Effects of alkyl polyglucoside (APG) on phytoremediation of PAH-contaminated soil by an aquatic plant in the yangtze estuarine wetland

This research evaluated the effects of alkyl polyglucoside (APG), an environment-friendly surfactant, on the removal of anthracene (ANT), phenanthrene (PHE), and pyrene (PYR) from the soil cultivated with Scirpus triqueter, an aquatic native pioneer plant in the Yangtze estuarine wetland, China. Soils spiked with about 200 mg kg^-1 of ANT, PHE, and PYR were individually irrigated with 0, 10, 20, 30, 40, 50, 100, and 150 mg L ^-1 of APG. Plant biomass yields, polycyclic aromatic hydrocarbons (PAHs) removal rates, soil microbial, and soil enzyme activities were quantified after 90 days' cultivation of Scirpus triqueter. Experiments demonstrated that APG has an ability to facilitate PAHs degradation at appropriate concentrations. The highest removal rate of the PAHs was observed in 40 mg L^-1 APG treatment, and the removal rates increased 23, 54, and 52 %, respectively, compared to the non-amended control pots. However, the PAHs removal rate decreased to a certain extent when high concentrations of APG were added. The effect on PAHs removal in the soil could be explained by the changed levels of plant biomass, soil microbial populations, and soil enzymatic activity affected by the APG. The results suggested that the use of Scirpus triqueter combined with APG was an effective means for the phytoremediation of the PAH-contaminated soil. At the same time, APG's optimal concentration should be determined before the application in the PAH-contaminated wetlands.