羧甲基化沙柳木粉负载纳米零价铁吸附水中Pb2+

Carboxymethylated Salix Psammophila Powder Supported Nanoscale Zero-Valent Iron: Preparation and Adsorption Behavior toward Pb2+ in Aqueous Solution

以羧甲基化沙柳木粉（CMS）为载体,采用液相还原法制得羧甲基化沙柳木粉负载纳米零价铁（NZVI/CMS）吸附剂。采用SEM、FTIR、XRD和TEM对纳米零价铁（NZVI）和NZVI/CMS的微观结构进行了表征。考察了不同吸附条件对NZVI和NZVI/CMS吸附Pb^（2＋）性能的影响。结果显示：NZVI成功负载在CMS上,负载后的NZVI分散性明显提高,团聚现象得到有效解决,CMS起到分散NZVI颗粒的作用。吸附结果显示：当NZVI和NZVI/CMS的投加量分别为0.05和0.01 g,Pb^（2＋）初始质量浓度分别为600和400 mg/L,吸附时间为120 min,吸附温度为30℃,Pb^（2＋）溶液pH分别为4.5和4.0时,NZVI和NZVI/CMS对Pb^（2＋）的吸附量最大,分别为390.3和535.5 mg/g。循环吸附实验表明,循环3次后,NZVI的吸附量为98.6 mg/g,而NZVI/CMS的吸附量可达469.7mg/g,NZVI/CMS呈现出比NZVI更优越的循环使用性能。

A new adsorption agent, carboxymethylated salix psammophila（CMS） powder supported nanoscale zero-valent iron（NZVI/CMS） was prepared by liquid phase reduction method with nanoscale zero-valent iron（NZVI） as a carrier. The micro structures of NZVI and NZVI/CMS were characterized by means of SEM, FTIR, XRD and TEM. The effects of different adsorption conditions on the adsorption capabilities of NZVI and NZVI/CMS for Pb^（2＋） were studied. The results showed that NZVI was successfully loaded on CMS. In addition, the introduction of CMS efficiently resolved the reunion of NZVI particles and improved the dispersibility of NZVI particles. The adsorption results indicated that the maximum adsorption capacity of NZVI/CMS for Pb^（2＋） reached 535.5 mg/g when the dosage of NZVI/CMS was 0.01 g, the initial mass concentration of Pb^（2＋） was 400 mg/L, the adsorption time was 120 min, the adsorption temperature was 30 ℃, and the pH value of Pb^（2＋） solution was 4.0. However, the maximum adsorption capacity of NZVI for Pb^（2＋） was only 390.3 mg/g under the optimum adsorption conditions of NZVI dosage 0.05 g, initial mass concentration of Pb^（2＋） 600 mg/L, adsorption time 120 min, adsorption temperature 30℃, p H value of Pb^（2＋） solution 4.5. The cyclic adsorption experiments revealed that after recycling for three times, the adsorption capacity of NZVI was 98.6 mg/g, whereas that of NZVI/CMS was 469.7 mg/g, indicating that NZVI/CMS had better reusability than NZVI.