In recent years, advanced oxidation processes (AOPs), especially sulfate radical based AOPs have been widely used in various fields of wastewater treatment due to their capability and adaptability in decontamination. Recently, metal-free carbon materials catalysts in sulfate radical production has been more and more concerned because these materials have been demonstrated to be promising alternatives to conventional metal-based catalysts, but the review of metal-free catalysts is rare. The present review outlines the current state of knowledge on the generation of sulfate radical using metal-free catalysts including carbon nanotubes, graphene, mesoporous carbon, activated carbon, activated carbon fiber, nanodiamond. The mechanism such as the radical pathway and non-radical pathway, and factors influencing of the activation of sulfate radical was also be revealed. Knowledge gaps and research needs have been identified, which include the perspectives on challenges related to metal-free catalyst, heterogeneous metal-free catalyst/persulfate systems and their potential in practical environmental remediation. (C) 2017 Elsevier Ltd. All rights reserved.
[Guan, Chunyun; Li, Xun; Guan, Mei; Xiong, Xinghua] Hunan Agr Univ, Dept Agron, Changsha 410128, Hunan, Peoples R China.;[Chen, Hong; Lu, Xin; Huang, Fenghong] Chinese Acad Agr Sci, Oil Crops Res Inst, Wuhan 430062, Peoples R China.
[Guan, Chunyun] Hunan Agr Univ, Dept Agron, Changsha 410128, Hunan, Peoples R China.;[Huang, Fenghong] Chinese Acad Agr Sci, Oil Crops Res Inst, Wuhan 430062, Peoples R China.
Brassica napus;Fatty acid;Triacylglycerol
The composition of fatty acids in triacylglycerides (TAGs) and their position on the glycerol backbone determine the nutritional value of vegetable oil. In this study, gas chromatography and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) were used to analyze the composition and distribution of fatty acids in TAGs of different rapeseed oils. Our results show the content of oleic acid in high-oleic-acid rapeseed oil to be about 80%. In terms of the number of acyl carbon atoms (CN), TAGs with CN52-54 were most abundant, with a maximum concentration at CN54 (80%). The main type of TAG was oleic-oleic-oleic (OOO), accounting for 71.75%, while oleic-oleic-linoleic (OOL) accounted for 7.56%, oleic-oleic-linolenic (OOLn) accounted for 4.81%, and stearic-oleic-oleic (SOO) accounted for 4.74%. Oleic acid in high-oleic-acid rapeseed oil was distributed in the following order of preference: sn-2 > sn-1/3. In high-erucic-acid rapeseed oil, however, oleic acid was enriched at the sn-1/3. These data show that the content of oleic acid can be as high as about 80% in high-oleic-acid material. This finding suggests that high-oleic-acid rapeseed oil has high nutritional value. (C) 2016 THE AUTHORS. Published by Elsevier LTD on behalf of Chinese Academy of Engineering and Higher Education Press Limited Company. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).