Regulation Of Interfacial Properties Of Polybenzoxazine For Removing Heavy Metal Ion Cr(?) From Aqueous Solution

Heavy metal pollution has long-lasting toxicity,and can harm human health by biomagnification and bioenrichment,which has aroused the attention of the whole society.Adsorption of heavy metal ions in water is an economical,efficient,and easy-to-handle treatment method that has been widely accepted.It is one of the hotspots in the research of the treatment of heavy metal pollution today that the preparation of adsorbent with strong pertinence,low cost and effective controllable functional groups by chemical methods.Based on the purpose of removing heavy metal ions Cr???from aqueous solution,different types of benzoxazine monomers were designed and synthesized,and the surface composition and structure of the polybenzoxazine adsorbents were regulated by changing the curing medium and curing method.The performance of the adsorbent was evaluated by the adsorption capacity of the heavy metal ion Cr???adsorbed in aqueous solution.High-resolution scanning electron microscopy,X-ray energy dispersive spectroscopy,fourier transform infrared spectroscopy,thermogravimetric analysis,and contact angle measuring instruments were used to characterize the structure and composition of the synthesized novel adsorbents.The influence of pH value on the adsorption capacity and the effect of the dosage of the adsorbent on the removal efficiency of Cr???were analyzed.The results show that the structure and raw material ratio of benzoxazine monomers have an important influence on the acid resistance of the adsorbent,the amount of amine groups on the surface of the adsorbent and the pH value of the solution are the main factors affecting the adsorption capacity of the adsorbent and the removal efficiency of heavy metal ions.Adsorption of heavy metal ion Cr???in aqueous solution by polybenzoxazine is monolayer adsorption.Adsorption kinetics and thermodynamic studies show that the mechanism of the adsorption of heavy metal ion Cr???from aqueous solution may be that the amine groups of the surface combine with HCrO₄^-after protonation in an acidic condition to remove Cr???from aqueous solution.In this study,polybenzoxazine was first applied to remove Cr???from aqueous solution,and a novel adsorbent with high adsorption capacity?116 mg/g?,high removal efficiency?96.7%?and good reusability was obtained.This has important theoretical and practical significance for the adsorption treatment of heavy metal pollution in water.