Investigating the Amount of Cadmium (Cd) Removal from Contaminated Soil Using the Biosurfactant Produced by the Tolerant Bacteria to Cd

Using efficient and environment-friendly techniques for the remediation of potentially toxic and harmful metals in contaminated soils plays a vital role in public health. The present study was conducted to assess the efficiency of the biosurfactant produced by the tolerant bacteria to cadmium (Cd) for the removal of Cd from contaminated soil as a completely randomized design with three replications.

Three native strains of bacteria including Bacillus pumilus, Alcanivorax dieselolei, Marinobacter hydrocarbonoclasticus were studied in terms of resistance to different levels of Cd contamination. In order to evaluate the production capacity of biosurfactants in the superior strain, 4 tests of emulsification measurement, oil spreading, drop collapsing, and hemolytic activity were used. Then, to investigate the amount of Cd removal from the contaminated soil, three treatments including the superior strain, the biosurfactant produced by it, and the control soil (i.e., without the strain and biosurfactant) were added to the contaminated soil.

By applying Marinobacter hydrocarbonoclasticus as the superior strain and the biosurfactant produced by it to the Cd contaminated soil, it was observed that the biosurfactant treatment significantly had more ability on Cd removal from the soil compared to other treatments. Also, there was no significant difference between the Marinobacter hydrocarbonoclasticus and the control treatment.

In general, it is concluded that after local calibration and also repeating and performing the experiment in natural conditions, the biosurfactant produced by Marinobacter hydrocarbonoclasticus can be more reliably used as a conditioner for the soils contaminated with Cd.