Jeehyeong Khim

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We investigated the dewaterability and physiochemical properties of digested sludge after treatment with ultrasonic energy for the purpose of reducing sludge. The study involved laboratory experimentation under varying test conditions of treatment time, volume of sludge and ultrasonic energy, which combined can be denoted as specific supplied energy (E(v)).(More)
In this study, the photocatalytic ozonation process using either UV lamps with a wavelength close to a solar wavelength (UVsolar) or natural solar light was established to study the effects of the major operating parameters on the removal of a toxic disinfection by-product (DBP), dichloroacetonitrile (DCAN), from drinking water. Based on the test results of(More)
This study investigated the degradation of diethyl phthalate (DEP) by sonolytic, photolytic and sonophotolytic processes. Two types of UV lamps, UVC (254 nm) and VUV (185 nm+254 nm), were combined with ultrasound (283 kHz). The pseudo-first order degradation rate constants were in the order of 10(-1)-10(-3) min(-1) depending on the processes. The sonolytic(More)
Vigorous physical effects including micro-jet and micro-streaming can be induced in heterogeneous systems by acoustic cavitation. This can be useful for the removal of pollutants from contaminated soil particles. In this study, the diesel removal efficiencies in ultrasonic, mechanical, and combined soil washing processes have been compared considering the(More)
The mechanism for the removal of Zn(II) by using coal mine drainage sludge (CMDS) was investigated by spectroscopic analysis and observations of batch tests using model materials. Zeta potential analysis showed that CMDS(25) (dried at 25 °C) and CMDS(550) (dried at 550 °C) had a much lower isoelectric point of pH (pH(IEP)) than either goethite or calcite,(More)
A bioactive foam reactor (BFR), a novel bioreactor operated using surfactant foams and suspended microorganisms for the treatment of gaseous toluene, was investigated to characterize its performance with respect to the mass transfer and biodegradation rates. The BFR system consisted of two reactors in series; a foam column for toluene mass transfer using(More)
There has been an increasing concern in recent years over the presence of numerous micropollutants in river water. Simultaneously, risk assessment of micropollutants has become increasingly important due to their high toxicity. Therefore, the aims of this study were to characterize the levels of micropollutants in rivers, to identify the sources of these(More)
To examine the reaction rates of sonochemical degradation of aqueous phase carbon tetrachloride, trichloroethylene and 1,2,3-trichloropropane at various temperatures, power intensities, and saturating gases, the batch tests were carried out. The degradations of chlorinated hydrocarbons were analyzed as pseudo first order reactions and their reaction rate(More)
Acoustic cavitation energy distributions were investigated for various frequencies such as 35, 72, 110 and 170 kHz in a large-scale sonoreactor. The energy analyses were conducted in three-dimensions and the highest and most stable cavitation energy distribution was obtained not in 35 kHz but in 72 kHz. However, the half-cavitation-energy distance was(More)
An analytical method has been developed for the determination of endocrine-disrupting phenols (eight alkylphenols and bisphenol A) in fish samples. The extraction of nine phenols from fish samples was carried out by ultrasonification. After the extraction, high levels of lipids were removed by freezing-lipid filtration instead of the traditional methods of(More)