Effects of Biochar Produced At Different Pyrolysis Temperatures On the Immobilization and Retention of Heavy Metals in the Soil.

Effects of biochar produced at different pyrolysis temperatures on the immobilization and retention of heavy metals in the soil

 

Yong-Seong Kim^a, Seunghun Hyun^a*, Taeyong Shim^a, Jinho Jung^a, Changkook Ryu^b

 

^a Division of Environmental Science and Ecological Engineering, Korea University, Anam-dong Seongbuk-Gu 136-701, Seoul, Republic of Korea

^b School of Mechanical Engineering, Sungkyunkwan University, Suwon, 440-746, Republic of Korea

drasound@korea.ac.kr, soilhyun@korea.ac.kr, xisor@korea.ac.kr, jjung@korea.ac.kr, cryu@me.skku.ac.kr

Biochar, by product of pyrolysis process of biomass, has attracted research interest due to its agricultural and environmental benefit such as increasing the soil carbon pool and improving crop productivity.  In addition, applying biochar to soil leads to environmental benefit such as improved acid soil and reduced immobilization of hazardous heavy metals because of increased soil pH.  However, the immobilization and retardation effects of biochar to soil application are largely unknown, because various physico-chemical properties derived from different pyrolysis temperatures.

The objectives of the this study was to evaluate the impacts of biochar (derived from Miscanthus) produced at different pyrolysis temperatures (at 400, 500, and 700 ^oC) on the immobilization and retention phenomenon of heavy metals in the soils.  To evaluate of effects of biochar on the immobilization and retention of heavy metals in the soils, the leaching column test use an acrylic column (7 cm in length, 2.5 cm I.D., and cross-sectional area of 4.91 cm²).  The column was packed with soil samples and biochar such as liner materials, and a displacement experiment was conducted under water-saturated conditions.  The column effluent solution was collected as a function of the pore volume using fraction collector.  The concentrations of aqueous heavy metals and the pH of the effluents were determined. In order to characterize the heavy metals leaching behavior through the biochar as a liner material in the column, the concentration profile of each heavy metals in the effluent solution collected as a function of the pore volume was interpreted using the moment analysis technique.