토양 세척 시 초음파 적용에 따른 유기 오염물 제거 특성 평가

Abstract

ABSTRACT Cavitation generated by ultrasonic irradiation can enhance the diffusional transport of organic contaminants from soilsurfaces or pores. Therefore, ultrasound soil washing can be an alternative of traditional soil washing process. In this study,soil was artificially contaminated with n-tetradecane, n-hexadecane and phenanthrene. A plate type ultrasonic reactor at25 kHz frequency and 1000 W power was used for laboratory soil washing experiments. Ultrasonic soil washingefficiency was compared with those of traditional soil washing using mechanical mixing. Various operational parametersuch as soil/liquid ratio, irradiation time, particle size, and soil organic matter content was tested to find out the optimumcondition. It was found that ultrasonic soil washing demonstrates better performance than mechanical soil washing.Optimum soil:liquid ratio for ultrasonic soil washing was 1 : 5. Desorption of organic contaminants from soils by ultrasonicirradiation was relatively fast and reached equilibrium within 10 minute. However, decrease in the soil particle sizes byultrasonic irradiation results in re-adsorption of contaminants to soil phase. It was also observed that soil particle sizedistribution and soil organic matter content have significant effects on the efficiency of ultrasonic soil washing. Key words :Ultrasound, Desorption, Soil Washing, Soil organic matter, Particle size distribution