Mycoremediation of Monocyclic Aromatic Hydrocarbons by a Local Marine Aspergillus oryzae (Statistical Analysis of the Main and Substrate Interaction Effects)

AN AROMATIC hydrocarbon utilizing fungus was isolated from a wastewater polluted sea spot in the Mediterranean, Alexandria, Egypt. It was identified to the species level as Aspergillus oryzae. The marine fungal isolate has the ability to remove BTHX compounds (benzene, toluene, hexylbenzene, and xylene), concentrations ranged between 15 and 75 mgl-1. Up to our knowledge, it is the first description of BTHX removal by a local marine strain of A. oryzae. The removal efficiencies of these compounds varied between 58 and 85 %, within 48hr. Experiments were conducted according to the 24 fraction fractorial design to identify the main and interaction effects of individual BTHX removal efficiency. A statistical interpretation of the results revealed that the main effect of benzene was significant (P < 0.05). High F values for the 4-way interaction between different hydrocarbons with low P values suggest that the interactions between individual BTHX are the most significant factors. The negative interactions between benzene and hexylbenzene, benzene and xylene concentrations were found to be statistically significant (P < 0.05). On the other hand, there was a positive significant interaction between hexylbenzene and xylene (P < 0.05). A successful trial showed the very good applicability of the marine fungal isolate to remove 80.00, 95.64 and 89.00 % of benzene, toluene, and xylene, respectively, in the waste effluent of Alexandria Petroleum Company after 48 hr. This effluent contains very high concentrations of BTX compounds (36.38gl-1). Using the diluted effluent (50%), the removal efficiency of the BTX reached a distinct value of 97, 98 and 98% for benzene, toluene, and xylene, respectively, after 72 hr. These significant quantitative removal capacities demonstrate the potential application of marine A. oryzae for the mycoremediation of BTX compounds from waste water systems