Synthesis And Performance Evaluation Of As(Ⅲ)-ION-Imprinted Polymer

Ion-imprinted technique has aroused widespread concern. And the variety is getting more increasingly. It can be used in various fields. As(Ⅲ)-ion-imprinted polymer was prepared with AsO2-ion as the template, MAA as the functional monomer, modified silica with Fe(NO3)3as the carrier and EGDMA as the cross-linking agent by using surface imprinting technique. The study supply the polymer kinds and provides a new method for arsenic removal.The determined optimal preparation condition is Pre-polymerization pH=5, cross-linking pH=5.5, the concentration ratio of MAA and EGDMA=1:7, and the concentration of eluant=1mol·L-1. The results of SEM and XRD characterization shows inruitive description, and the FT-IR and UV spectrogram confirms the imprinting process.The adsorption conditions were determined by static adsorption experiments. Suitable adsorption pH=6and initial concentration=100mg-L-1are determined through static adsorption test. Temperature has a positive correlation with adsorption capacity.In subsequent kinetics and thermodynamics analysis, adsorption kinetics results explain that the material reach the adsorption equilibrium in6h and the rates constant is0.041h-1under the condition of pH=6and T=25℃, which can be described using pseudo-second order kinetic equation. Under the same adsorption condition, the saturation absorptive capacity of imprinted polymer is1.5times that of non-imprinted one. The process follows the Langmuir isotherm model. And the adsorption is spontaneous and endothermic reaction.Selection for arsenic is one of the polymer advantages. In the single competitive system, material performs good selectivity, especially in the NO3-system the selective coefficient reaches5.09. In the mixed competitive system, the selective capacity decreases. NO2-is considered as the strongest competitor. When the NO2-density is less than40mg-L-1, the competitiveness is relatively weak. The material is economic, the adsorption amount is about94.78%of the original capacity after9times reuse.In the mechanism research, two Scatchard lines are summarized through Scatchard analysis, which explains that there are2combination modes between material and As(Ⅲ). As(Ⅲ) ion-imprinted-polymer has an ideal arsenic removal performance and practical application value.