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Saputra E, Prawiranegara BA, Nugraha MW, Sambudi NS, Sugesti H, Awaluddin A, Utama PS, Manawan M. Fabrication of hybrid covalent triazine framework-zinc ferrite spinel to uplift visible light-driven photocatalytic organic pollutant degradation. Environ Sci Pollut Res Int 2023; 30:39961-39977. [PMID: 36602743 DOI: 10.1007/s11356-022-25021-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
The tunability of porous covalent triazine frameworks (CTFs) can mitigate poor photostability and rapid hole-electron recombination. Herein, an excellent improvement of visible light-driven photocatalytic pollutant degradation was achieved using a hybrid semiconductor of covalent triazine framework-zinc ferrite spinel catalysts (CTF-ZnFe2O4). The as-prepared CTF-ZnFe2O4 composites were fabricated using a facile one-pot ionothermal method. The hybrid photocatalysts were identified using X-ray diffraction (XRD), scanning electron microscopy/energy-dispersive X-ray (SEM-EDX), X-ray photoelectron spectrometer (XPS), Brunauer-Emmett-Teller (BET), Fourier transform infrared (FTIR), and UV-visible diffuse reflection spectroscopy (UV-vis DRS) characterizations. The analysis reveals that hybridization successfully ensued and altered the crystallinity structure, morphology, surface area, and bandgap energy of hybrid material. It was found that CTF-ZnFe2O4 90:10 is very effective for the degradation of MB in a UV-vis light photocatalytic process with the efficiency of 95.4% and kobs of 0.421 min-1 for degradation of 50 mg/L MB with 0.5 g/L dosages for 120 min. Additionally, the scavenger study, effect of additional oxidants, and stability were performed for the practical application of a hybrid photocatalyst. CTF-ZnFe2O4 90:10 shows outstanding pollutant degradation in sunlight irradiation and high stability with only a 5.2% reduction after a five-times sequential recycling process. Moreover, the photocatalytic mechanism of as-prepared CTF-ZnFe2O4 was mainly influenced by [Formula: see text] radical compared to [Formula: see text] and [Formula: see text] radicals. Overall, The as-prepared CTF-ZnFe2O4 shows significant potential to be utilized for photocatalytic wastewater treatment.
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Affiliation(s)
- Edy Saputra
- Department of Chemical Engineering, Universitas Riau, Pekanbaru, 28293, Indonesia.
| | - Barata Aditya Prawiranegara
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Riau, Pekanbaru, 28293, Indonesia
| | - Muhammad Wahyu Nugraha
- Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Nonni Soraya Sambudi
- Department of Chemical Engineering, Universitas Pertamina, Simprug, Jakarta, 12220, Indonesia
| | - Heni Sugesti
- Department of Chemical Engineering, Universitas Riau, Pekanbaru, 28293, Indonesia
| | - Amir Awaluddin
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Riau, Pekanbaru, 28293, Indonesia
| | - Panca Setia Utama
- Department of Chemical Engineering, Universitas Riau, Pekanbaru, 28293, Indonesia
| | - Maykel Manawan
- Teknologi Daya Gerak, Universitas Pertahan Indonesia, Bogor, 16810, Indonesia
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Tian X, Wang X, Nie Y, Yang C, Dionysiou DD. Hydroxyl Radical-Involving p-Nitrophenol Oxidation during Its Reduction by Nanoscale Sulfidated Zerovalent Iron under Anaerobic Conditions. Environ Sci Technol 2021; 55:2403-2410. [PMID: 33543936 DOI: 10.1021/acs.est.0c07475] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Sulfidated zerovalent iron (S-ZVI) has been extensively used for reducing pollutants. In this study, the oxidation process in the reductive removal of p-nitrophenol (PNP) by S-ZVI was confirmed under anaerobic conditions. We revealed that a PNP oxidation process involving •OH resulted from the H2O2 activation by surface-bound Fe(II) in S-ZVI, in which H2O2 was generated via a surface-mediated reaction between water and FeS2. Only the PNP reduction process occurred for ZVI. Herein, efficient PNP degradation by S-ZVI resulted from two functions: reduction into p-aminophenol due to enhanced electron transfer and PNP oxidation into p-benzoquinone by •OH radicals from the interaction of surface-bound Fe(II) and in situ generated H2O2, the contributions of the oxidation and reduction processes to PNP degradation over S-ZVI were 10 and 90%, respectively. Sulfur in S-ZVI suppressed the pH increase in the reaction media and produced more surface-bound Fe(II) than ZVI for •OH generation via the heterogeneous Fenton reaction process. Since different degradation pathways could lead to different effects on the water environment, such as toxicity, our findings suggest that the oxidizing process induced by S-ZVI during groundwater decontamination should be considered.
