Magnetic nanocatalysts for oxidative decomposition of persistent organic pollutants

95 Pages·2015·2.48 MB·English

School of Chemical and Petroleum Engineering
Department of Chemical Engineering

Magnetic nanocatalysts for oxidative
decomposition of persistent organic
pollutants (POPs) in contaminated water
Yilin Liu

This thesis is presented for Degree of
Master of Philosophy (Chemical Engineering)
Of
Curtin University

August 2015
Declaration

To the best of my knowledge and belief this thesis contains no material previously published
by any other person except where due acknowledgment has been made. This thesis contains
no material which has been accepted for the award of any other degree or diploma in any
university.
Signature: Yilin Liu Date: 6 Aug 2015

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Acknowledgement

I would like to express my sincere gratitude to my supervisor, Professor Shaobin Wang, for
his selfless and continuous supports of my master study and research. I had no chance to
complete this thesis without his intelligence and warm encouragement.
I am also grateful to my co-supervisor, Dr. Hongqi Sun whose knowledge always gives me
inspiration and helps me to make everything possible during my postgraduate years.
My sincere gratitude must go to Mr. Yuxian Wang and Xiaoguang Duan who are always
ready to help me at various occasions.
I am also thankful to all laboratory technical staff, Karen Haynes, Jason Wright, Ann Carrol
and Roshanak Doroushi for their kindly technical support.
And last, but not the least, I would like to thank my parents for everything they give me.
They support everything I want and I must say that I have the best parents in the world.

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Abstract
In the past decades, applications of advanced oxidation processes (AOPs) for persistent
organic pollutants (POPs) treatment in wastewater have been thoroughly investigated. The
AOPs can improve biodegradability of pollutants and they are useful for cleaning biologically
toxic and non-degradable materials in waste water. Among these processes, the sulfate
radical-based reaction has been employed as a low-cost, environmentally-friendly and
sustainable technique to purify wastewater.
The aim of this work is to synthesize different magnetic nanocatalysts by a hydrothermal
method which can present high activity and good magnetic performance in the oxidation of
phenol solutions. Three types of catalysts were synthesized with either one-pot or two-step
hydrothermal method. All of these synthesized catalysts were examined for
peroxymonosulfate (PMS, Oxone) activation for the decomposition of phenol.
In all the catalysts, the magnetic carbon nanospheres supported Mn nanoparticles which were
synthesized by a one-pot hydrothermal method and self-reduction in N atmosphere with the
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carbon from hexamethylenetetramine (HMTA) showed the best oxidizing ability which could
give effectively phenol decomposition in about 42 minutes.
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Contents
Declaration ............................................................................................................................................. i
Abstract .................................................................................................................................................. iii
1.1 Motivation ............................................................................................................................... 2
1.2 Objectives of thesis .................................................................................................................. 2
1.3 Thesis organization .................................................................................................................. 3
1.4 References ............................................................................................................................... 4
2. Literature Review ........................................................................................................................... 6
2.1 Introduction ............................................................................................................................. 7
2.2 The overview of water pollutions .......................................................................................... 11
2.3 The methods of water pollution control ................................................................................ 12
2.4 The classification of AOPs ...................................................................................................... 12
2.5 The classification of catalysts ................................................................................................. 14
3 Synthesis of magnetic carbon nanosphere supported manganese catalysts with a one-pot
hydrothermal method ..................................................................................................................... 35
A B S T R A C T ................................................................................................................................... 35
3.1 Introduction ........................................................................................................................... 36
3.2 Experimental .......................................................................................................................... 37
3.3 Results and discussion ........................................................................................................... 39
3.4 Summary ................................................................................................................................ 47
3.5 References ............................................................................................................................. 48
4 Synthesis of magnetic carbon nanosphere supported manganese catalysts for phenol
degradation ...................................................................................................................................... 53
A B S T R A C T ................................................................................................................................... 53
4.1 Introduction ........................................................................................................................... 54
4.2. Experimental ......................................................................................................................... 54
4.3 Results and discussion ........................................................................................................... 57
4.4 Summary ................................................................................................................................ 63
4.5 References ............................................................................................................................. 65
5 Magnetic mesoporous Fe/carbon aerogel structures with enhanced phenol removal efficiency 69
A B S T R A C T ................................................................................................................................... 69
5.1 Introduction ........................................................................................................................... 69
5.2. Experimental ......................................................................................................................... 71
5.3 Results and discussion ........................................................................................................... 73
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5.4 Summary ................................................................................................................................ 81
5.5 References ............................................................................................................................. 81
6. Conclusion and Future work ........................................................................................................ 87
6.1 Concluding comments ........................................................................................................... 88
6.2 The one-pot hydrothermal method ....................................................................................... 88
6.3 Effect of Mn on magnetic carbon nanocatalysts ................................................................... 88
6.4 Effect of temperature on phenol degradation of the catalysts ............................................. 89
6.5 Recommendation for future work ......................................................................................... 89

