Effect of nitric acid modification on structure and adsorption properties of coal-based electrode materials

In order to improve the adsorption performance of coal-based electrode materials, the effect of nitric acid concentration on pore structure and electroche mical performance of coal-based electrode materials and its effect on the treatment of cyanide wastewater by electrode adsorption were studied. The pore size distributi on and electrochemical performance of coal-based electrode materials were characterized by low temperature ( 77 K) N2 absorption and cyclic voltammetry. The study shows that the specific surface area, the total pore volume and micro pore ratio of coal-based electrode materials increase at first and then decrease with increasing nit ric acid concentration, their specific capacitance increases, and the AC impedance decreases gradually. After mass fraction 40% nitric acid activation of coal-based elec trode materials has developed pore structure, specific surface area to reach 325 m2/g and average pore diameter 1.899 nm and total pore volume of 0.162 cm3/g, as electrode material for the mass specific capacitance of 120. 576 F/g. Nitric acid activation of coal-based electrode materials as anode and cathode, the electro adsorpti on technology for the treatment of cyanide wastewater, various ions in the solution removal rate increases with the increase of the concentration of nitric acid, when the nitric acid concentration is 40%, the removal effect is the best.