Combined Application of Ozone and Hydrogen Peroxide to Degrade Diesel Contaminants in Soil and Groundwater

Abstract

Environmental pollution has been a major concern in recent times, and soil and groundwater pollution are areas which have received particular focus. This has led to the development of various remediation techniques such as excavation, soil vapor extraction, bioremediation, chemical oxidation, and so on. Among all remediation techniques, chemical oxidation has been proven to be the most effective and feasible technique around the world. In this study, various combinations of ozone and hydrogen peroxide were used to treat diesel-contaminated soil and groundwater in an experimental setup. Experimental soil and groundwater were prepared with properties similar to the contaminated soil. An ozone generator and a pump injection system were deployed for combining ozone and hydrogen peroxide. Five different experiment batches were prepared based on the hydrogen peroxide concentration and its ratio to the soil. The diesel concentration in the water dropped from 300 mg/L to 7 mg/L in the first hour of treatment, which dropped below the detection limit (0.01 mg/L) thereafter. Similarly, 63.9% degradation was achieved with the combined sparging of ozone and hydrogen peroxide in the soil. Ozone combined with 7% hydrogen peroxide was the most promising combination for removing the contaminants. In addition, this research explored the hydroxyl radical conversion rate of ozone and the perozone, the difference in order of magnitude is greater than one which shows that the perozone has better oxidation capacity than ozone only. The findings of this study show that combining ozone with hydrogen peroxide is a competent and feasible onsite remediation method for diesel contaminants in soil and groundwater. Thus, this method can be applied in local gas stations, accidental spillage sites, and small-scale refineries for onsite treatment in a cost-effective and technically sound way within a short time span.