Study of Photodegradation of Methylene Blue by Microbial Synthesized ZnS Material

Abstract

The microbial synthesized ZnS obtained from a pilot-scale sulfate reducing bacteria (SRB) fixed bed reactor was investigated as photocatalyst. The SRB fixed bed reactor as used to treat the Zinc containing wastewater with the influent concentration of 200~300 mg Zn/L. The microbial synthesized ZnS was used as photocatalyst for methylene blue (MB) photodegradation. The results indicated that the photodegradation process could be promoted when the dosage of microbial synthesized ZnS increased. High initial MB concentration could promote the photodegradation reaction. The excellent performance of microbial synthesized ZnS in photodegradation could be explained as the formation of ZnS nanoparticles. The photodegradation with microbial synthesized ZnS were simulated by pseudo-first-order kinetics model. The apparent first-order rate constant of the ZnS catalyst was 0.15 min-1.