Removal of Cu2+ ions from aqueous solution by the abandoned mushroom compost of Flammulina velutipes.

The abandoned mushroom compost of Flammulina velutipes, a cheap and easy by-product to get, was used as biosorbent for removing copper ions from aqueous solution. Batch experiments were carried out to investigate the effect of contact time, solution pH, biomass dosage, initial concentration of Cu2+ ions and temperature on biosorption efficiency. The maximum sorption capacity could be reached at pH 5.0 in 60 min. Langmuir, Freundlich, and Redlich- Peterson isotherm models were used to fit the experimental data and their model parameters were evaluated. The calculated qm based on Langmuir equation was 35.608 mg g(-1) at 288 K, 48.711 mg g(-1) at 298 K, and 42.330 mg g(-1) at 308 K, respectively. The kinetics were discussed by pseudo- first order and pseudo-second order models, and the result showed that the latter was more suitable. The thermodynamics of biosorption was also investigated, and the biosorption process was feasible, spontaneous and endothermic in nature.