功能化凹凸棒吸附材料的制备及其对重金属废水中Pb2+的吸附行为

重金属离子废水会对人体健康和环境造成严重威胁,吸附法是去除重金属废水中重金属离子的重要方法.对凹凸棒土(ATP)接枝磁性Fe₃O₄纳米粒子,再使用3-氨基丙基三乙氧基硅烷(APTES)进行改性,制备了具有良好吸附性能的凹凸棒复合纳米材料吸附剂(ATP-Fe₃O₄-APTES),并将其用于重金属离子废水的处理.利用FT-IR、 XRD、 SEM及TEM、 BET吸脱附法、 Zeta电位和VSM分析等方法对材料的结构和表面性质进行了分析表征.研究了所制备材料对重金属离子Pb²⁺的吸附行为,考察了溶液pH、吸附时间、吸附温度和Pb²⁺初始浓度等因素对材料吸附性能的影响作用,探讨了吸附过程的吸附动力学、吸附等温线和吸附热力学行为.结果表明,材料对Pb²⁺的最大吸附容量为129.32 mg·g^-1.吸附过程符合准二级动力学模型和Langmuir吸附等温式,表明材料对Pb²⁺的吸附是单分子层化学吸附;吸...

Preparation of Functional Attapulgite Composite and Its Adsorption Behaviors for Congo Red

Heavy metal ion wastewater poses a serious threat to human health and the environment. The adsorption method is an important method to remove heavy metal ions from heavy metal wastewater. Magnetic attapulgite (ATP) composite nanomaterials with excellent adsorption properties were prepared by grafting the Fe₃O₄ nanoparticles and using 3-aminopropyl triethoxy silane (APTES) modification. The prepared ATP-Fe₃O₄-APTES materials were used as adsorbents and applied to the treatment of heavy metal ion wastewater. The structure and surface properties of the materials were characterized by FT-IR, XRD, SEM, TEM, and BET characterization, Zeta potential, and VSM. The effects of pH, adsorption time, adsorption temperature, and initial concentration of Pb²⁺ on the adsorption properties of the ATP-Fe₃O₄-PEI materials were investigated. The results show that the maximum adsorption capacity of the materials for Pb²⁺ was 129.32 mg·g^-1 under optimum conditions. The adsorption process conformed to the pseudo second order kinetic model and Langmuir adsorption isotherm, which indicates that the adsorption of Pb²⁺ is a monolayer chemical adsorption and a spontaneous endothermic process. The driving force of adsorption mainly comes from the coordination between the amino group (-NH₂) on the ATP-Fe₃O₄-APTES surface and Pb²⁺. These results indicate that the functionalized magnetic attapulgite adsorbent has good adsorption properties for heavy metal ions and is expected to be used in the treatment of heavy metal ion wastewater.