Bioremediation of Cd-Contaminated Soil around Bauxite with Stimulants and Microorganisms

Abstract

Heavy metal pollution in the soil around bauxite mines, especially cadmium pollution, is becoming more and more severe due to this mining becoming more frequent. Therefore, it is urgent to develop green and safe remediation technology. Biostimulants have been studied extensively, but their practical application is still challenging. In this study, the effects of humic acid (HA), glucose (GLU), and tetrasodium glutamate diacetate (GLDA), as well as their synergistic complex bacterial flora, on Cd-contaminated soil were analyzed. It has been shown that applying these three types of stimulants, individually or with complex bacterial flora, can enhance soil environment and quality. Nevertheless, the remediation efficacy of stimulants in combination with microbial communities surpasses that achieved through the use of stimulants alone. Among them, 1%GLU combined with complex bacterial flora had the best passivation effect on Cd, reducing the available Cd by 25%, followed by 0.5% GLU combined with complex bacterial flora and 0.5%HA combined with complex bacterial flora, which reduced the available Cd by 21.92% and 19.17%, respectively. The synergistic remediation method using stimulants and microorganisms can reduce the harm caused to the environment by conventional remediation methods and improve the effectiveness of soil remediation. It has broad application prospects in the field of bauxite-contaminated soil remediation.

Keywords

• Cd-contaminated soil
• stimulants
• complex bacterial flora
• bioremediation
• soil enzyme activity