Screening Effective Factors in Slurry Phase Bioremediation of

Soil contamination with TNT is a serious environmental hazard due to the toxic and mutagenic effects of TNT. Bioremediation is an environmentally safe method in the treatment of explosive-contaminated sites. In the present research, after selection of superior bacteria in the aqueous phase, bioremediation of TNT contaminated clay soil at 1000mg/kg was performed in slurry phase, which resulted in a maximum TNT removal of 89% after 15 days. Afterwards, the effects of operational and environmental factors were examined via the two-level fractional factorial design method ( ) for seven factors, i.e., glucose (2, 8g/l), yeast extract (0, 0.2g/l), (NH4)2SO4 (0.1, 0.5g/l), Tween80 (1, 5g/l) and slurry concentrations (20, 40%w/v) as well as inoculum size (5, 10%v/v) and temperature (20, 35?C). Among these factors, significant factors were found to be slurry, surfactant and glucose concentrations as well as inoculum size. In addition, considerable interactions were observed between glucose and the other significant factors.