Application of a Novel Semiconductor Catalyst, CT, in Degradation of Aromatic Pollutants in Wastewater: Phenol and Catechol

Water-soluble phenol and phenolic compounds were generally removed via advanced oxidation processes. A novel semiconductor catalyst, CT, was the first-time employed in the present study to degrade phenol and catechol. The phenolic compounds (initial concentration of 88 mg L−1) were completely mineralized by the CT catalytic nanoparticles (1%) within 15 days, under acidic condition and with the presence of mild UV radiation (15 w, the emitted wavelength is 254 nm and the light intensity <26 μw/cm2). Under the same reaction condition, 1% TiO2(mixture of rutile and anatase, nanopowder, <100 nm) and H2O2had lower removal efficiency (phenol: <42%; catechol: <60%), whereas the control (without addition of catalysts/H2O2) only showed <12% removal. The processes of phenol/catechol removal by CT followed pseudo-zero-order kinetics. The aromatic structures absorbed the UV energy and passed to an excited state, which the CT worked on. The pollutants were adsorbed on the CT’s surface and oxidized via charge-transfer and hydroxyl radical generation by CT. Given low initial concentrations, a circumstance encountered in wastewater polishing, the current set-up should be an efficient and less energy- and chemical-consumptive treatment method.

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Persulfate Process Activated by Homogeneous and Heterogeneous Catalysts for Synthetic Olive Mill Wastewater Treatment

Water ◽

10.3390/w13213010 ◽

2021 ◽

Vol 13 (21) ◽

pp. 3010

Author(s):

Eva Domingues ◽

Maria João Silva ◽

Telma Vaz ◽

João Gomes ◽

Rui C. Martins

Keyword(s):

Phenolic Compounds ◽

Red Mud ◽

Advanced Oxidation Processes ◽

Heterogeneous Catalysts ◽

Advanced Oxidation ◽

Iron Sulfate ◽

Toxicity Tests ◽

Oxidation Processes ◽

Toc Removal ◽

Olive Mill

Wastewaters from the olive oil industry are a regional environmental problem. Their phenolic content provides inherent toxicity, which reduces the treatment potential of conventional biological systems. In this study, Sulfate Radical based Advanced Oxidation Processes (SRbAOPs) are compared with advanced oxidation processes (namely Fenton’s peroxidation) as a depuration alternative. Synthetic olive mill wastewaters were submitted to homogeneous and heterogeneous SRbAOPs using iron sulfate and solid catalysts (red mud and Fe-Ce-O) as the source of iron (II). The homogenous process was optimized by testing different pH values, as well as iron and persulfate loads. At the best conditions (pH 5, 300 mg/L of iron and 600 mg/L of persulfate), it was possible to achieve 39%, 63% and 37% COD, phenolic compounds and TOC removal, respectively. The catalytic potential of a waste (red mud) and a laboratory material (Fe-Ce-O) was tested using heterogenous SRbAOPs. The best performance was achieved by Fe-Ce-O, with an optimal load of 1600 mg/L. At these conditions, 27%, 55% and 5% COD, phenolic compounds and TOC removal were obtained, respectively. Toxicity tests on A. fischeri and L. sativum showed no improvements in toxicity from the treated solutions when compared with the original one. Thus, SRbAOPs use a suitable technology for synthetic OMW.

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Ultrafine bubbles as an augmenting agent for ozone-based advanced oxidation

Water Science & Technology ◽

10.2166/wst.2021.475 ◽

2021 ◽

Author(s):

Tatek Temesgen ◽

Mooyoung Han

Keyword(s):

