ZnMnCo-LDHs的制备及其对磷酸根废水吸附性能研究

Preparation of ZnMnCo-LDHs and its Adsorption Properties to Phosphate Wastewater

采用水热法合成三元过渡金属ZnMnCo-LDHs纳米材料,探究Co元素的含量对磷酸根废水吸附性能的影响。在温度100℃、2 h、1 mL三乙醇胺的条件下,制备不同比例ZnMnCo-LDHs纳米材料,以浓度为100 mg/L的KH_(2)PO_(4)溶液模拟含磷废水测试材料的吸附性能。利用SEM、XRD和FT-IR等技术表征。结果表明:3种ZnMnCo-LDHs纳米材料均为片层状结构,层间插层离子为NO-3。随着Co含量的增加,ZnMnCo-LDHs片状的厚度逐渐变薄,证明Co含量的增加对片状结构具有调控作用。3种ZnMnCo-LDHs纳米材料对磷酸根废水的最大吸附量分别为738.14、732.69、709.6 mg/g。吸附等温线符合Freundlich模型;吸附动力学符合准二级动力学;吸附热力学得出为自发进行的吸热反应。ZnMnCo-LDHs纳米材料经过6次循环性能的测试,去除率仍保持在80%以上,具有良好的循环性能。

The ternary transition metal-based ZnMnCo-LDHs nanomaterials were synthesized by hydrothermal method to investigate the effect of the Co contents on the adsorption performance of phosphate wastewater.ZnMnCo-LDHs nanomaterials were prepared at different ratios under the conditions of 100℃,2 h,and 1 mL triethanolamine.The adsorption performance of the materials was tested with KH 2PO 4 solution at a concentration of 100 mg/L as simulating phosphate-containing wastewater.The materials were characterized by SEM,XRD and FT-IR techniques.The results showed that the three ZnMnCo-LDHs nanomaterials were all lamellar structures with NO-3 as the intercalating ion between the layers.The thickness of ZnMnCo-LDHs lamellae gradually became thinner with the increase of Co content,which proves that the increase of Co content has a modulating effect on the lamellae structure.The maximum adsorption capacities of the three ZnMnCo-LDHs nanomaterials on phosphate wastewater were 738.14,732.69,and 709.6 mg/g,respectively.The adsorption isotherms were in accordance with the Freundlich model;the adsorption kinetics followed quasi-secondary kinetics;and the adsorption thermodynamics indicated that the process was a spontaneous endothermic reaction.The ZnMnCo-LDHs nanomaterials were tested for six cycles,and the removal rate remained above 80%with good cycling performance.