Effects of soil temperature and agitation on the removal of 1,2-dichloroethane from contaminated soil

Abstract

Mechanical soil aeration is an effective and low cost ex-situ remediation technique suitable for large sites contaminated by volatile organic compounds. However, this technique is still in the testing and development phase. To understand the effectiveness of this remediation technique and the main factors influencing its efficacy, an abandoned typical chlor-alkali chemical industry site was remediated using this technology on a pilot-scale. The results showed that this technology is effective for the remediation of volatile organic compounds, with a removal efficiency of greater than 99%. During the experiment, a better result was observed in the first 120h than the last 120h. Both temperature and agitation affected the remediation. Higher environmental or soil temperatures resulted in more rapid attenuation of 1,2-dichloroethane (1,2-DCA). Agitation had an obvious effect during the first 120h. A preliminary dynamic characteristic study showed that the volatilization process can be described by a function similar to y=a+be(−kt). Temperature (both environmental and soil temperature) had a greater effect on the reaction rate constant and the half-life of 1,2-DCA compared with agitation. This study aims to improve the remediation of contaminated sites, especially large areas contaminated by volatile organic contaminants.