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Jia J, Minella M, Ruiz MC, Decker J, Li D, Gonçalves NPF, Prevot AB, Lin T, Giannakis S. Small concentrations, big results: μM addition of photoactive iron oxides with PMS, PDS, or H 2O 2, leads to enhanced removal of viruses at near-neutral pH. WATER RESEARCH 2024; 258:121760. [PMID: 38795547 DOI: 10.1016/j.watres.2024.121760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 03/25/2024] [Accepted: 05/08/2024] [Indexed: 05/28/2024]
Abstract
The photo-Fenton process is effective for pathogen removal, and its low-cost versions can be applied in resource-poor contexts. Herein, a photo-Fenton-like system was proposed using low concentrations of iron oxides (hematite and magnetite) and persulfates (peroxymonosulfate - PMS, and peroxydisulfate - PDS), which exhibited excellent inactivation performance towards MS2 bacteriophages. In the presence of bacteria, MS2 inactivation was inhibited in H2O2 and PDS systems but promoted in PMS-involved systems. The inactivation efficacy of all the proposed systems for mixed bacteria and viruses was greater than that of the sole bacteria, showing potential practical applications. The inactivation performance of humic acid-incorporated iron oxides mediating photo-Fenton-like processes was also studied; except for the PMS-involved system, the inactivation efficacy of the H2O2- and PDS-involved systems was inhibited, but the PDS-involved system was still acceptable (< 2 h). Reactive species exploration experiments indicated that ·OH was the main radical in the H2O2 and PDS systems, whereas 1O2 played a key role in the PMS-involved system. In summary, hematite- and magnetite-mediated persulfate-assisted photo-Fenton-like systems at low concentrations can be used as alternatives to the photo-Fenton process for virus inactivation in sunny areas, providing more possibilities for point-of-use drinking water treatment in developing countries.
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Affiliation(s)
- Jialin Jia
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China; Universidad Politécnica de Madrid, E.T.S. Ingenieros de Caminos, Canales y Puertos, Departamento de Ingeniería Civil: Hidráulica, Energía y Medio Ambiente, Unidad docente Ingeniería Sanitaria, c/ Profesor Aranguren, s/n, ES-28040, Madrid, Spain
| | - Marco Minella
- Dipartimento di Chimica, Università di Torino, Via Pietro Giuria 5, 10125 Turin, Italy
| | - Mercedes Cid Ruiz
- Universidad Politécnica de Madrid, E.T.S. Ingenieros de Caminos, Canales y Puertos, Departamento de Ingeniería Civil: Hidráulica, Energía y Medio Ambiente, Unidad docente Ingeniería Sanitaria, c/ Profesor Aranguren, s/n, ES-28040, Madrid, Spain
| | - Jeremie Decker
- Universidad Politécnica de Madrid, E.T.S. Ingenieros de Caminos, Canales y Puertos, Departamento de Ingeniería Civil: Hidráulica, Energía y Medio Ambiente, Unidad docente Ingeniería Sanitaria, c/ Profesor Aranguren, s/n, ES-28040, Madrid, Spain
| | - Dong Li
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Nuno P F Gonçalves
- CICECO - Instituto de Materiais de Aveiro, Departamento de Química, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; Dipartimento di Chimica, Università di Torino, Via Pietro Giuria 5, 10125 Turin, Italy
| | | | - Tao Lin
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China.
| | - Stefanos Giannakis
- Universidad Politécnica de Madrid, E.T.S. Ingenieros de Caminos, Canales y Puertos, Departamento de Ingeniería Civil: Hidráulica, Energía y Medio Ambiente, Unidad docente Ingeniería Sanitaria, c/ Profesor Aranguren, s/n, ES-28040, Madrid, Spain.
