Cellulose derived from corn straw for the efficient adsorption of Cd(II) from water

Abstract

In order to study the adsorption performance of modified cellulose on Cd(II) in wastewater, cellulose was extracted from corn straw by the extraction method of nitric acid-ethanol, and three modified cellulose materials, that is, chitosan-cellulose (Cell-CS), citric acid-cellulose (Cell-CA) and chitosan/citric acid-cellulose (Cell-CA-CS) were prepared by single and compound modification of chitosan and citric acid. The adsorption properties of modified cellulose materials for Cd(II) in water were studied by laboratory simulation. The results from the structure characterization with Fourier-transform infrared spectroscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy showed that the group of C=O occurred on the surface of Cell-CA, chitosan particles were attached to the surface of Cell-CS; Cell-CA-CS was being of the structural characteristics of both of Cell-CS and Cell-CA. The results from the adsorption test showed that the adsorption kinetic characteristics of Cd(II) in water can be described by pseudo-second-order kinetic model, and the adsorption thermodynamic characteristics can be described by Langmuir equation. The adsorption capacity of cellulose materials for Cd(II) in water was in the order of Cell-CA-CS > Cell-CS > Cell-CA > Cell. The result from the five times of adsorption-regeneration showed that Cell-CA-CS still had a large adsorption capacity for Cd(II) in water and consequently had great potential for the treatment of Cd(II) containing wastewater.