Impact of Reaction Parameters and Water Matrices on the Removal of Organic Pollutants by TiO2/LED and ZnO/LED Heterogeneous Photocatalysis Using 365 and 398 nm Radiation

Alapi, Tünde; Bencsik, Gábor; Janáky, Csaba

doi:10.3390/nano12010005

Cited by 18 publications

(14 citation statements)

References 105 publications

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“…The separation rate of photo-induced electron-hole pairs is a critical factor that directly influences photocatalytic efficiency. The heterostructure is the most commonly used method to improve the separation efficiency of photo-induced electron-hole pairs [24][25][26]. The adsorption performance of the heterostructure also affects photocatalytic efficiency by increasing the effective concentration of pollutants.…”

Section: Introductionmentioning

confidence: 99%

Efficient Removal of Cr(VI) by TiO2 Based Micro-Nano Reactor via the Synergy of Adsorption and Photocatalysis

Liu

et al. 2022

Nanomaterials

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The low-toxicity treatment of chromium-containing wastewater represents an important way of addressing key environmental problems. In this study, a core-shell structural ZIF-8@TiO2 photocatalyst was synthesized by a simple one-step hydrothermal method. The obtained composite photocatalyst possessed improved photocatalytic activity compared with TiO2. The results indicated that the optimized ZIF-8@TiO2 composite exhibited the highest removal efficiency with 93.1% of Cr(VI) after 120 min under UV-vis irradiation. The removal curves and XPS results indicated that the adsorbed Cr(VI) on the ZIF-8 during the dark process was preferentially reduced. The superior removal efficiency of ZIF-8@TiO2 is attributed to the combination of both high adsorption of ZIF-8, which attracted Cr(VI) on the composite surface, and the high separation efficiency of photo-induced electron-hole pairs. For the mixture of wastewater that contained methyl orange and Cr(VI), 97.1% of MO and 99.7% of Cr(VI) were removed after 5 min and 60 min light irradiation, respectively. The high removal efficiency of multiple pollutants provides promising applications in the field of Cr(VI) contaminated industrial wastewater treatment.

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Section: Introductionmentioning

confidence: 99%

Efficient Removal of Cr(VI) by TiO2 Based Micro-Nano Reactor via the Synergy of Adsorption and Photocatalysis

Liu

et al. 2022

Nanomaterials

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“…• radical species, which promote the photodegradation of pesticides, especially those for which indirect photolysis is the main reaction pathway [23,33,38]. Some anions and cations present in water are transparent to solar radiation, while nitrate (λ = 303 nm) and nitrite (λ = 355 nm) can absorb some of the radiation.…”

Section: Effect Of Inorganic Anion Content On Herbicide Photodegradat...mentioning

confidence: 99%

“…In addition to dissolved organic matter, the unfavorable effects of some inorganic ions (mainly anions), such as Cl − , HCO3 − /CO3 2− , NO3 − /NO2 − , PO4H 3− , and/or SO4 2− , can be explained by the fact that they reduce the oxidizing power of the solution. The scavenging of HO • and SO4 •− by various anions generates corresponding radicals such as ClOH •− , Cl • , Cl2 •− , CO3 •− , HCO3 • , Br • , Br2 •− , NO • , and/or H2PO4 • , which have a lower E 0 than HO • and SO4 •− or promote the formation of ROS, as in the case of NO3 − , which is capable of generating HO • and NO2 • radical species, which promote the photodegradation of pesticides, especially those for which indirect photolysis is the main reaction pathway [23,33,38]. Some anions and cations present in water are transparent to solar radiation, while nitrate (λ = 303 nm) and nitrite (λ = 355 nm) can absorb some of the radiation.…”

Section: Effect Of Inorganic Anion Content On Herbicide Photodegradat...mentioning

confidence: 99%

Impact of Inorganic Anions on the Photodegradation of Herbicide Residues in Water by UV/Persulfate-Based Advanced Oxidation

