Effect of site-specific conditions and operating parameters on the removal efficiency of petroleum-originating pollutants by using ozonation

Soil contamination is a worldwide problem, mainly caused by a wide range of organic compounds: e.g., alkanes, aromatics, and polynuclear aromatics. Using ozone to help remediate contaminated soils is gaining interest due to its capability in oxidizing recalcitrant contaminants in short application time., although studies using ozonation for soil remediation are so far limited to the laboratory scale. This review attempts to summarize and discuss the state of the art in the treatment of soils contaminated with recalcitrant organic contaminants by using ozone, emphasizing the influence of operating conditions, such as the content and age of soil organic matter, grain size, moisture content, pH, and ozone dose. Special attention is given to the combination of ozonation and biodegradation. The main advantages in using ozonation as a remediation technique are its high oxidation potential applicable to a wide range of organic pollutants and its oxygen release after chemical decomposition that allow aerobic biodegradation. The review results show that ozonated soils can be reused after ozonation treatment, therefore ozonation can be considered an excellent remediation technique, even if combined with biodegradation, allowing removal percentages of 90% and more.