Biopolymer-based porous adsorbents able to retain a wider spectrum of aquatic pollutants are important in the context of actual complex water pollution challenges. By blending cellulose with chitosan and by simultaneous doping it with activated carbon the spectrum of pollutants that can be adsorbed by such porous nanocomposites can be expanded.

Abstract

Porous spherical adsorbents based on natural biopolymers, pure and co-doped with activated carbon (AC), were prepared via dropping cum non-solvent-induced phase separation from ionic liquid–based solution. Their adsorption properties toward different types of model pollutants were evaluated. Blending of cellulose with chitosan (cellulose/chitosan = 75/25 wt/wt) led to improved adsorption of Cu²⁺ and methyl orange (MO). Co-doping with AC (10 wt % with respect to the biopolymer) clearly improved adsorption of dyes and tetracycline (TC) but slightly reduced adsorption of Cu²⁺. From mixed pollutant solutions, it was observed that TC and methylene blue can be adsorbed without competing for the same adsorption sites, whereas Cu²⁺ and MO slightly compete.