Capacitive Deionization Using Activate Carbon Electrodes Obtained from Different Precursors

Abstract

Capacitive deionization (CDI) is a promising technique for brackish water desalination and water softening. It has been recognized that its performance is strongly dependent of the electrode properties such as specific surface area, pore volume, pore size distribution, and surface functional groups. Carbon is main material that fits all these requirements, allied to its lo high capacitance, conductivity, and low cost. Here, we present a comparison of the different activated carbons (AC) prepared in the Laboratory of Environmental Technologies using sugarcane bagasse fly ash (BFA) 1,2 , polyaniline activated carbon (PAC) 3,4 , and lignin activated carbon (LAC) 5 . Electrodes prepared with these materials were used in symmetric (SY) and asymmetric configurations (ASY) 4,5 , and in membrane CDI (MCDI) 4 as well. The best result was achieved using PAC electrodes prepared applying 500 o C as carbonization temperature. In this case, maximum adsorption capacity was 22.2 mg of NaCl removed per g of electrode, which is among the highest values reported in literature. References: Lado et al. (2016) J. Appl. Pyrolysis 120, 389. Lado et al. (2017) J. Appl. Pyrolysis 126, 143. Zornitta et al. (2017) Carbon 123, 318. Zornitta and Ruotolo (2018) Chem. Eng. J. 332, 33. Zornitta et al. (2018) ChemSusChem 11, 2101.