Experimental study of the factors influencing heptane volatilization from sands

Abstract

In the remediation design of organic contaminated sites with soil vapor extraction method or thermal desorption method, one of the key problems is the volatilization of organic compounds from soil. In this research, the heptane was selected as the organic contaminants. Through a series of laboratory experiments, the volatilization process of heptane from unsaturated sands were studied under controlled conditions. The heptane-contaminated sand samples with different water content and organic content were prepared, and the kinetic process of volatilization was simulated in the laboratory. A thermostatic water bath was adopted to control the temperature of sand samples in the experiments. The results indicate that the removal process of heptane from soil by volatilization can be divided into two stages. It evaporates quickly in the first stage and then the removal rate becomes slower and slower. The volatilization rate of heptane is higher under high concentration than that under low concentration in the same period of time. In addition, the temperature has a great impact on heptane removal efficiency. Increasing temperature can improve the volatilization rate of heptane from soil samples.