Abstract
BACKGROUND: Heavy metals and petroleum hydrocarbon pollution are important environmental problems. This research was conducted to evaluate the effect of nano Fe-oxide and endophytic fungus (P. indica) on petroleum hydrocarbons degradation in an arsenic and petroleum hydrocarbons contaminated soil using barley plant. METHODS: Treatments consisted of the presence (E(+)) and the absence (E(-)) of P.indica fungi, soil contaminated with As in the rates of 0 (AS(0)), 12 (AS(12)) and 24 (As(24)) mg As /kg of soil, and application of 0 (Fe(0)) and 1% (Fe(1)) (W/W) nano Fe-oxide. The plant used in this study was the barley plant. After 7 weeks, the root and shoot As concentration was measured using atomic absorption spectroscopy. The concentration of total soil petroleum hydrocarbon (TPHS) was measured using GC-mass. RESULTS: Application of nano Fe-oxide in soil treated with 12 and 24 mg As/kg soil decreased root As concentration by 30 and 20.6%, respectively. The presence of P.indica caused a significant reduction in the shoot As concentration. With increasing shoot Fe concentration the shoot As concentration was decreased. The highest TPHS degradation was observed in non As-polluted soil that containing 1% (W/W) nano Fe-oxide in the presence of P.indica, while the lowest that was in As polluted soil (24 mg As/kg soil) without applying nano Fe-oxide and in the absence of P.indica. CONCLUSION: Increasing soil sorption properties due to nano Fe-oxide application had significant effect on TPHS degradation in the presence of P.indica. However the role of soil condition on the amount of TPHS degradation cannot be ignored.