标題: Dissolved Silicate Enhances the Oxidation of Chlorophenols by Permanganate: Important Role of Silicate-Stabilized MnO2 Colloids

作者: Yu, MD (Yu, Minda); He, XS (He, Xiaosong); Xi, BD (Xi, Beidou); Xiong, Y (Xiong, Ying); Wang, ZC (Wang, Zhicheng); Sheng, DG (Sheng, Dige); Zhu, L (Zhu, Li); Mao, XH (Mao, Xuhui)

來源出版物: ENVIRONMENTAL SCIENCE & TECHNOLOGY  卷: 54  期: 16  頁: 10279-10288  DOI: 10.1021/acs.est.0c00826  出版年: AUG 18 2020  

摘要: Dissolved silicate is an important background constituent of natural waters, but there is little clarity regarding the effect of silicate on the oxidizing capability of permanganate (Mn(VII)) and on its efficiency for remediation applications. In the present study, we found that dissolved silicate, metasilicate or disilicate (DS), could significantly promote the oxidation of 2,4-dichlorophenol (2,4-DCP) by Mn(VII), and the extent of the promoting effect was even more evident than that of pyrophosphate (PP). The experiments showed that, unlike PP, DS was not capable of coordinating with Mn(III) ions, and the promoting effect of DS was not due to the oxidizing capability of complexed Mn(III). Instead, DS ions, as a weak base, could combine with the hydroxyl groups of MnO2 via hydrogen bonding to limit the growth of colloidal MnO2 particles. The DS-stabilized colloidal MnO2 particles, with hydrodynamic diameters less than 100 nm, could act as catalysts to enhance the oxidation of 2,4-DCP by Mn(VII). The best promoting effect of DS on the performance of Mn(VII) oxidant was achieved at the initial solution pH of 7, and the coexisting bicarbonate ions further improved the oxidation of 2,4-DCP in the Mn(VII)/DS system. Sand column experiments showed that the combined use of Mn(VII) and DS additive could mitigate the problem of permeability reduction of sand associated with the retention of MnO2 particles. This study not only deepens our understanding on the role of dissolved silicate in a Mn(VII) oxidation process but also provides an effective and green method to enhance the oxidizing capacity of Mn(VII)-based treatment systems.

入藏号: WOS:000563025000055

PubMed ID: 32702240

語言: English

文獻類型: Article

KeyWords Plus: ARSANILIC ACID DEGRADATION; MANGANESE-DIOXIDE; IRON COLLOIDS; HUMIC-ACID; KINETICS; ELECTROLYSIS; CHEMISTRY; DYNAMICS; PHENOLS; IMPACT

地址: [Yu, Minda; Xi, Beidou; Wang, Zhicheng; Sheng, Dige; Zhu, Li; Mao, Xuhui] Wuhan Univ, Sch Resource & Environm Sci, Hubei Int Sci & Technol Cooperat Base Sustainable, Wuhan 430079, Peoples R China.

[Yu, Minda; He, Xiaosong; Xi, Beidou] Chinese Res Inst Environm Sci, State Key Lab Environm Criteria & Risk Assessment, Beijing 100012, Peoples R China.

[Xiong, Ying] Southern Univ Sci & Technol, Sch Environm Sci & Engn, Guangdong Prov Key Lab Soil & Groundwater Pollut, Shenzhen 518055, Peoples R China.

通訊作者地址: Xi, BD; Mao, XH (corresponding author)，Wuhan Univ, Sch Resource & Environm Sci, Hubei Int Sci & Technol Cooperat Base Sustainable, Wuhan 430079, Peoples R China.

Xi, BD (corresponding author)，Chinese Res Inst Environm Sci, State Key Lab Environm Criteria & Risk Assessment, Beijing 100012, Peoples R China.

電子郵件地址: xibeidou@yeah.net; clab@whu.edu.cn

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