Iranian Journal of Chemical Engineering (IJChE)

Abstract Polycyclic aromatic hydrocarbons (PAH) are toxic, mutagenic, and carcinogenic compounds. Removal of these compounds has a great importance for environment. Removal of PAHs from soil is difficult as these chemicals are persistent in the soil. In this research, bioremediation of soil contaminated by (PAH) using Bacillus subtilis DSMZ 3256 (B.subtilis) strains was studied. The effect of electrokinetic on biodegradation of PAH was investigated. Fluorene and phenanthrene were selected as PAH and were mixed with soil. The bioremediation experiment was initially performed at 30oC and different humidities. The results represented 12.2 and 11.9% removal of fluorene and phenanthrene at 40% relative humidity after 7 days, respectively. The effects of electrokinetic on this process were studied at different current densities. It was found that the electrokinetic can reduce the biodesulfurization time. According to the results, the removal percents of fluorene and phenanthrene after 4 days under current density 1.82 mA/cm2 were 39.4 and 37.2, respectively.

Abstract Biodegradation of a mixture of benzene, toluene, ethyl benzene, and o-xylene (BTEX) was studied in a two-bed biofilter. The packing material was a mixture of sugarcane bagasse and granulated activated carbon. Aspergillus Brasiliensis and Aspergillus Niger fungi were inoculated in the biofilter, separately. The effects of BTEX concentration, Empty Bed Residence Time (EBRT) and temperature on the biofilter efficiency have been studied. The results indicate that in the biofilter with Aspergillus Brasiliensis fungus, the removal efficiency approaches to 100% for the inlet load of 71.5 g.m -3 h -1 and EBRT of 2.7 min while total removal efficiency in the biofilter with Aspergillus Niger fungus is obtained for the inlet load of 140.3 g.m-3 h -1 and EBRT of 1.3 min. The maximum elimination capacity for this biofilter at inlet load of 223.08 g.m-3 h -1 and EBRT of 0.9 min is 188.95 g.m^-3 h ^-1 .