Co(Ⅱ)活化过一硫酸盐降解氨基三亚甲基膦酸的性能及反应机制 |
摘要点击 3716 全文点击 863 投稿时间:2022-07-13 修订日期:2022-09-17 |
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中文关键词 Co(Ⅱ) 过一硫酸盐(PMS) 氨基三亚甲基膦酸(NTMP) 正磷酸盐(PO43-) 非自由基机制 |
英文关键词 Co(Ⅱ) peroxymonosulfate (PMS) nitrilotris (methylene phosphonic acid) (NTMP) orthophosphate (PO43-) nonradical mechanism |
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中文摘要 |
Co (Ⅱ)活化过一硫酸盐(PMS)能有效降解有机膦酸,但氨基有机膦酸的降解机制并不明确.以氨基三亚甲基膦酸(NTMP)为例,采用电子顺磁共振波谱(EPR)、自由基捕获实验和化学探针实验等探究其在Co (Ⅱ)/PMS体系下的降解机制,并分析了NTMP可能的降解路径和影响其降解的因素.结果表明,Co (Ⅱ)/PMS体系20 min内NTMP已经被完全降解,反应60 min后,78.3% NTMP被氧化生成正磷酸盐(PO43-).1O2、HO ·和SO4- ·对Co (Ⅱ)/PMS体系氧化NTMP的贡献较小,Co (Ⅱ)-PMS络合物是NTMP降解的主要活性氧化物种.NTMP与Co (Ⅱ)-PMS络合物反应,使其C—N键和C—P键断裂生成多种含膦酸基团的中间产物,并最终被氧化为PO43-.随着PMS投加量和Co (Ⅱ)投加量的增加,NTMP氧化过程中PO43-的产生率显著增加.此外,HCO3-和天然有机物(NOM)的存在显著抑制了Co (Ⅱ)/PMS体系PO43-的产生.研究进一步完善了有机膦酸在Co (Ⅱ)/PMS体系下的氧化机制,为废水中有机膦酸的去除提供参考. |
英文摘要 |
Co(Ⅱ) mediated activation of peroxymonosulfate (PMS) could degrade phosphonate effectively, whereas the degradation of amino phosphonate remains unclear. Herein, nitrilotris (methylene phosphonic acid) (NTMP) was used as a target pollutant; the degradation mechanism was investigated using the electron paramagnetic resonance spectrum (EPR), free radical trapping experiments, and chemical probe experiments; and the possible degradation pathways of NTMP and the influencing factors were analyzed. The results showed that NTMP was completely degraded within 20 min in the Co(Ⅱ)/PMS system, and 78.3% of NTMP was oxidized to orthophosphate (PO43-) after 60 min of reaction. The Co(Ⅱ)-PMS complex was the main active oxidizing species, whereas 1O2, HO·, and SO4-· contributed little to the oxidation of NTMP in the Co(Ⅱ)/PMS system. A variety of intermediates containing phosphate groups were obtained through the breakage of the C-N bond and C-P bond as NTMP reacted with the Co(Ⅱ)-PMS complex and finally were oxidized to PO43-. With the increase in PMS dosage and Co(Ⅱ) dosage, the generation rate of PO43- during the oxidation process of NTMP was significantly improved. In addition, the presence of HCO3- and natural organic matter (NOM) greatly inhibited the generation of PO43- in the Co(Ⅱ)/PMS system. This study further improved the oxidation mechanism of phosphonate in the Co(Ⅱ)/PMS system and provides a reference for the removal of phosphonate in wastewater. |