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In this study, we evaluated the feasibility of in situ electrokinetic remediation for arsenic (As)-, copper (Cu)-, and lead (Pb)-contaminated soil, in a pilot-scale field application with two-dimensional electrode configurations. Square and hexagonal configurations with different electrode spacing, 1 m and 2 m, were investigated under a constant 100 V. A square configuration with electrode spacing of 2 m removed 61.5 % of As, 11.4 % of Cu, and 0.9 % of Pb, respectively, and a hexagonal configuration with the same spacing showed a higher removal efficiency in top (59 % of As, 0-0.5 m) and middle (53 % of As, 0.5-1.0 m) layers, but much lower removal efficiency in the bottom layer (1-1.5 m), which was thought to be due to groundwater flow through periodic rise and fall of tides. Fractionation analysis showed that As bound to Fe-Mn oxyhydroxide was the main form of As removed by the electrokinetic process. The two-dimensional configuration wasted less electrical energy by Joule heating, and required fewer electrode installations, compared to the one-dimensional electrode configuration.

This study was conducted to evaluate the slurping process affecting the variation of free product and VOCs concentration and the bioaugmentation effect on bioremediation process. Free products and soil gas were extracted from 30 extraction wells installed in a petroleum contaminated area. The extraction system was operated for 10 hours per day with 1 hour onand-off mode. The thickness of free product in extraction well was decreased from 11.7 cm to 4.5 cm and the VOCs concentration was increased from 10.37 ppm to 30.78 ppm during the operation period. After the slurping process for 2 months, contaminated soil was treated with bioremediation process in 2 cells, 15 × 40 m, biologically enhanced with adjusting oxygen, moisture and nutrients concentration. Total 1,400 L of microbial inoculant, Naturesys. (Dong Myung Ent. Co.) was added to the pile B, which has an outstanding ability for degrading petroleum hydrocarbons. The results showed that bioremediaton effect in soil with the microorganisms solution is 33% higher than that in soil with only residual bacteria.

For As(V) removal aqueous system, 3 types slag which is a waste product from steel making process was used. Arsenic was mainly removed by Ca-As precipitation such as form Ca 3 (AsO 4) 2. The removal efficiency of arsenic on slag was affected by iron oxide contents because arsenic was removed by adsorption on iron oxide. The experimental results were well fitted by pseudo-second-order and Langmuir isotherm model compared to other models. Arsenic was completely removed by Slag Y and Slag J within 12 h, 0.5 g and 0.7 g of Slag Y and Slag J are sufficient to remove arsenic of 20 mg/l arsenic. The removal efficiency increases with the decrease of initial pH and the decrease of initial arsenic concentration. The calcium that is a major component comes from dissolution of the lime (CaO). The calcium concentration increased at low initial pH because the solubility of the lime (CaO) increases at acidic condition. The equilibrium pH sharply increase after reaction because of creation of hydroxide ion.