Adsorption Of Bisphnol Compounds In Aqueous Solution By Spent FCC Catalyst

Fluidized catalytic cracking?FCC?catalyst is one of the most widely used catalysts in petroleum processing.Most of the spent FCC catalysts after deactivation are disposed as waste landfills,but the rare earth elements and cobalt,nickel,vanadium and other metals contained in them are bound to pollute the environment and waste resources.In this paper,acid leaching method is used to dissolve the substances blocking the holes of FCC waste catalyst and restore the holes.It was used as adsorbent to remove the bisphenol compounds?bisphenol A,bisphenol S,bisphenolic acid?in aqueous solution.It not only makes waste useful,but also provides an economical and effective way to solve the reuse of FCC waste catalyst,and also removes harmful substances from water.The adsorption properties of waste FCC catalysts for bisphenols were studied by static and dynamic adsorption experiments,and the technical and economic analysis of waste FCC catalysts and activated carbon was carried out.Static experimental results show that the optimal adsorption time of waste FCC catalyst for bisphenol A,bisphenol S and bisphenolic acid are 70,60 and 50minutes respectively,and the maximum saturated adsorption capacity are 32.9,26.2,and 20.9 mg.g^-1,respectively.Increasing temperature inhibited the adsorption of bisphenol A,bisphenol S and bisphenolic acid.The optimum pH range of bisphenol A and bisphenol S is 2-6 and bisphenolic acid is 2-5.Kinetics conformes to pseudo-second-order adsorption kinetics model and isothermal adsorption conformed to Langmuir adsorption isotherm model.The desorption and regeneration of spent FCC catalyst are good and can be reused at least 6 times.Dynamic experimental results show that the penetration time and saturation time advance with the increase of volume space velocity and initial concentration of solution.The maximum saturated adsorption capacity calculated by Thomas dynamic adsorption model are 28.2 mg g^-1,23.1 mg g^-1and 20.3 mg g^-1,respectively,which are close to the maximum saturated adsorption capacity of static adsorption.Spent FCC catalyst has good dynamic regeneration performance for bisphenol A,bisphenol S and bisphenolic acid,and has suitable production cycle.The techno-economic analysis shows that the spent FCC catalyst has the advantages of low cost,mild regeneration conditions,good regeneration effect and environmental friendliness compared with the commonly used adsorbent activated carbon.