Lou Xiaoyi, Fang Changling, Geng Zhuning, Jin Yuming, Xiao Dongxue, Wang Zhaohui, Liu Jianshe, Guo Yaoguang
East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, China; State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China.
State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China.
Chemosphere. 2017 Apr;173:529-534. doi: 10.1016/j.chemosphere.2017.01.093. Epub 2017 Jan 21.
Base activation of peroxydisulfate (PDS) is a common process aiming for water treatment, but requires high doses of PDS and strongly basic solutions. Peroxymonosulfate (PMS), another peroxygen of sulfurate derived from PDS, may also be activated by a less basic solution. However, enhancing the base-PMS reactivity is still challenging. Here it is reported that pyrophosphate (PA) and tripolyphosphate (PB) can efficiently enhance PMS activation under weakly alkaline conditions (pH 9.5) via the formation of superoxide anion radical (O) and singlet oxygen (O). The rate constant of Acid Orange 7 (AO7) degradation in PA/PMS system (k) was nearly 4.4-15.9 fold higher than that in PMS/base system (k) without any polyphosphates. Increases in PA (or PB) concentration, PMS dose and pH favored the rapid dye degradation. Gas chromatograph-mass spectrometer (GC-MS) data confirmed AO7 and 2,4,6-trichlorophenol (2,4,6-TCP) were decomposed to a series of organic intermediates. The radical quenching and probe oxidation experiments indicate the degradation of organic compounds in the PA/PMS and PB/PMS processes was not reliant on sulfate radical (SO) and hydroxyl radical (OH) species but on O and O reactive species. Comparison experiments show that the polyphosphate/PMS process was much more favorable than PDS/base process. The present work provides a novel way to activate PMS for contaminant removal using industrial polyphosphate wastewaters.
过二硫酸盐（PDS）的碱活化是一种常见的水处理工艺，但需要高剂量的PDS和强碱性溶液。过一硫酸盐（PMS）是另一种由PDS衍生而来的硫酸过氧化物，也可以被碱性较弱的溶液活化。然而，提高碱-PMS的反应活性仍然具有挑战性。本文报道，焦磷酸盐（PA）和三聚磷酸盐（PB）可以在弱碱性条件（pH 9.5）下通过形成超氧阴离子自由基（O）和单线态氧（O）有效地增强PMS的活化。在没有任何聚磷酸盐的情况下，PA/PMS体系中酸性橙7（AO7）降解的速率常数（k）比PMS/碱体系中的速率常数（k）高出近4.4-15.9倍。PA（或PB）浓度、PMS剂量和pH值的增加有利于染料的快速降解。气相色谱-质谱联用仪（GC-MS）数据证实AO7和2,4,6-三氯苯酚（2,4,6-TCP）分解为一系列有机中间体。自由基猝灭和探针氧化实验表明，PA/PMS和PB/PMS过程中有机化合物的降解不依赖于硫酸根自由基（SO）和羟基自由基（OH），而是依赖于O和O活性物种。对比实验表明，聚磷酸盐/PMS工艺比PDS/碱工艺更具优势。本研究为利用工业聚磷酸盐废水活化PMS去除污染物提供了一种新方法。
