Study on Degradation of Acid-red B in Wastewater by Electro-catalytic Oxidation with TiO2-loaded Activated Carbon

LI Feizhen; XIE Di; ZHAO Yuan; LI Xue; LIANG Wenyan

doi:10.3969/j.issn.1003-6504.2017.01.004

Abstract：A bench scale experimental study was conducted with catalytic particle electrodes of granular activated carbon coated by titanium dioxide prepared by the sol-gel method,which was applied to degradation of acid red B in dyeing wastewater.The X-ray diffraction pattem showed that the loaded TiO2 was the mixed crystal type of anatase and rutile phase,and the FESEM-EDS (field emission scanning electron microscope energy dispersive) spectrometer indicated that the quality percentage of Ti element on the GAC surface was approximately 14.4％.Besides,N2 adsorption-desorption curves showed that the BET specific area and pore volume of TiO2/GAC were 708.5 m2/g and 0.395 4 cm3/g,respectively,and the particles were of mostly micro-pores,similar to GAC.The treatment of acid red B in the wastewater by use of TiO2/GAC was conducted under the condition,i.e.the current was 0.6 A,concentration of Na2SO4 0.03 mol/L,and the hydraulic retention time 20 min;and thus the removal efficiency in terms of COD and TOC by TiO2/GAC particle electrode were 68.60％ and 45.12％,respectively,an increase of 35％ for COD and 30％ for TOC,in comparison with the use of GAC.The investigation on the dye degradation process by UV-Vis and fluorescence absorption spectra showed that the high current was conductive to the degradation of acid red B,and the intermediate degradation products were mainly consisted of fulvic acid-like substances;in addition,degradation of acid red B led to an increase of the concentration of fulvic acid-like substances that possessed fluorescent absorption character.