Macro-fungal (Agaricus bisporus) wastes as an adsorbent in the removal of the acid red 97 and crystal violet dyes from ideal colored effluents.

Abstract

The wastes from the macro-fungus Agaricus bisporus were used as an eco-friendly and low-cost adsorbent for the treatment of colored effluents containing the recalcitrant dyes, acid red 97 (AR97) and crystal violet (CV). The macro-fungal waste presented an amorphous structure, composed of particles with different sizes and shapes. Also, it presents typical functional chemical groups of proteins and carbohydrates with a point of zero charge of 4.6. The optimum conditions for the dosage were found to be as follows: 0.5gL-1 with an initial pH at 2.0 for the AR97 and 8.0 for the CV. From the kinetic test, it was found that it took 210min and an adsorption capacity of 165mgg-1 for the AR97. Concerning the CV kinetics, it took 120min to reach the equilibrium and it achieved an adsorption capacity of 165.9mgg-1. The Elovich model was the most proper model for describing the experimental data, achieving an R2≥ 0.997 and MSE ≤ 36.98 (mgg-1)2. The isotherm curves were best represented by the Langmuir model, predicting maximum adsorption capacity of 372.69 and 228.74mgg-1 for the AR97 and CV, respectively. The process was spontaneous and favorable for both dyes. The ∆H0 values were 9.53 and 10.69kJmol-1 for AR97 and CV, respectively, indicating physical and endothermic adsorption. Overall, the wastes from Agaricus bisporus have the potential to adsorb cationic and anionic dyes, thus solving environmental problems related to water quality and residue disposal.