  Environmental pollutants, such as colors from the textile industry, affect
water quality indicators like color, smell, and taste. These substances in the
water cause the obstruction of filters and membranes and thereby reduce the
efficiency of advanced water treatment processes. In addition, they are harmful
to human health because of reaction with disinfectants and production of
by-products. Iron oxide nanoparticles are considered effective absorbents for
the removal of pollutants from aqueous environments. In order to increase the
stability and dispersion, nanospheres with iron oxide core and titanium dioxide
coating were used in this research and their ability to absorb Congo red color
was evaluated. Iron oxide-titanium oxide nanospheres were prepared based on the
coprecipitation method and then their physical properties were determined using
a tunneling electron microscope (TEM) and an X-ray diffraction device.
Morphological investigation of the absorbent surface showed that iron
oxide-titanium oxide nanospheres sized about 5 to 10 nm. X-ray dispersion
survey also suggested the high purity of the sample. In addition, the
absorption rate was measured in the presence of ultrasound waves and the
results indicated that the capacity of the synthesized sample to absorb Congo
red is greatly dependent on the intensity power of ultrasound waves, as the
absorption rate reaches 100% at powers above 30 watts.
