Korea University · Environmental Science
Professor Ho Young Jo's research lab specializes in the environmental and geochemical behavior of clay-based materials, particularly bentonite and geosynthetic clay liners (GCLs), under varying chemical conditions. The lab investigates cation exchange, hydraulic conductivity, and long-term performance of clay barriers in engineered barriers for nuclear waste repositories and landfill liners. Key research directions include the impact of ionic strength, valence, and pH on swelling and transport properties, as well as the use of advanced spectroscopic and modeling techniques to understand mineral transformation and nuclide retention. The lab also explores innovative applications of Vis-NIR spectroscopy for rapid, non-destructive characterization of clay mineral mixtures.
Figures are computed from collected data and may differ slightly.
The influence of single-species salt solutions of various concentration, cation valence, and pH on swelling and hydraulic conductivity of nonprehydrated GCLs was examined. At similar concentration, swell was largest with NaCl, KCl, and LiCl solutions (monovalent cations Na+, K+, and Li+) and smallest with LaCl3 solutions (trivalent cation La3+). Intermediate swell volumes were obtained with divalent solutions (CaCl2, MgCl2, ZnCl2, and CuCl2). Analogous results were obtained from hydraulic conduc
Hydraulic conductivity tests were conducted on a geosynthetic clay liner (GCL) for more than 2.5years and as many as 686 pore volumes of flow (PVF) using single-species salt solutions (NaCl, KCl, or CaCl2) to (1) evaluate how the long-term hydraulic conductivity (KL) is affected by cation concentration and valence and (2) demonstrate the relevance and importance of termination criteria when measuring hydraulic conductivity of GCLs to salt solutions. Permeation with CaCl2 solutions resulted in an
Abstract Sets of replicate hydraulic conductivity tests were conducted using 100 mM KCl and 20 and 40 mM CaCl 2 solutions to evaluate how changes in hydraulic conductivity are related to changes in the exchange complex and physical properties (water content and free swell) of prehydrated and non-prehydrated bentonite used for geosynthetic clay liners (GCLs). Essentially no change in hydraulic conductivity and water content (or void ratio) occurred during tests with the 100 mM KCl solution even t
A three-compartment model was developed for simulating cation transport in bentonitic barrier layers that incorporates diffusion-controlled cation exchange among the mobile intergranular water (bulk pore water), immobile interparticle and interlayer water, and the montmorillonite mineral solid. Exchange on the external surfaces and interlayer region of montmorillonite is included. The model was evaluated for divalent-for-monovalent cation exchange in bentonite with experiments. A parametric stud
The nuclide retention capacity of bentonite can be affected by changes in the repository environments, such as alkaline and saline conditions. This study investigated the effects of bentonite alteration on the nuclide retention capacity of Ca-bentonite. A series of batch experiments was conducted at room temperature (25°C) for 7 d using Ca-bentonite and alkaline and saline solutions spiked with 10 mM each of cesium (Cs) and iodide (I). Cation exchange and a decrease in the basal spacing (d001) o
The aim of this study was to evaluate whether Na- and Ca-montmorillonite and the swell-indicating properties (i.e., free swell index, water uptake capacity, and cation exchange capacity (CEC)) of clay mineral mixtures can be estimated using visible-near-infrared (Vis-NIR) spectral features. The data regarding four types of reference clay minerals (KGa-1b, kaolinite; IYd, illite; SWy-3, Na-montmorillonite; STx-1b, Ca-montmorillonite) and binary and ternary mixtures of the reference clay minerals
Open papers in the app to read, cite, and organize with AI.
