Integrated electrochemically enhanced adsorption with electrochemical regeneration for removal of acid orange 7 using activated carbon fibers

The main objective of this study is to explore the feasibility of the combination of enhanced adsorption for acid orange 7 (AO7) in solution and regeneration of activated carbon fibers (ACFs) by electrochemical method. Electrochemical polarization can cause an increase of the adsorption rate and capacity for AO7 on the ACFs. The adsorption rate and capacity at the polarization of 600 mV increase by 120% and 115%, respectively. In all these cases the adsorption isotherms are in good agreement with Langmuir isotherm model. The effective electrochemical regeneration of ACFs saturated with AO7 is realizable. The regeneration efficiency of over 90% is achievable at -5 V, and the regeneration potential higher than -5 V is not advantageous to the readsorption of AO7. The results of the integrative electrosorption/regeneration cycle experiment show that the regeneration efficiency still maintains over 70% after 10 cycles. The integrative electrosorption/regeneration cycle process can reduce the regeneration procedure, and also decrease the adsorption costs. These indicate that the integrative electrosorption/regeneration cycle process is technically feasible and promising for the treatment of industrial effluents and the purification of supplying water. (C) 2007 Elsevier B.V. All rights reserved.