Advanced Oxidation Based Treatment of Soil Wash Water Contaminated with Sulfolane

This study investigates advanced oxidation processes (AOPs) as post-treatment techniques to degrade sulfolane in soil washing water. Soil washing experiments were conducted with different soil/water ratios, shaking times, and number of extraction cycles. The soil wash water containing sulfolane was treated with four AOPs including H2O2/ultraviolet (UV), O-3/UV, alkaline ozonation, and neutral Fenton reagent. Results show that sulfolane can be effectively removed from the soil using water as a washing solvent, where optimum conditions were found with 30 min of vigorous shaking, using 1:2 soil/water mass ratio, and a three-cycle extraction procedure. Moreover, the sulfolane in the soil wash water was also effectively degraded using appropriate AOPs. Among the four AOPs investigated, neutral Fenton was the least effective method to treat sulfolane in the wash water, while H2O2/UV, O-3/UV, and alkaline ozonation can achieve more than 99% of sulfolane degradation within 1 h.