Catalytic Degradation Of Typicle Dye Wastewater By Spent Lithium Cobalt Battery Cathode Materials

In recent years,with the rapid development of the economy and industry of human society,people can not live without a large number of portable electronic products,and the demand for lithium-ion batteries?LIBs?is becoming more and more large,leading to the huge number of waste LIBs are produced.The cathode materials of these spent LIBs contain various transition metals,and these transition metals are widely used in the Advanced Oxidation Technologies?AOPs?of sewage treatment.Therefore,this paper mainly takes the most common LiCoO₂ batteries as the research object for the catalyst,and takes Rhodamine B?RhB?as the main model pollutants,carries out the following two aspects works:?1?the catalytic degradation of organic pollutants induced by activation of NaHSO₃?S?IV?below,simulation of aqueous sulfur?IV??with the spent LiCoO₂ battery cathode materials was achieved,which is based on Co-catalyzed bisulfite oxidation.First,the effects of initial LiCoO₂ concentration,initial NaHSO₃ concentration and initial pH value on degradation efficiency were investigated.The results show that the degradation rate of RhB first increases with the increase of the initial concentration of LiCoO₂ and NaHSO₃ in the solution,and then tends to be stable,the maximum degradation rate is close to 100%,and the acid condition is beneficial to the degradation of RhB.The free radical quenching activity identification test shows that the effective free radical of RhB degradation were ¹O₂/O₂^·-,SO₄^·-and^·OH,and ¹O₂/O₂^·-free radicals were played a major role.Through the XRD,XPS,SEM analysis of lithium cobalt powder before and after the reaction,it was proved that there were no changes of valence state on cobalt and LiCoO₂ did not transformed into other substances.Then,the possible reaction path of the process of ¹O₂/O₂^·-was proposed.In the end,the cathode material powder of spent LIBs was used for the LiCoO₂/S?IV?system to degrade RhB.The results showed that the degradation rate of RhB was above 99.5%after 50min,and it could be reused.?2?The peroxymonosulfate?PMS?is a common precursor of AOPs.Therefore,the LiCoO₂/PMS system degradation of RhB and its main influence parameters are studied in this experiments.It was found that the degradation rate of RhB in LiCoO₂/PMS system was increases with the increase of initial concentration of LiCoO₂ and PMS in the solution and tends to be stable,and it is beneficial to RhB degradation reaction under neutral conditions.The degradation rate of LiCoO₂/PMS system is generally faster than that of LiCoO₂/S?IV?system.And the identification of free radical quenching activity species showed that the ¹O₂and SO₄^·-radicals played a positive role in the process of RhB degradation,and ¹O₂ radicals were the main promoter.At last,the LiCoO₂/PMS system was used to pretreat the spent lithium cobalt lithium battery cathode material powder.The degradation rate of RhB was above 99.5%when the reaction was 5min,and the degradation rate of MB,AO7 and other dyes was also reached to 99.5%,and it could be reused.