Kinetic Monitoring of Bioremediators for Biodegradation of Gasoil-Polluted Soil

In the present study, total petroleum hydrocarbon biodegradation by wheat straw biochar and active carbon (TPH) was investigated in gasoil-polluted soil around oil refinery of Shiraz, Iran. The experiment was conducted as split-split-plot in time based on completely randomized design with three replications. Various weights of biochar and active carbon (0, 20, 40, 60, 80, and 100 g kg−1) were assigned to main plots, whereas particle sizes (1–2 mm for biochar and 0.05–2.05 mm for active carbon) were assigned to subplots, and the effects were monitored weekly. Biodegradation constant (K) for active carbon ranged from 0.0139 to 0.0328 day−1, whereas it varied from 0.0145 to 0.0369 day−1 for biochar. Also, this value was 0.0088 for control soil. Half-life for control soil was 78.7 days, which decreased as result of applying various size and weights of active carbon (21.13–49.8 days) and biochar (18.7–47.8 days). Thus, the technology used in this study provides a cheap, efficient, and environment friendly method which may be successfully applied in gasoil-polluted soils to enhance the environment for plants and soil microorganisms.