A systematic review on the effectiveness of remediation methods for oil contaminated soils

Abstract

• Field application studies on clean-up of oil contaminated soil are limited • Combined method integrates the strength of two or more soil remediation methods • Biological method is cheap and eco-friendly • Chemical method is expensive and impacts negatively on the environment • The high cost of most physical method stem from their high energy consumption There is no doubt that several soil remediation methods have been applied in removing oil contaminants in the soil. Selecting an appropriate method is critical for effective cleanup of a contaminated site. The aim of this study is to review field studies of soil remediation methods to determine their effectiveness in cleaning oil contaminated soils. A systematic search of literature was conducted in different databases to extract mainly field studies, few pilot studies, and greenhouse experiments. One grey literature (conference paper) was also selected. Studies selected were published between 2000 to 2021, and 51 literatures were chosen for this review. The review of field application studies on soil remediation revealed that combined method has high oil removal efficiency, short cleanup duration, moderate remediation cost, and low environmental impact. Followed by biological method which is considered a green and cheap remediation method. While chemical method was reported as the least effective soil remediation method, concerns exist over their negative environmental impact, and high remediation cost. Similarly, physical method showed low remediation effectiveness resulting from high energy consumption of most technologies under physical method and the need for further treatment of gases produced during remediation. Therefore, combined method was considered the most effective remediation method for oil contaminated soil.