铜渣铁基类沸石地质聚合物吸附Pb2+、Cu2+、Zn2+性能及机理

Adsorption properties and mechanism of Pb2+, Cu2+ and Zn2+ by iron base zeolite-like geopolymer derived from copper slag

摘要:

以铜渣为原料，在NaOH+工业水玻璃活化条件下制备出了铜渣Fe3O4@铁基类沸石地质聚合物（F3O4@GM），并将其用于三种重金属Pb2+、Cu2+、Zn2+吸附。探究了溶液pH、吸附剂投加量和初始浓度对Pb2+、Cu2+、Zn2+吸附性能的影响，并通过吸附动力学、热力学以及XRD、FTIR、SEM、BET、XPS等表征手段对其吸附机理进行探讨。结果表明，F3O4@GM对Pb2+、Cu2+、Zn2+的吸附符合Langmuir模型，吸附容量分别为555 mg/g、489 mg/g、125 mg/g；吸附过程符合拟二级动力学模型。F3O4@GM高比表面积提高了材料的吸附性能，吸附机理主要为离子交换、静电吸引、表面络合和孔隙固定作用。F3O4@GM为重金属污染处理提供了一种价格低廉、制备方便的选择，同时实现了铜渣资源化和无害化处理，具有良好的经济效益和环境效应。

Abstract:

Using copper slag as raw material, NaOH and industrial sodium silicate as alkaline activator, copper slag-based magnetic zeolite-like geopolymer (Fe3O4@GM) was prepared, and then use the as-obtained geopolymer to removal Pb2+, Cu2+ and Zn2+. The effects of initial pH, adsorbent dosage and initial concentration on the adsorption performance were investigated. Meanwhile, adsorption isotherm and adsorption kinetic were analyzed, the adsorption behavior of the F3O4@GM was studied, and the adsorption mechanism was assumed. Moreover, a series of characterizations were employed to analyze the physical and chemical properties of adsorbent, including XRD, FTIR, SEM, BET and XPS. This isothermal adsorption results show that the Langmuir model is more suitable than the Freundlich model to describe the adsorption behavior, and the adsorption capacities for Pb2+, Cu2+, Zn2+ can reach up to 555 mg/g, 489 mg/g and 125 mg/g, respectively. The adsorption process fits the pseudo-second-order kinetic model. The high specific surface area of F3O4@GM improves the adsorption properties of the materials. The adsorption mechanisms are associated with ion exchange, electrostatic attraction, surface complexation and pore fixation. Overall, the F3O4@GM can be used as an eco-friendly, desirable and economic adsorbent in heavy metal polluted water treatment, providing a cheap and convenient choice for the treatment of heavy metal pollution, and realizing the recycling and harmless treatment of copper slag.