Junghyun Lim

Application of ultrasound and ozone for the removal of aqueous tannin

In order to investigate the enhancement of combination of ultrasound process and ozonation for the removal of aqueous tannin, tannin concentration, chemical oxygen demand (COD), and total organic carbon (TOC) were analyzed in ultrasound process, ozonation, and ultrasound/ozone process. Even though ultrasound process was not effective for the removal of aqueous in terms of tannin concentration, COD, and TOC, ultrasound process could enhance the removal efficiency significantly when it was combined with ozonation. It was also revealed that COD removal resulted in partly mineralization due to insufficient oxidation power, which was induced by ultrasound and ozone. However average oxidation state of all organics in the solution was increased cogently and as a result, biodegradability could be increased meaningfully. Therefore ultrasound/ozone process could be effective pre-treatment process to biological process for the removal of aqueous tannin.

Stabilization of Heavy Metal Contaminated Soil Amended with Waste Cow Bone

A stabilization/solidification (S/S) process for lead (Pb) contaminated soils was evaluated using waste cow bone containing apatite like compounds. Soil samples obtained form firing range were treated with waste cow bone. The effectiveness of stabilization was evaluated based on the Korean Standard Leaching Test (KSLT) and soil pH. The leached concentration reduced with increased in dose of waste cow bone. Overall, the KSLT results showed that Pb concentration in soils are significantly affected by amount of waste cow bone. When soil amended with 20 % of waste cow bone, less than 0.1 mg/kg was leached, and soil pH was increased from 6.5 to 8.4. Same results were obtained when finer waste cow bone was applied. The reachable concentration of Pb in soil showed in inversely proportional to solid/liquid ratio. Aging periods indicate improving mix design was applied. Relatively high lead concentrations was observed at the first 1 days, however leaching profile are reduced significantly over time for all mix designs.

Stabilization for Heavy Metal Contamination Soils which Uses the Coal Mine Drainage Sludge

In this study, to stabilize the heavy metal in the contaminated soils, the column leaching test based on rainfall and pH value was performed by using coal mine drainage sludge(CMDS): which was generated during electrical purification of abandoned coal mine wastewater. Four types of testing column were used in this study. That were the CMDS and the heavy metal contaminated soils well mixed in 0 wt%, 1 wt%, 3 wt% and 3 wt% layered column. According to the investigation, when the influent pH was , there were no heavy metal elution at all conditions, and when the influent pH was , the order of Cu, Zn, Pb, Cr elution concentration was 3 wt% M(mixed)