Chloride ion improving the electro-degradation of artificial sweetener alitame by porous three-dimensional membrane anode

In the present work, the electrochemical degradation of artificial sweetener alitame was performed by using two-dimensional plate anode and three-dimensional porous membrane anode. The results show that the alitame degradation rate increased about 10 times and energy consumption reduced 10 times, when the plate anode was replaced by porous membrane anode. The degradation rate constant of alitame was 0.305 min −1 and the energy consumption was 0.27 Wh L −1 using membrane anode at current density of 2 mA cm −2 . The presence of NO 3 − and HCO 3 − inhibited the alitame degradation, while Cl − improved the alitame removal significantly. The promotion effect was mainly ascribed to free chlorine specie in high chlorine content, and the effect in low chlorine content was attributed to ·OH, chlorine radical and free chlorine specie together. Twenty-six degradation products including three chlorinated intermediates were identified in the presence of chloridion. The degradation process mainly included hydroxylation, dehydrogenation, sulfur-replaced reaction, dehydration condensation and chlorinated reaction. Toxicity analysis results show that potential risks in developmental toxicity and mutagenicity should be not ignored when chloridion exists. These results demonstrate that electrocatalysis with three-dimensional membrane anode exhibits high efficiency in removing artificial sweeteners especially in a chlorine environment.