Solar light-induced degradation of bisphenol-A with TiO< sub> 2 immobilized on Ti (original) (raw)
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Solar light-induced degradation of bisphenol-A with TiO2 immobilized on Ti
Catalysis Today, 2011
The photocatalytic degradation of bisphenol-A (BPA) was investigated over immobilized TiO 2 /Ti-film catalysts irradiated by artificial solar light. Catalysts were prepared either by a sol-gel method (TIP catalyst) or deposition of Degussa P-25 slurry (P-25 catalyst) and characterized by X-ray diffraction. The effect of TiO 2 loading (0.65 and 1.3 mg), initial BPA concentration (150, 300 and 600 ppb) and initial solution pH (3, 6, 8 and 10) on degradation was studied. The latter was assessed following changes in BPA concentration by means of high performance liquid chromatography equipped with a fluorescence detector. It was found that both catalysts, consisting of about 75:25 anatase:rutile, were equally active in degrading BPA (e.g. 85% reduction at 300 ppb BPA concentration, 180 min of reaction, 0.65 mg catalyst loading and inherent pH) and conversion increase with increasing the TiO 2 loading; however, the P-25 catalyst was considerably unstable at high loadings suffering about 50% active phase dissolution. Conversion decreased with increasing BPA concentration and it was favored in the pH range 6-8. BPA degradation can be approached by a pseudo-first order rate expression with the apparent kinetic constant taking values between 6 × 10 −3 and 2 × 10 −2 s −1 .
Photocatalytic degradation of bisphenol A in aqueous media: A review
Journal of Environmental Management, 2018
Photocatalytic degradation of bisphenol A (BPA) in aqueous solution under UV irradiation with 253.7 nm, by nano titanium dioxide (TiO 2) as a photocatalyst, was investigated in a batch photocatalytic reactor. The degradation effect was studied under different conditions such as TiO 2 dosage, irradiation time, pH, and BPA initial concentration. Results show that the photodegradation efficiency of BPA increases with irradiation time, but decreases with increasing BPA initial concentration. Alkaline conditions are favorable for the degradation. When TiO 2 was dosed at 1.0 g/L and a BPA initial concentration of 10 mg/L with pH ‡ 9.5, BPA degradation was almost complete after UV irradiation for 90 min. Photocatalytic degradation of BPA by UV/TiO 2 exhibited pseudo-first-order reaction kinetics. According to the results of determining the intermediate degradation products using gas chromatography/mass spectrometry, there are multiple pathways of BPA degradation that involve reactions not only between $OH and BPA or the intermediates but also between various unstable intermediates such as carboxylic, phenolic, and other types of intermediates.
Solar Photocatalytic Degradation of Bisphenol A on Immobilized ZnO or TiO2
International Journal of Photoenergy, 2013
The removal of bisphenol A (BPA) under simulated solar irradiation and in the presence of either TiO 2 or ZnO catalysts immobilized onto glass plates was investigated. The effect of various operating conditions on degradation was assessed including the amount of the immobilized catalyst (36.1-150.7 mg/cm 2 for TiO 2 and 0.5-6.8 mg/cm 2 for ZnO), initial BPA concentration (50-200 g/L), treatment time (up to 90 min), water matrix (wastewater, drinking water, and pure water), the addition of H 2 O 2 (25-100 mg/L), and the presence of other endocrine disruptors in the reaction mixture. Specifically, it was observed that increasing the amount of immobilized catalyst increases BPA conversion and so does the addition of H 2 O 2 up to 100 mg/L. Moreover, BPA degradation follows first-order reaction kinetics indicating that the final removal is not practically affected by the initial BPA concentration. Degradation in wastewater is slower than that in pure water up to five times, implying the scavenging behavior of effluent's constituents against hydroxyl radicals. Finally, the presence of other endocrine disruptors, such as 17 -ethynylestradiol, spiked in the reaction mixture at low concentrations usually found in environmental samples (i.e., 100 g/L), neither affects BPA degradation nor alters its kinetics to a considerable extent.
