Seok-Oh Ko

Partitioning of two hydrophobic organic compounds (HOCs), phenanthrene and naphthalene, to surfactant micelles, kaolinite, and sorbed surfactants was studied to provide further insight on (1) the effectiveness of using sorbed surfactants to remove HOCs from water and (2) the feasibility of surfactant-enhanced remediation (SER) for contaminated subsurface systems. Sorbed surfactant partition coefficients, K ss, showed a strong dependence on the surfactant sorption isotherms: at low sorbed surfact

Removal of hydrophobic organic contaminants (HOCs) from saturated low-permeability subsurface environments using a solubility-enhanced electrokinetic remediation process is demonstrated for a model system. Phenanthrene, hydroxypropyl-β-cyclodextrin (HPCD), and kaolinite were selected as a representative HOC, HOC solubility-enhancing agent, and model clay soil, respectively. Electrokinetic (EK) column experiments were conducted under various operating conditions, and the results were interpreted

Recently, yolk–shell structured materials with active metal cores have received considerable attention in heterogeneous Fenton-like systems, which have excellent catalytic performance. In this study, we initially attempted the nonsacrificial template synthesis of yolk–shell structured nanoparticles with magnetite cores encapsulated in a mesoporous silica shell (Fe 3 O 4 @SiO 2 ) via a modified sol–gel process and then evaluated their catalytic activity for acetaminophen degradation in Fenton-lik

Partitioning studies of hydrophobic organic compounds (HOCs) to hydroxypropyl-β-cyclodextrin (HPCD) and one-dimensional transport simulations were conducted to evaluate the feasibility of using HPCD to remove sorbed HOCs in surfactant-enhanced remediation (SER) applications. HOC partitioning to HPCD was very fast, with over 95% of the complexation occurring within 10 min. Some influence of solution chemistry and HOC concentration on HOC−HPCD complex formation coefficients was observed; in genera

Solution chemistry effects on surfactant micelle formation, surfactant sorption on kaolinite, and phenanthrene partitioning to surfactant micelles and sorbed surfactants were studied. For the anionic surfactant sodium dodecyl sulfate (SDS), critical micelle concentration (cmc) values decreased with increasing ionic strength but were unaffected by pH changes. For the nonionic surfactant Tween 80, the cmc was unaffected by pH and ionic strength changes. SDS sorption on kaolinite showed strong pH a

Biogenic Mn oxides are expected to have great potential in the control of water pollution due to their high catalytic activity, although information on biological Mn oxidation is not currently sufficient.In this study, the growth of a Mn oxidizing microorganism, Pseudomonas putida MnB1, was examined, with the Mn oxides formed by this strain characterized.The growth of P. putida MnB1 was not significantly influenced by Mn(II), but showed a slightly decreased growth rate in the presence of Pb(II)

Kinetic models for pollutants reduction by Nano-scale Zero Valent Iron (NZVI) were tested in this study to gain a better understanding and description of the reaction. Adsorption kinetic models and a heterogeneous catalytic reaction kinetic equation were proposed for nitrate removal and for ammonia generation, respectively. A widely used pseudo-first-order reaction model was a poor fit for nitrate removal in an iron-limiting condition and for ammonia generation in an excess iron condition. Howev