Advanced Oxidation Processes ◽

Advanced Oxidation ◽

Negative Influence ◽

Oh Radicals ◽

Oh Radical ◽

Oxidation Processes ◽

Acidic Conditions ◽

Ph Conditions ◽

First Time ◽

Influence Of Ph

Abstract In this study, the influence of nanobubbles (NBs) application in ozone (O3) based advanced oxidation processes (AOP) is investigated. The results demonstrate the potential of NBs application to O3 – based AOP. It was observed that NBs suppress the negative influence of pH and operating temperatures on the efficiency of ozonation. In addition, the application of NBs tends to improve the solubility of O3 and the rate of mass transfer under the influence of a broad range of temperature and pH conditions. The results of this research indicate that application of NBs minimized the reduction in concentration of dissolved O3 with an increase in temperature. Furthermore, application of NBs highly improved the OH radical formation in acidic conditions. The results of this research depicted for first time that the application of NBs strongly encourages the initiation of reactions involving OH radicals. It was found by this research that NBs can boost the concentration of OH radicals up to 3.5 fold compared to equivalent MB supported ozonation systems. This is assumed to improve the efficiency of currently existing conventional bubble supported O3 – based AOP systems.

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The Treatment of Wastewater Containing Pharmaceuticals

Journal of Environmental Treatment Techniques ◽

10.47277/jett/9(2)504 ◽

2021 ◽

Vol 9 (2) ◽

pp. 499-504

Keyword(s):

Conventional Treatment ◽

Advanced Oxidation Processes ◽

Treatment Method ◽

Degradation Pathway ◽

Ideal Solution ◽

Pharmaceutical Treatment ◽

Oxidation Processes ◽

Appropriate Treatment ◽

Excessive Consumption ◽

The Difference

The massive production of pharmaceuticals and excessive consumption will lead to their leakage into various water sources. Conventional treatment methods have proven ineffective in the treatment of these contaminants. Thus, choosing the appropriate treatment method is extremely important to deal with these pollutants. This review presents an overview of pharmaceuticals in wastewater and studies the difference between the conventional and advanced oxidation processes (AOPs) for pharmaceutical treatment. AOPs can be an ideal solution for the degradation of these contaminants. The factors that affect the removal efficiency for AOPs were discussed, such as type of catalyst, light intensity, initial concentration of contamination, catalyst dose, and pH of the solution. The degradation pathway for some pharmaceuticals has also been discussed.

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Efficiency of advanced oxidation processes in lowering bisphenol A toxicity and oestrogenic activity in aqueous samples

Archives of Industrial Hygiene and Toxicology ◽

10.2478/10004-1254-65-2014-2415 ◽

2014 ◽

Vol 65 (1) ◽

pp. 77-87 ◽

Cited By ~ 7

Author(s):

Maja Plahuta ◽

Tatjana Tišler ◽

Mihael Jožef Toman ◽

Albin Pintar

Keyword(s):

Chemical Analysis ◽

Bisphenol A ◽

Photocatalytic Oxidation ◽

Advanced Oxidation Processes ◽

Vibrio Fischeri ◽

Advanced Oxidation ◽

Aqueous Samples ◽

Yeast Saccharomyces Cerevisiae ◽

Oxidation Processes ◽

Set Up

Summary Bisphenol A (BPA) is a well-known endocrine disruptor with adverse oestrogen-like effects eliciting adverse effects in humans and wildlife. For this reason it is necessary to set up an efficient removal of BPA from wastewaters, before they are discharged into surface waters. The aim of this study was to compare the efficiency of BPA removal from aqueous samples with photolytic, photocatalytic, and UV/H2O2 oxidation. BPA solutions were illuminated with different bulbs (halogen; 17 W UV, 254 nm; and 150 W UV, 365 nm) with or without the TiO2 P-25 catalyst or H2O2 (to accelerate degradation). Acute toxicity and oestrogenic activity of treated samples were determined using luminescent bacteria (Vibrio fischeri), water fleas (Daphnia magna), zebrafish embryos (Danio rerio), and Yeast Estrogen Screen (YES) assay with genetically modified yeast Saccharomyces cerevisiae. The results confirmed that BPA is toxic and oestrogenically active. Chemical analysis showed a reduction of BPA levels after photolytic treatment and 100 % conversion of BPA by photocatalytic and UV/H2O2 oxidation. The toxicity and oestrogenic activity of BPA were largely reduced in photolytically treated samples. Photocatalytic oxidation, however, either did not reduce BPA toxic and oestrogenic effects or even increased them in comparison with the baseline, untreated BPA solution. Our findings suggest that chemical analysis is not sufficient to determine the efficiency of advanced oxidation processes in removing pollutants from water and needs to be complemented with biological tests.

