Study On Critical Temperatures For Naphthalene And Chlorobenzene Removal During In Situ Steam Injection Remediation

Abstract Steam injection is an effective technique for the in situ remediation of volatile and semi-volatile organic contaminants. In this study, the influence of temperature and media on the removal of organic pollutants, such as naphthalene and chlorobenzene, was investigated in the remediation process through batch and remediation experiments, and the solid, liquid, and gaseous phase migration and transformation of organic pollutants during remediation were evaluated. The results demonstrated that the temperature significantly influenced the removal of organic pollutants. It was found that the critical temperatures for naphthalene and chlorobenzene were 50°C and 30°C, respectively. When the temperature was higher than the critical temperature, the final removal rates of naphthalene and chlorobenzene reached over 94% and 96%, respectively. The remediation area of chlorobenzene determined according to the critical temperature has a good result; the error compared with the actual remediation area in both coarse sand and fine sand was approximately 8.7%. In the simulation tank, the temperature changes can be divided into three stages: the ambient temperature stage, the temperature rapid rise stage, and the stable stage. Moreover, we found that the remediation effect of aquifers is not only related to temperature, but also to the location of the SVE well (soil vapour extraction). These findings reveal the main factors affecting the application of hot steam technology and the relationship between the temperature field and contamination field in the remediation process.