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, Kss, showed a strong dependence on the surfactant sorption isotherms: at low sorbed surfacta

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

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

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

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)

We examined the relationship between the intrinsic structure of a carbocatalyst and catalytic activity of peroxomonosulfate (PMS) activation for acetaminophen degradation. A series of nitrogen-doped carbon nanotubes with different degrees of oxidation was synthesized by the unzipping method. The linear regression analysis proposes that pyridinic N and graphitic N played a key role in the catalytic oxidation, rather than pyrrolic N and oxidized N. Pyridinic N reinforce the electron population in

We investigated the effect of co-existing anions of Cl − , SO 4 2− , NO 3 − , CO 3 2− , and HCO 3 − on potassium persulfate (PS) activation by multiwalled carbon nanotubes (MWCNTs) and N-doped MWCNTs (MWCNTs) for acetaminophen (ACP) degradation.

Laboratory-scale reductive dechlorination studies using bimetals were conducted to detoxify chlorinated biphenyls, which are known as one of the most recalcitrant organic compounds. Palladized iron and palladized zinc readily dechlorinated mono- and di-chlorinated biphenyls while plain metals were not active. Biphenyl and less chlorinated biphenyls were detected as the major products and calculated mass balance was around 100%, indicating that predominant degradation reaction was dechlorination.