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2
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Jia J, Minella M, Del Castillo González I, Lehmann AH, Li D, Gonçalves NPF, Prevot AB, Lin T, Giannakis S. From rust to robust disinfectants: How do iron oxides and inorganic oxidants synergize with UVA light towards bacterial inactivation? THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 931:172740. [PMID: 38677424 DOI: 10.1016/j.scitotenv.2024.172740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 03/30/2024] [Accepted: 04/22/2024] [Indexed: 04/29/2024]
Abstract
Pathogens in drinking water remain a challenge for human health, photo-Fenton process is a promising technique for pathogen inactivation, herein, two common iron oxides, hematite and magnetite mediate persulfate (peroxymonosulfate-PMS - and peroxydisulfate-PDS) involved photo-Fenton-like processes were constructed for E. coli inactivation, and the inactivation performance was investigated and compared with the photo-Fenton process under a low intensity UVA irradiation. Results indicated that with a low dose of iron oxides (1 mg/L) and inorganic peroxides (10 mg/L), PMS-involved photo-Fenton-like process is the best substitute for the photo-Fenton one over pH range of 5-8. In addition, humic acid (HA, one of the important components of natural organic matter) incorporated iron oxide-mediated photo-Fenton-like processes for bacteria inactivation was also studied, and facilitating effect was found in UVA/hematite/PMS and UVA/magnetite/PDS systems. Reactive oxygen species (ROS) exploration experiments revealed that ·OH was the predominant radical in H2O2- and PDS-containing systems, whereas 1O2 was one of the principal reactive species in the PMS systems. In addition to the semiconductor photocatalysis of iron oxides and UVA-activated oxidants, iron-complexes (iron-oxidant complexes and iron-bacteria complexes) mediated ligand-to-metal charge transfer (LMCT) processes also made contribution to bacterial inactivation. Overall, this study demonstrates that it is feasible to replace H2O2 with PMS in a photo-Fenton-like process for water disinfection using a low dose of reagents, mediated by cheap catalysts, such as hematite and magnetite, it is also hoped to provide some insights to practical water treatment.
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Affiliation(s)
- Jialin Jia
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China; Universidad Politécnica de Madrid, E.T.S. Ingenieros de Caminos, Canales y Puertos, Departamento de Ingeniería Civil: Hidráulica, Energía y Medio Ambiente, Unidad docente Ingeniería Sanitaria, c/ Profesor Aranguren, s/n, ES-28040 Madrid, Spain
| | - Marco Minella
- Dipartimento di Chimica, Università di Torino, Via Pietro Giuria 5, 10125 Turin, Italy
| | - Isabel Del Castillo González
- Universidad Politécnica de Madrid, E.T.S. Ingenieros de Caminos, Canales y Puertos, Departamento de Ingeniería Civil: Hidráulica, Energía y Medio Ambiente, Unidad docente Ingeniería Sanitaria, c/ Profesor Aranguren, s/n, ES-28040 Madrid, Spain
| | - Aurelio Hernández Lehmann
- Universidad Politécnica de Madrid, E.T.S. Ingenieros de Caminos, Canales y Puertos, Departamento de Ingeniería Civil: Hidráulica, Energía y Medio Ambiente, Unidad docente Ingeniería Sanitaria, c/ Profesor Aranguren, s/n, ES-28040 Madrid, Spain
| | - Dong Li
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, PR China
| | - Nuno P F Gonçalves
- CICECO - Instituto de Materiais de Aveiro, Departamento de Química, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; Dipartimento di Chimica, Università di Torino, Via Pietro Giuria 5, 10125 Turin, Italy
| | | | - Tao Lin
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China.
| | - Stefanos Giannakis
- Universidad Politécnica de Madrid, E.T.S. Ingenieros de Caminos, Canales y Puertos, Departamento de Ingeniería Civil: Hidráulica, Energía y Medio Ambiente, Unidad docente Ingeniería Sanitaria, c/ Profesor Aranguren, s/n, ES-28040 Madrid, Spain.
