Comparative Effects of Bone Char and NPK Agricultural Fertilizers on Hydrocarbon Utilizing Bacteria and Fungi in Crude Oil Polluted Soil

Bone char and NPK fertilizers are stimulants for bioremediation of crude oil polluted soil were investigated. Cells were constructed in-situ with dimensions of 1.5m by 1.5m. Crude oil samples were applied to cells with crude penetration depths of 30 cm. The hydrocarbon content (THC), total organic carbon (TOC), bacterial and fungal contents of the soils of the cells were investigated before and 8 weeks after addition of 0.5kg, 2kg and 3.5kg of bone char and NPK fertilizer. The control cells had no bone char or NPK fertilizer. The results showed that bone char and NPK fertilizer significantly reduced THC and TOC when compared with the control. Furthermore, both bone char and NPK fertilizers significantly increased the number of hydrocarbon utilizing bacteria and fungi as well as total heterotrophic bacteria population. Consequently, THC removal efficiency ranged from 62.24 to 87.74% and TOC removal efficiency ranged from 62.93 to 77.37% for NPK fertilizer and bone char amended cells, respectively. The stimulatory efficiency for THC ranged from 82.00 to 87.23% and stimulatory efficiency for TOC ranged from 72.40 to 77.55% for NPK and bone char respectively. In conclusion, our results suggest that the stimulatory effects of bone char for bioremediation of crude oil contaminated soil are comparative with those of NPK fertilizer