Effect of the presence of various natural organic matters on anodic oxidation of electrified carbon nanotube membrane.

Abstract

The widespread adoption of electrified carbon nanotube membranes (ECM) requires to better understand process effectiveness according to limiting phenomena of natural organic matters (NOMs). In this study, the influences of various NOM fractions were investigated on the oxidative degradation of Rhodamine B (RhB) in ECM. The results showed the decolorizing efficiencies of RhB in the presence of humic acid (HA) were still above 96%, while bovine serum albumin (BSA) reduced firstly and then increased the decolorizing efficiencies of RhB. The decolorizing efficiencies of RhB with alginate (AA) were over 98% at the first 15 min but decreased gradually to 76% after 150 min. These different performances of HA, BSA and AA were mainly due to their influences on the electrochemical reactivity characterization of ECM. ECM with the BSA depositing layer showed the highest exchange current density (j0), while the AA depositing layer restrained electron-transfer activity of ECM. Cyclic voltammetry (CV) experiments showed that the partial electrooxidation of BSA would occur in ECM with its degradation product observed in the effluent. The variation of electrochemical reactivity characterization of ECM resulted into its electri-oxidation and electri-adsorption rates to be the largest with BSA, followed by AA and HA.