| dc.description.abstract | Phosphates are common inorganic salts in our lives and are often used as food additives, chemical fertilizers, etching liquids used in TFT-LCD processes, and etc. When phosphate is discharged into the natural water, it may cause the eutrophication and lead to deterioration of water quality.
In this study, capacitive deionization was employed to remove phosphate. Sodium phosphate (NaH2PO4) solution was prepared to simulate the phosphorus-containing wastewater. Activated carbon were used as electrode material of CDI to adsorb phosphates. The deionization efficiency was investigated by changing flow rate, voltage, initial concentration, and pH. Four kinetic models, including pseudo-first-order, pseudo-second-order, Elovich, and intra-particle diffusion models, were employed to fit the electrosorption kinetic of phosphate and two isotherm models, including Langmuir and Freundlich, were employed to fit the electrosorption equilibrium of phosphate.
The specific surface area and pore size distribution and cyclic voltammogram of the activated carbon electrode showed that the mesopore was the major structure and the AC electrode had good electrochemical stability. The results suggested that slow flow rate, voltage at 1.2 V, and low pH are good for the removal of phosphate by activated carbon electrodes via CDI. The adsorption kinetics could be described by the Elovich and the intra-particle diffusion models, and the Freundlich model agreed with the isotherm for the adsorption of phosphate on activated carbon electrode. | en_US |