Photocatalytic degradation of bisphenol A over Rh/TiO 2 suspensions in different water matrices
Catalysis Today, 2017
A series of noble metal-promoted Me/TiO 2 (P25) photocatalysts (Me: Pt, Ru, Pd, Rh) of the same metal loading (0.5 wt.%) were synthesized by the wet impregnation method and their photocatalytic activity was tested for the degradation of bisphenol A (BPA) under simulated solar irradiation. Results of H 2 chemisorption, XRD, BET and UV-vis DRS experiments showed that dispersion of small metal crystallites on the TiO 2 surface did not affect appreciably the phase composition (∼85% anatase), specific surface area (47-49 m 2 /g) and optical band gap (3.2 eV) of the semiconductor. Pt/TiO 2 catalyst exhibited the higher efficiency under solar irradiation. In contrast to other Me/P25 catalysts investigated, the Rh/P25 catalyst exhibited increased activity for the title reaction in the presence of 20 mg/L humic acid (HA), which was about 2.5 times higher than that obtained in ultrapure water (UPW). The apparent rate constant for the degradation of BPA in UPW + HA was found to increase proportionately with an increase of catalyst concentration in the range 50-400 mg/L. The rate was not affected appreciably by the presence of inorganic ions contained in bottled water but decreased substantially in a secondary treated wastewater matrix. Results of liquid chromatography-time-of-flight-mass spectrometry (LC-TOF-MS) showed that degradation of BPA proceeds via two main pathways, which involve (i) hydroxylation, and (ii) cleavage of isopropylidene group with subsequent formation of para-substituted phenol derivatives.
Photocatalytic Degradation of Bisphenol A in Aqueous Suspensions of Titanium Dioxide
Environmental Engineering Science, 2012
Photocatalytic degradation of bisphenol A (BPA) in aqueous solution under UV irradiation with 253.7 nm, by nano titanium dioxide (TiO 2) as a photocatalyst, was investigated in a batch photocatalytic reactor. The degradation effect was studied under different conditions such as TiO 2 dosage, irradiation time, pH, and BPA initial concentration. Results show that the photodegradation efficiency of BPA increases with irradiation time, but decreases with increasing BPA initial concentration. Alkaline conditions are favorable for the degradation. When TiO 2 was dosed at 1.0 g/L and a BPA initial concentration of 10 mg/L with pH ‡ 9.5, BPA degradation was almost complete after UV irradiation for 90 min. Photocatalytic degradation of BPA by UV/TiO 2 exhibited pseudo-first-order reaction kinetics. According to the results of determining the intermediate degradation products using gas chromatography/mass spectrometry, there are multiple pathways of BPA degradation that involve reactions not only between $OH and BPA or the intermediates but also between various unstable intermediates such as carboxylic, phenolic, and other types of intermediates.
Photocatalytic Degradation of Bisphenol-A using N, Co Codoped TiO2 Catalyst under Solar Light
Scientific Reports, 2019
Advanced oxidation processes (Aops) including heterogeneous photocatalysis has proven as one of the best technique for waste-water treatment. photocatalytic process using semiconductor like tio 2 based heterogeneous photocatalysis is a promising method for the treatment of toxic pollutants. In the present study, visible-light photoactive cobalt and nitrogen co-doped tio 2 nanoparticles were synthesized via wet impregnation method. the photocatalysts were characterized using X-ray diffraction (XRD), Raman Spectra, Fourier Transform Infrared (FTIR) Spectroscopy, Scanning Electron Microscopy (seM), transmission electron Microscope (teM), UV-vis spectrophotometer and X-ray photoelectron spectrophotometer (Xps). the photocatalytic activitiy of prepared (N, Co)-codoped tio 2 on the mineralization of Bisphenol-A (BpA) under visible light irradiation was studied and the results were compared to commercial tio 2 (Degussa P25). The results demonstrated that 1.5% Co and 0.5% N-codoped tio 2 samples revealed higher activity than commercial tio 2. total organic carbon (toC) removal was observed to be 97%, which indicate the complete mineralization of BPA. GC-MS analysis was carried to find out the possible intermediates formed and reaction pathway. In today's world poor sanitation, waterborne infections, water quality declination, and absence of clean water supply are a great concern arose due to increase in population. The impacts of chemicals like