A fixed-bed electrochemical reactor with nano-TiO_2 loading flat-sheet carbon membrane as anode for phenolic wastewater treatment

摘要

Nano-TiO2 loading flat-sheet microporous carbon membranes with four different thicknesses (4.9-10.3 mm) were prepared and employed as an anode to constitute fixed-bed electrochemical reactor (FBER) for phenolic wastewater treatment. Electroanalytic measurements were used to investigate the electrochemical properties of TiO2/carbon membranes. Results showed that the TiO2/carbon membrane with a thickness of 10.3 mm exhibited the best electrochemical performance. The peak current, effective surface area, charge transfer resistance (R-CT), and the diffusion coefficients obtained from TiO2/carbon membrane with a thickness of 10.3 mm were 7.3 mA, 4.74 cm(2), 2.49 Omega, and 6.88 x 10(-3) cm(2)/s, respectively. Meanwhile, the thickness of carbon membrane electrode is also closely related to its hydrodynamic resistance and the permeability. Further, the removal rates of phenol and chemical oxygen demand (COD) obtained from TiO2/carbon membrane with a thickness of 10.3 mm under the operating conditions of 10.0 mmol/L phenolic wastewater, residence time of 7.8 min, and current density of 1.0 mA/cm(2) were up to 89.3% and 97.5%, respectively. Moreover, the energy consumption of FBER was only 0.36 kWh/kg COD. FBER also demonstrated an excellent stability.