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Affiliation(s)
- Xike Tian
- Faculty of Materials and Chemistry, China University of Geosciences, Wuhan 430074, P. R. China
| | - Xiang Wang
- Faculty of Materials and Chemistry, China University of Geosciences, Wuhan 430074, P. R. China
| | - Yulun Nie
- Faculty of Materials and Chemistry, China University of Geosciences, Wuhan 430074, P. R. China
| | - Chao Yang
- Faculty of Materials and Chemistry, China University of Geosciences, Wuhan 430074, P. R. China
| | - Dionysios D Dionysiou
- Environmental Engineering and Science Program, Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, Ohio 45221-0012, United States
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Li W, Xu X, Lyu B, Tang Y, Zhang Y, Chen F, Korshin G. Degradation of typical macrolide antibiotic roxithromycin by hydroxyl radical: kinetics, products, and toxicity assessment. Environ Sci Pollut Res Int 2019; 26:14570-14582. [PMID: 30877533 DOI: 10.1007/s11356-019-04713-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/25/2019] [Indexed: 06/09/2023]
Abstract
The degradation of roxithromycin (ROX) by hydroxyl radical (·OH) generated by UV/H2O2 was systematically investigated in terms of degradation kinetics, effects of water chemistry parameters, oxidation products, as well as toxicity evaluation. The degradation of ROX by UV/H2O2 with varying light irradiation intensity, initial ROX concentration, and H2O2 concentration in pure water and wastewater all followed pseudo-first-order kinetics. The second-order rate constant for reaction between ROX and ·OH is 5.68 ± 0.34 × 109/M/s. The degradation rate of ROX increased with the pH; for instance, the apparent degradation rates were 0.0162 and 0.0309/min for pH 4 and pH 9, respectively. The presence of natural organic matter (NOM) at its concentrations up to 10 mg C/L did not significantly affect the removal of ROX. NO3- and NO2- anions inhibited the degradation of ROX due to the consumption of ·OH in reactions with these ions. Fe3+, Cu2+, and Mg2+ cations inhibited the degradation of ROX, probably because of the formation of ROX-metal chelates. A total of ten degradation products were tentatively identified by HPLC/LTQ-Orbitrap XL MS, which mainly derived from the attack on the oxygen linking the lactone ring and the cladinose moiety, tertiary amine and oxime side chain moiety by ·OH. The toxicity evaluation revealed that UV/H2O2 treatment of ROX induced the toxicity to bioluminescent bacteria increased.
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Affiliation(s)
- Wei Li
- Co-Innovation center for sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Longpan Road 159, Nanjing, 210037, China.
| | - Xiujuan Xu
- Co-Innovation center for sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Longpan Road 159, Nanjing, 210037, China
| | - Baoling Lyu
- Co-Innovation center for sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Longpan Road 159, Nanjing, 210037, China
| | - Ying Tang
- Advanced Analysis and Testing Center, Nanjing Forestry University, Longpan Road 159, Nanjing, 210037, China
| | - Yinlong Zhang
- Co-Innovation center for sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Longpan Road 159, Nanjing, 210037, China.