colors, herbicides, pesticides etc. discharge in streams and lakes that are suspected to be endocrine-disrupting chemicals (EDCs) are creating havoc on the biological systems. Despite of the fact that it is still perplex for analysts whether such chemicals have an impact upon people or not, nevertheless it is important to create productive strategies for degradation of these EDCs from wastewater 1. Bisphenol-A [2,2-bis (4-hydroxyphenyl) propane] or BPA is generally utilized as a beginning material for epoxy and polycarbonate plastics. BPA from plastic items into water has as of late been identified as a genuine reason of water contamination. Also, high concentrations of BPA can be contained in wastewater from its creation plants. BPA enters into the water bodies through generation units and by drainage made by BPA-based saps 2. Microorganism can effectively degrade BPA but requires long time for the wastewater containing BPA. Therefore, we require the simple and cheap strategies for degradation of BPA in wastewater. A number of physical, chemical, and biological techniques have been developed over the last two decades to remove toxicity from pharmaceutical wastewater but these treatment methods have also their disadvantages. These methods are not much efficient to bring down the pollution parameters to the satisfactory level. The current techniques for treatment relies on the development of receptive synthetic species, a method termed as advance oxidation processes (AOPs). AOPs are used for degradation of wastewater containing bio-recalcitrant organic pollutants or removal of pathogens. AOPs produced highly reactive chemical species like hydroxyl radicals that completely destroy the pollutants present in wastewater. The central point influencing the AOPs are pH, convergence of the waste to be dealt with, catalyst loading included, UV illumination and time 3 .
i TECH MAG
In this work focus was paid to the photocatalytic degradation of Bisphenol E with nano-scaled TiO2 solution under sunlight. Instruments used for characterization and study the removal efficiency were; visible ultraviolet spectrophotometer, SEM (acceleration voltage 25kV) and TEM (acceleration voltage 80kV), X-ray diffraction and BET surface area. Under the optimum conditions; (pH;6, Radiation time; 90 min, Catalyst wt; 0.2g, reaction temperature; 20 oC), complete degradation was obtained. Byproducts from this study could be similar to our previous ones since Bisphenol A and Bisphenol E have very similar structures, hence their decomposition intermediates most probable not to be far. it was found that the decomposition reaction of bisphenol E follows the pseudo-first-order reaction kinetics.
Photocatalytic activity of Pr-modified TiO 2 for the degradation of bisphenol A
SN Applied Sciences, 2021
Praseodymium doped TiO 2 nanoparticles were successfully prepared by the sol-gel method and characterized by X-ray powder diffraction, N 2 adsorption-desorption isotherm, and UV-vis spectroscopy. The effects of the dopant on the crystallite size, specific surface area, average pore diameter, pore volume, and bandgap energy were investigated. The photocatalytic activity of the catalysts was evaluated by bisphenol A degradation and mineralization, which is a representative endocrine disruptor. Furthermore, under visible light irradiation the Pr-modified TiO 2 photocatalysts exhibited higher photocatalytic efficiency than unmodified TiO 2. When praseodymium was loaded (1.0-5.0%) onto the surface of TiO 2 , the rates of degradation and mineralization were increased 3-5 times.
DESALINATION AND WATER TREATMENT, 2017
The anatase TiO 2 (a-TiO 2) nanoparticles with controlled size have been successfully prepared by a facile solution phase method without using any surfactants, employing titanium isopropoxide as precursors in various alcohol (methanol, ethanol, propanol and butanol) media. Both XRD and Raman results revealed that the products are the phase of anatase TiO 2. Morphological studies performed by TEM showed that the products were nanoparticles with the particle size in the range of 5-20 nm, the size of a-TiO 2 nanoparticles could be easily turned by changing the types of alcohol. The photocatalytic activity studies of the a-TiO 2 nanoparticles demonstrated their excellent performance in photodegrading methylene blue and bisphenol aqueous solution by using UV-A light irradiation. This higher photocatalytic activity of the a-TiO 2 nanoparticles was mainly attributed to the smaller particle size.