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Autoxidation of SIV inhibited by chlorophenols reacting with sulfate radicals

Environmental Chemistry ◽

10.1071/en07045 ◽

2007 ◽

Vol 4 (5) ◽

pp. 355 ◽

Cited By ~ 17

Author(s):

Józef Ziajka ◽

Krzysztof J. Rudzinski

Keyword(s):

Rate Constants ◽

Advanced Oxidation Processes ◽

Natural Waters ◽

Food Additives ◽

Advanced Oxidation ◽

Detailed Knowledge ◽

Sulfate Radicals ◽

Oxidation Processes ◽

First Time ◽

Kinetics Of

Environmental context. Chlorophenols pollute natural waters and soils, as well as urban waste water systems. Although toxic and carcinogenic to animals and humans, a detailed knowledge of their action is limited. A new approach to effective degradation in the environment is advanced oxidation processes with sulfate radicals. The radicals can originate from the oxidation of sulfur dioxide or sulfites to make these common pollutants and food additives interact with chlorophenols. The main goal of this work is to determine rate constants for reactions of these chlorophenols with sulfate radicals in order to shed some light on the chemical kinetics of these reactions. Abstract. Kinetic experiments have shown that six chlorophenols (CPs) inhibit the autoxidation of SIV catalysed by Fe(ClO4)3 in aqueous solution at 25°C and pH ≈ 3.0. Efficiency of the inhibition decreases with the number of chlorine substituents for all CPs except for 2,5-dichlorophenol (2,5-DCP), which ranked between the tri- and tetrachlorophenols. The inhibition is explained by reactions of chlorophenols with sulfate radicals, the chain carriers in the mechanism of autoxidation. Rate constants for these reactions are determined for the first time, using the reversed-rates method with ethanol as a reference inhibitor: 8.7 × 109 (4-CP), 7.4 × 109 (2,4-DCP), 1.9 × 109 (2,5-DCP), 2.4 × 109 (2,4,5-TCP), 2.9 × 109 (2,4,6-TCP), and 7.5 × 108 (2,3,5,6-TTCP); 4.3 × 107 (ethanol reference) M–1 s–1. Linear correlations were derived for the estimation of rate constants for the remaining chlorophenols using sums of Brown substituent coefficients or relative strengths of O–H bonds. The results can be used in the development of advanced oxidation processes that utilise sulfate radicals for mineralisation of chlorophenols in wastewaters, and also demonstrate that chlorophenols can extend the lifetimes of SO2 and sulfites in natural and atmospheric waters.

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Hydroxyl Radical Generation by Recyclable Photocatalytic Fe3O4/ZnO Nanoparticles for Water Disinfection

Air Soil and Water Research ◽

10.1177/1178622120970954 ◽

2020 ◽

Vol 13 ◽

pp. 117862212097095

Author(s):

Oscar D Maynez-Navarro ◽

Miguel A Mendez-Rojas ◽

D Xanat Flores-Cervantes ◽

Jose L Sanchez-Salas

Keyword(s):

Escherichia Coli ◽

Wastewater Treatment ◽

Large Scale ◽

Advanced Oxidation Processes ◽

Water Disinfection ◽

Oh Radicals ◽

Bacterial Inactivation ◽

Oxidation Processes ◽

Radical Generation ◽

Improved Performance

Advanced oxidation processes based on photocatalytic generation of •OH radicals have emerged as promising technologies for the removal of recalcitrant pollutants in water. However, their poor recyclability has reduced their potential large-scale application. Herein, a Fe3O4-embedded ZnO system has been prepared and its photocatalytic •OH radicals activity was evaluated by monitoring the photo-assisted bleaching of p-nitrosodimethylaniline ( pNDA). Water disinfection performance was determined by measuring Escherichia coli inactivation under different conditions. Bleaching of nearly 80% of the initial pNDA concentration after just 120 minutes under UV365nm irradiation was determined. Bacterial inactivation at different concentrations (0.1, 1.0, and 5.0 mg mL−1) of the Fe3O4/ZnO nanocomposite was determined, finding that the best performance was obtained at 0.1 mg mL−1 (90%) just after the first 30 minutes under UV irradiation. The materials are easily magnetically recovered and their performance evaluated after 3 consecutive cycles of reuse. These magnetic and photoactive nanocomposites showed improved performance and could be used for wastewater treatment or disinfection processes of water.

