不同MnO2納米晶催化臭氧氧化去除美托洛爾和布洛芬的效率、轉(zhuǎn)化和機(jī)理

1. 文章信息

標(biāo)題：Catalytic ozonation for metoprolol and ibuprofen removal over different MnO2 nanocrystals: Efficiency, transformation and mechanism

中文標(biāo)題：不同MnO2納米晶催化臭氧氧化去除美托洛爾和布洛芬的效率、轉(zhuǎn)化和機(jī)理

2. 文章鏈接

https://doi.org/10.1016/j.cep.2020.108296

3. 期刊信息

期刊名：Science of the Total Environment 785 (2021) 147328

涉及研究方向：環(huán)境科學(xué)

4. 作者信息：Yuan He a, Liangjie Wang a,b, Zhan Chen a, Bo Shen a, Jinshan Wei a, Ping Zeng b, Xianghua Wen a,?

a School of Environment, Tsinghua University, Beijing 100084, China

b State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China

5.文中所用產(chǎn)品型號：3S-T3-D，3S-J5000

重點(diǎn)

?與β-MnO2和γ-MnO2相比，α-MnO2在水中對IBU和MET的降解活性最高；

?α-MnO2的最高活性歸因于其豐富的氧空位和易還原的吸附氧；

?氧空位促進(jìn)了臭氧利用率和ROS生成的增加；

?所有·OH、·O2-和1 O2在MET和IBU降解中都起著顯著作用；

?根據(jù)確定的有機(jī)中間介體和通過密度函數(shù)理論計算的反應(yīng)位點(diǎn)，提出了PPCP的降解途徑

介紹

近幾十年來，二氧化錳被廣泛認(rèn)為是催化臭氧氧化去除廢水中有機(jī)污染物的催化劑。然而，很少有研究關(guān)注MnO2的構(gòu)效關(guān)系和水中催化臭氧氧化機(jī)理。在本研究中，評估了MnO2的三種不同晶相（對應(yīng)于α-MnO2、β-MnO2和γ-MnO2）對美托洛爾（MET）和布洛芬（IBU）的氧化反應(yīng)性。發(fā)現(xiàn)α-MnO2含有最豐富的氧空位和易還原的表面吸附氧（O2-，O-，OH-），這有助于提高臭氧利用率和最高的催化性能，IBU和MET的降解效率為99%。然后選擇α-MnO2來研究最佳的關(guān)鍵操作參數(shù)，結(jié)果催化劑用量為0.1 g/L，臭氧用量為1 mg/min，初始pH值為7。α-MnO2的引入促進(jìn)了活性氧（O2-、O-、OH-）的產(chǎn)生，這在IBU降解中起著重要作用。根據(jù)所鑒定的有機(jī)中間體和基于密度泛函理論（DFT）計算的反應(yīng)位點(diǎn)，提出了MET和IBU的可能降解途徑。本研究加深了我們對二氧化錳催化臭氧氧化的認(rèn)識，并提供了

提高工藝效率的參考。

臭氧設(shè)備

2.4. Catalytic ozonation experiments

The catalytic ozonation of MET and IBU were performed in a 500 mL glass reactor equipped with a magnetic stirrer at 25 °C. Both of MET and IBU concentration was 10 mg/L at the beginning. Ozone was generated by an ozone generator (3S-T3-D, Tonglin Technology, China). The inlet ozone concentration was 2.5 mg/L with the flow rate of 200 mL/min.Then ozone was added to the bottom of the glass reactor through an aeration head. 500 mL stock solution was prepared in the glass reactor equipped with magnetic stirrers. 0.2 g/L catalyst was added and mixed with the stock water. During the experiment, 5 mL water samples were taken every 5 min in 30 min and filtered by PTFE filters for further analysis. All the catalytic ozonation experiments were conducted in parallel under the same condition. Ozone concentrations were detected with an ozone detector (3S-J5000, Tonglin Technology, China) for gas and an ozone detector (DOZ30P, Tonglin Technology, China) for liquid phase. The solution pH was adjusted by NaOH or HCl to maintain 7.0 ± 0.5.

2.4. 催化臭氧氧化實(shí)驗(yàn)

MET和IBU的催化臭氧氧化在配備磁力攪拌器的500 mL玻璃反應(yīng)器中在25°C下進(jìn)行。MET和IBU的初始濃度均為10mg/L。臭氧由臭氧發(fā)生器（3S-T3-D，同林科技，中國）產(chǎn)生。入口臭氧濃度為2.5mg/L，流速為200mL/min。然后通過曝氣頭將臭氧添加到玻璃反應(yīng)器的底部。在配備有磁力攪拌器的玻璃反應(yīng)器中制備500mL儲備溶液。加入0.2g/L催化劑并與原料水混合。在實(shí)驗(yàn)過程中，在30分鐘內(nèi)每5分鐘取5毫升水樣，用PTFE過濾器過濾以進(jìn)行進(jìn)一步分析。所有催化臭氧氧化實(shí)驗(yàn)均在相同條件下并行進(jìn)行。使用臭氧檢測器（3S-J5000，中國同林科技）檢測氣體中的臭氧濃度，使用臭氧檢測器。用NaOH或HCl調(diào)節(jié)溶液pH至7.0±0.5。