Sulfhydryl-Modified Chitosan Aerogel for the Adsorption of Heavy Metal Ions and Organic Dyes

Heavy metal ions and organic dyes are the main hazardous substances in natural waters, and the treatment of one single component can no longer meet the increasingly severe water pollution situation. In this paper, sulfhydryl-modified chitosan was made into an aerogel by a freeze-drying process that can effectively adsorb heavy metal ions and organic dyes. The adsorption capacities on Cu(II), Pb(II), and Cd(II) ions were 81.15, 38.87, and 38.15 mg g–1, respectively, whereas the adsorption capacities for different organic dyes (methyl orange, methylene blue, rhodamine B, and Sudan I) can all reach 50 mg L–1. The results showed that the optimal adsorption pH values of Cu(II) and Cd(II) was 6.0 and that of Pb(II) was 5.0. Besides, the decolorization rate of organic dyes can reach 99% (methyl orange). The present findings of the as-synthesized sulfhydryl-modified chitosan aerogel with low cost and environmental-friendly property all demonstrate its potential for practical treatment of waste water.