Phytoremediation of diesel contaminated soil by jack bean Canavalia sp. Inoculated with rhizobium and arbuscular mycorrhiza

Abstract

Phytoremediation is the outstanding way to remediate the diesel contaminated soil for both environmental and economic reasons but there is a major concern about the low bioavailability. Therefore the use of symbiosis of plants and microorganisms in order to stimulate the phytoremediation should be considered. In this study, phytoremediation of diesel contaminated soil by Canavalia sp. inoculated with rhizobium and arbuscular mycorrhiza ( AM) was established. The AM fungi were isolated and cultivated in sorghums for inoculums production. Canavalia sp. was biostimulated in non contaminated soil with only AM at 10, 20, 50 or 100 spores or 10 g rhizobium or the mixture of both microorganisms. The results after three months inoculation showed that the presence of AM and rhizobium in soil significantly stimulated the growth of Canavalia sp. and increased % AM infection. Analysis of diesel contaminated soil after treating with Canavaria sp. co-inoculated with 100 spores AM with 10 g rhizobium resulted in the decrease of diesel contaminated in soil. In addition, hydrocarbon products of diesel oil were also detected in plant shoots but very little in roots. This phenomenon proved that the phytoaccumulation was occurred and played a role in diesel contaminated removal of soil.