Development of Spirulina/chitosan foam adsorbent for phenol adsorption

A new adsorbent composed with Spirulina and chitosan was developed to phenol removal from aqueous solution. The material was synthesized to obtain a hybrid foam, and then it was characterized by scanning electron microscopy (SEM), infrared spectrum (FT-IR), thermogravimetric analysis (TGA) and Bennett, Emmet and Teller (BET) method. Isotherms were performed in different temperatures and thermodynamic parameters were estimated. Kinetics behavior was evaluated using different stirring rates (50, 100 and 150 rpm) and was adjusted to different kinetic models. The results show the adsorbent presented a rough and irregular surface, which indicates good accessibility to phenol onto an adsorbent surface, a specific surface area of 1112 m2 g−1 and pore sizes from 45 to 140 μm. Dubinin-Radushkevich isotherm was the most appropriated to represent the equilibrium data and the maximum adsorption capacity was 447.6 mg g−1. Thermodynamics parameters indicated that the adsorption was exothermic. Pseudo-first-order kinetic model was the most adequate to represent the adsorption phenomenon at all rotations. [Display omitted] •New adsorbent of Spirulina and chitosan was developed and used for phenol removal.•The adsorbent presented a specific surface area of 1112 m2 g−1.•The maximum adsorption capacity was 447.6 mg g−1 at 30 °C.•Phenol adsorption operation was favorable and exothermic.