Microbial upgradation of Meghalaya coal by Rhodococcus rhodochrous and Pseudomonas aeruginosa

Abstract

Meghalaya Coal contains 1.61 to 8.92 % of sulfur. The sulfur commonly exists as inorganic sulfur Meghalaya found mainly as pyrite and organic sulfur (mainly found as heterocyclic aromatic compounds like thiophene, dibenzothiophene and phenyl disulphide). In this investigation, bacterial strain enriched with L.ferrooxidans isolated from Tirap coal mines, Assam in 9K media at 40oC and pH 1.6-1.8, was able to remove 51.4% pyritic sulfur using 10%( w/v) Meghalaya coal sample of <50m size in 3 days. Consequently, two different bacteria Rhodococcus rhodochrous and Pseudomonas aeruginosa pre-adapted on 75mM of dibenzothiophene (DBT) and Phenyl disulphide (PDS) respectively resulted in maximum 51% and 52% desulfurization 10 %(w/v) non-depyritised feed coal sample at an optimum pH 6 and 40oC, in 72h. The various parameters governing the process are discussed.