A novel color removal adsorbent from heterocoagulation of cationic and anionic clays

We report the preparation and characterization of a novel nanocomposite adsorbent for anionic dye removal. The nanocomposite adsorbent was prepared by heterocoagulation of delaminated bentonite and layered double hydroxide (LDH) colloids. The effects of preparation conditions, LDH loading, particle size, and calcination temperature of the modified material on the physicochemical properties of this composite adsorbent have been investigated. The optimal conditions for best Reactive Yellow 2 (RY2) dye removal efficiency are a weight ratio of LDH to bentonite of 1:1, LDH particle size 100 nm, and calcination temperature 673 K. The adsorption equilibrium data can be fitted well by the widely accepted adsorption isotherm models.

After modification, the small flakes of LDH nanoparticles seem to be bound onto the bentonite surface, evidenced by a large number of overlapped hexagonal LDH structures on the bentonite surface.SEM image of LDH-modified bentoniteFigure optionsDownload as PowerPoint slide