Preparation of Silk Sericin/Lignin Blend Beads for the Removal of Hexavalent Chromium Ions.
In the present study, novel adsorbents having high adsorption capability and reusability were prepared using agricultural by-products: silk sericin and lignin. Silk sericin and lignin blend beads were successfully prepared using simple coagulation methods for the removal of hexavalent chromium (Cr(VI)) from aqueous solution. A 1 M lithium chloride (LiCl)/dimethyl sulfoxide (DMSO) solvent system successfully dissolved both sericin and lignin and had sufficient viscosity for bead preparation. Compared to the conventional sericin bead adsorbent, sericin/lignin blend beads showed higher Cr(VI) adsorption capacity. The amount of lignin added to the adsorbent greatly affected the adsorption capacity of the beads, and a 50:50 sericin/lignin blend ratio was optimal. Adsorption behavior followed the Freundlich isotherm, which means the adsorption of Cr(VI) occurred on the heterogeneous surface. Cr(VI) adsorption capability increased with temperature because of thermodynamic-kinetic effects. In addition, over 90% of Cr(VI) ions were recovered from the Cr(VI) adsorbed sericin/lignin beads in a 1 M NaOH solution. The adsorption-desorption recycling process was stable for more than seven cycles, and the recycling efficiency was 82%. It is expected that the sericin/lignin beads could be successfully applied in wastewater remediation especially for hazardous Cr(VI) ions in industrial wastewater.
Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea. bk0502@snu.ac.kr.
Hyo Won
HW
Kwak
Department of Biosystems & Biomaterials Science and Engineering, Seoul National University, Seoul 151-921, Korea. smj0626@snu.ac.kr.
Munju
M
Shin
Department of Biosystems & Biomaterials Science and Engineering, Seoul National University, Seoul 151-921, Korea. finale17@snu.ac.kr.
Haesung
H
Yun
Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea. prolee@snu.ac.kr.|Department of Biosystems & Biomaterials Science and Engineering, Seoul National University, Seoul 151-921, Korea. prolee@snu.ac.kr.|Center for Food and Bioconvergence, Seoul National University, Seoul 151-921, Korea. prolee@snu.ac.kr.
Ki Hoon
KH
Lee
D000327:Adsorption; D002857:Chromium / Q000737:chemistry*; D008031:Lignin / Q000737:chemistry*; D008863:Microspheres; D047030:Sericins / Q000737:chemistry*
D047030:Sericins; D002857:Chromium; C076151:Kraft lignin; D008031:Lignin
adsorption; beads; hexavalent chromium; lignin; silk sericin