| | - Fang Chen
- School of Resources and Materials, Northeastern University at Qinhuangdao, Qinhuangdao, 066004, Hebei, China
| | - Gregory Korshin
- Department of Civil and Environmental Engineering, University of Washington, Box 352700, Seattle, WA, 98195-2700, USA
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Lou X, Xiao D, Fang C, Wang Z, Liu J, Guo Y, Lu S. Comparison of UV/hydrogen peroxide and UV/peroxydisulfate processes for the degradation of humic acid in the presence of halide ions. Environ Sci Pollut Res Int 2016; 23:4778-4785. [PMID: 26538259 DOI: 10.1007/s11356-015-5232-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 08/11/2015] [Indexed: 06/05/2023]
Abstract
This study compared the behaviors of two classic advanced oxidation processes (AOPs), hydroxyl radical-based AOPs ((•)OH-based AOPs) and sulfate radical-based AOPs (SO4 (•-)-based AOPs), represented by UV/ hydrogen peroxide (H2O2) and UV/peroxydisulfate (PDS) systems, respectively, to degrade humic acid (HA) in the presence of halide ions (Cl(-) and Br(-)). The effects of different operational parameters, such as oxidant dosages, halide ions concentration, and pH on HA degradation were investigated in UV/H2O2/Cl(-), UV/PDS/Cl(-), UV/H2O2/Br(-), and UV/PDS/Br(-) processes. It was found that the oxidation capacity of H2O2 and PDS to HA degradation in the presence of halides was nearly in the same order. High dosage of peroxides would lead to an increase in HA removal while excess dosage would slightly inhibit the efficiency. Both Cl(-) and Br(-) would have depressing impact on the two AOPs, but the inhibiting effect of Br(-) was more obvious than that of Cl(-), even the concentration of Cl(-) was far above that of Br(-). The increasing pH would have an adverse effect on HA decomposition in UV/H2O2 system, whereas there was no significant impact of pH in UV/PDS process. Furthermore, infrared spectrometer was used to provide the information of degraded HA in UV/H2O2/Cl(-), UV/PDS/Cl(-), UV/H2O2/Br(-), and UV/PDS/Br(-) processes, and halogenated byproducts were identified in using GC-MS analysis in the four processes. The present research might have significant technical implications on water treatment using advanced oxidation technologies.
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Affiliation(s)
- Xiaoyi Lou
- State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, People's Republic of China
| | - Dongxue Xiao
- State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, People's Republic of China
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of East China Sea & Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, Shanghai, 200090, People's Republic of China
| | - Changling Fang
- State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, People's Republic of China
| | - Zhaohui Wang
- State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, People's Republic of China
| | - Jianshe Liu
- State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, People's Republic of China.
| | - Yaoguang Guo
- State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, People's Republic of China.
- School of Environmental and Materials Engineering, Shanghai Second Polytechnic University, Shanghai, 201209, People's Republic of China.
| | - Shuyu Lu
- State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, People's Republic of China
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Silva TFCV, Ferreira R, Soares PA, Manenti DR, Fonseca A, Saraiva I, Boaventura RAR, Vilar VJP. Insights into solar photo-Fenton reaction parameters in the oxidation of a sanitary landfill leachate at lab-scale. J Environ Manage 2015; 164:32-40. [PMID: 26342264 DOI: 10.1016/j.jenvman.2015.08.030] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 08/17/2015] [Accepted: 08/21/2015] [Indexed: 06/05/2023]
Abstract
This work evaluates the effect of the main photo-Fenton (PF) reaction variables on the treatment of a sanitary landfill leachate collected at the outlet of a leachate treatment plant, which includes aerated lagooning followed by aerated activated sludge and a final coagulation-flocculation step. The PF experiments were performed in a lab-scale compound parabolic collector (CPC) photoreactor using artificial solar radiation. The photocatalytic reaction rate was determined while varying the total dissolved iron concentration (20-100 mg Fe(2+)/L), solution pH (2.0-3.6), operating temperature (10-50 °C), type of acid used for acidification (H2SO4, HCl and H2SO4 + HCl) and UV irradiance (22-68 W/m(2)). This work also tries to elucidate the role of ferric hydroxides, ferric sulphate and ferric chloride species, by taking advantage of ferric speciation diagrams, in the efficiency of the PF reaction when applied to leachate oxidation. The molar fraction of the most photoactive ferric species, FeOH(2+), was linearly correlated with the PF pseudo-first order kinetic constants obtained at different solution pH and temperature values. Ferric ion speciation diagrams also showed that the presence of high amounts of chloride ions negatively affected the PF reaction, due to the decrease of ferric ions solubility and scavenging of hydroxyl radicals for chlorine radical formation. The increment of the PF reaction rates with temperature was mainly associated with the increase of the molar fraction of FeOH(2+). The optimal parameters for the photo-Fenton reaction were: pH = 2.8 (acidification agent: H2SO4); T = 30 °C; [Fe(2+)] = 60 mg/L and UV irradiance = 44 WUV/m(2), achieving 72% mineralization after 25 kJUV/L of accumulated UV energy and 149 mM of H2O2 consumed.
