The influence of different Tween surfactants on biodesulfurization of ground tire rubber by Sphingomonas sp.

In present work, three non-ionic surfactants (Tween 20, Tween 60 and Tween 80) were used to improve the affinity between the lipophilic ground tire rubber (GTR) and hydrophilic microbes. The growth characteristic of the Sphingomonas in the co-culture process was studied. The effects of different Tween surfactants on the biodesulfurization of GTR were investigated. Tween 20, among these three surfactants, showed best effect on enhancement of biodesulfurization. Results of SEM-EDS showed that the amount of sulfur in rubber surface layer of 0-4 μm was significantly decreased by 67%. XPS analysis data showed that the area of S-S bonds and S-C bonds were decreased while the S-O bonds were obviously increased. The mechanical properties of desulfurized-GTR/styrene butadiene rubber composite were improved. Also, the mechanism of the surfactants in improving the affinity between the GTR and Sphingomonas was proposed.