Response of mixed bacterial culture towards dibenzothiophene desulfurization under the influence of surfactants and microscopically (SEM and TEM) characterized magnetic Fe3 O4 nanoparticles.

Abstract

Excessive emission of sulfur dioxides from the combustion of coal and other fossil fuels for thermal and industrial purposes has been associated with serious environmental hazards. Biodesulfisation (BDS) can be an effective approach for reducing the impact of toxic gases to its inbuilt operational feasibility under ambient environmental conditions. In the present research, two strategies for BDS of a standard organosulfur compound such as dibenzothiophene (DBT) were investigated under laboratory conditions. In the first treatment, the role of different surfactants such as Tween-20, Tween-80, SDS, and EDTA on the desulfurization of DBT was investigated by the application of bacterial consortium IQMJ-5. In the second treatment, Iron oxidenanoparticles were synthesized and immobilized on the surface of bacteria cells. Shake flask experiments were conducted with immobilized cells, surfactant amended immobilized cells, and control or noncoated cells. Among different surfactant treatments, Tween-80 was found to be the most effective surfactant, showing maximum desulfurization activity at a concentration of 5g/L. The transmission electron microscopy and X-ray diffraction analysis indicated that produced nanoparticles were spherical in shape with a size of about 46 nm and had a stoichiometric ratio of 55.85% and 44.15% between O and Fe, respectively. The nanoparticle treatment enhanced the DBT desulfurization process up to 11.37% as compared to the control, specifically when immobilized cells were used. Therefore, it was concluded that nanoparticles treatments with immobilization of the bacterial cells enhanced the desulfurization rate of DBT under ambient reaction conditions and provide a sustainable alternative for commercial coal BDS.