Accelerated Solvent Extraction of Chlorobenzenes and Polychlorinated Biphenyls from Municipal Fly Ash

摘要

The study investigated the effect of extraction temperature (100, 125, 150, and 175) on the a ℃ ccelerated solvent extraction (ASE) of polychlorinated biphenyls and chlorobenzenes from a municipal fly ash. To provide basic data that will help to determine the optimum conditions for ASE, four solvents (toluene, nhexane, methanol, acetone/toluene (1:1, v/v) and acetone-hexane (1:1, v/v)) were used as extraction solvents. The results obtained by ASE were compared with those obtained by soxhlet extraction (SE) by using toluene. Result demonstrated that ASE using acetone-haxene and acetone/toluene produced better recoveries than the other two solvents. The efficiency of ASE for CBzs and PCBs showed an increase with increasing extracting temperature. The ASE efficiency of Di-CBz and Di-PCB to Tetra-PCB was more dependent on the solvent. The recoveries of CBzs and PCBs obtained by ASE using mixed solvents were similar to or higher than those obtained by SE. Repeated extractions at optimized settings of the tested variables show that ASE is a safe and effective extraction technique that generally results in high yields.