Research on Heavy Metal Removal by SA@PG Composite Material

以海藻酸钠作为改性材料，通过共混、交联和接枝反应改性磷石膏，成功制备海藻酸钠接枝磷石膏复合材料(SA@PG)，用于水体中重金属Cd(II)、Cu(II)和Pb(II)的移除。系统地优化了吸附条件，包括吸附时间、吸附剂用量和溶液pH值等。采用各种分析表征方法对SA@PG复合材料的形貌和结构进行表征，结果表明，复合材料具有三维多孔结构和多活性作用位点等优点，这些优点使SA@PG具有良好的吸附能力，对Cd(II)、Cu(II)和Pb(II)的最大平衡吸附量可达48.02 mg/g、58.86 mg/g和123.39 mg/g，优于单独的PG。使用Langmuir、Freundlich 等温模型研究了SA@PG复合材料的吸附行为和机制，结果表明为单分子层吸附；热力学分析表明吸附过程是吸热和自发的。Sodium alginate was used as a modified material to successfully prepare sodium alginate grafted phosphogypsum composites (SA@PG) for the removal of heavy metals from water by blending, cross-linking, and grafting reactions. The adsorption conditions, including adsorption time, adsorbent dosage and solution pH, were systematically optimized. Various analytical characterization methods were used to characterize the morphology and structure of SA@PG composites, and the results showed that the composites had advantages of three-dimensional porous structure and multiple active sites of action, which gave SA@PG good adsorption capacity, and the maximal equilibrium adsorption of Cd(II), Cu(II), and Pb(II) could reach 48.02 mg/g, 58.86 mg/g, and 123.39 mg/g, which is better than PG alone. The adsorption behavior and mechanism of SA@PG composites were investigated using Langmuir and Freundlich isothermal model, and the results showed monomolecular layer adsorption; thermodynamic analyses showed that the adsorption process was heat-absorbing and spontaneous.