Bioremediation of Soil Artificially Contaminated with Petroleum Hydrocarbon Oil Mixtures: Evaluation of the Use of Animal Manure and Chemical Fertilizer

The search for cheaper and environmentally friendly options of enhancing petroleum hydrocarbon degradation has continued to elicit research interest. One of such options is the use of animal manure as biostimulating agents. A combination of treatments consisting of the application of poultry manure, piggery manure, goat manure, and chemical fertilizer was evaluated in situ during a period of 4 weeks of remediation. Each treatment contained petroleum hydrocarbon mixture (kerosene, diesel oil, and gasoline mixtures) (10% w/w) in soil as a sole source of carbon and energy. After 4 weeks of remediation, the results showed that poultry manure, piggery manure, goat manure, and NPK (nitrogen, phosphorous, and potash [potassium]) fertilizer exhibited 73%, 63%, 50%, and 39% total petroleum hydrocarbon degradation, respectively. Thus, all the biostimulating treatment strategies showed the ability to enhance petroleum hydrocarbon microbial degradation. However, poultry manure, piggery manure, and goat manure treatments showed greater petroleum hydrocarbon reductions than NPK fertilizer treatment. A first-order kinetic equation was fitted to the biodegradation data and the specific degradation rate constant (k) values obtained showed that the order of effectiveness of these biostimulating strategies in the cleanup of soil contaminated with petroleum hydrocarbon mixtures (mixture of kerosene, diesel oil, and gasoline) is NPK fertilizer goat manure piggery manure poultry manure. Therefore, this present work has indicated that the application of poultry manure, piggery manure, goat manure, and chemical fertilizer could enhance petroleum hydrocarbon degradation with poultry manure, showing a greater effectiveness and thus could be one of the severally sought environmentally friendly ways of remediating natural ecosystem contaminated with crude oil.