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Affiliation(s)
- Tânia F C V Silva
- LSRE - Laboratory of Separation and Reaction Engineering - Associate Laboratory LSRE/LCM, Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
| | - Rui Ferreira
- LSRE - Laboratory of Separation and Reaction Engineering - Associate Laboratory LSRE/LCM, Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Petrick A Soares
- LSRE - Laboratory of Separation and Reaction Engineering - Associate Laboratory LSRE/LCM, Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Diego R Manenti
- LSRE - Laboratory of Separation and Reaction Engineering - Associate Laboratory LSRE/LCM, Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; Programa de Pós-Graduação em Engenharia Química da Universidade Estadual de Maringá, Av. Colombo 5790, Maringá-PR, Brazil
| | - Amélia Fonseca
- Efacec Engenharia e Sistemas S.A. (Unidade de Negócios Ambiente), SA, Rua Eng. Frederico Ulrich - Guardeiras, Apartado 3003, 4471-907 Moreira da Maia, Portugal
| | - Isabel Saraiva
- Efacec Engenharia e Sistemas S.A. (Unidade de Negócios Ambiente), SA, Rua Eng. Frederico Ulrich - Guardeiras, Apartado 3003, 4471-907 Moreira da Maia, Portugal
| | - Rui A R Boaventura
- LSRE - Laboratory of Separation and Reaction Engineering - Associate Laboratory LSRE/LCM, Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Vítor J P Vilar
- LSRE - Laboratory of Separation and Reaction Engineering - Associate Laboratory LSRE/LCM, Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
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Li H, Pan B, Liao S, Zhang D, Xing B. Formation of environmentally persistent free radicals as the mechanism for reduced catechol degradation on hematite-silica surface under UV irradiation. Environ Pollut 2014; 188:153-8. [PMID: 24594596 DOI: 10.1016/j.envpol.2014.02.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 02/06/2014] [Accepted: 02/08/2014] [Indexed: 05/16/2023]
Abstract
Iron is rich in soils, and is recently reported to form stable complexes with organic free radicals, generating environmentally persistent free radicals (EPFRs). The observation may challenge the common viewpoint that iron is an effective catalyst to facilitate the degradation of various organic chemicals. But no study was specifically designed to investigate the possible inhibited degradation of organic chemicals because of the formation of EPFRs in dry environment. We observed that catechol degradation under UV irradiation was decreased over 20% in silica particles coated with 1% hematite in comparison to uncoated silica particles. Stabilized semiquinone or quinine and phenol radicals were involved in HMT-silica system. EPFR formation was thus the reason for the reduced catechol degradation on HMT-silica surface under UV irradiation at ambient temperature. EPFRs should be incorporated in the studies of organic contaminants geochemical behavior, and will be a new input in their environmental fate modeling.
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Affiliation(s)
- Hao Li
- Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, China
| | - Bo Pan
- Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, China.
| | - Shaohua Liao
- Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, China
| | - Di Zhang
- Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, China
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, USA
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Espinoza LAT, ter Haseborg E, Weber M, Karle E, Peschke R, Frimmel FH. Effect of selected metal ions on the photocatalytic degradation of bog lake water natural organic matter. Water Res 2011; 45:1039-1048. [PMID: 21093013 DOI: 10.1016/j.watres.2010.10.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2010] [Revised: 09/14/2010] [Accepted: 10/13/2010] [Indexed: 05/30/2023]
Abstract
Herein we report the photocatalytic degradation of natural organic matter from a bog lake (Lake Hohloh, Black Forest, Germany) in the presence of 0, 5, and 10 μmol L(-1) of added Cu(2+), Mn(2+), Zn(2+) and Fe(3+). The reactions were followed by size exclusion chromatography with organic carbon detection (SEC-DOC) and by measurements of low molecular weight organic acids. Addition of Cu(2+) had the largest effect of all four studied metals, leading to a retardation in the molecular size changes in NOM: degradation of the larger molecular weight fraction was inhibited leading to reduced production of smaller molecular weight metabolites. Similarly, addition of Cu(2+) reduced the production of formic and oxalic acids, and reduced the bioavailability of the partially degraded NOM.
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Affiliation(s)
- Luis A Tercero Espinoza
- Water Chemistry, Engler-Bunte-Institut, Karlsruhe Institute of Technology, Engler-Bunte-Ring 1, 76131 Karlsruhe, Germany.
