The Study Of Degradation Of Organic Pollutants On Cathode

With the method of membrane electrolysis cell,this paper studied the electrolytic degradation of Nitrobenzene(short for NB) and Rhodamine B(short for RhB) on cathodal room.It also talked about the electrochemical deoxidization characteristics of organics on cathodal room on the present of dissolved oxygen and without the prensent of dissolved oxygen.As a contrastive experiment,it also focused on the electrochemic degradation of RhB on the room of anode.It studied the reaction mechanism of NB with OH and H on cathodal room.The results showed:The experiment showed that,the volatilization of NB and its products during the process of eletroclysis is too little to be ignored;the membrane used in the study was so good that it can avoid the infiltration of organics during the electrolysis.On the condition of applied voltage 20 V,the original pH of the electrolyte 5.3,the concentration of electrolyte Na2SO41 g/L,concentration of RhB 50 mg/L,electrolysis time 2 h and with the present of dissolved oxygen,the removal rate of RhB and COD_Cr is 45%and 21%respectively,contracting to that of 40%and 15%without the prensent of dissolved oxygen.On the condition of applied voltage 20 V,the original pH of the electrolyte 5.3, the concentration of Nitrobenzene 120 mg/L,the concentration of electrolyte Na₂SO₄ 0.025 mol/L,electrolysis time 2 h,and with the present of dissolved oxygen,the removal rate of COD_Cr was 36%,contracting to that of 16%without the prensent of dissolved oxygen.The electrolytic degradatons of NB and RhB belonged to pseudo-first order reaction.And different factors had different effect on the degradation of organics.The electrolytic reaction mechanism of cathodal room was:during the courses of electrolysis,the H⁺ of H₂O get an electron,become H.H and O₂ react quickly in the electrolyte,and make HO₂ and OH,which are strong active.HO₂ and OH can oxidate NB.