CHANGE IN NICKEL BEHAVIOUR DURING PHENANTHRENE REMOVAL BY BIOAUGMENTATION

摘要

Although many studies of PAH degradation in soil have been performed, little attention has been paid to the effect of the removal of organic contaminants on metal speciation. Researchers are beginning to recognize that the total metal in soil embraces large fractions, which are unavailable to plants or soil microorganisms (Zhang et al., 2001). Assessments of the metal availability in soils need to consider solution speciation, mobility and the kinetics of exchange between solution and solid phase. In this study, we used the Diffusive Gradients in Thin-films technique (DGT) to measure cadmium mass in soil solution during the bioremediation process by bioaugmentation. This technique is able to quantify potentially bioavailable metal species. We found that microbial activity in soil during phenanthrene removal increased the nickel mass in soil solution. The results are important for understanding metal behaviour in soil subsequent to bioremedation. Additionally, the results indicate the complexity of these environmental systems with a reduction in one pollutant resulting in a increased load of another pollutant. Consideration of such processes facilitates the choice of the best overall option for pollution remediation.