Optimum condition of in-situ remediation of Cr(VI) polluted soil from chromium-containing slag heap by indigenous microorganism

Based on the optimization of culture medium composition, the growth conditions and ability of Cr(VI) reduction, the in-situ remediation of Cr-contaminated soil can be achieved by adding culture medium in soils to stimulate the activity of indigenous microorganism. The results show that the optimal conditions for the Cr(VI) reduction by indigenous microorganism are 5 g glucose and 5 g nitrogenous compounds A per kilogram soil at 30°C and the mass ratio of soil to water is 1: 1. Under the optimal condition, the water soluble Cr(VI) in the soil contaminated by chromium-containing slag heap is completely removed in the fourth day. The initial pH value of culture medium do not affect Cr(VI) reduction. The inorganic salt does not need to be added into the culture medium when the in-situ remediation of Cr(VI) is carried out by the indigenous microorganism.