Abstract: The waste Aspergillus niger mycelium and chitosan were cross-linked by epichlorohydrin and then solidified sodium tripolyphosphate to prepare the Aspergillus niger mycelium-chitosan biosorbent for Cu²⁺. The effects of adsorption time, pH value, temperature, the initial concentration of Cu²⁺ and the amount of biosorbent on the adsorption efficiency were investigated. Kinetics, intragranular diffusion model, adsorption isotherm equation, thermodynamic model were used to fit the experimental data. The results showed that the adsorption rate increased by increasing the adsorption temperature, adsorption time and pH value. The adsorption rate of Cu²⁺ reached 99.42% at the adsorption conditions of 0.4 g Aspergillus niger mycelium-chitosan biosorbent, adsorption time 180 min, adsorption temperature 50℃, mass concentration of Cu²⁺ 20 mg/L. The adsorption process conformed to the Freundlich isotherm model. The adsorbed Gibbs free energy became negative, and ΔH^ɵ were ΔS^ɵ are 6.104 2 kJ/mol and 45.258 1 J/(mol·K), respectively, ie the adsorption was a spontaneous endothermic process. Kinetic data analysis showed that the adsorption of Cu²⁺ by Aspergillus niger mycelia-chitosan biosorbents fitted quasi-second-order kinetic model.

Key words: Aspergillus niger, mycelium, chitosan, Cu²⁺, adsorption process