1BACKGROUND: Several techniques have been conventionally proposed to recover chitin from

The contamination of soils by metals such as arsenic, chromium, copper and organic compounds such as pentachlorophenol (PCP) and dioxins and furans (PCDD/F) is a major problem in industrialized countries. Excavation followed by disposal in an appropriate landfilling is usually used site to manage these contaminated soils. Many researches have been conducted to develop physical, biological, thermal and chemical methods to allow the rehabilitation of contaminated sites. Thermal treatments including thermal desorption seemed to be the most appropriate methods, allowing the removal of more than 99.99% of organic contaminants but, they are ineffective for inorganic compounds. Biological treatments have been developed to remove inorganic and hydrophobic organic contaminants but their applications are limited to soils contaminated by easily biodegradable organic compounds. Among the physical technologies available, attrition is the most commonly used technique for the rehabilitation of soils contaminated by both organic and inorganic contaminants. Chemical processes using acids, bases, redox agents and surfactants seemed to be an interesting option to simultaneously extract organic and inorganic contaminants from soils. This paper will provide an overview of the recent developments in the field of decontamination technologies applicable for the removal of As, Cr, Cu, PCP and/or PCDD/F from contaminated soils.

Comparison of different interpolation methods and sequential Gaussian simulation to estimate volumes of soil contaminated by As, Cr, Cu, PCP and dioxins/furans

8The objective of this study was to evaluate, at a pilot plant scale, the performance of an attrition 9 process for removing As, Cr, Cu, pentachlorophenol (PCP) and polychlorodibenzodioxins and 10 furans (PCDDF) from a 1-4 mm soil fraction. Once optimized, this attrition process would be 11 applied to the coarse fractions (> 0.250 mm) whereas the fine particles might be treated using a 12 chemical leaching process. The tests were carried out on 2 kg of soil (fraction 1-4 mm) in a 10 L 13 stainless reactor, using tap water. A Box-Behnken experimental design was utilized to evaluate 14 the influence of several parameters (temperature, surfactant concentration and pulp density) and 15 to optimize the main operating parameters of this attrition process. According to the results, the 16 concentration of surfactant (cocamidopropylbetaine-BW) was the main parameter influencing 17 both PCP and PCDDF removal from the 1-4 mm soil fraction by attrition. The behavior of each 18 dioxin and furan congener during the attrition process was studied. The results indicated that the 19 concentration of surfactant had a significant and positive effect on the removal of almost all of 20 the dioxin and furan. The removal of 56%, 55%, 50%, 67% and 62% of the contaminants were 21 obtained for As, Cr, Cu, PCP and PCDDF, respectively, using the optimized conditions ([BW] = 22 2% (w.w -1 ), T = 25°C and PD = 40% (w.w -1 )). These results showed that attrition in the presence 23 of a surfactant can be efficiently used to remediate the coarse fractions of soil contaminated by 24As, Cr, Cu, PCP and PCDDF. 25 26