Application of Vermicompost, Spent Mushroom Substrate, Domestic Compost and Leachate as Inoculum on Bioremediation of Oil Sludge

The research on utilization of spent mushroom substrate (SMS), vermicompost (VC), domestic compost (DC) and leachate (L) as inoculum of microorganisms in bioremediation of 30% oil sludge was conducted. The aim of this study was to obtain the most suitable inoculum in bioremediation of oil sludge. TPH and C/N ratios were analyzed on 15 days of interval, while Polycyclic Aromatic Hydrocarbon (PAH) and heavy metals were measured at the beginning (H-0) and the end of experiment (H-45) for 45 days of experiment. The additional parameters such as acidity (pH), temperature (°C), and humidity of medium (%) were measured. The results showed that all inoculums (SMS, VC, DC and L) affect the diminution of TPH as much as 27.7%, 20.9%, 24.8% and 24.20%, respectively. On the other hand, SMS and VC were able to decrease C/N ratio as much as 18% and 4%, respectively. By contrast, DC and L increased C/N ratio as much as 33% and 1.14%, respectively. In this study, inoculum of SMS and L were able to decrease Cr content (16% and 5.88%, respectively). However, Hg content diminished (29%) only in oil sludge medium with SMS inoculum. The PAH compound can be degraded by all types of inoculum with carbon chain ranged from C6-C54 into shorter carbon chain (C6-C30).