Study on Synthesis of Comb-Shaped Chitosan-Graft-Polyethylenimine Dithiocarbamate Material and Its Adsorption to Heavy Metal Ions

How to efficiently and economically remove heavy metals from sewage has been a huge challenge in the world. This article reports on an adsorbing material with comb-shaped chitosan–grafted polyethyleneimine dithiocarbamate (CC-GP-D), which is prepared by grafting polyethyleneimine on chitosan as main chain via glutaraldehyde, then reduce the generated C=N double bond using NaBH4, and finally functionalizing primary and secondary amino groups with CS2. This comb-shaped structure adsorbent material can better contact with heavy metal ions, so that it can absorb more heavy metal ions at a faster rate. This material is more green, environmentally friendly and economical with chitosan as the main chain. The material can effectively adsorb heavy metals in sewage, such as cadmium (II), copper (II), lead (II), nickel (II), and cobalt (II). After 80 min of adsorption, its adsorption capacity for cadmium (II), copper (II), lead (II), nickel (II), and cobalt (II) reached 178.7 mg/g, 138.9 mg/g, 337.7 mg/g, 109.2 mg/g, 157.6 mg/g respectively.