The Controllable Construction Of Cobalt-Based Confined Mass Transfer Catalytic Membranes For Organic Arsenic Harmless Treatment

The harmfulness of arsenic containing chemical agents due to their high toxicity and high fluidity has become one of the public health and safety issues of global focus.Recently,powder heterogeneous catalysis activated peroxymonosulfate（PMS）advanced oxidation reaction has been widely used in the arsenic containing agent harmless treatment due to the advantages of environmental friendliness,high efficiency,wide working p H.Cobalt-based catalysts have become a research hotspot for PMS activation due to their high reactivity and activity.However,the traditional batch-reaction cobalt-based catalyst activation PMS process has problems such as low mass transfer efficiency,low production/utilization efficiency of reactive species（ROS）,low efficiency of in-situ generation of inorganic arsenic and difficulty in powder agglomeration and recovery.Therefore,in response to the significant demand for harmless treatment of arsenic containing chemical agents,this paper uses p-aminophenylarsenate（p-ASA）as an organic arsenic simulant and GO as an assembly unit.Based on vacancy engineering,confinement effects,and bimetallic synergistic effects,controllable construction of different dimensions of confinement mass transfer catalytic membranes is carried out to improve PMS activation efficiency,ROS production/utilization efficiency,organic arsenic degradation and synchronous immobilization of inorganic arsenic.The specific research content is as follows:1.The controllable construction of oxygen vacancy-rich Co-Mo O3/GO 2D/2D confined mass transfer catalytic membranes for p-ASA harmless treatmentTo improve mass transfer efficiency and ROS generation/utilization efficiency,In this study,the Co-Mo O₃/GO 2D/2D confined mass transfer catalytic membranes were fabricated by using vacancy-rich Co Mo O₃ and GO as assembly units.Compared to Mo O₃/GO membranes,Co-Mo O₃/GO membranes have more oxygen vacancies and electron-poor Co reaction centers,transforming the reaction path from a traditional free radical path to a non-free radical one,and are resistant to external environmental influences（such as the 2-10 p H range and coexisting anions）.The optimized Co-Mo O₃/GO catalytic membrane/PMS system degrades 97.91%organic arsenic,and its degradation rate constant(23.79 s^-1)is increased by 4 orders of magnitude compared to that of powder catalysts.It achieves harmless treatment for more than 10 hours in long-performance experiments.2.The controllable construction of Hollow PBA/GO 3D/2D confined mass transfer catalytic membranes for p-ASA harmless treatmentTo improve the effective exposure area of the active sites and the efficiency of immobilization of the in-situ released inorganic arsenic.In this study,coupling of hollow structure（CFHC）Co Fe-PBA using solvothermal etching and GO acts as an assembly unit to prepare the CFHC/GO 3D/2D confined mass transfer catalytic membrane.Compared with Co Fe PBA,CFHC has more accessible active sites and large specific surface area,and achieves higher organic arsenic removal rate under the synergistic effect of localized mass transfer.The rate constant of the optimized CFHC/GO membrane/PMS system activated PMS degradation rate constant of p-ASA is 0.1 s^-1,which is nearly two orders of magnitude higher than the powder Co Fe-PBA/PMS system.Originally confirmed by infrared and electrochemical analysis,the catalyst-PMS*complex and ¹O₂ non-free radical dominated p-ASA degradation.In the catalytic membrane persistence experiment,the p-ASA harmless treatment was stable for 24 hours,and compared to the previous chapter,its achieved almost 100%total arsenic removal within 24 hours.3.The controllable construction of Hollow Co Fe-LDH@Mo S2 3D/2D confined mass transfer catalytic membranes for p-ASA harmless treatmentTo improve the activation efficiency of PMS and the production/utilization efficiency of ROS.this chapter focuses on Co Fe-LDH@Mo S₂ Build with GO as an assembly unit LDH@Mo S₂/GO limited mass transfer catalytic membrane.Compared to Co Fe-LDH,Co Fe-LDH@Mo S₂ The catalyst support interaction between LDH and Mo S₂ changes the electron density at the interface,so that PMS and p-ASA are enriched at the interface.The LDH@Mo S₂/GO membrane/PMS system degrades 95.6%p-ASA at a rate constant of 0.08 s^-1,which is two orders of magnitude higher than that of Co Fe-LDH@Mo S₂/PMS batch-reaction,and the total arsenic removal efficiency is close to 100%.The original infrared,in situ Raman,and electrochemical analysis confirmed that the catalyst PMS*complex mediated the production of ¹O₂,achieving higher than24-hour harmless treatment of organic arsenic.