Comprehensive Model for Remediation of Sandy Soils Contaminated with Volatile Organic Compounds Using Thermal Enhancement of Soil Vapor Extraction Method

Abstract

In today's world, remediation of the environmental pollutants including soil contaminations is among the main issues and concerns considered by environmental scientists. Vapor extraction method is an in situ method to clean up volatile and semi-volatile contaminants of soil especially in unsaturated areas. Thermal enhancement to extract vapors includes different technologies. Its purpose is to transfer heat to the subsurface of the soil to increase the vapor pressure of volatile organic compounds and, consequently, to increase the amount of extracted VOCs. In this study, modeling was done by using laboratory data after screening. Validation was also done with the help of an artificial neural network using the response surface methodology. After training and evaluating the model, it was found that this model determines the amount of contaminant removal rate according to available data and different temperatures by good measures. The correlation coefficient square was equal to 0.95 in the validation section by the neural network. This coefficient was equal to 0.99 in the original model. At the end, a contaminant removal formula for sandy soils has been presented. As a result, due to the proximity of the correlation coefficient to 1, this model can be used to predict the removal rate of thermal enhancement in the relevant circumstances with a slight error.

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