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Ratanatamskul C, Chintitanun S, Masomboon N, Lu MC. Inhibitory effect of inorganic ions on nitrobenzene oxidation by fluidized-bed Fenton process. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.molcata.2010.08.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Tercero Espinoza LA, Rojas Malerba R, Frimmel FH. Influence of dissolved organic carbon source, photocatalyst identity and copper(II) ions on the formation of bromoform in irradiated titanium dioxide suspensions. Catal Today 2010; 151:84-8. [DOI: 10.1016/j.cattod.2010.02.060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Zhao XH, Zhao YQ. Decolouration of H2SO4 leachate from phosphorus-saturated alum sludge using H2O2 and advanced oxidation processes in phosphorus recovery strategy. J Environ Sci Health A Tox Hazard Subst Environ Eng 2009; 44:1557-1564. [PMID: 20183514 DOI: 10.1080/10934520903263504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
As a part of attempt for phosphorus (P) recovery from P-saturated alum sludge, which was used as a low-cost P-adsorbent in treatment reed bed for wastewater treatment, decolouration of H(2)SO(4) leachate obtained from previous experiment, possessing a great deal of P, aluminum and red-brown coloured materials (RBCMs), by using H(2)O(2) and advanced oxidation processes (AOPs) was investigated. The use of H(2)O(2) and AOPs in the forms of Fenton (H(2)O(2)/Fe(2 +)) and photo-Fenton (UV/H(2)O(2)/Fe(2 +)) were tested. The changes in colour and total organic carbon (TOC) were taken place as a result of mineralization of RBCMs. The results revealed that all of these three processes examined were efficient. It was found that about 98% colour and 47% TOC can be removed under photo-Fenton treatment after 8 hours of UV irradiation.Correspondingly, the reaction rates of H(2)O(2) and Fenton systems were slow, but 100% colour and 59% TOC removal of H(2)O(2) process and 100% colour and 67% TOC reductions of Fenton process can be achieved after 72 hours of reaction. The changes of structure and molecular weight/size of RBCMs were also evaluated by HPLC and UV-vis spectroscopic analysis. From the results, some chromophores of RBCMs such as aromatic groups were appeared to be easily degraded to the smaller refractory components. Hence, based on the experimental results and considering the investment and expediency of operation, H(2)O(2) and Fenton oxidation could be suitable technologies for the treatment of the RBCMs derived from P-extraction stage by using H(2)SO(4) leaching.
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Affiliation(s)
- X H Zhao
- Centre for Water Resources Research, School of Architecture, Landscape and Civil Engineering, Newstead Building, University College Dublin, Belfield, Dublin, Ireland.
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Terkhi M, Taleb F, Gossart P, Semmoud A, Addou A. Fourier transform infrared study of mercury interaction with carboxyl groups in humic acids. J Photochem Photobiol A Chem 2008. [DOI: 10.1016/j.jphotochem.2008.03.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Alkan U, Teksoy A, Atesli A, Baskaya HS. Efficiency of the UV/H2O2 process for the disinfection of humic surface waters. J Environ Sci Health A Tox Hazard Subst Environ Eng 2007; 42:497-506. [PMID: 17365320 DOI: 10.1080/10934520601188375] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The efficiency of the UV/H2O2 process for the disinfection of total coliforms and the prevention of bacterial regrowth in humic surface waters were investigated. Inactivation of total coliforms was determined in water samples containing various concentrations ranging from 0-10 mg/L dissolved organic carbon (DOC) of fulvic acid, which were exposed to various doses (68-681 mWs/cm2) of UV radiation in the presence of 0.125 mg/L and 3.000 mg/L of hydrogen peroxide. Disinfection efficiencies of the UV radiation and the UV/H2O2 processes were compared. The results of bacterial inactivation experiments showed that the performances of the UV and the UV/H2O2 (0.125) were comparable whereas the UV/H2O2 (3.000) process showed significant improvement in performance, especially, in highly humic waters. Inactivation coefficient appeared to be almost doubled by the addition of 3.000 mg/L hydrogen peroxide during the treatment of highly humic waters. In contradiction to significant regrowth which occurred in the single UV radiation treatment, residual bacteria following the UV/H2O2 (0.125) and the UV/H2O2 (3.000) treatments were completely inactivated during dark incubation indicating the elimination of possible bacterial regrowth.
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Affiliation(s)
- Ufuk Alkan
- Department of Environmental Engineering, Uludağ University, Görükle, Bursa, Turkey.
