碳改性纳米零价铁对水中六价铬的强化吸附还原研究  

Study on enhanced adsorption and reduction of hexavalent chromium in water by carbon⁃modified nano zero⁃valent iron

作　　者：陈海峰[1] 张路萍 CHEN Haifeng;ZHANG Luping(Jiangsu Engineering Center of the Pesticide Wastewater Treatment and Resource Reuse,School of Pharmaceutical and Environmental Engineering,Nantong Vocational University,Nantong 226007,Jiangsu,China)

机构地区：[1]江苏省农药废水处理及资源化利用工程研究中心,南通职业大学药品与环境工程学院,江苏南通226007

出　　处：《安全与环境学报》2024年第1期353-360,共8页Journal of Safety and Environment

基　　金：南通市科技项目(JC2021158)。

摘　　要：纳米零价铁材料因其还原性强的特点而多用于水中Cr(Ⅵ)污染治理。以葡萄糖和氯化铁为原料,通过碳化煅烧还原,制备碳改性纳米零价铁复合材料(nZVI@GC)。材料形貌及结构性质的分析显示,nZVI@GC上纳米零价铁为体心立方的α-Fe^(0),且颗粒分散均匀,平均粒径为32 nm。批处理试验显示,24 h内nZVI@GC对水体中Cr(Ⅵ)的吸附还原质量比为178.6 mg/g,是纳米零价铁(nZVI)的5.7倍,且吸附还原反应符合准二级动力学模型(R^(2)=0.9993)。其中,在pH值为2~3,Cr(Ⅵ)的初始质量浓度为50 mg/L,纳米零价铁的投加质量浓度为0.5 g/L的条件下,nZVI@GC可在30 min内完全吸附还原水中的Cr(Ⅵ)。在干燥空气中无保护存放nZVI@GC时,复合材料上的碳可以有效抑制氧气对纳米零价铁的侵蚀。与新制备材料相比,30 d后nZVI@GC对水中Cr(Ⅵ)的吸附还原率仅下降3.4%。nZVI@GC为材料高效、经济地吸附还原水中Cr(Ⅵ)提供了一种选择。Nano zero⁃valent iron(nZVI)composites are widely used for the removal of hazardous hexavalent chromium[Cr(Ⅵ)]from water owing to their strong reducibility and high adsorption.To reduce the cost,the environmentally friendly carbon⁃modified nano⁃zero⁃valent iron(nZVI@GC)was successfully synthesized via facile carbonization and calculations of glucose and ferric chloride mixtures,which effectively solved the problem that nZVI was easy to agglomerate and easilyto oxidate in the preparation.Combined with the characterization results,XRD and TEM data showed that the zero⁃valent iron nanoparticles on the nZVI@GC were body⁃centered cubicαFe^(0) particles with an average particle size of 32 nm.The batch experiments were conducted to investigate the effects of nZVI@GC dosage,initial Cr(Ⅵ)concentration,and pH on the Cr(Ⅵ)adsorption and reduction.The results indicated that the maximum adsorption reduction capacity of Cr(Ⅵ)in water by nZVI@GC within 24 h was 178.6 mg/g,which was 5.7 times that of nZVI(31.5 mg/g).Kinetic studies indicated that the adsorption and reduction reaction of Cr(Ⅵ)by the nZVI@GC followed a pseudo⁃second⁃order rate equation(R^(2)=0.9993).When the initial concentration of Cr(VI)was 50 mg/L and pH was 23,the Cr(Ⅵ)in the water were completely adsorbed and reduced after 0.5 g/L nZVI@GC were added for 30 min.After nZVI@GC was stored in dry air for a period of time,carbon on the composite material can effectively inhibit the erosion of zero⁃valent iron nanoparticles by oxygen.Compared with the newly synthesized material,the adsorption reduction rate of Cr(Ⅵ)in water by nZVI@GC stored for 30 days only decreased by 3.4%.The nZVI@GC exhibited a stronger adsorption reductionrate of Cr(Ⅵ)and was proved to be more stable in ambient conditions than nZVI.These results show that nZVI@GC has efficient and economical application potential in treating Cr(Ⅵ)⁃contaminated water.

关 键 词：环境工程学 六价铬 纳米零价铁 碳基材料 吸附还原 

分 类 号：X52[环境科学与工程—环境工程]