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3
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Lalas K, Arvaniti OS, Panagopoulou EI, Thomaidis NS, Mantzavinos D, Frontistis Z. Acesulfame degradation by thermally activated persulfate: Kinetics, transformation products and estimated toxicity. CHEMOSPHERE 2024; 352:141260. [PMID: 38272137 DOI: 10.1016/j.chemosphere.2024.141260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 12/27/2023] [Accepted: 01/17/2024] [Indexed: 01/27/2024]
Abstract
The existence of the artificial sweetener acesulfame (ACE) in quantities of significance can negatively impact water quality, and its consumption has been associated with deleterious health effects. The present investigation explores the efficacy of heat-activated sodium persulfate (SPS) for eliminating ACE. The complete degradation of 0.50 mg L-1 of ACE was achieved within 45 min under a reaction temperature of 50 °C and 100 mg L-1 of SPS. The impact of thermal decomposition on ACE at a temperature of 60 °C was negligible. This study considers several factors, such as the SPS and ACE loading, the reaction temperature, the initial pH, and the water matrix of the reactor. The results indicate that the method's efficiency is positively correlated with higher initial concentrations of SPS, whereas it is inversely associated with the initial concentration of ACE. Furthermore, higher reaction temperatures and acidic initial pH levels promote the degradation of acesulfame. At the same time, certain constituents of the water matrix, such as humic acid, chlorides, and bicarbonates, can hinder the degradation process. Additionally, the data from LC-QToF-MS analysis of the samples were used to investigate transformation through suspect and non-target screening approaches. Overall, ACE's eight transformation products (TPs) were detected, and a potential ACE decomposition pathway was proposed. The concentration of TPs followed a volcano curve, decreasing in long treatment times. The ecotoxicity of ACE and its identified TPs was predicted using the ECOSAR software. The majority of TPs exhibited not harmful values.
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Affiliation(s)
- Kosmas Lalas
- Department of Chemical Engineering, University of Western Macedonia, GR-50132, Kozani, Greece
| | - Olga S Arvaniti
- Department of Agricultural Development, Agrofood and Management of Natural Resources, National and Kapodistrian University of Athens, Psachna, GR-34400, Greece
| | - Eleni I Panagopoulou
- Department of Chemistry, Laboratory of Analytical Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, GR 15771, Athens, Greece
| | - Nikolaos S Thomaidis
- Department of Chemistry, Laboratory of Analytical Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, GR 15771, Athens, Greece
| | - Dionissios Mantzavinos
- Department of Chemical Engineering, University of Patras, Caratheodory 1, University Campus, GR-26504, Patras, Greece
| | - Zacharias Frontistis
- Department of Chemical Engineering, University of Western Macedonia, GR-50132, Kozani, Greece.
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Zheng H, Zhang Y, Li S, Feng X, Wu Q, Kit Leong Y, Chang JS. Antibiotic sulfadiazine degradation by persulfate oxidation: Intermediates dependence of ecotoxicity and the induction of antibiotic resistance genes. BIORESOURCE TECHNOLOGY 2023; 368:128306. [PMID: 36372382 DOI: 10.1016/j.biortech.2022.128306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 11/03/2022] [Accepted: 11/05/2022] [Indexed: 06/16/2023]
Abstract
To preserve the water resources, this study has analyzed the ecotoxicity and antibiotic resistance genes (ARGs) induction capacity of sulfadiazine degradation intermediates resulting from persulfate activation oxidation enhanced by ultraviolet, ultrasound and microwave. The five degradation pathways caused by the contribution discrepancy of electron transfer and singlet oxygen (1O2) and variations in the ecotoxicity of different degradation products were analyzed. Microcosm experiment exhibited that the microbial community in actual water changed significantly with SDZ and degradation intermediates, in which the dominant genera were Aeromonas, Cupriavidus, Elizabethkingia and Achromobacter. Except for the selective pressure on bacteria, the degradation intermediates also exert a certain degree or even stronger induction on sulfonamide ARGs (sul4, sul1 and sul2) than SDZ. Furthermore, the potential hosts for sulfonamide ARGs were revealed by network analysis. These results provide a better understanding of antibiotics degradation mechanism and ARGs occurrence, which is useful for controlling the spread of ARGs.
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Affiliation(s)
- Heshan Zheng
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006, China
| | - Yunfei Zhang
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006, China
| | - Shuo Li
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006, China; Urban Water Resources Development and Northern National Engineering Research Center, Harbin 150090, China; School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Xiaochi Feng
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong 518055, China
| | - Qinglian Wu
- School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yoong Kit Leong
- Department of Chemical and Materials Engineering, Tunghai University, Taichung 407, Taiwan; Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung 407, Taiwan
| | - Jo-Shu Chang
- Department of Chemical and Materials Engineering, Tunghai University, Taichung 407, Taiwan; Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung 407, Taiwan; Department of Chemical Engineering, National Cheng-Kung University, Tainan, Taiwan; Department of Chemical Engineering and Materials Science, Yuan Ze University, Chung-Li 32003, Taiwan.
