文献速递|齐鲁工业大学JWPE:具有核壳结构的分层纳米反应器通过异质催化臭氧有效去除阿特拉津：实验参数、动力学和性能分析

第一作者：Teer Ba

通讯作者：王晨 教授

通讯单位：齐鲁工业大学环境科学与工程学院

DOI：10.1016/j.jwpe.2023.103716

在这项研究中，通过水热法和溶胶-凝胶法制备了一个核壳MnO2@mSiO2纳米反应器。该材料被评估为一种异质催化剂，通过HCOP降解水中的ATZ。本研究的主要目的是为HCOP的工程应用提供一种开发高效异质催化剂的新策略。系统地研究了实验参数对ATZ降解的影响，包括催化剂用量、臭氧用量、ATZ浓度和初始溶液pH值。淬火实验和化学动力学模型被用来识别和评估ROS的作用。还研究了活性点对臭氧分解的影响。最后，提出了ATZ降解的机制和途径。

Fig. 1. Preparation of catalyst (a) MnO2, (b) MnO2@mSiO2.Fig. 2. SEM images of MnO2 (a), and corresponding EDS element mapping spectrum (b and c). SEM images of MnO2@mSiO2 (d). HR-TEM images of MnO2@mSiO2 (e). SAED pattern of MnO2 (f). HAADF-STEM images of MnO2@mSiO2 (g), and corresponding element mapping (h-l).Fig. 3. XRD patterns (a), and FT-IR spectra (b) of MnO2 and MnO2@mSiO2. XPS spectra of SiO2 (C), and of MnO2@mSiO2 (d).Fig. 4. (a) ATZ degradation curves, (b) ATZ removal efficiency of various reaction, (c) the linear fit of ln (Ct/C0) versus reaction time, (d) values of the apparent first order reaction rate constant (Kapp) corresponding with linear fit. (e) Residual ozone concentration, (f) TOC removal efficiency. Experimental conditions: [ATZ] = 15uM, [catalyst] = 30 mg/L, [ozone] = 7.5 mg/L, pH = 7.0, T = 25 ± 2 °C, agitation speed = 300 rpm.Fig. 5. The effect of parameters changes. ATZ removal efficiency affected by (a) catalyst dosage, (d) ozone concentration, (g) ATZ concentration and (j) pH. Catalytic activity and synergy effect affected by (b) catalyst dosage, (e) ozone concentration, (h) ATZ concentration and (k) pH. TOC removal efficiency and residual ozone concentration affected by (c) catalyst dosage, (f) ozone concentration, (i) ATZ concentration and (l) pH. Experimental conditions: [ATZ] = 5-25uM, [catalyst] = 10 mg/L-50 mg/L (if used), [ozone] = 2.5 mg/L-12.5 mg/L (if used), pH = 3–11, T = 25 ± 2 °C, agitation speed = 300 rpm.Fig. 6. (a) Adsorbed ozone concentration on catalyst, (b) quenching experiment, (c) the linear fit of ln (Ct/C0) versus reaction time (insert: ozone decay curves), (c) the ozone exposure of SOP, MnO2 and MnO2@mSiO2 (insert: ozone decay curves), (d) ·OH exposure of SOP, MnO2 and MnO2@mSiO2 (linear fit) and contribution of ozone, ·OH and adsorption. Experimental conditions: [ATZ] = 15 uM (if used), [catalyst] = 30 mg/L (if used), [ozone] = 7.5 mg/L (if used), pH = 7, T = 25 ± 2 °C, agitation speed = 300 rpm.Fig. 7. XPS spectra of Mn 2p of (a) MnO2 and (b) MnO2@mSiO2 before and after the degradation reaction. XPS spectra of O 1 s of (c) MnO2 and (d) MnO2@mSiO2 before and after the degradation reaction.Fig. 8. The possible degradation pathway of ATZ in the MnO2@mSiO2 heterogeneous catalytic ozonation system. ATZ degradation initiated by (1) De-alkylation (1), (2) Alkylic-hydroxylation, (3) Alkylic-oxidation, (4) Dechlorination-hydroxylation. Experimental conditions: [ATZ] = 15 uM, [MnO2@mSiO2] = 30 mg/L, [ozone] = 7.5 mg/L (if used), pH = 7, T = 25 ± 2 °C, agitation speed = 300 rpm.Fig. 9. Assessment of acute and chronic toxicity toward fish, daphnia and green algae. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)Fig. 10. The proposed reaction mechanism of in the MnO2@mSiO2 heterogeneous catalytic ozonation system.Fig. 11. Catalyst stability and reusability. (a) SEM images of MnO2@mSiO2 after 5th, (b) TEM images of MnO2@SiO2 after 5th, (c) XRD spectra of MnO2@mSiO2 and (d) ATZ removal efficiency of MnO2@mSiO2.