In-Situ H2O2 Cleaning for Fouling Control of Manganese-Doped Ceramic Membrane through Confined Catalytic Oxidation Inside Membrane

This work presents an effective approach for manganese-doped Al2O3 ceramic membrane (Mn-doped membrane) fouling control by in-situ confined H2O2 cleaning in wastewater treatment. An Mn-doped membrane with 0.7 atomic percent Mn doping in the membrane layer was used in a membrane bioreactor with the aim to improve the catalytic activity toward oxidation of foulants by H2O2. Backwashing with 1 mM H2O2 solution at a flux of 120 L/m2/h (LMH) for 1 min was determined to be the optimal mode for in-situ H2O2 cleaning, with confined H2O2 decomposition inside the membrane. The Mn-doped membrane with in-situ H2O2 cleaning demonstrated much better fouling mitigation efficiency than a pristine Al2O3 ceramic membrane (pristine membrane). With in-situ H2O2 cleaning, the transmembrane pressure increase (ΔTMP) of the Mn-doped membrane was 22.2 kPa after 24-h filtration, which was 40.5% lower than that of the pristine membrane (37.3 kPa). The enhanced fouling mitigation was attributed to Mn doping, in the Mn-doped membrane layer, that improved the membrane surface properties and confined the catalytic oxidation of foulants by H2O2 inside the membrane. Mn3+/Mn4+ redox couples in the Mn-doped membrane catalyzed H2O2 decomposition continuously to generate reactive oxygen species (ROS) (i.e., HO• and O21), which were likely to be confined in membrane pores and efficiently degraded organic foulants.

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Effective fabrication of porous Au–Ag alloy nanorods for in situ Raman monitoring catalytic oxidation and reduction reactions

Journal of Material Science and Technology ◽

10.1016/j.jmst.2021.01.095 ◽

2021 ◽

Author(s):

Shanlin Ke ◽

Caixia Kan ◽

Xingzhong Zhu ◽

Changshun Wang ◽

Weijian Gao ◽

...

Keyword(s):

Catalytic Oxidation ◽

Reduction Reactions ◽

In Situ Raman

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Effect of Pre-Oxidation on Coagulation/Ceramic Membrane Treatment of Yangtze River Water

Membranes ◽

10.3390/membranes11050369 ◽

2021 ◽

Vol 11 (5) ◽

pp. 369

Author(s):

Shengji Xia ◽

Xinran Zhang ◽

Yuanchen Zhao ◽

Fibor J. Tan ◽

Pan Li ◽

...

Keyword(s):

Water Treatment ◽

Membrane Fouling ◽

Membrane Filtration ◽

Ceramic Membrane ◽

Membrane Separation ◽

Membrane System ◽

Coagulation System ◽

Fouling Control ◽

Filtration System ◽

Membrane Treatment

The membrane separation process is being widely used in water treatment. It is very important to control membrane fouling in the process of water treatment. This study was conducted to evaluate the efficiency of a pre-oxidation-coagulation flat ceramic membrane filtration process using different oxidant types and dosages in water treatment and membrane fouling control. The results showed that under suitable concentration conditions, the effect on membrane fouling control of a NaClO pre-oxidation combined with a coagulation/ceramic membrane system was better than that of an O3 system. The oxidation process changed the structure of pollutants, reduced the pollution load and enhanced the coagulation process in a pre-oxidation-coagulation system as well. The influence of the oxidant on the filtration system was related to its oxidizability and other characteristics. NaClO and O3 performed more efficiently than KMnO4. NaClO was more conducive to the removal of DOC, and O3 was more conducive to the removal of UV254.

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Au Modified F-TiO2 for Efficient Photocatalytic Synthesis of Hydrogen Peroxide

Molecules ◽

10.3390/molecules26133844 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3844

Author(s):

Lijuan Li ◽

Bingdong Li ◽

Liwei Feng ◽

Xiaoqiu Zhang ◽

Yuqian Zhang ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Reaction System ◽

Reaction Medium ◽

Pure Tio2 ◽

H2o2 Production ◽

Tio2 Photocatalyst ◽

H2o2 Decomposition ◽

Spin Resonance ◽

Photocatalytic Synthesis

In this work, Au-modified F-TiO2 is developed as a simple and efficient photocatalyst for H2O2 production under ultraviolet light. The Au/F-TiO2 photocatalyst avoids the necessity of adding fluoride into the reaction medium for enhancing H2O2 synthesis, as in a pure TiO2 reaction system. The F− modification inhibits the H2O2 decomposition through the formation of the ≡Ti–F complex. Au is an active cocatalyst for photocatalytic H2O2 production. We compared the activity of TiO2 with F− modification and without F− modification in the presence of Au, and found that the H2O2 production rate over Au/F-TiO2 reaches four times that of Au/TiO2. In situ electron spin resonance studies have shown that H2O2 is produced by stepwise single-electron oxygen reduction on the Au/F-TiO2 photocatalyst.

