RESEARCH ARTICLE Macro-fungal (Agaricus bisporus) wastes as an adsorbent in the removal of the acid red 97 and crystal violet dyes from ideal colored effluents Fernanda Caroline Drumm 1 & Dison Stracke Pfingsten Franco 1 & Jordana Georgin 2 & Patrícia Grassi 1 & Sérgio Luiz Jahn 1 & Guilherme Luiz Dotto 1 Received: 11 June 2020 /Accepted: 12 August 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 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: 0.5 g L -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 210 min and an adsorption capacity of 165 mg g -1 for the AR97. Concerning the CV kinetics, it took 120 min to reach the equilibrium and it achieved an adsorption capacity of 165.9 mg g -1 . The Elovich model was the most proper model for describing the experimental data, achieving an R 2 ≥ 0.997 and MSE ≤ 36.98 (mg g -1 ) 2 . The isotherm curves were best represented by the Langmuir model, predicting maximum adsorption capacity of 372.69 and 228.74 mg g -1 for the AR97 and CV, respectively. The process was spontaneous and favorable for both dyes. The ΔH 0 values were 9.53 and 10.69 kJ mol -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. Keywords Acid red 97 . Crystal violet . Eco-friendly adsorbent . Fungal wastes Introduction Currently, the industrial activities are more intensive, thereby the consumption of tons of dyes in different industrial process- es has been growing. It is recognized that after each of these processes, a considerable number of effluents are generated, which need proper treatment before being disposed into the environment. The key problem is due to high toxicity, which affects the aquatic biome and other living beings (Gupta et al. 2013). Among the employed dyes, the crystal violet (CV) is known to be carcinogenic and mutagenic. However, it is still highly used in diverse sections of the textile industry, biolog- ical coloration, and dermatological agent. At lower concentra- tions, it can penetrate the skin, causing irritation and problems in the digestive system; in extreme cases, it can lead to breath- ing difficulties, kidney failure, and permanent blindness (Sarma et al. 2016). Another highly used dye in the textile and leather industries is the acid red 97 (AR97). Living organ- isms cannot degrade it, so in small concentrations, it can al- ready damage animals and humans (Bankole et al. 2018). In this sense, the removal of these dyes from water resources is of great importance (Rigueto et al. 2020). The adsorption is an efficient and easy operation method and is economical when employing low-cost adsorbents (Dotto and McKay 2020). Several studies utilizing different biomass based on macro-fungi for the removal of dyes have been reported. These fruiting bodies present great advantages: Editorial Responsibility: Philippe Garrigues Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11356-020-10521-9) contains supplementary material, which is available to authorized users. * Guilherme Luiz Dotto guilherme_dotto@yahoo.com 1 Chemical Engineering Department, Federal University of Santa Maria, Santa Maria 97105-900, Brazil 2 Civil Engineering Department, Federal University of Santa Maria, Santa Maria 97105-900, Brazil Environmental Science and Pollution Research https://doi.org/10.1007/s11356-020-10521-9