| Title |
Effect of Humic acid on the Distribution of the Contaminants with Black Shale |
| Authors |
민지은 ( Jee Eun Min ) ; 박재우 ( Jae Woo Park ) |
| Keywords |
Sorption; Humic acid; Black shale; Reduction; Trichloroethylene; Chromate; Lead; Cadmium |
| Abstract |
Humic acids are macromolecules originated from natural water, soil, and sediment. The characteristics of humic acid enable it to change the distribution of metals as well as many kinds of organic contaminants and to determine the sorption of them from soil solution. To see the effect of humic acid on the removal rate of organic contaminants and heavy metals, batch-scale experiments were performed. As a natural geosorbent, black shale was used as a sorbent media, which showed hight sorption capacity of trichloroethylene (TCE), lead, cadmium and chromium. The effect of sorption-desorption, pH, ionic strength and the concentration of humic acid was taken into consideration. TCE sorption capacity by black shale was compared to natural bentonite and hexadecyltrimethylammonium (HDTMA) modified bentonite. The removal rate was good and humic acid also sorbed onto black shale very well. The organic part of humic acid could effectively enhance the partition of TCE and it act as an electron donor to reduce Cr(Ⅵ) to Cr(Ⅲ). Cationic metal of Pb(Ⅱ) and Cd(Ⅱ) also removed from the water by black shale. With 3 mg/L of humic acid, both Pb(Ⅱ) and Cd(Ⅱ) were removed more than without humic acid. That could be explained by sorption and complexation with humic acid and that was possible when humic acid could change the hydrophobicity and solubility of heavy metals. Humic acid exhibited desorption-resistivity with black shale, which implied that black shale could be an alternative sorbent or material for remediation of organic contaminants and heavy metals. |