Single‐Stage Optimized Microwave‐Induced Activated Carbon from Coconut Shell for Cadmium Adsorption

The toxicity of heavy metals motivated the synthesis of coconut shell‐based activated carbon (CSAC) through single‐stage microwave irradiation technique to scavenge cadmium ions (Cd(II)). Response surface methodology revealed the optimum radiation power and radiation time which translated into 85.45 % of Cd(II) removal and 41.78 % of CSAC's yield. Isotherm and kinetic data were best described by Freundlich and pseudo‐first‐order (PFO) models, respectively. The changes of enthalpy, entropy, and activation energy were determined as well as the reduction of CSAC yield and Cd(II) removal after six regeneration cycles.