreased.At low concentration range (0¹0mg L^-1), promoting effect is not obvious. Thebiodegradation rate reached maximum at a concentration of40mg L^-1. But thebiodegradation showed a gradual downward trend with larger concentration of APG.（4） Increasing APG concentrations from0to30mg L^-1increased both rootsconcentrations and RCF of phenanthrene in Scirpus tripueter. Further increases inAPG concentrations (30¹50mgL^-1) resulted in decreased root concentrations andRCFs.（5） APG has an ability to facilitate PAHs degradation at appropriateconcentrations. The highest removal rate of the PAHs was observed in40mg L^-1 APG treatment. The PAHs removal rate decreased to a certain extent whenhigh concentrations (100¹50mg L^-1) APG were added, but they were stillsignificantly higher than non-amended control treatments（6） APG has an ability to facilitate PAHs degradation and Pb uptake in the plantbody at appropriate concentrations (0⁴0mg L^-1). The highest PAHs removal rate wasobserved in30mg L^-1APG treatment, and the highest accumulation of Pb wasdetected as40mg L^-1APG. Meanwhile, too high concentration of APG would restrainthe degradation of PAHs and the uptake and translocation of Pb.（7）The effects of APG on soil enzymatic activities, community diversity,microbial community structure and soil microbial biomass were quantified to furtherexplore how the surfactant affects the pollutant removal. Experiments demonstratedthat in the presence of APG community diversity, aerobic bacteria/anaerobicbacteria and the activities of polyphenol oxidase, dehydrogenase and catalasematch exactly the pollutant removal.