Study On Mesoporous Carbon-loaded Transition Metal Activated Peroxymonosulfate For The High-efficiency Degradation Of Norfloxacin

With the advancement of globalization and the development of industry and agriculture,environmental pollution has become a critical issue that plagues people’s daily lives.With the detection of multiple antibiotic organic pollutants in various water bodies and the conventional treatment methods of sewage treatment plants are insufficient to effectively remove these organic pollutants.Therefore,it is particularly important to develop a method that can efficiently treat antibiotic wastewater.In this study,coconut shell biochar was used as the carrier in order to obtain a supported transition metal catalyst by the impregnation method.The obtained materials was characterized by using Scanning electron microscope(SEM),Specific surface area and pore size analyzer(BET),Fourier infrared spectroscopy(FTIR).Taking norfloxacin(NOR)as the target pollutant and combining the advanced oxidation technology of transition metal activated peroxymonosulfate(PMS)to explore the removal effect of NOR and by this way the catalytic performance of Co@AC,Co Ag@AC,and Co Fe@AC can be evaluated.The main contents are as follows:(1)SEM results show that coconut shell biochar has a loose and porous structure,and the three materials Co@AC,Co Ag@AC and Co Fe@AC have fine particles on the surface;The specific surface areas of the three materials are 414.58,394.23,and 396.08 m~2/g,and the average pore diameters are all greater than 2μm,which are belong to mesoporous material;FTIR results show that different materials contain abundant oxygen-containing functional groups such as alcoholic hydroxyl,lactone,carboxyl,and hydroxyl groups,and there is no significant difference.(2)The Co@AC can achieve the best performance when the coconut shell biochar has a particle size of 80～100 mesh and the cobalt loading is 7%,The experimental results of bimetallic catalyst activated PMS to generate free radicals to degrade NOR showed that the performance of the composite material reached the best state when the catalyst loading was controlled to 7%and the mass ratio of Co:Ag and Co:Fe were both 3:1.(3)The three best catalysts were determined and the effects of conventional factors such as catalyst dose,PMS dose,p H and temperature of the reaction system on the degradation efficiency of the reaction system were systematically investigated.It is concluded that when the catalyst dosage is 0.1 g/L,the PMS concentration is 1 mmol/L,the temperature is 25℃,and the rotation speed is 140 r/min,when the reaction reaches 70 min,the removal rates of NOR by Co@AC/PMS,Co Ag@AC/PMS and Co Fe@AC/PMS were 97.14%,96.62%,and97.73%,respectively.And with the increase of temperature and alkalinity,the reaction rate of the three systems in the initial stage of the reaction is greatly increased.(4)By simulating the first-level and second-level kinetic equations,it is found that the Co@AC,Co Ag@AC,and Co Fe@AC activated PMS degradation NOR processes all conform to the second-level reaction kinetics;Free radical quenching experiments prove that three heterogeneous activated PMS systems play a major role under different p H conditions.Under different p H conditions,sulfate radicals play a major role in three kinds of heterogeneously activated PMS systems,Under the premise of the same reaction conditions,the properties of the three materials are Co Fe@AC>Co@AC>Co Ag@AC in order.