摘要
本实验采用介质阻挡放电方法降解水溶液中的双氯芬酸钠,考察了初始浓度、Fe2+、腐植酸、硝酸根离子对双氯芬酸钠降解的影响,及降解过程中溶液TOC含量和UV的变化,并初步探讨了其降解动力学.结果表明,双氯芬酸钠在介质阻挡放电反应器中的降解符合一级反应动力学.对于初始浓度为10mg.l-1、20mg.l-1和30mg.l-1的双氯芬酸钠,降解率随着初始浓度的增加而降低.影响因子腐植酸和硝酸根离子的添加均能显著提高双氯芬酸钠的降解率,但相同实验条件下,亚铁离子的添加抑制了双氯芬酸钠的降解,当Fe2+添加量为1.0mmol.l-1时,双氯芬酸钠的降解率仅为74.94%.降解过程中溶液TOC的含量减少缓慢,TOC残留含量仅从13.69mg.l-1降为11.1mg.l-1,可见双氯芬酸钠的矿化程度不高,而双氯芬酸钠的紫外-可见吸收光谱在吸收波段递减,介质阻挡放电对双氯芬酸钠有稳定的降解效果.
Degradation of diclofenac sodium in aqueous solution was conducted in a dielectric barrier discharge reactor. The effect of initial diclofenac sodium concentration,HA,Fe2＋,NO-3concentration on the degradation efficiency of diclofenac sodium were examined and changs of TOC concentration and UV-vis absorbance was monitored.The initial investigation on the degradation kinetics of diclofenac sodium was analyzed. The results showed that the degradation of diclofenac sodium by dielectric barrier modeled could be depicted by first-order reaction kinetics.For the initial diclofanac sodium concentration of 10 mg·l^-1,20 mg·l^-1and 30 mg·l^-1,the removal rate decreased with the increase of initial concentration.Under the same experimental conditions,the degradation efficiency of increased dramatically in the presence of HA and NO-3. On the contrary,the addition of Fe2＋hindered the degradation process.When the concentration of Fe^2＋ reached 1.0 mmol·l-1,the removal rate was only 74.94 %.TOC concentration changed slowly from 13.69 mg·l^-1to 11.1 mg·l^-1. So the degree of minerlization of diclofenac sodium was not high.The gradual decrease of diclofanac sodium absorption band with reaction time suggests that the dielectric barrier discharge method was effective in the degradation of the pollutant.
出处
《环境化学》
CAS
CSCD
北大核心
2010年第4期675-679,共5页
Environmental Chemistry
关键词
双氯芬酸钠
介质阻挡放电
降解率
动力学
diclofenac sodium
dielectric barrier discharge
degradation efficiency
kinetics.