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5
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Masud MAA, Shin WS, Kim DG. Degradation of phenol by ball-milled activated carbon (AC BM) activated dual oxidant (persulfate/calcium peroxide) system: Effect of preadsorption and sequential injection. CHEMOSPHERE 2023; 312:137120. [PMID: 36334750 DOI: 10.1016/j.chemosphere.2022.137120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 10/30/2022] [Accepted: 10/31/2022] [Indexed: 06/16/2023]
Abstract
This study explored pre-adsorption and sequential injection of dual oxidant (DuOx) of persulfate (PS) and calcium peroxide (CP) for phenol degradation in an aqueous solution. Ball-milled activated carbon (ACBM) was used as the catalyst in the following systems: pre-adsorption and sequential injection of PS and CP (ACBM + PS + CP), pre-adsorption and simultaneous injection of PS and CP (ACBM + PS/CP), simultaneous injection of ACBM, PS, and CP (ACBM/PS/CP), simultaneous injection of ACBM and PS (ACBM/PS), and simultaneous injection of ACBM and CP (ACBM/CP). The ACBM had a larger specific surface area, more graphitic structures, and more defects. Moreover, it showed better phenol removal when introduced simultaneously with PS and CP. The phenol removal was most the efficient in ACBM + PS + CP (98.8%) with a near-neutral final pH, followed by ACBM + PS/CP, ACBM/PS, ACBM/PS/CP, and ACBM/CP. This indicates that pre-adsorption and separate injection of PS and CP were the key strategy for improved performance and maintained favorable pH for the activation of PS and CP. The dual oxidant system (PS/CP) is superior to single oxidant systems (PS or CP). Scavenger experiments and the electron spin resonance spectra (ESR) demonstrated that non-radical species (1O2) were dominantly involved in ACBM + PS + CP, but radical species (HO•, SO4•-) also contributed. HCO3- and HPO42- inhibited phenol degradation in ACBM + PS + CP, whereas Cl- and HA had negligible effects. The ACBM + PS + CP showed high total organic carbon removal and ACBM was recyclable with a slight decrease in activity. This work is important as it provides a detailed insight into the strategy of pre-adsorption and sequential injection of dual oxidants for a practical and cost-effective method of groundwater remediation.
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Affiliation(s)
- Md Abdullah Al Masud
- School of Architecture, Civil, Environmental and Energy Engineering, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Won Sik Shin
- School of Architecture, Civil, Environmental and Energy Engineering, Kyungpook National University, Daegu, 41566, Republic of Korea.
| | - Do Gun Kim
- Department of Environmental Engineering, Sunchon National University, Suncheon, Jeollanam-do, 57922, Republic of Korea.
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Masud MAA, Kim DG, Shin WS. Highly efficient degradation of phenolic compounds by Fe(II)-activated dual oxidant (persulfate/calcium peroxide) system. CHEMOSPHERE 2022; 299:134392. [PMID: 35331746 DOI: 10.1016/j.chemosphere.2022.134392] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/15/2022] [Accepted: 03/18/2022] [Indexed: 06/14/2023]
Abstract
This study demonstrates the feasibility, reaction mechanisms, and potential of practical applications of a dual oxidant (DuOx) system comprising calcium peroxide (CP) and persulfate (PS) catalyzed using Fe(II) [PS/CP/Fe(II)]. The DuOx system was superior in phenol degradation to single oxidant systems, i.e., PS/Fe(II) or CP/Fe(II), with 95.5% phenol removal under an optimum condition of a phenol/PS/CP/Fe(II) molar ratio of 1/1/5/6 ([Phenol]0=0.5 mM). Based on scavenger studies and electron spin resonance (ESR) spectroscopy, the phenol removal in the DuOx system was barrierless, with negative activation energy assisted by robust reactive species. The phenol degradation results in the presence of methanol, t-butanol, l-histidine, and NaN3. The ESR spectroscopy indicates that phenol degradation is attributed dominantly to 1O2 generated by recombining O2•- and radicals, such as hydroxyl (HO•) and sulfate (SO4•-). The performance of the DuOx system was highly efficient in pH 3-11, up to 10 mM Cl-, SO42-, or NO3-, and up to 50 mg/L humic acids but was strongly suppressed by more than 10 mM HCO3- and H2PO4-. In addition, the DuOx system was efficient in phenol removal in natural groundwater as well as removing and mineralizing other phenolic compounds (PCs) such as bisphenol A, chlorophenol, dichlorophenol, trichlorophenol, and nitrophenol. These results provide insights into the reactions induced by the DuOx system and confirm its applicability of in situ chemical oxidation in refractory organic pollutants.
