Novel Modified Nanocatalysts Development and Application to Wastewater Remediation

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Novel Modified Nanocatalysts Development and
Application to Wastewater Remediation
Fang Han
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Content

• Introduction
• Objectives
• Methods
• Results
• Conclusions
• Future studies

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Introduction

• Synthetic dyes are used extensively in numerous
  industrial processes including textile dyeing.
• Mega Litres of wastewater containing residual
  dyes are often disposed to land water bodies.
• Such disposals have led to severe contamination
  of our environment.
• The toxicity and carcinogenic nature of these
  dyes pose risk to environmental and human health.

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Objectives
To develop a cost-effective and reliable
technique for the remediation of textile industry
wastewater.
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Current Dyes Degradation Techniques

• Biological processes
• Activated sludge, bacterial, fungal processes
  etc.
• Physico-Chemical processes
• Adsorption, coagulation, ion exchange,
  filtration, chemical oxidation etc.

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Current Dyes Degradation Techniques

• Advanced Oxidation processes
• Photochemical, Fenton, wet air
  oxidation,
• photocatalysis etc.

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Photocatalysis Technique
Semiconductor oxides, Binary Oxides, Zeolites and
Clays etc.
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Some difficulties with existing techniques

• High recombination ratio of photo-induced
  electrons (e) and positive holes (h) produced.
• Difficult separation of nanomaterial particles.
• 5 60 nm in diameter.
• Sedimentation, centrifugation and
  filtration.
• Reduced efficiency of immobilized material.
• Exposure of only part of the material.
• Need of an UV excitation source.

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Specific Objectives

• To synthesize novel nanocatalysts material with
• high efficiency, easy retrieval, visible
  light active.
• To design, construct and optimize an efficient
  photocatalytic reactor.
• To investigate the kinetics of dye degradation
  using synthesized nanocatalysts.
• To assess the degradation process using textile
  industry wastewaters.

Study addresses CRC milestones 2.5.3 (R) and
2.5.2 (C)
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Methods Nanocatalysts syntheses

• Nine syntheses methods were explored for novel
  nanocatalysts preparation followed by initial
  photocatalysis efficiency assessment.
• The best one was selected, modified and optimized
  for high yield.

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Development of the Reactor

• The New Reactor
• hybrid technique.
• utilizes the optimum light intensity.
• ensures uniform suspension of catalyst.
• avoids mass transfer limitations.
• overcomes dissolved oxygen depletion.
• operates in both batch and continuous mode.

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Photocatalytic Reactor Efficiency
Reactor efficiency test through acid orange-7
degradation with commercial photocatalyst
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Results
Degradation of acid orange-7
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Results
Synthesized Photocatalyst
0 h
2 h
Acid orange-7 degradation
Commercial Photocatalyst
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Conclusions

• An efficient reactor system has been established
  with provisional patent application in progress.
• A novel nanocatalyst has been achieved with great
  patent potentiality.

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Where to now ?

• Mechanism of degradation process
• Field Application

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Acknowledgements

• CRC CARE research funding
• CERAR, UniSA for infrastructure
• Prof. Ravi Naidu
• Dr. Venkata Subba Rao Kambala

Thank you!