Biodegradation of crude oil-contaminated soil using canned-food-industry wastewater sludge for soil application

The objective of this study was to evaluate the effects of crude oil (application doses of 0.5% and 5%) from hydrocarbon contamination on the removal of the Total Petroleum Hydrocarbons (TPH) from soil and to determine the removal of TPH at different temperatures (18°C and 28°C) during an incubation period of 240 days. The possible use of wastewater sludge as a biostimulating agent in crude oil-contaminated soils was also evaluated. The results of the 240 days of incubation indicated that the TPH removal percentages in crude oil-contaminated and sludge-treated soils at 18°C were 89% and 79%, for doses of 0.5 and 5%, respectively. Incubation at 28°C resulted in higher TPH removal with removal percentages of 83% (dose of 0.5%) and 91% (dose of 5%). The degradation of crude oil in contaminated soil treated with a 5% dose was significantly enhanced by the addition of wastewater sludge, whereas no apparent biostimulating effect on TPH removal was observed in the case of low-dose (0.5%) crude oil contamination.