It mainly involved biostimulation where organic or inorganic
components were introduced to enhance indigenous microbial growth that directly degrades the contaminants. This
paper aims to identify potential organic wastes in enhancing the biodegradation of used lubricating oil in
contaminated soil. To achieve the objective, sewage sludge and cow dung were selected as the organic components to
be added individually into the 10% (w/w) used lubricant oil-contaminated soil.