Composting and Phytoremediation Treatment of Petroleum Sludge

Composting and phytoremediation using elephant grass (Penninsetum purpureum) were compared in experiments aimed at investigating the potential of both techniques in the treatment of petroleum sludge. The compost consisted of poultry manure and sawdust. N-P-K fertilizer was used for biostimulation of indigenous microbes. It also served to enhance the growth of the elephant grass. The sludge was mixed with agricultural soil and both techniques were then utilized for treatment. The total hydrocarbon content (THC) of the sludge-soil mixture before treatment was 64,494 mg/kg. After an 84-day treatment period, the composting treatment recorded 47% reduction in THC, the phytoremediation treatment showed 69% THC reduction, while the combination of composting and phytoremediation had 29% THC reduction. Microbial numbers corroborated the THC reduction observed. The results of the study show considerable promise for the deployment of elephant grass in phytoremediation treatment of petroleum sludge.