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Affiliation(s)
- Md Abdullah Al Masud
- School of Architecture, Civil, Environmental and Energy Engineering, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Do Gun Kim
- Department of Environmental Engineering, Sunchon National University, Suncheon, Jeollanam-do, 57922, Republic of Korea.
| | - Won Sik Shin
- School of Architecture, Civil, Environmental and Energy Engineering, Kyungpook National University, Daegu, 41566, Republic of Korea.
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Motamedi M, Yerushalmi L, Haghighat F, Chen Z. Recent developments in photocatalysis of industrial effluents ։ A review and example of phenolic compounds degradation. CHEMOSPHERE 2022; 296:133688. [PMID: 35074327 DOI: 10.1016/j.chemosphere.2022.133688] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 01/16/2022] [Accepted: 01/17/2022] [Indexed: 06/14/2023]
Abstract
Industrial expansion and increased water consumption have created water scarcity concerns. Meanwhile, conventional wastewater purification methods have failed to degrade recalcitrant pollutants efficiently. The present review paper discusses the recent advances and challenges in photocatalytic processes applied for industrial effluents treatment, with respect to phenolic compounds degradation. Key operational parameters including the catalyst loading, light intensity, initial pollutants concentration, pH, and type and concentrations of oxidants are evaluated and discussed. Compared to the other examined controlling parameters, pH has the highest effect on the photo-oxidation of contaminants by means of the photocatalyst ionization degree and surface charge. Furthermore, major phenolic compounds derived from industrial sources are comprehensively presented and the applicability of photocatalytic processes and the barriers in practical applications, including high energy demand, technical challenges, photocatalyst stability, and recyclability have been explored. The importance of energy consumption and operational costs for realistic large-scale processes are also discussed. Finally, research gaps in this area and the suggested direction for improving degradation efficiencies in industrial applications are presented. In the light of these premises, selective degradation processes in real water matrices such as untreated sewage are proposed.
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Affiliation(s)
- Mahsa Motamedi
- Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, H3G 1M8, Canada
| | - Laleh Yerushalmi
- Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, H3G 1M8, Canada
| | - Fariborz Haghighat
- Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, H3G 1M8, Canada
| | - Zhi Chen
- Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, H3G 1M8, Canada.
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Shukla BK, Rawat S, Gautam MK, Bhandari H, Garg S, Singh J. Photocatalytic Degradation of Orange G Dye by Using Bismuth Molybdate: Photocatalysis Optimization and Modeling via Definitive Screening Designs. Molecules 2022; 27:2309. [PMID: 35408707 PMCID: PMC9000439 DOI: 10.3390/molecules27072309] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 03/24/2022] [Accepted: 03/31/2022] [Indexed: 12/29/2022] Open
Abstract
In the current study, Bismuth molybdate was synthesized using simple co-precipitation procedure, and their characterization was carried out by various methods such as FT-IR, SEM, and P-XRD. Furthermore, the photocatalytic degradation of Orange G (ORG) dye using synthesized catalyst under visible light irradiation was studied. Response surface Method was used for the optimization of process variables and degradation kinetics evaluated by modeling of experimental data. Based on the experimental design outcomes, the first-order model was proven as a practical correlation between selected factors and response. Further ANOVA analysis has revealed that only two out of six factors have a significant effect on ORG degradation, however ORG concentration and irradiation time indicated the significant effects sequentially. Maximum ORG degradation of approximately 96% was achieved by keeping process parameters in range, such as 1 g L-1 loading of catalyst, 50 mg L-1 concentration of ORG, 1.4 mol L-1 concentration of H2O2 at pH 7 and a temperature of 30 °C. Kinetics of ORG degradation followed the pseudo first order, and almost complete degradation was achieved within 8 h. The effectiveness of the Bi2MoO6/H2O2 photo-Fenton system in degradation reactions is due to the higher number of photo-generated e- available on the catalyst surface as a result of their ability to inhibit recombination of e- and h+ pair.