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1. Introduction and Overview

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1.1 Motivation
During the last several years, how to reduce environmental pollutants has been a serious
issue1. To deal with this problem, a lot of researchers have shown interest in the production of
environmentally-friendly materials and treatment techniques2. Normally, the pollutants
include two kinds of contaminations: water and solid pollution3, which can not only reduce
the availability of fertile land for agricultural use but also pose a risk to public health4, food
system5 and groundwater6. As one kind of most serious pollutant, persistent organic
pollutants (POPs) have attracted particular concern for their long life-time, toxicity and
resistance against nature attenuation7.
To provide satisfied POPs degradation, advanced oxidation processes (AOPs) have been
considered to be one of the most effective treatments due to their ability of fully degradation
of POPs8. They also support a new path for novel technology. Numerous studies have been
reported to use magnetic catalysts to activate OXONE (potassium monopersuphate) for
oxidation of POPs in soil and water9. The magnetic catalysts have attracted great attention
due to their high specific surface area10, unique size11 and morphology-dependent physical
and chemical properties12.
1.2 Objectives of thesis
The main objective of this research is to synthesize a new kind of magnetic nanocatalyst by a
novel hydrothermal method which can appear high activity and good magnetic performance
in the reaction of oxidizing phenol solutions.
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1.3 Thesis organization
Chapter one briefly introduced the major technique for removal of persistent organic
pollutants. Chapter two presented a comprehensive literature review on pollutant removal
techniques in four aspects: the methods of water pollution control, the classification of AOPs,
the classification of catalysts and the introduction of magnetic nanocatalysts. Chapter three
described a one-pot hydrothermal method to synthesize the carbon nanospheres supported by
Mn catalysts with glucose to supply the carbon elementary substances. Chapter four showed a
two-step hydrothermal method to synthesize the carbon nanospheres supported by Mn
catalysts with glucose to supply the carbon elementary substances. Chapter five showed a
one-pot hydrothermal method to synthesize the carbon nanospheres supported by Mn
catalysts with hexamethylenetetramine to supply the carbon elementary substances. Chapter
six summarized the overall thesis and discussed the performance of all the materials which
were synthesized during the research work for organic degradation. The final part of this
chapter was devoted to the possible suggestions and future work.

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1.4 References
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Fe2+/H2O2/UV-C versus TiO2/UV-A treatment for reactive dye wastewater. Journal of
Environmental Engineering-Asce 2000, 126 (10), 903-911.
2. (a) Chen, J.; Wang, X.; Liu, X.; Huang, J.; Xie, Z., Removal of Dye Wastewater COD
by Sludge Based Activated Carbon. Journal of Coastal Research 2015, 1-3; (b) Chen, Z.;
Zayed, T.; Qasem, A., An Efficiency-Centred Hierarchical Method to Assess Performance of
Wastewater Treatment Plants. International Journal of Environmental Research 2015, 9 (1),
1-8; (c) Guo, J.; Peng, Y.; Ni, B.-J.; Han, X.; Fan, L.; Yuan, Z., Dissecting microbial
community structure and methane-producing pathways of a full-scale anaerobic reactor
digesting activated sludge from wastewater treatment by metagenomic sequencing. Microbial
cell factories 2015, 14 (1), 218-218; (d) Lee, O. M.; Kim, H. Y.; Park, W.; Kim, T.-H.; Yu, S.,
A comparative study of disinfection efficiency and regrowth control of microorganism in
secondary wastewater effluent using UV, ozone, and ionizing irradiation process. Journal of
hazardous materials 2015, 295, 201-8.
3. Nasrabadi, T., An Index Approach to Metallic Pollution in River Waters. International
Journal of Environmental Research 2015, 9 (1), 385-394.
4. Ahmad, K.; Khan, Z. I.; Ashfaq, A.; Ashraf, M.; Akram, N. A.; Yasmin, S.; Sher, M.,
Assessment of Heavy Metals and Metalloids in Solanum tuberosum and Pisum sativum
Irrigated with Urban Wastewater in the Suburbs of Sargodha City, Pakistan. Human and
Ecological Risk Assessment 2015, 21 (4), 1109-1122.
5. Asgari, K.; Cornelis, W. M., Heavy metal accumulation in soils and grains, and health
risks associated with use of treated municipal wastewater in subsurface drip irrigation.
Environmental monitoring and assessment 2015, 187 (7), 4565-4565.
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