TOXICITY IMMOBILIZATION OF REFINERY SLUDGE CONTAINING HEAVY METALS VIA VITRIFICATION PROCESS

Abstract

Heavy metals are known to be toxic to human and the environment. Despite the growing of petrochemical and refinery industries, the world is facing problems with the heavy metals cont amination from the sludge by the industries. Many m ethods have been applied to address these issues from the refinery sludge. In t his study, stabilization and solidification of refinery sludge containing heavy metals using vitrification method was utilized to solve th is problem. The ashing temperature of 550 o C was selected in preparing the ash of the dried sludge prior to the vitrification process at 1110 o C to 1400 o C. After vitrification, all samples were morphologi cally, thermally and toxically analyzed using Scanning Electron Micr oscopy, Thermogravimetric Analysis and Toxicity Cha racteristic Leaching Procedure. The sludge contained high amount of iron and aluminum, followed by some amount of magnesium , gold, arsenic and zinc with some traces of nickel and lead. Results showed that at maximum vitrified temperature of 1400 o C, no magnesium, nickel and lead were detected in the sludge and only some traces of other heavy metals with less than 1 ppm. The vitri fication method exhibits excellent output in immobilizing the transition met als leading to a reduction in environmental polluti on caused by petrochemical and refinery sludge containing heavy metals. Index Terms: Vitrification, Heavy metals contamination, Refiner y sludge, Toxicity, Leaching analysis