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Affiliation(s)
- Brijesh Kumar Shukla
- Department of Chemistry, Amity Institute of Applied Sciences, Amity University, Sector-125, Noida 201313, India;
| | - Shalu Rawat
- Department of Environmental Science, Babasaheb Bhimrao Ambedkar University, Lucknow 226025, India; (S.R.); (M.K.G.)
| | - Mayank Kumar Gautam
- Department of Environmental Science, Babasaheb Bhimrao Ambedkar University, Lucknow 226025, India; (S.R.); (M.K.G.)
| | - Hema Bhandari
- Department of Chemistry, Maitreyi College, University of Delhi, Delhi 110021, India;
| | - Seema Garg
- Department of Chemistry, Amity Institute of Applied Sciences, Amity University, Sector-125, Noida 201313, India;
| | - Jiwan Singh
- Department of Environmental Science, Babasaheb Bhimrao Ambedkar University, Lucknow 226025, India; (S.R.); (M.K.G.)
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9
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Jung H, Schimpf AM. Photochemical reduction of nanocrystalline maghemite to magnetite. NANOSCALE 2021; 13:17465-17472. [PMID: 34647940 DOI: 10.1039/d1nr02973h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We present a method for thephotochemical conversion of the inverse spinel iron oxides in which the mixed-valent magnetite phase (Fe3O4) is accessed from the maghemite phase (γ-Fe2O3) via a stable, colloidal nanocrystal-to-nanocrystal transformation. Anaerobic UV-irradiation of colloidal γ-Fe2O3 nanocrystals in the presence of ethanol as a sacrificial reductant yields reduction of some Fe3+ to Fe2+, resulting in a topotactic reduction of γ-Fe2O3 to Fe3O4. This reduction is evidenced by the emergence of charge-transfer absorption and increased d-spacing in UV-irradiated nanocrystals. Redox titrations reveal that ∼43% of Fe in <d> = 4.8 nm nanocrystals can be reduced with this method and comparison of optical data indicates similar reduction levels in <d> = 7.3 and 9.0 nm nanocrystals. Addition of excess acetaldehyde during photoreduction shows that the extent of reduction is likely pinned by the hydrogenation of acetaldehyde back to ethanol and can be increased with the use of an alkylborohydride sacrificial reductant. Photochemical reduction is accompanied by increased magnetization and emergence of magnetic features characteristic of Fe3O4. Overall, this work provides a reversible, post-synthetic strategy to obtain Fe3O4 nanocrystals with well-controlled Fe2+ compositions.
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Affiliation(s)
- Hankyeol Jung
- Materials Science and Engineering Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Alina M Schimpf
- Materials Science and Engineering Program, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA.
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10
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Environmental Assessment of Humic Acid Coated Magnetic Materials Used as Catalyst in Photo-Fenton Processes. Catalysts 2020. [DOI: 10.3390/catal10070771] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Persistent organic pollutants have been increasingly detected in natural waters, and this represents a real challenge to the quality of this resource. To remove these species, advanced treatment technologies are required. Among these technologies, Fenton-like and photo-Fenton-like processes have been investigated for the removal of pollutants from water. Delicate aspects of photo-Fenton processes are that light-driven processes are energy intensive and require a fair amount of chemical inputs, which strongly affects their overall environmental burdens. At present, aside from determining the efficiency of the processes to remove pollutants of a particular technology, it becomes fundamental to assess also the environmental sustainability of the overall process. In this work, the methodology of the life cycle assessment (LCA) was applied to identify the hotspots of using magnetite particles covered with humic acid (Fe3O4/HA) as a heterogeneous photo-Fenton catalyst for water remediation. The sustainability of the overall process was considered, and a comparative LCA study was performed between H2O2 and persulfate activation at different pH. The addition of humic substances to the particles allows the effectiveness of the catalyst to improve without increasing the environmental impacts; these processes are strongly correlated with energy consumption and therefore with the efficiency of the process. For this reason, working at acidic pH allows us to contain the impacts.
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