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Advanced oxidation processes for the treatment of chlorpyrifos, dimethoate and phorate in aqueous solution

Journal of Water Reuse and Desalination ◽

10.2166/wrd.2015.062 ◽

2015 ◽

Vol 6 (1) ◽

pp. 195-203 ◽

Cited By ~ 7

Author(s):

Kavita Gandhi ◽

Summaiya Lari ◽

Dhananjay Tripathi ◽

Gajanan Kanade

Keyword(s):

Aqueous Solution ◽

Advanced Oxidation Processes ◽

Degradation Products ◽

Advanced Oxidation ◽

Chemical Transformations ◽

Oxidation Processes ◽

Degradation Rates ◽

End Products ◽

Low Toxicity ◽

Set Up

Photo-chemical-transformations of organophosphate pesticides, chlorpyrifos, dimethoate and phorate, using advanced oxidation processes (AOPs) namely UV photolysis, UV/H2O2, UV/Fenton and Fenton systems in aqueous solution were investigated in this work. A laboratory set-up was designed to evaluate and select the optimal oxidation process. Results show that addition of hydrogen peroxide/Fenton's reagent increased the UV degradation rates of all pesticides, and data were simulated through kinetic modeling. Kinetic results evidence pseudo first-order degradation, with the rate constant of reaction as 3.3 × 10–4, 2.07 × 10–2 and 1.88 × 10–2 for chlorpyrifos, dimethoate and phorate, respectively. Furthermore treatment efficiencies obtained for the studied AOPs indicate that UV/Fenton was most efficient for chlorpyrifos (50.3% degradation) and UV/H2O2 for dimethoate (96.9%) and phorate (89.6%). Finally, the identification of degradation products indicated that the UV/H2O2 technique results in the formation of fewer end products, with low toxicity. However, UV irradiation of phorate results in information of more toxic degradation end products such as phorateoxonsulfone.

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Simulated Ageing of Crude Oil and Advanced Oxidation Processes for Water Remediation since Crude Oil Pollution

Catalysts ◽

10.3390/catal11080954 ◽

2021 ◽

Vol 11 (8) ◽

pp. 954

Author(s):

Filomena Lelario ◽

Giuliana Bianco ◽

Sabino Aurelio Bufo ◽

Laura Scrano

Keyword(s):

Crude Oil ◽

Advanced Oxidation Processes ◽

Advanced Oxidation ◽

Water Soluble ◽

Water Remediation ◽

Solar Irradiation ◽

Polluted Water ◽

Slight Reduction ◽

Artificial Ageing ◽

Oxidation Processes

Crude oil can undergo biotic and abiotic transformation processes in the environment. This article deals with the fate of an Italian crude oil under simulated solar irradiation to understand (i) the modification induced on its composition by artificial ageing and (ii) the transformations arising from different advanced oxidation processes (AOPs) applied as oil-polluted water remediation methods. The AOPs adopted were photocatalysis, sonolysis and, simultaneously, photocatalysis and sonolysis (sonophotocatalysis). Crude oil and its water-soluble fractions underwent analysis using GC-MS, liquid-state 1H-NMR, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), and fluorescence. The crude oil after light irradiation showed (i) significant modifications induced by the artificial ageing on its composition and (ii) the formation of potentially toxic substances. The treatment produced oil oxidation with a particular effect of double bonds oxygenation. Non-polar compounds present in the water-soluble oil fraction showed a strong presence of branched alkanes and a good amount of linear and aromatic alkanes. All remediation methods utilised generated an increase of C5 class and a decrease of C6–C9 types of compounds. The analysis of polar molecules elucidated that oxygenated compounds underwent a slight reduction after photocatalysis and a sharp decline after sonophotocatalytic degradation. Significant modifications did not occur by sonolysis.

