The Rapid Preparation Of Mussel Bionic Functionalized Non-woven Fabric And Its Adsorption Performance For Heavy Metals

In recent years,pollution of heavy metal ions in water has become increasingly serious.The complex interaction between coexisting metal ions makes it difficult to remove heavy metals and seriously threatens human health.Therefore,the treatment of coexisting heavy metal pollution is imminent.This research focuses on the functionalization of the material surface,and the biomimetic chemistry of mussels is the modification strategy.Combining ammonium persulfate and ethylenediamine to promote the polymerization of dopamine and its derivatives,greatly reducing the synthesis time of multifunctional non-woven fabrics.Faced with the need for adsorption materials for the simultaneous removal of coexisting heavy metal ions,and the functional group characteristics of the mussel bionic modified layer.In this study,four adsorbent materials were prepared:dopamine modified non-woven fabric?PP/PDA?,dopamine and aminosalicylic acid modified non-woven fabric?PP/PDA/ASA?,dopamine quaternary ammonium salt non-woven fabric,and caffeic acid modified non-woven fabric?PP/PCA?.The synthesized adsorbents were characterized by SEM,FTIR and XPS techniques.The adsorption studies under different experimental conditions were carried out,and the results are as follows:Aiming at the problems in the simultaneous removal of heavy metals in the coexisting system,PP/PDA/ASA adsorbents were prepared by introducing salicylic acid groups at the end of the dopamine polymer.The adsorption results show that PP/PDA/ASA showed better adsorption performance than PP/PDA.PP/PDA/ASA could remove 90%of Cu²⁺,Cd²⁺and Pb²⁺from 5mg/L of single metal solution at the sorbent:solution mass ratio of 1:1000.Although competitive adsorption in a multi-component system leads to a decrease in adsorption capacity,PP/PDA/ASA can technology was used to analyze the mechanism.The results showed that the adsorption process included coordination and ion exchange between metal ions and functional groups,and that the PP/PDA/ASA adsorption mechanisms for Cu²⁺,Cd²⁺and Pb²⁺were different.Aiming at the problem that the surface functional groups of dopamine functional materials are single and can only adsorb positively charged heavy metal ions,a dopamine quaternary ammonium salt non-woven fabric adsorbent was prepared by a quaternization method.The adsorption results show that the adsorbent efficiently adsorbs Cr?VI?at p H=3,and the removal efficiency reaches 95%.The research of isothermal model proves that the adsorption is monolayer,and the theoretical maximum adsorption capacity is 31.92 mg/g.The XPS technology was used to analyze the mechanism.The results showed that the adsorption of Cr?VI?was related to the quaternary ammonium salt groups and protonated amino groups on the surface of the non-woven fabrics.The quaternized non-woven fabric exhibits good reproducibility.Aiming at the problems of single functional groups on the surface of dopamine functionalized non-woven fabric and poor removal ability of Cu²⁺and Cd²⁺,caffeic acid was used to prepare PP/PCA adsorbent.The adsorption results show that PP/PCA has a strong adsorption capacity for Cu²⁺and Pb²⁺.The theoretical maximum Langmuir equation as 88.6 mg/g,83.9 mg/g,and 36.93 mg/g,respectively.Using XPS technology to analyze the mechanism,the results show that-COOH,-NH-and-OH groups are involved in the adsorption of heavy metals.