| Abstract |
| The purposes of this research are to know the heavy metal removal capability of EPSs(Extracellular Polymeric Substances) extracted from activated sludge, and also to find out which kinds of EPSs is the most effective substances for heavy metal removal. To study the heavy metal removal by EPSs, the biosorption tests were performed with bound-EPSs extracted from activated sludge, soluble-EPSs in effluent of activated sludge cultivation reactor, and alkaline soluble-EPSs added NaOH solution to soluble-EPSs to study the effect of OH- radical on biosorption, respectively. Experiments were investigated on Pb, Cd, Cu, As and Zn metal ions and the EPS components were polysaccharides, proteins, uronic acids, humic substances. In the biosorption removal results for heavy metal the soluble-EPSs showed much more removal efficiency than bound-EPSs. Further, as EPS concentration is higher, in case of the soluble-EPSs, the removal efficiency represented the upward trend in order of Pb, Cu, Zn, Cd except for As. The heavy metal removal efficiency by the alkaline soluble-EPSs was more effective than by the soluble-EPSs. From the analysis results for variation of the soluble-EPSs components, which performed coincidently with studying on heavy metal removal, the protein portions of them showed more reducing in concentration than others, and also was observed intensive peaks formations and disappearances corresponding to protein and polysaccharide groups with FT-IR spectra. Consequently, the major component of metal biosorption by EPSs was considered the protein component corresponding to amino functional group. |
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| Key Words |
| Bound-EPSs, Soluble-EPSs, EPSs, metal biosorption |
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