Contaminant removal from dry and wet sands by thermal desorption

Abstract

Infrared heating was used to determine the effects of temperature and moisture on the removal of selected organic compounds from contaminated sand matrices. Quartz sand was used as a chemically inert surrogate for soil to isolate the heat transfer and mass transfer effects without any chemical contribution from soil. The selected organic contaminants were 3-nitrobenzene sulphonic acid, sodium salt (NBSS) and naphthalene (NAPH). The results of the weight loss data and concentration analyses of the contaminants in the sand showed that at similar concentrations and operating temperatures, a short period of time was required for NAPH, compared to the time required for NBSS, for achieving the same removal level. Temperature profiles in dry quartz sand were determined experimentally and predicted by a one-dimensional conduction model with variable thermal conductivity. The results from the wet sand experiments indicate that the presence of small moisture content can help the removal process by providing an additional convective heat transfer mechanism.

Low-temperature thermal desorption of diesel polluted soil: Influence of temperature and soil texture on contaminant removal kinetics

“…Several studies on thermal desorption treatment have been performed in order to understand the fundamentals of contaminant release [8][9][10] and to investigate the effects of process physical parameters on the remediation efficiency of hydrocarbon contaminants such as PCBs [11,12], PCPs [13], chlorinated solvents [14,15], and PAHs [16,17]. Temperature, treatment time and soil characteristics have been identified as key factors of remedial processes.…”