Pérez-Lucas,

Campillo,

Navarro

2024

Catalysts

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The removal of pesticides and other organic pollutants from water through advanced oxidation processes (AOPs) holds great promise. The main advantage of these technologies is that they remove, or at least reduce, pesticide levels by mineralization rather than transfer, as in conventional processes. This study first evaluated the effectiveness of UV/S2O8= compared to heterogeneous photocatalysis using UV/TiO2 processes on the degradation of two commonly used herbicides (terbuthylazine and isoproturon) in aqueous solutions using a laboratory photoreactor. In addition, the effect of the UV wavelength on the degradation efficiency of both herbicides was investigated. Although the degradation rate was greater under UV(254)/S2O8= nm than under UV(365)/S2O8= nm, complete degradation of the herbicides (0.2 mg L−1) was achieved within 30 min under UV-366 nm using a Na2S2O8 dose of 250 mg L−1 in the absence of inorganic anions. To assess the impact of the water matrix, the individual and combined effects of sulfate (SO4=), bicarbonate (HCO3−), and chloride (Cl−) were evaluated. These can react with hydroxyl (HO•) and sulfate (SO4•−) radicals generated during AOPs to form new radicals with a lower redox potential. The results showed negligible effects of SO4=, while the combination of HCO3− and Cl− seemed to be the key to the decrease in herbicide removal efficiency found when working with complex matrices. Finally, the main intermediates detected during the photodegradation process are identified, and the likely pathways involving dealkylation, dechlorination, and hydroxylation are proposed and discussed.

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“…The surface charge of TiO 2 and the rate of ROS formation can be strongly affected by the components dissolved in the water matrix. The generated negative effect, mainly at high concentrations, is generally attributed to the occupancy sites on the photocatalyst surface by inorganic and organic components, the scavenging of HO • , and/or the aggregation of TiO 2 particles when the ionic strength is high (Ahmed et al, 2011;Náfrádi et al, 2022). The unfavorable effects of some inorganic ions (mainly anions, such as Cl − , CO , and/or H 2 PO 4 • , which have a lower oxidation potential (E 0 ) than HO • (Ahmed et al, 2011;Bi et al, 2016;Ribeiro et al, 2019Náfrádi et al, 2022).…”

Section: Impact Of Water Matrix Compositionmentioning

confidence: 99%

Removal of Contaminants of Emerging Concern from a Wastewater Effluent by Solar-Driven Heterogeneous Photocatalysis: A Case Study of Pharmaceuticals

Gabriel

Aatik

Aliste

et al. 2023

Water Air Soil Pollut

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The occurrence of emerging micropollutants (pharmaceuticals, pesticides, personal care products, industrial compounds, etc.) in the environment is considered a major threat to human health and aquatic ecosystems. These micropollutants enter the environment through anthropogenic actions and have been identified in surface, ground, waste, and even in drinking water, in quantities ranging from ng L−1 to µg L−1. Currently, the pollution of the global water cycle with persistent organic pollutants remains one of the major challenges of the twenty-first century. Most of these organic substances are only partially removed by conventional wastewater treatment plants. Particularly, considerable amounts of pharmaceuticals are used in human and veterinary medicine, which are not efficiently removed during conventional wastewater treatments and subsequently continuously enter freshwater systems and even agricultural crops. Accordingly, we have evaluated the effectivity of TiO2 as a photocatalyst in tandem with Na2S2O8 as an oxidant for the treatment of a wastewater effluent polluted with pharmaceutical (atenolol, carbamazepine, clarithromycin, erythromycin, irbesartan, and ketoprofen) residues. Results show that the use of solar heterogeneous photocatalysis by means of band-gap semiconductor materials, especially TiO2 in combination with a strong oxidant such as Na2S2O8, significantly enhances their disappearance from the wastewater effluent. However, the selected pharmaceuticals show a slow degradation in wastewater effluent compared to pure water indicating that the occurrence of dissolved salts and organic carbon in wastewater effluent noticeably slows down the efficiency of the treatment. A single first-order model satisfactorily explains the photocatalytic degradation of the compounds studied for both, pure and wastewater. In the case of wastewater effluent, the highest DT50 values were observed for macrolides (13 and 16 min for erythromycin and clarithromycin, respectively), while the other compounds studied showed DT50 values below 10 min. This methodology has a notorious interest in some areas of the Mediterranean basin with water shortage, such as SE of Spain, where more than 3000 h of sunlight per year are recovered.

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Impact of Reaction Parameters and Water Matrices on the Removal of Organic Pollutants by TiO2/LED and ZnO/LED Heterogeneous Photocatalysis Using 365 and 398 nm Radiation

Cited by 18 publications

References 105 publications

Efficient Removal of Cr(VI) by TiO2 Based Micro-Nano Reactor via the Synergy of Adsorption and Photocatalysis

Efficient Removal of Cr(VI) by TiO2 Based Micro-Nano Reactor via the Synergy of Adsorption and Photocatalysis

Impact of Inorganic Anions on the Photodegradation of Herbicide Residues in Water by UV/Persulfate-Based Advanced Oxidation

Removal of Contaminants of Emerging Concern from a Wastewater Effluent by Solar-Driven Heterogeneous Photocatalysis: A Case Study of Pharmaceuticals

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