Preparation and Performance Research of Pb(II)-Imprinted Acrylonitrile-Co-Acrylic Acid Composite Material with Modified Sand Particles as Carrier.

Lead (Pb) is classified as a prevalent metallic pollutant, significantly impacting the ecological environment, especially human health. Consequently, it is crucial to develop adsorbent materials that are environmentally friendly, cost-effective, and which possess high selectivity. This study aims to fabricate a Pb(II)-imprinted acrylonitrile-co-acrylic acid composite material by using modified sand particles as the carrier, and then to investigate its properties. Through pretreatment of sand particles, acrylonitrile and acrylic acid were polymerized on the surface of modified sand particles, and Pb(II) served as a template ion for imprinting. A variety of characterization methods were used to verify the composite material and conduct an analysis of its morphology, chemical composition, and pore characteristics. The adsorption efficiency of this composite material for Pb(II) is comprehensively explored, with the process involving adsorption kinetics, adsorption isotherms, selective adsorption, and reuse experiments. Through static adsorption experiments, multiple elements influencing the adsorption ability of the composite material towards Pb(II) are investigated. It was demonstrated by the results that the composite material prepared possesses a rich pore structure and excellent Pb(II) recognition ability. The investigation on adsorption kinetics is in line with the quasi-first-order and quasi-second-order kinetic models, while the adsorption isotherm, obeys the Langmuir model. The ideal adsorption conditions were pH = 7, with the adsorption reaching equilibrium within 105 min. Even when multiple interfering ions were present, it still had high selectivity for Pb(II). The composite material showed an adsorption saturation capability reaching 41.83 mg·g^-1, considerably surpassing the non-imprinted counterpart. After being reused eight times, the composite material can still maintain an adsorption efficiency for Pb(II) that is above 79% and demonstrates high potential in the practical application environment.