Reactive dye degradation by combined Fe(III)/TiO2 catalyst and ultrasonic irradiation: Effect of Fe(III) loading and calcination temperature

Abstract

The development of Fe(III)/TiO(2) catalysts for sonocatalytic degradation of Reactive Blue 4 (RB4) dye in water was carried out using sol-gel method. Their surface morphology, phase transformation and surface characteristics were studied using SEM, XRD and surface analyzer, respectively. Phase transformation from amorphous to anatase occurred at 500°C and transformation of anatase to rutile phase occurred at 700°C. Complete rutile phase was formed at 900°C with corresponding increase in the particle size. Increasing in Fe(III) loading led to a reduction in the anatase phase and with the formation of weaker and broader of diffraction peaks. Surface morphology of the prepared catalyst was clearly observed with increasing calcination temperature. Surface area of the prepared catalyst decreased with increasing calcination temperature or increasing Fe(III) loading. The combination of 0.4 mol% of Fe(III)/TiO(2) with ultrasonic irradiation gave the highest sonocatalytic activity in the removal of RB4 from the aqueous solution. On the other hand, the presence of even small amount of rutile inhibited the catalytic activity of catalyst. 1.5 g/L was the optimum amount of catalyst that led to the highest sonocatalytic degradation of RB4 with an efficiency of 90%. Aeration significantly accelerated the reaction rate. Higher removal at 96% could be achieved with the combination of 0.4Fe(III)/TiO(2) and aeration under ultrasonic irradiation.

Elucidation of Reaction Behaviors in Sonocatalytic Decolorization of Amaranth Dye in Water Using Zeolite Y Co-Incorporated with Fe and TiO<sub>2</sub>

“…Above the optimum value of 30 mg/L of the initial dye concentration, the decolorization efficiency after 60 min decreased from 100% to 85% for 30 and 100 mg/L of initial dye concentration, respectively. Jamalluddin Abdullah [29] reported the low decolorizetion efficiency with increasing the concentration of dye could be affected by the mutual screening between the found in the solution after 120 min of reaction were 0.011, 0.017, 0.033, 0.051 and 0.06 mg/L for 10, 30, 50, 70 and 100 mg/L, respectively. The more Fe 3+ leached out from the catalyst, the more loss in active sites of catalyst was expected [30].…”

Structural Aspects of Anatase to Rutile Phase Transition in Titanium Dioxide Powders Elucidated by the Rietveld Method

“…The water losses associated to that event were close to 2.8% for SiZr-doped titanium dioxide sample and 2.6% for pure one. It is also possible to notice that the exothermic peaks (DTA) precede the water weight loss (DTG) in almost 20 C, which prove that the water loss is slower than the dehydroxylation process.…”

“…Several works repot related the insertion of heterovalent metallic cations in titanium dioxide lead to the decreasing in the temperature of anatase-to-rutile phase transition and also to more amounts of rutile phase if the powder samples are heat treated up to 600 C [19][20][21][22]. Most of the doping approaches aim to shift the absorption edge to lower frequencies than ultraviolet range in order to utilize the titanium dioxide in solar photocatalysis.…”

Maya endüstrisi atıksuyunun ultrasonik arıtılmasında işletme parametrelerinin etkisi

“…According to some studies sonolytic degradation rate inversely proportional to the initial concentration of pollutant. It means sonolytic degradation rate decreases with increasing initial concentration [20,26,[28][29][30][31]. On the other hand, a number of intermediate products increases with increasing initial concentration and these compounds inhibit degradation [31].…”