微波活化过硫酸盐降解典型选矿药剂水杨羟肟酸

Degradation of salicylhydroxamic acid by microwave activated persulfate

以水杨羟肟酸为目标污染物,利用微波活化过硫酸盐的高级氧化技术考察微波功率、过硫酸盐投加量、反应溶液初始pH、主要金属离子和常见阴离子等因素对水杨羟肟酸降解影响.结果表明,水杨羟肟酸的降解率随着微波功率和过硫酸盐投加量的增加而提高;当反应溶液pH=3时,水杨羟肟酸的降解率最高,而提高pH对水杨羟肟酸的降解有抑制作用;Fe^(2+),Cu^(2+)的添加对水杨羟肟酸的降解表现出低促高抑的效果,最佳添加量分别为0.25 mmol·L^(−1)、0.1 mmol·L^(−1);无机阴离子Cl^(−)、HCO_(3)^(−)、NO_(3)^(−)、SiO_(3)^(2−)的添加均抑制水杨羟肟酸的降解;反应180 min后,水杨羟肟酸得到明显矿化,主要中间产物为水杨酸和邻二苯酚.研究证明了热活化效应在微波活化过硫酸盐降解水杨羟肟酸过程中的重要性,以及SO_(4)^(−)·的主导作用.

An advanced oxidation technology of persulfate activated by microwave was developed with salicylhydroxamic acid as the target pollutant.The effects of microwave power,persulfate dosage,initial pH of reaction solution,main metal ions and common anions on the degradation of salicylhydroxamic acid were investigated.The results showed that the degradation rate of salicylhydroxamic acid increased with the increase of microwave power and the dosage of persulfate.When the pH of the reaction solution was 3,the degradation rate of salicylhydroxamic acid was the highest,and the degradation of salicylhydroxamic acid was gradually inhibited with the increase of the initial pH of the reaction solution.The addition of Fe^(2+) and Cu^(2+) in the reaction system had the effect of low promoting and high inhibiting on the degradation of salicylhydroxamic acid,and the optimal supplemental levels were 0.25 mmol·L^(−1) and 0.1 mmol·L^(−1).The addition of inorganic anions Cl^(−),HCO_(3)^(−),NO_(3)^(−),SiO_(3)^(2−) inhibited the degradation of salicylhydroxamic acid.After reaction for 180 min,salicylhydroxamic acid was mineralized obviously,and the main products were salicylic acid and o-diphenol.The study proved the importance of thermal activation effect in the process of microwave activated persulfate degradation of salicylhydroxamic acid,and the leaded role of SO_(4)^(−)·.