Monitoring hydrocarbon levels during bioremediation by enhanced bio-stimulants using GC-FID

Abstract

The efficacy of bio-stimulants on the remediation of hydrocarbon polluted soil was assessed using Gas Chromatography with Flame Ionization Detector (GC-FID). The enhanced bio-stimulants were discarded melon pulps, discarded breadfruit pulps and poultry droppings. These were applied to the polluted soil in the ratio of 1:5; the blend was observed for sixty days. Inferring from the chromatographs, the carbon compounds present in the polluted and remediated soils ranged from C12 – C40 with varying concentrations; C12 to C19 were dominant, C9 to C11 were residual with negligible concentrations. The total petroleum hydrocarbon (TPH) of polluted soil was 42,229.73 mg/kg, and the remediated soils were: biodegraded melon pulp - 23,786.3 mg/kg, biodegraded breadfruit pulp - 15,322.82 mg/kg, and chicken droppings, - 7,314.29 mg/kg. The results indicated that TPH of the polluted soil was reduced by 43.67% in sample remediated with biodegraded melon pulp, 63.71% in sample remediated with biodegraded breadfruit pulp, and 82.67% in sample remediated with chicken droppings. Therefore, a decreasing order of the effectiveness of the bio-stimulants is thus: chicken droppings > biodegraded breadfruit pulp > biodegraded melon pulp. The higher remediation potential of poultry droppings is attributable to high nitrogenous content. The study showed that the aforementioned bio-stimulants are effective in remediation of petroleum polluted soil. GC-FID detected the hydrocarbon present and their concentrations in the polluted and remediated soils. GC-FID is preferred to other analytical techniques due to its precision in identification and quantification of hydrocarbon fractions.