Enhanced mineralization of atrazine by surface induced hydroxyl radicals over light-weight granular mixed-quartz sands with ozone

Da Wang; Haodan Xu; Jun Ma; Stefanos Giannakis; Xiaohui Lu; Huizhong Chi; Shuang Song; Jingyao Qi

doi:10.1016/j.watres.2018.11.002

Enhanced mineralization of atrazine by surface induced hydroxyl radicals over light-weight granular mixed-quartz sands with ozone

Water Res. 2019 Feb 1:149:136-148. doi: 10.1016/j.watres.2018.11.002. Epub 2018 Nov 5.

Authors

Da Wang¹, Haodan Xu², Jun Ma³, Stefanos Giannakis⁴, Xiaohui Lu², Huizhong Chi², Shuang Song⁵, Jingyao Qi⁶

Affiliations

¹ State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China; School of Basic Sciences (SB), Institute of Chemical Science and Engineering (ISIC), Group of Advanced Oxidation Processes (GPAO), École polytechnique fédérale de Lausanne (EPFL), Station 6, CH-1015, Lausanne, Switzerland.
² State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
³ State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China. Electronic address: majun@hit.edu.cn.
⁴ School of Basic Sciences (SB), Institute of Chemical Science and Engineering (ISIC), Group of Advanced Oxidation Processes (GPAO), École polytechnique fédérale de Lausanne (EPFL), Station 6, CH-1015, Lausanne, Switzerland.
⁵ College of Environment, Zhejiang University of Technology, Hangzhou, 310032, China.
⁶ State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China. Electronic address: jyq@hit.edu.cn.

PMID: 30439577
DOI: 10.1016/j.watres.2018.11.002

Abstract

A light-weight granular mixed-quartz sand (denoted as L-GQS) combined with stirring-assisted bubble column reactor was firstly applied in catalytic ozonation of atrazine. The L-GQS, with a density of 2.36 g cm^-3 and average diameter of ca. of 4 mm, was readily churned up and uniformly distributed within the solution in the reactor. The introduction of L-GQS was found to exhibit enhanced catalytic ozonation of atrazine, with the increase in degradation rate and the dissolved organic carbon (DOC) removal being more than 2-fold for the catalytic process (L-GQS dosage = 5 g L^-1, [atrazine]₀ = 50 μM, [O₃] = 25 mg L^-1, gas flow = 0.2 L min^-1, at pH 7.0 and 293 K). The L-GQS settled at the bottom of the reactor after experimentation, allowing its easy separation from the solution. A complete characterization of the material (XRD, XPS, FTIR, FE-SEM/EDS, BET and pH_pzc) revealed that L-GQS consisted of α-quartz, β-cristobalite, anorthoclase and small amount of iron oxy-hydroxides. Hydroxyl groups, Bronsted acid sites and Lewis acid sites on the surface of L-GQS all contributed to the atrazine adsorption, ozone decomposition and ·OH generation. The L-GQS catalyzed ozonation exhibited superior atrazine degradation and mineralization rates in a wide range of pH (3.0-9.0) and reaction temperatures (278 K-293 K). Also, an enhancement of DOC abatement was observed both in presence of natural organic matter isolates and natural water matrices (river water) when L-GQS was used. Finally, the degradation mechanism was proposed, based on the intermediates and by-products formation analyzed by LC-QTOF-MS/MS and ionic chromatography. Our results indicate that the L-GQS combined with stirring-assisted bubble column reactor could be utilized as an enhancement of ozone-based advanced oxidation processes.

Keywords: Atrazine; Catalytic ozonation; Heterogeneous catalysis; Hydroxyl radical; Mixed quartz sand.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Atrazine*
Catalysis
Hydroxyl Radical
Oxidation-Reduction
Ozone*
Quartz
Silicon Dioxide
Tandem Mass Spectrometry
Water Pollutants, Chemical*

Substances

Water Pollutants, Chemical
Quartz
Hydroxyl Radical
Ozone
Silicon Dioxide
Atrazine