ZnO@NiO纳米晶粒吸附去除氰化物的动力学和热力学（英文）

发布时间：2018-04-04 15:04

  本文选题：氰化物去除　切入点：纳米晶粒　出处：《Transactions of Nonferrous Metals Society of China》2017年06期

【摘要】：合成了ZnO、NiO和ZnO@NiO纳米晶粒,采用红外光谱(FTIR)、X射线衍射(XRD)和扫描电镜(SEM)技术对其进行表征。ZnO、NiO和ZnO@NiO的平均颗粒尺寸为32、50和48 nm。对这些纳米晶粒去除氰化物的能力进行了测定。实验结果表明,与ZnO和NiO相比较,ZnO@NiO纳米晶粒去除氰化物的能力更强。ZnO@NiO纳米晶粒对氰化铁的去除能力比对氰化钠的更高。研究了反应时间、溶液pH值(2~12)、纳米晶粒用量(0.02~0.4 g)和氰化物浓度(5~50 mg/L)等参数对氰化物去除效果的影响。在最优条件下:pH5,纳米晶粒用量0.2 g,反应时间30 min,ZnO@NiO纳米晶粒对20 mg/L氰化物的去除率可达到90%以上。ZnO@NiO纳米晶粒对氰化物的吸附去除动力学影响规律符合Langmuir准二级吸附动力学模型(k2=4.66×10-2,R=0.999)。热力学研究表明,25°C下,反应的标准焓变化为7.87 kJ/mol,自由能变化为-18.62 kJ/mol。纳米晶粒对氰化物的吸附是一个吸热的自发过程。ZnO@NiO纳米晶粒是一种能有效的去除水或废水中氰化物的吸附剂。
[Abstract]:ZnO nio and ZnO@NiO nanocrystals were synthesized and characterized by FTIR and SEM techniques. The average particle sizes of ZnO@NiO and ZnONiO were 32 ~ 50 and 48 nm respectively.The ability of these nanocrystals to remove cyanide was measured.The experimental results show that ZnO- @ nio nanocrystalline is more capable of removing cyanide than that of ZnO and NiO. The removal capacity of ferric cyanide by ZnO- @ nil nanoparticles is higher than that of sodium cyanide.The effects of reaction time, pH value of solution, amount of nanocrystalline (0.02g) and concentration of cyanide (50 mg / L) on the removal of cyanide were studied.鍦ㄦ渶浼樻潯浠朵笅:pH5,绾崇背鏅剁矑鐢ㄩ噺0.2 g,鍙嶅簲鏃堕棿30 min,ZnO@NiO绾崇背鏅剁矑瀵，

本文编号：1710470