Mechanical Properties and Toxicity Characteristic of Petroleum Sludge Incorporated with Palm Oil Fuel Ash and Quarry Dust in Solidification/Stabilization Matrices

This paper discussed the treatment of Malaysian petroleum sludge by incorporating palm oil fuel ash (POFA) to replace Portland cement and quarry dust (QD) replaces sand in the solidification /stabilization (S/S) method. Preliminary studies, including chemical composition, heavy metal characterization, density test, compressive strength test, and toxicity characteristic leaching procedure (TCLP), were done to evaluate POFA and QD suitability in S/S matrices. The 10% replacement of POFA recorded a considerable density value ranging from 1500 kg/m3 to 1660 kg/m3. As for S/S matrices containing petroleum sludge, the results indicate the possibility to of encapsulating the sludge in the matrices up to 10%. The highest strength of S/S matrices with petroleum is from PS5% samples with 15.61 MPa at 28 days. The toxicity characteristic of heavy metals from the S/S matrices was below the permissible limit set by USEPA. This investigation could be an alternative solution for petroleum sludge, POFA, and QD disposal and has excellent potential for replacing other treatment approaches employed at the advanced treatment stage for petroleum refinery effluents.