Sunflower seed husk combined with poultry droppings to degrade petroleum hydrocarbons in crude oil-contaminated soil

To remediate crude oil-contaminated soil, poultry droppings and sunflower seed husk were incorporated at various concentrations. Initially, the pH, moisture content, total organic carbon (TOC), total nitrogen content, and bacterial population of soil, poultry droppings, and sunflower seed husk were determined. The initial bacterial population was 35 × 108 colony forming units/g soil (dry weight basis). The total petroleum hydrocarbon (TPH) content in crude oil-contaminated soil was 7,048.4 mg/kg, in which 857.9 mg/kg accounted for eicosane. Naphthalene and acenaphthalene were the two polyhydroxy aromatic hydrocarbons present in soil at low concentrations. After the amendment, the pH, moisture content, microbial population, and TPH content of soil were determined on days 20, 40, and 60. The TPH concentration was considerably decreased in the treatment T4 wherein 250 g of soil was mixed with 125 g of poultry droppings and 125 g of sunflower seed husk. The indigenous bacterial population was also increased tremendously. The dehydrogenase enzyme activity was increased in the amended soil (T4: 0.74 ± 0.06 μg TPF/g/h). After the treatment of soil, the germination percentage and vigour index of maize, lady’s finger and tomato seeds were enhanced.