Preparation of Waste Coffee-grounds Carbon and Study on Phenol Adsorption Ability

The waste coffee-grounds carbon (WCGC) was prepared with H3PO4 treated using waste coffee-grounds as precursor. Its adsorption ability was studied using phenol as test molecule. The influence of H3PO4 treated, calcined temperature, the initial phenol concentration, the doge of carbon and original pH values on phenol adsorption ability were investigated. Characterization of WCGC was performed by N2 adsorption isotherms, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) techniques. First, the second order and Weber-Morris model reaction rate models were used to estimate the WCGC adsorption ability. The results show that the produced WCGC (700 °C, 2 h) has been graphitized and the layered structure increased BET surface to 435.98 m2/g and adsorption phenol ability. The initial phenol concentration is 50 mg/L, the amount of WCGC (700 °C, 2 h) is 0.2 g, and the phenol adsorption rate is 97% after 270 min and no intermediate product formation. The adsorption kinetics of the selected WCGC is best fitted by the Weber-Morris model.