| Autor: |
Crist, Ray H., Martin, J. Robert, Crist, Delanson R. |
| Předmět: |
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| Zdroj: |
Separation Science & Technology; May2004, Vol. 39 Issue 7, p1535-1545, 11p |
| Abstrakt: |
Kraft lignin, a by-product in paper production, was converted to a material with high potential for applications in removing toxic metals from process waters. The acid form of kraft lignin in powder form was first converted to Ca-loaded material by treatment with various amounts of calcium hydroxide and then to a hard solid by combination with a resin in dimethylformamide (DMF) and heating. Strips of these lignin products (LP) were effective in removing Pb and Cd from solutions, with a Pb capacity of ca. 350 µmol/g. One mole of Ca was released to solution for each mole of Pb sorbed, thereby demonstrating that metal uptake was an ion exchange process and not simple adsorption. Advantages to these LP are that 1) they are reuseable with no loss in Pb uptake after eight cycles of uptake/regeneration, 2) their high structural stability is maintained even after immersion in water for 6 weeks, and 3) the DMF used in their preparation can be recovered and recycled. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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