Quantitative study of in situ chemical oxidation remediation with coupled thermal desorption

In situ chemical oxidation (ISCO) is widely used as an efficient remediation technology for groundwater pollu-tion. However, quantitative studies of its reactive remediation process under coupled thermal desorption tech-nology are scarce. Based on laboratory experiments and site remediation, the chemical oxidation remediation reaction process was quantified, and the apparent reaction equation of the ISCO process was constructed. And then, a numerical model coupled with Hydraulic-Thermal-Chemical (HTC) fields was built to quantitatively describe the remediation process of an actual contaminated site. The simulation results fit well with the site monitoring data, and the results indicated that thermal desorption strengthens the ISCO remediation effect. In addition, the HTC model is expanded to build a conceptual and numerical model of a coupled remediation system, including heating and remediation wells. The results showed that high-temperature conditions enhance the activity of remediation chemicals and increase the rate of remediation reaction to obtain a better remediation effect. The heating wells increase the regional temperature, accelerating the diffusion of pollutants and reme-diation chemicals, and promoting adequate contact and reaction. Based on this crucial mechanism, thermal desorption coupled with ISCO technology can significantly improve remediation efficiency, shorten the reme-diation cycle, and precisely control agent delivery with the help of numerical simulation to avoid secondary contamination.

Automated summary

Based on laboratory experiments and site remediation, the remediation process of in situ chemical oxidation (ISCO) under coupled thermal desorption technology was quantified and modeled using a Hydraulic-Thermal-Chemical (HTC) numerical model. The simulation results showed that thermal desorption strengthens the ISCO remediation effect and high-temperature conditions enhance the activity of remediation chemicals, increasing the rate of remediation reaction. The coupled remediation system including heating and remediation wells, based on this crucial mechanism, significantly improves remediation efficiency and precisely controls agent delivery to avoid secondary contamination.