Kinetic and Thermodynamic Studies on Adsorption of Cu 2+ , Pb 2+ , Methylene Blue and Malachite Green from Aqueous Solution Using AMPS-modified Hazelnut Shell Powder

A high-efficiency, low-cost and environment-friendly 2-acrylamide-2-methyl propane sulfonic acid (AMPS)-modified hazelnut-shell-based adsorbent(AHS) was synthesized and used to adsorb Cu2+, Pb2+, methylene blue(MB) and malachite green(MG) from aqueous solutions. The AHS was characterized by means of SEM, BET, FTIR and XPS. Different experimental parameters were evaluated in batch adsorption experiments to determine the optimal adsorption conditions. Adsorption kinetics shows that the adsorption rate is well represented by the pseudo- second-order rate model, and the Langmuir model gives the best fit adsorption isotherm. The Langmuir maximum adsorption capacities were found to be 21.14 mg/g for Cu2+, 32.74 mg/g for Pb2+, 68.03 mg/g for MB and 263.16 mg/g for MG, respectively, while the adsorption capacities could be maintained above 90% even after ten adsorp-tion-desorption cycles. The experimental results show that AHS could be applied to treat both industrial and munici-pal wastewaters.