Treatment system for solid matrix contaminated with fluoranthene. I––Modified extraction technique

A laboratory-scale ultrasonication technique was developed for fluoranthene extraction from soils and sediments where the utilized organic solvent would be recovered after the extraction process. Therefore, the remedied soils and sediments would be free from toxicant and trace of added chemicals. The developed ultrasonication technique outlined here is an integrated part of a complete remediation system consisting of extraction and solar detoxification reactors. This paper investigates extraction efficiencies under different conditions, outlines solvent recovery technique and compares extraction efficiency of the developed ultrasonication technique with a commercially available laboratory-scale sonication bath. The spiked soil sample with fluoranthene (19.4 μg g−1) and organic solvent was ultrasonicated at 40°C for 20 min. The sonicated mixture was allowed to settle for 10 min before the extract gravitated into the modified solar reactor for fluoranthene detoxification. The added solvents were removed from the remedied soil before it was released to site. The mixture of cyclohexane and ethanol (CH:ETOH) (3:1) was the favorable solvent from among 10 organic solvents because of its high extraction efficiency, safety and low cost. Preliminary results indicated that the developed extraction technique recovered more than 93% of fluoranthene from soil samples.