Removal of lead from aqueous solution via single stage microwave-assisted coconut shell based activated carbon

Coconut shell-based activated carbon (CSAC) adsorbent has been utilized for the adsorption of Pb2+ ions from aqueous solution. The CSAC was prepared by single stage microwave-assisted irradiation technique under CO2 gas condition. Results showed a high BET surface area and total pore volume of CSAC which are 602.15 m2/g and 0.39 cm3/g, respectively with average pore diameter of 4.20 nm. The adsorption uptakes of Pb2+ increased from 0.96 to 7.84 mg/g as the initial concentration increased from 1 to 10 mg/L. The modelling study reveals that Freundlich isotherm and pseudo-second order fits well with CSAC-Pb system which suggested multilayer adsorption and the rate limiting step was contributed by chemisorption. The Langmuir maximum monolayer adsorption capacity, Qm was revealed to be 9.36 mg/g.