铁锰层状双氢氧化物的制备及其对废水中Sb(III)的吸附行为

Preparation of Fe-Mn layered double hydroxides andits adsorption behavior of antimony(III) from wastewater

  • 摘要: 为更好地处理水环境中的锑(III)污染问题,本论文采用超声共沉淀法制备了铁锰层状双氢氧化物(Fe-Mn LDH),并研究初始pH、投加量、共存离子、吸附时间及温度等因素对Fe-Mn LDH去除废水中Sb(III)的影响。通过SEM、EDS、XRD、XPS和FTIR等表征手段对材料晶体结构、形貌、吸附机制等进行了表征及分析。结果表明,Fe-Mn LDH去除Sb(III)的适宜条件为:pH=5、投加量为0.4 g/L、吸附时间150 min;在此条件下,在温度45℃时最大吸附量为77.39 mg/g。吸附过程符合拟二级动力学模型,Freundich吸附等温线模型能够很好地描述Fe-Mn LDH对Sb(III)的吸附行为。Sb(III)吸附去除机制主要为离子交换、配位络合和静电吸附。通过四次吸附-解析实验发现,Sb(III)去除率在83.03%以上,表明Fe-Mn LDH具备处理与修复含Sb(III)废水污染的潜力。

     

    Abstract: In order to solve the problem of antimony(III) pollution in water environment, Fe-Mn layered double hydroxides (Fe-Mn LDH) were prepared by ultrasonic co-precipitation method, and the effects of initial pH, dosage, coexisting ions, adsorption time and temperature on the removal of antimony(III) from wastewater by Fe-Mn LDH were studied. The crystal structure, morphology and adsorption mechanism were characterized and analyzed by SEM, EDS, XRD, XPS and FTIR. The results show that the suitable conditions for antimony(III) removal are pH of 5, dosage of 0.4 g/L and adsorption time of 150 min under 45℃. Under these conditions, the maximum adsorption capacity is 77.39 mg/g. The adsorption process conforms to the pseudo-second-order kinetic model, and the Freundich isotherm model can well describe the adsorption behavior of antimony(III). The adsorption mechanisms of antimony(III) mainly include ion exchange, coordination complex and electrostatic interaction. The removal efficiency of antimony(III) is found to be over 83.03% by four adsorption-desorption experiments. This study indicates that Fe-Mn LDH has the potential to treat and repair wastewater containing antimony(III).

     

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