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Activation of Peracetic Acid with Lanthanum Cobaltite Perovskite for Sulfamethoxazole Degradation under a Neutral pH: The Contribution of Organic Radicals

Molecules ◽

10.3390/molecules25122725 ◽

2020 ◽

Vol 25 (12) ◽

pp. 2725 ◽

Cited By ~ 1

Author(s):

Xuefei Zhou ◽

Haowei Wu ◽

Longlong Zhang ◽

Bowen Liang ◽

Xiaoqi Sun ◽

...

Keyword(s):

Peracetic Acid ◽

Organic Contaminants ◽

Advanced Oxidation Processes ◽

Organic Radicals ◽

Organic Radical ◽

Excellent Performance ◽

Lanthanum Cobaltite ◽

Oxidation Processes ◽

Neutral Ph ◽

Radical Generation

Advanced oxidation processes (AOPs) are effective ways to degrade refractory organic contaminants, relying on the generation of inorganic radicals (e.g., •OH and SO4•−). Herein, a novel AOP with organic radicals (R-O•) was reported to degrade contaminants. Lanthanum cobaltite perovskite (LaCoO3) was used to activate peracetic acid (PAA) for organic radical generation to degrade sulfamethoxazole (SMX). The results show that LaCoO3 exhibited an excellent performance on PAA activation and SMX degradation at neutral pH, with low cobalt leaching. Meanwhile, LaCoO3 also showed an excellent reusability during PAA activation. In-depth investigation confirmed CH3C(O)O• and CH3C(O)OO• as the key reactive species for SMX degradation in LaCoO3/PAA system. The presence of Cl− (1–100 mM) slightly inhibited the degradation of SMX in the LaCoO3/PAA system, whereas the addition of HCO3− (0.1–1 mM) and humic aid (1–10 mg/L) could significantly inhibit SMX degradation. This work highlights the generation of organic radicals via the heterogeneous activation of PAA and thus provides a promising way to destruct contaminants in wastewater treatment.

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Heterogeneous Electro-Fenton-like Designs for the Disposal of 2-Phenylphenol from Water

Applied Sciences ◽

10.3390/app112412103 ◽

2021 ◽

Vol 11 (24) ◽

pp. 12103

Author(s):

Antía Fdez-Sanromán ◽

Rocío Martinez-Treinta ◽

Marta Pazos ◽

Emilio Rosales ◽

María Ángeles Sanromán

Keyword(s):

Advanced Oxidation Processes ◽

Heterogeneous Catalysts ◽

Advanced Oxidation ◽

Complete Removal ◽

Order Kinetic ◽

Carbon Felt ◽

Oxidation Processes ◽

First Order ◽

Order Kinetic Model ◽

Radical Generation

The hunt for efficient and environmentally friendly degradation processes has positioned the heterogeneous advanced oxidation processes as an alternative more interesting and economical rather than homogenous processes. Hence, the current study lies in investigating the efficiency of different heterogeneous catalysts using transition metals in order to prevent the generation of iron sludge and to extend the catalogue of possible catalysts to be used in advanced oxidation processes. In this study, nickel and zinc were tested and the ability for radical-generation degradation capacity of both ions as homogeneous was evaluated in the electro-Fenton-like degradation of 2-phenylphenol. In both cases, the degradation profiles followed a first-order kinetic model with the highest degradation rate for nickel (1 mM) with 2-phenylphenol removal level of 90.12% and a total organic reduction near 70% in 2 h. To synthesise the heterogeneous nickel catalyst, this transition metal was fixed on perlite by hydrothermal treatment and in a biochar or carbon nanofibers by adsorption. From the removal results using the three synthesized catalysts, it is concluded that the best catalysts were obtained by inclusion of nickel on biochar or nanofibers achieving in both with removal around 80% before 1 h. Thus, to synthetize a nickel electrocatalyst, nickel doped nanofibers were included on carbon felt. To do this, the amount of carbon black, nickel nanofibers and polytetrafluoroethylene to add on the carbon felt was optimized by Taguchi design. The obtained results revealed that under the optimised conditions, a near-complete removal was achieved after 2 h with high stability of the nickel electrocatalyst that open the applicability of this heterogeneous system to operate in flow systems.

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