Bioremediation of petroleum hydrocarbons in crude oil contaminated soil from wonocolo public oilfields using aerobic composting with yard waste and rumen residue amendments

The efficiency of composting method with yard waste and rumen residue amendments to reduce soil pollution by total petroleum hydrocarbon in Wonocolo public oilfields was investigated in the laboratory scale for 150 days. Crude oil contaminated soil was mixed with yard waste and rumen residue mixture at 1:1 ratio then composted in 2 replicates. Pure crude oil contaminated soil was composted in parallel. The results showed that total petroleum hydrocarbon degradation efficiency of soils amended with yard waste and rumen residue mixture was 31 times higher than contaminated soil, which fulfilled the soil quality standard (6,974.58 mg/kg). The degradation of total petroleum hydrocarbon might be performed by Bacillus sp., and Bacillus cereus as the dominant bacteria at the end of composting process. These results showed that yard waste and rumen residue transformation could accelerate the degradation of aliphatic and aromatic fractions of petroleum hydrocarbon in crude oil contaminated soil. Both of these wastes are generally easy to obtain around Wonocolo public oilfield and highly recommended to use as the main substrate in the composting process.