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Alkali-assisted membrane cleaning for fouling control of anaerobic ceramic membrane bioreactor

Bioresource Technology ◽

10.1016/j.biortech.2017.02.052 ◽

2017 ◽

Vol 240 ◽

pp. 25-32 ◽

Cited By ~ 29

Author(s):

Xiaojie Mei ◽

Pei Jun Quek ◽

Zhiwei Wang ◽

How Yong Ng

Keyword(s):

Membrane Bioreactor ◽

Ceramic Membrane ◽

Membrane Cleaning ◽

Fouling Control

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In-situ regulation of acid sites on Mn-based perovskite@mullite composite for promoting catalytic oxidation of chlorobenzene

Journal of Colloid and Interface Science ◽

10.1016/j.jcis.2021.08.145 ◽

2021 ◽

Author(s):

Lizhong Liu ◽

Bing Zhou ◽

Yuwei Liu ◽

Jingyin Liu ◽

Lanping Hu ◽

...

Keyword(s):

Catalytic Oxidation ◽

Acid Sites

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Thermoelectric Properties of Mn Doped Cu12-xMnxSb4S13 Tetrahedrites

Materials Science Forum ◽

10.4028/www.scientific.net/msf.847.161 ◽

2016 ◽

Vol 847 ◽

pp. 161-165 ◽

Cited By ~ 8

Author(s):

Ju Yi Wang ◽

Xiao Ya Li ◽

Ye Feng Bao

Keyword(s):

Electrical Conductivity ◽

Substitution Effect ◽

Hot Press ◽

X Ray Diffraction ◽

Doping Amount ◽

Spectroscopy Analysis ◽

Mn Doping ◽

Thermoelectric Transport Properties ◽

Hot Press Sintering ◽

Mn Doped

In this study, Mn doped Cu12-xMnxSb4S13(x=0, 0.5, 1.0, and 2.0) tetrahedrite samples were prepared by melting and annealing followed by hot press sintering. Powder X-ray diffraction and scanning electron microscopy and electron energy dispersive spectroscopy analysis were performed for the samples, and the thermoelectric transport properties of samples were characterized. The experimental results showed that the synthetic tetrahedrites were consisted of principal Cu12Sb4S13 phase and a small amount of secondary Cu3SbS4 and CuSbS2. The electrical conductivity of the tetrahedrites decreased with increasing the Mn doping amount. Contrary to the electrical conductivity, the Seebeck coefficient of the tetrahedrites increased with increasing Mn doping amount. The thermal conductivity decreased with increasing Mn doping amount due to the suppression of the carrier contribution, as well as due to the substitution effect of Mn on the Cu site. For the Mn doped Cu12-xMnxSb4S13 compounds with x=0.5, 1.0, and 2.0, the ZT values decreased with the increase of Mn doping amount, a maximum ZT=0.89 was obtained for the Mn doped compound with x=0.5.

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Band gap tuning and p to n-type transition in Mn-doped CuO nanostructured thin films

Journal of Semiconductors ◽

10.1088/1674-4926/43/1/012801 ◽

2022 ◽

Vol 43 (1) ◽

pp. 012801

Author(s):

R. Rahaman ◽

M. Sharmin ◽

J. Podder

Keyword(s):

Thin Films ◽

Band Gap ◽

Spray Pyrolysis Technique ◽

Band Gap Energy ◽

Dielectric Constants ◽

X Rays ◽

Electron Effective Mass ◽

Mn Doping ◽

Type Transition ◽

Mn Doped

Abstract Here we discuss the synthesis of copper (II) oxide (CuO) and manganese (Mn)-doped CuO thin films varying with 0 to 8 at% Mn using the spray pyrolysis technique. As-deposited film surfaces comprised of agglomerated spherical nanoparticles and a semi-spongy porous structure for 4 at% Mn doping. Energy dispersive analysis of X-rays confirmed the chemical composition of the films. X-ray diffraction spectra showed a polycrystalline monoclinic structure with the predominance of the ( 11) peak. Optical band gap energy for direct and indirect transitions was estimated in the ranges from 2.67–2.90 eV and 0.11–1.73 eV, respectively. Refractive index and static dielectric constants were computed from the optical spectra. Electrical resistivity of CuO and Mn-doped CuO (Mn:CuO) thin films was found in the range from 10.5 to 28.6 Ω·cm. The tiniest electron effective mass was calculated for 4 at% Mn:CuO thin films. P to n-type transition was observed for 4 at% Mn doping in CuO films. Carrier concentration and mobility were found in the orders of 1017 cm–3 and 10–1 cm2/(V·s), respectively. The Hall coefficient was found to be between 9.9 and 29.8 cm3/C. The above results suggest the suitability of Mn:CuO thin films in optoelectronic applications.

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