复合材料包埋纳米铁去除废水中Cr(Ⅵ)

Composite Material Covered nZVI to Remove Cr(Ⅵ) in Wastewater

采用微乳液法合成纳米零价铁(nZVI)颗粒。以壳聚糖、聚丙烯酸-苯乙烯(PAA-b-PS)为外壳采用离位法制备了壳聚糖/PAA-b-PS双包埋纳米零价铁颗粒(CS-PAA-b-PS-Fe);运用TEM、XRD对CS-PAA-b-PS-Fe材料进行表征,并用于水中Cr(Ⅵ)的去除。表征结果显示C-PAA-b-PS-Fe具有核壳结构,能有效地防止纳米零价铁的团聚。实验结果表明:CS-PAA-b-PS-Fe还原Cr(Ⅵ)的最佳质量浓度比为0.2∶1∶1;温度为25℃,Cr(Ⅵ)初始浓度C0=100 mg/L下,投入0.1 g/L的CS-PAA-b-PS-Fe材料,反应100 min达到平衡,其Cr(Ⅵ)最大去除率达到100%。在酸性环境下,C-PAA-b-PS-Fe去除Cr(Ⅵ)主要以吸附和还原反应为主。

Nano-zero-valent iron(nZVI) particles were synthesized by microemulsion method. Chitosan and polyacrylic acidstyrene(PAA-b-PS) as the shell were used prepare the chitosan/PAA-b-PS double-embedded nano-zero iron particles(CSPAA-b-PS-Fe) by the off-site method;CS-PAA-b-PS-Fe material characterized by TEM and XRD, and be used to remove Cr(Ⅵ) in water. Characterization results show that CS-PAA-b-PS-Fe has a core-shell structure, which can effectively prevent the agglomeration of nZVI. The experimental results show that: the optimal mass concentration ratio of CS-PAA-b-PS-Fe for reducing Cr(Ⅵ) is 0.2∶1∶1;Under the conditions of Cr(Ⅵ) mass concentration 100 mg/L, CS-PAA-b-PS-Fe dosage 0.1 g/L and reaction time 100 min to reach equilibrium, the maximum removal rate of Cr(Ⅵ) reaches 100%.