Tio
2
/SiO
2
/Fe
3
O
4
magnetic nanoparticles synthesis and
application in methyl orange UV photocatalytic removal
Shabnam Behzadi, Behrouz Nonahal, Sayed Javid Royaee and
Amir Atabak Asadi
ABSTRACT
Three main parameters affecting TiO
2
/SiO
2
/Fe
3
O
4
nanoparticles activity in photocatalytic degradation
of methyl orange were investigated using response surface methodology (SRM). Precipitation
method and sol-gel technique were used to prepare SiO
2
/Fe
3
O
4
electromagnetic composite support
and TiO
2
/SiO
2
/Fe
3
O
4
photocatalytically active nanoparticles. The specific surface area, pore volume,
and average pore size of the synthesized nanoparticles were respectively equal to 56 m
2
/g,
0.12 cm
3
/g and 9.4 nm. The point of zero charge (PZC) of the catalyst was measured to be 5.9.
The maximum and minimum photocatalytic degradation of methyl orange using the synthesized
nanoparticles were 100% and 30%, respectively. A linear model was fitted to the obtained results
with R
2
adjusted
equal to 0.87. The results of analysis of variance (ANOVA) revealed that catalyst
concentration, reaction media pH and aeration rate were significantly affected the photocatalytic
activity. Optimization was performed considering photocatalytic activity as the main objective
functions. In order to maximize photocatalytic activity, catalyst loading, reaction media pH and
aeration rate were respectively adjusted to 2,000 ppm, 3 and 2.5 L/min, which resulted in total
methyl orange removal. Considering promising photocatalytic activity of TiO
2
/SiO
2
/Fe
3
O
4
along with
core-sell nanocomposite separation performance led us to propose this photocatalyst as an
alternative solution for treating waste waters.
Key words | composite nanoparticles, dye wastewater, magnetic immobilization, nanocomposite
photocatalyst, TiO
2
nanostructure
HIGHLIGHTS
•
Enhancing TiO
2
photocatalytic activity by optimizing process conditions.
•
Modeling and optimization of photocatalytic wastewater treatment performance.
•
Achieving total contaminant and TiO
2
nanoparticles removal.
Shabnam Behzadi
Department of Chemical Engineering,
Amirkabir University of Technology,
Tehran, 15875-4413,
Iran
Behrouz Nonahal
Sayed Javid Royaee
Amir Atabak Asadi (corresponding author)
Petroleum Refining Technology Development
Division,
Research Institute of Petroleum Industry (RIPI),
Tehran, 14857-33111,
Iran
E-mail: asadiaa@ripi.ir
INTRODUCTION
One of the most significant current discussions in the field of
wastewater treatment is to find the most efficient method to
convert the pollution from industrial wastewater into less
harmful species (Luyten et al. ; Krzywicka & Kwar-
ciak-Kozlowska ). Industrial wastewaters are sources
for variety of contaminant species which should be elimi-
nated from the stream through one of the physical (Kesari
et al. ), chemical and biological (Beltran-Heredia et al.
) methods as well as coupled processes (Mozia et al.
). Releasing these wastewaters without further treatment
will no doubt affect our environment and especially limited
available water resources (Samaei et al. ). In one way or
another, any contamination or pollution in one resource will
eventually, if not immediately, affect the other. Contami-
nation of groundwater resources by pathogenic organisms,
inorganic and organic contaminants is going to be one of
2432 © IWA Publishing 2020 Water Science & Technology | 82.11 | 2020
doi: 10.2166/wst.2020.509
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