An innovative method for soil vapor extraction to improve extraction and tail gas treatment efficiency

Abstract

This study aims to improve soil vapor extraction (SVE) to address its shortcomings in treating halogenated hydrocarbon-contaminated soil. Indoor simulation experiments based on SVE were conducted to provide technical guidance for the remediation of 1,2-DCA-contaminated soil, with the overall intention of soil repair and ecological restoration. A thermal oxidation SVE (TOSVE) system was designed on the basis of SVE technology for application in the remediation of low-permeability soil contaminated with halogenated hydrocarbons from a chemical plant in Northeast China. Laboratory simulation experiments were conducted based on TOSVE technology to study the removal of target pollutants under different organic contents, moisture and air speeds. For the first time, a new material, scoria, was added to the oxidant at different proportions, and its effect on the exhaust gas treatment efficiency was examined. Thermal extraction improved the extraction efficiency of pollutants from low-permeability soil. Moreover, the adsorption–oxidation effect of 0.1–0.25 mm scoria prepared by 20% Na2S2O8 on 1,2-dichloroethane (1,2-DCA) in tail gas was higher than that of the oxidant without scoria, indicating that scoria is effective in tail gas treatment.

Volatile Organic Compounds (VOCs) in Soil: Transport Mechanisms, Monitoring, and Removal by Biochar-Modified Capping Layer

“…For instance, the results of indoor soil column tests by Yin et al [17] showed that the SVE technology can reduce the concentration of multicomponent VOCs in soil columns by up to 99.52%. Nevertheless, when SVE technology is applied in the field compared to indoor test results, its efficiency in removing VOCs can be greatly reduced due to limitations such as large site areas and poor permeability of contaminated soil [18]. Labianca et al [19] reported from field tests that after four years of SVE treatment, the concentration of VOCs in organic pollution sites was reduced by only 73%, which is lower than the results observed by Yin et al [17].…”

Study on heat and mass transfer characteristics of porous media with different pore structures under continuous wave laser irradiation

“…Generally, the higher the gas temperature, the higher the saturation vapour pressure of the contaminants, displaying properties similar to water. This makes it more favourable for contaminants to transfer to the gas phase and be removed [10,39]. This indicates that when considering the capability of CW laser remediation for soils with different pore structures, the magnitude of the Nusselt number from the perspective of gas temperature is a determining factor.…”

Modeling and Analysis of the Soil Vapor Extraction Equipment for Soil Remediation

“…In order to reduce the number and scale of experiments, the use of numerical simulations to analyze and predict the SVE process before formal testing has become an important way to develop SVE technology [14,15]. Numerical models can assist in the setting of soil parameters [16,17] and process flow design in SVE systems [18,19], as well as in the evaluation of the duration and effectiveness of SVE [20][21][22].…”

“…In order to reduce the number and scale of experiments, the use o ical simulations to analyze and predict the SVE process before formal testing has an important way to develop SVE technology [14,15]. Numerical models can ass setting of soil parameters [16,17] and process flow design in SVE systems [18,19] as in the evaluation of the duration and effectiveness of SVE [20][21][22]. While soil parameters and process flow are important, the final evaluation al to consider the performance parameters of the equipment, which will affect whe equipment performs fully or whether it can achieve the VOC removal rate and required to complete the cleanup target as assessed by theoretical calculations a tests, which is important for government departments and project operators to before investing in the project [23].…”