Destruction of PAHs from contaminated marine sediment by washing with surfactants and oxidizing with hydrogen peroxide

Abstract

Marine bottom sediment in busy urban harbors in South Korea is often found to be highly contaminated with polyaromatic hydrocarbons (PAHs) from various sources and pose significant health concerns for the local human population as well as marine wildlife. Therefore it is necessary to decontaminate the PAHs from the bottom sediment either in situ or ex situ. In this study some collateral effects for PAHs in marine sediment, caused by chemical oxidants and surfactants to PAHs in contaminated marine sediments, were evaluated. Hydrogen peroxide was used as chemical oxidation reagent for Fenton-like reaction. Surfactants including Triton X-100, Tween 60 and Tween 80 were used to enhance the solubility of PAHs as washing reagents. A combination of using various concentrations of hydrogen peroxide and surfactants was evaluated to degrade PAHs in contaminated marine sediments and was yielded 0-30% removal of PAHs in the sediment for 1 hr duration of the treatment. The largest amount of removal was found in the case of applying 5M hydrogen peroxide and 0.5% Tween 80. The 30% reduction of PAHs in sediment are found to satisfy the government regulatory limit for most PAHs contaminated harbor marine sediments in South Korea. Using these findings, we are currently designing bench scale pilot system to develop a commercial system to be used in harbors around the nation.arine wildlife. Therefore it is necessary to decontaminate the PAHs from the bottom sediment either in situ or ex situ. In this study some collateral effects for PAHs in marine sediment, caused by chemical oxidants and surfactants to PAHs in contaminated marine sediments, were evaluated. Hydrogen peroxide was used as chemical oxidation reagent for Fenton-like reaction. Surfactants including Triton X-100, Tween 60 and Tween 80 were used to enhance the solubility of PAHs as washing reagents. A combination of using various concentrations of hydrogen peroxide and surfactants was evaluated to degrade PAHs in contaminated marine sediments and was yielded 0-30% removal of PAHs in the sediment for 1 hr duration of the treatment. The largest amount of removal was found in the case of applying 5M hydrogen peroxide and 0.5% Tween 80. The 30% reduction of PAHs in sediment are found to satisfy the government regulatory limit for most PAHs contaminated harbor marine sediments in South Korea. Using these findings, we are currently designing bench scale pilot system to develop a commercial system to be used in harbors around the nation.