Study on Utilization of Ash from Incineration Process of Hazardous and Toxic Waste PT. Kawasan Industri Makassar

The study of the utilization of hazardous and toxic waste ash residue by the Incinerator of PT. Kawasan Industri Makassar (KIMA) was carried out with a stabilization/solidification (S/S) process by utilizing ash residue as a substitute for cement and sand for the manufacture of paving blocks. The raw materials were printed in cube and cylindrical moulds. Variations in the proportion of the mixture (cement/sand: ash residue) were 100:0, 80:20, 70:30, and 60:40; then, the influence of the water-cement factor was 30% and 35%. The quality of the S/S object tests was tested by compressive strength and heavy metal concentrations using the Atomic Absorption Spectroscopy (AAS) method. The results showed the ash content of the PT. KIMA was declared a hazardous and toxic waste because the content of Pb exceeded the quality standard limit for hazardous waste. The optimum compressive strength value was found in the mix design factor of 30% water-cement on specimens (cement: ash for cement: sand: ash for sand) 100: 0: 80: 20, 100: 0: 70: 30, 80: 20: 100: 0, and 80: 20: 80: 20 of 27.05 MPa, 24.03 MPa, 21.24 MPa, and 20.14 MPa, then with the water factor 35% cement on specimens 100%: 0 %: 80%: 20% and 100%: 0 %: 70%: 30% of 24.87 MPa and 23.24 MPa at the age of 14 days which met the requirements for quality B paving blocks as parking equipment.