Preparation Of Lanthanum-Based Composite Adsorption Material And Study On Its Performance Of Phosphate Removal

Phosphorus is an essential nutrient element for the growth of aquatic plants,but excessive phosphorus will lead to eutrophication of water body,which is the main reason for water pollution,lake eutrophication and red tide in the bay.Therefore,the solution to solve these problems is to remove excessive phosphate in water body.Because of the advantages of rapid and efficient phosphate removal,simple process and convenient operation,adsorption method has become a research hotspot.Lanthanum oxycarbonate modified acidified dioatomite?La₂O₂CO₃@AD?and lanthanum oxycarbonate modified acidified montmorillonite?La₂O₂CO₃@AMt?were prepared by Glycine-nitrate Process.The two kinds of adsorbents were characterized,and the adsorption performance of phosphate was tested.The optimum mass ratio of lanthanum oxycarbonate,effect of varying conditions on the adsorption of phosphate,adsorption mechanism and regeneration efficiency were also discussed.Firstly,a series of characterization methods were used to observe the surface morphology and to analyze the phase composition of the adsorbent,which proved that La₂O₂CO₃@AD and La₂O₂CO₃@AMt adsorbent were successfully prepared.Secondly,the phosphate removal performance of the adsorbents was investigated.Various adsorption conditions,such as adsorption time,pH value,substrate concentration,adsorbent dosage and coexisting ions were studied.The adsorption of phosphate was well described by both the Freundlich isotherm and pseudo second-order kinetic models.The results show that the adsorption of phosphate by the two adsorbents is multi-layer adsorption.The adsorption process of La₂O₂CO₃@AD adsorbent is mainly attributed to ligand exchange force and chemical bond force.The adsorption of La₂O₂CO₃@AMt adsorbent is mainly based on ligand exchange force.Finally,the results of the adsorbent regeneration experiment show that the adsorption effect of La₂O₂CO₃@AD adsorbent after regeneration is stronger than that of La₂O₂CO₃@AMt adsorbent.