Stabilization/solidification of sand contaminated with organic compounds using regenerated activated carbon and cement

Abstract

The potential for neutralizing p-chlorophenol- or isooctane-contaminated sand by means of the stabilization/solidification (S/S) process using regenerated activated carbon and cement was investigated in this study. The activated carbon used was recovered from a spent activated carbon -Cu-Cr-Ag (KS-z) catalyst by treating it with a solution of 0.05 M H₂SO₄ in the presence of 35 kHz ultrasound at 298 K for 60 min. The regenerated activated carbon had a specific surface area of 760 m²/g and an iodine number of 820 mg/g. It was mixed with p-chlorophenol- or isooctane-contaminated sand (in a concentration range of 0.32–1.28 and 1.3–44.3 mg/g, respectively), and then all of it was solidified with cement. The addition of 0.5% regenerated activated carbon to the sand effectively stabilizes wastes and reduces the leaching of organic contaminants from the solidified matrix to the water phase. It was also observed that the addition of activated carbon cannot be higher than 2.5% because it undesirably affects the quality of the obtained cement paste. © 2009 American Institute of Chemical Engineers Environ Prog, 2009