标题:Selective decolorization of cationic dyes by peroxymonosulfate: non-radical mechanism and effect of chloride作者:Lei, Yang; Chen, Chuh-Shun; Ai, Jia; Lin, Heng; Huang, Yao-Hui; Zhang,Hui
来源出版物:RSC ADVANCES 卷:6 期:2 页:866-871 DOI:10.1039/c5ra19718j 出版年:2016
摘要:How to effectively activate oxidants like hydrogen peroxide (H2O2), peroxydisulfate (PDS) and peroxymonosulfate (PMS) is the focus of advanced oxidation processes (AOPs). In this study, we have found that PMS can directly decolorize cationic dyes without activation in a wide pH range (2.0-12.0). In addition, the presence of Cl- results in the formation of free available chlorine species and thus improves the degradation efficiency as well as broadening the scope of target pollutants. The first-order rate constant increased by 4.3 times when 2.5 mM Cl- was added as observed by an increase from 0.021 to 0.089 min(-1), which further rose to 1.371 min(-1) when Cl- was present at a level of 50 mM. Furthermore, it was found that only PMS has such an amazing effect while H2O2 and PDS do not. Radical quenching experiments and electron paramagnetic resonance (EPR) studies show that the decolorization of cationic dyes by PMS does not rely on the formation of sulfate radicals. A plausible mechanism is that cationic dyes (i.e., RhB+) first form a complex with the active component of PMS (HSO5-) owing to their electrical interaction. Subsequently, direct electron transfer from cationic dyes to HSO5- may occur and probably this is responsible for the bleaching of cationic dyes.
入藏号:WOS:000367953200005
文献类型:Article
语种:English
扩展关键词:ACID ORANGE 7; AQUEOUS-SOLUTION; ULTRASONIC IRRADIATION; EFFICIENT DEGRADATION; SULFATE RADICALS; AZO DYES; OXIDATION; PERSULFATE; REMOVAL; COMBINATION
通讯作者地址:Lei, Y, Wuhan Univ, Dept Environm Engn, Wuhan 430072, Peoples R China.
电子邮件地址:eeng@whu.edu.cn; yhhuang@mail.ncku.edu.tw
地址:
[Lei, Yang; Ai, Jia; Lin, Heng; Zhang, Hui] Wuhan Univ, Dept Environm Engn, Wuhan 430072, Peoples R China.
[Lei, Yang; Chen, Chuh-Shun; Huang, Yao-Hui] Natl Cheng Kung Univ, Dept Chem Engn, Tainan 701, Taiwan.
[Huang, Yao-Hui] Natl Cheng Kung Univ, Sustainable Environm Res Ctr, Tainan 701, Taiwan.
研究方向:Chemistry
ISSN:2046-2069
影响因子(2014):3.84