Preparation Of Magnetic Cerium Oxide And Its Application In Dye Wastewater Treatment

In wastewater treatment,adsorption efficiency and recyclability are the keys to the application of adsorbents.CeO_2,with smaller particle size,has strong adsorption capacity,but is restricted to widespread use due to high cost and difficulty to recycle and reuse that cause secondary pollution.Magnetic ceria materials,however,finds its promising application in pollutant adsorption for not only its strong adsorption capacity,but also the magnetism that facilitates separation and recycle.In this study,a magnetic Fe₃O₄/CeO₂ composite was prepared by gel sol method,which improves the removal capacity of dyes,and separation and recycle of the adsorbents.In addition,magnetic Fe₂O₃@CeO₂ hollow microsphere was prepared using sol-gel and calcination based on PSAA to further enhance the adsorption and recycling properties.This provides a new method for producing adsorbent with quick adsorption,regeneration and good stability.Moreover,factors that influence the adsorption capabilities?molar ratio of Ce to Fe sources,initial concentration of dyes and initial pH of dye solution?,and the adsorption kinetics and thermodynamic mechanismare studied.The results are as follows:?1?Being irregular granular in structure,the magnetic Fe₃O₄/CeO₂ composite synthesized has such good adsorption capacity for dye AB210 that 82.37%of 50 mL 50mg·L^-1 AB210 was adsorbed within 120 minutes,with maximum adsorption quantity reaching90.50 mg·g^-1.In addition,the adsorption activity fitted well with Langmuir adsorption isotherm model and pseudo-first-order kinetics was the best for the adsorption,as physical one.After four cycles,the regenerated adsorbent could still remove over 70%of dye from the solution,indicating good reusability.?2?The prepared magnetic Fe₂O₃@CeO₂ material,hollow microspheres with a diameter of 230 nm,and a shell thickness of 15 nm with mesoporous on it,can provide more adsorption sites theoretically.The adsorption performance is better than that of Fe₃O₄/CeO₂composites in that 88.58%of 50 mL 80 mg·L^-1 AB210 was adsorbed within 120 minutes with maximum adsorption capacity of 145.77 mg·g^-1,55.27 mg·g^-1 higher than that of Fe₃O₄/CeO₂.The adsorption activity conformed to pseudo-second-order kinetic model and the adsorption model fitted to Langmuir adsorption isotherm model.After four cycles,more than 82%of dye can still be adsorbed,indicating good reusability and stability.