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Behnajady MA, Modirshahla N. Kinetic modeling on photooxidative degradation of C.I. Acid Orange 7 in a tubular continuous-flow photoreactor. Chemosphere 2006; 62:1543-8. [PMID: 16005938 DOI: 10.1016/j.chemosphere.2005.05.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2004] [Revised: 05/11/2005] [Accepted: 05/12/2005] [Indexed: 05/03/2023]
Abstract
The decolorization of C.I. Acid Orange 7 (AO7), an anionic monoazo dye of acid class, was investigated using UV radiation in the presence of H2O2 in a tubular continuous-flow photoreactor as a function of oxidant and dye concentrations, reactor length and volumetric flow rate. The removal efficiency of AO7 depends on the operational parameters and increases as the initial concentration of H2O2 is increased but it decreases when the flow rate and initial concentration of AO7 are increased. The decolorization rate follows pseudo-first order kinetic with respect to the dye concentration. A rate equation for decolorization of AO7 was achieved by kinetic modeling. This model allows predicting concentration of AO7 in different photoreactor lengths for different volumetric flow rates and initial concentrations of H2O2 and AO7. The calculated results obtained from kinetic model were in good agreement with experimental data.
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Affiliation(s)
- M A Behnajady
- Research Laboratory, Department of Applied Chemistry, Islamic Azad University, Tabriz Branch, Tabriz, Iran.
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Liao CH, Kang SF, Hsu YW. Zero-valent iron reduction of nitrate in the presence of ultraviolet light, organic matter and hydrogen peroxide. Water Res 2003; 37:4109-4118. [PMID: 12946892 DOI: 10.1016/s0043-1354(03)00248-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This paper describes the use of metallic iron (Fe(0)) powder for nitrate removal in a well-mixed batch reactor. Important variables explored include Fe(0) dosage (1-3g/L), UV light intensity (64-128 W), and the presence of propanol (20 mg/L as DOC) and H(2)O(2) (100-200 mg/L). Accumulation of ferrous ions released from the Fe(0) surface can be expressed by an S-curve, which involves lag growth phase, exponential phase, rate-declining phase, and saturation phase. The removal of nitrate increases with increasing Fe(0) dosage; however, the removal makes no difference as the Fe(0) dosage is greater than 2 g/L. UV irradiation retards the dissolution of ferrous ion and the removal of nitrate. The species of propanol, which has a functional group of -OH, plays a role of organic inhibitor for Fe(0) corrosion. The presence of H(2)O(2) appears to inactivate all reactions as the Fe(0) of 10 microm was used; the final H(2)O(2) remains intact throughout the entire reaction period, and there were no removal of nitrate and no dissolution of ferrous ion. Surprisingly, with the use of a larger Fe(0) particle size of 150 microm, the H(2)O(2) was seen to decompose rapidly through Fenton reaction. Nevertheless, the rate of ferrous accumulation or nitrate removal is slow.
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Affiliation(s)
- Chih-Hsiang Liao
- Department of Environmental Engineering and Health, Chia-Nan University of Pharmacy and Science, Tainan, Taiwan.
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Brinkmann T, Hörsch P, Sartorius D, Frimmel FH. Photoformation of low-molecular-weight organic acids from brown water dissolved organic matter. Environ Sci Technol 2003; 37:4190-8. [PMID: 14524452 DOI: 10.1021/es0263339] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
This work describes the effects of simulated solar UV light on the bulk properties of dissolved organic matter (DOM) of bog lake water and on the formation of low-molecular-weight organic acids (LMWOAs). By means of size-exclusion chromatography it was shown that the more hydrophilic moieties of the DOM were preferentially photodegraded while the more hydrophobic ones remained relatively unaffected or were even formed. The combined photochemical-biological degradation proved to be more important than the pure photochemical mineralization. Formic, acetic, pyruvic, oxalic, malonic, and succinic acids were identified as important degradation products. Their contribution to the dissolved organic carbon increased from 0.31% before to 6.4% after 24 h irradiation. About 33% of the bioavailable photoproducts of DOM were comprised of these LMWOAs. The influence of nitrate on the formation of carboxylic acids could not be observed in the investigated system. Kinetic experiments indicated that degradation of LMWOAs occurred simultaneously during irradiation experiments, alpha-oxygen-substituted LMWOAs being more amenable to these processes. Dissolved iron acted as a catalyst of DOM photodegradation and LMWOA photoformation. Copper played an antagonistic role in the irradiation experiments, reducing the formation of formic, acetic, and malonic acids while increasing the formation of oxalic acid.
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Affiliation(s)
- Thomas Brinkmann
- Water Chemistry, Engler-Bunte-Institute, University of Karlsruhe, 76128 Karlsruhe, Germany
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