纳米零价锌降解甲基橙效率探讨

Discussion on efficiency of methyl orange degradation by nanoscale zero-valent zinc particles

将普通零价锌在滚压振动磨中研磨13h后,制备出不规则片状、粒径为20~30nm 的纳米零价锌（NZVZ）.采用所制备的NZVZ降解甲基橙,系统研究了搅拌速度、NZVZ 投入量、甲基橙初始浓度和NaCl的加入对甲基橙降解效率的影响.结果表明,NZVZ表面反应活性增高,反应60 min时,2g/L 的NZVZ对甲基橙降解率为98.5%,比4g/L的普通零价锌高60.3%,其中间降解产物有对氨基苯磺酸和对氨基二甲基苯胺.降解率随转速、NZVZ投入量的增加而升高,随MO 初始浓度的增加而降低;加入NaCl能促进反应进行,且随着投入量增加降解率增加.通过对实验数据的分析,验证NZVZ降解MO 过程符合伪-级动力学方程式.

The ordinary zinc powder was milled for 1 3 h with roller vibration milling and produced irregular sheet nanoscale zero-valent zinc particles(NZVZ).The particle size was between 20 and 30 nm.This paper here was focused on the degradation of water soluble methyl orange(MO)by NZVZ,and rotation speed of magnetic stirrer,NZVZ dosage,initial MO concentration and NaCl dosage were studied systematically.It was found that the degradation of MO with 2 g/L of NZVZ was 98.5% in 60 min,which was 60.3% higher than that of using 4 g/L of ordinary zinc powder,the sulfanilic acid and 1 ,4-benzenediamine,N,N-dimethyl-as degradation pro-gress products were identified.Degradation was enhanced with increase of rotation speed and NZVZ dosage, while decreased with increase of initial MO concentration.Moreover,the existence of NaCl can promote the re-action procress and degradation increased with increase of NaCl dosage.Kinetic analyses based on the experi-mental data elucidated that the degradation process followed the pseudo first-order kinetic equation.