Growth and physio-biochemical responses of Vetiveria Zizanioides to Solidification/Stabilization products made from dredged sediment

摘要

Large amount of dredged sediments has caused a series of social and environmental problems, because of serious heavy metal contamination. A novel method is reported here to recycle the dredged sediments in an eco-friendly manner by combining solidification/stabilization (S/S) treatment and vegetation. In this work, we formulated Portland cement, bontonite and quicklime with fly ash to solidify/stabilize the sediment dredged from a polluted river in Guangzhou, China. The stabilization effect was evaluated, and the influences of S/S products on plant growth were also investigated. The results indicate that S/S products have stable fixing capacities for Cd, Pb, and Ni in the dredged sediment. The results of subsequent plant growth experiment suggest that S/S products could be used as a media to grow plants, and fertilizer to sustain the growth of the plants. Vetiver growing in S/S products would stress on the plants and enhance the expression of enzymes, thus increasing the tolerance of the plants to the stress. Our research on combining S/S product and vegetation has demonstrated that it is feasible to recycle the dredged sediment eco-friendly. S/S product combined with vetiver grass has great potential in ecological restoration.