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An Overview of Emerging Cyanide Bioremediation Methods. Processes (Basel) 2022. [DOI: 10.3390/pr10091724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022] Open
Abstract
Cyanide compounds are hazardous compounds which are extremely toxic to living organisms, especially free cyanide in the form of hydrogen cyanide gas (HCN) and cyanide ion (CN−). These cyanide compounds are metabolic inhibitors since they can tightly bind to the metals of metalloenzymes. Anthropogenic sources contribute significantly to CN− contamination in the environment, more specifically to surface and underground waters. The treatment processes, such as chemical and physical treatment processes, have been implemented. However, these processes have drawbacks since they generate additional contaminants which further exacerbates the environmental pollution. The biological treatment techniques are mostly overlooked as an alternative to the conventional physical and chemical methods. However, the recent research has focused substantially on this method, with different reactor configurations that were proposed. However, minimal attention was given to the emerging technologies that sought to accelerate the treatment with a subsequent resource recovery from the process. Hence, this review focuses on the recent emerging tools that can be used to accelerate cyanide biodegradation. These tools include, amongst others, electro-bioremediation, anaerobic biodegradation and the use of microbial fuel cell technology. These processes were demonstrated to have the possibility of producing value-added products, such as biogas, co-factors of neurotransmitters and electricity from the treatment process.
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Rao S, A S S, Jayaprakash GK, Swamy MM, K S, Kumar D. Plant seed extract assisted, eco-synthesized C-ZnO nanoparticles: Characterization, Chromium (VI) ion adsorption and kinetic studies. LUMINESCENCE 2022. [PMID: 35166440 DOI: 10.1002/bio.4213] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 01/20/2022] [Accepted: 02/11/2022] [Indexed: 11/09/2022]
Abstract
This report attempts to elucidate the potential of plant seed extract assisted synthesis of Graphite based zinc oxide nanoparticles (C-ZnO NPs) towards removal of chromium (VI) ions from the water samples. The Graphene-zinc oxide composites were characterised using TGA, XRD, FTIR and SEM. The C-ZnO nanocomposites have found to remove chromium from the sample through adsorption process. The sensitivity of chromium removal through adsorption is found to be in the range of 40-240 mg. The adsorption behaviour was found to be fitting with Langmuir isotherm model and the adsorption reaction follows pseudo second order kinetics.
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Affiliation(s)
- Srilatha Rao
- Department of Chemistry, Nitte Meenakshi Institute of Technology, Yelahanka, Bangalore, Karnataka, India
| | - Sowmyashree A S
- Department of Chemistry, Nitte Meenakshi Institute of Technology, Yelahanka, Bangalore, Karnataka, India
| | | | - M Mahadeva Swamy
- PG Department of Chemistry, JSS College of Arts, Commerce and Science, Mysuru, Karnataka, India
| | - Swamynathan K
- Department of Chemistry, Nitte Meenakshi Institute of Technology, Yelahanka, Bangalore, Karnataka, India
| | - Deepak Kumar
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Shoolini University, Solan, Himachal Pradesh, India
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Islam JB, Furukawa M, Tateishi I, Katsumata H, Kaneco S. Formic acid motivated photocatalytic reduction of Cr(VI) to Cr(III) with ZnFe 2O 4 nanoparticles under UV irradiation. ENVIRONMENTAL TECHNOLOGY 2021; 42:2740-2748. [PMID: 31916510 DOI: 10.1080/09593330.2020.1713902] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 01/05/2020] [Indexed: 06/10/2023]
Abstract
UV-light irradiated photocatalytic reduction of Cr(VI) to Cr(III) in aqueous solution using ZnFe2O4 nanoparticles in the presence of formic acid was reported. X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS) and UV-Vis diffuse reflectance spectroscopy (DRS) were employed to characterize ZnFe2O4 nanoparticles. The photocatalytic activity of pure ZnFe2O4 under UV irradiation was significantly low. However, the Cr(VI) reduction efficiency on nano-sized ZnFe2O4 in the presence of 0.40% formic acid reached 95.4% within 4 h. Herein, the effect of pH, photocatalyst amount, initial concentration of Cr(VI) and formic acid concentration on the photocatalytic reduction of Cr(VI) was investigated. The results indicated that the photocatalytic reduction of Cr(VI) decreased with increase in the initial concentration of Cr(VI), photocatalyst dosage and pH. The reduction rate constant declined from 0.017 min-1 to 0.0023 min-1 with the increase in initial concentration of Cr(VI) from 5 to 25 mg L-1. However, the reduction rate constant sharply increased from 0.000075 min-1 to 0.0127 min-1 with the increase in formic acid concentration from 0.05% to 0.40%. The formic acid could capture the photogenerated holes, and eventually formate (HCOO-) ions could be converted into carbon dioxide radicals (•CO2-). Because of more negative redox potential for •CO2- radicals, Cr(VI) species could easily be reduced to Cr(III) under UV irradiation. The pseudo-first-order kinetic reaction was confirmed for this reduction process. A tenable mechanism for the photocatalytic Cr(VI) reduction has also been demonstrated.
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Affiliation(s)
- Jahida Binte Islam
- Department of Chemistry for Materials, Graduate School of Engineering, Mie University, Tsu, Japan
| | - Mai Furukawa
- Department of Chemistry for Materials, Graduate School of Engineering, Mie University, Tsu, Japan
| | - Ikki Tateishi
- Global Environment Center for Education & Research, Mie University, Tsu, Japan
| | - Hideyuki Katsumata
- Department of Chemistry for Materials, Graduate School of Engineering, Mie University, Tsu, Japan
| | - Satoshi Kaneco
- Department of Chemistry for Materials, Graduate School of Engineering, Mie University, Tsu, Japan
- Global Environment Center for Education & Research, Mie University, Tsu, Japan
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Ruellas TMO, Peçanha LOO, Domingos GHS, Sciena CR, Malafatti JOD, Paris EC, Maestrelli SC, Giraldi TR. Zinc oxide pieces obtained by pressing and slip casting: physical, structural and photocatalytic properties. ENVIRONMENTAL TECHNOLOGY 2021; 42:1861-1873. [PMID: 31630636 DOI: 10.1080/09593330.2019.1683078] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 10/15/2019] [Indexed: 06/10/2023]
Abstract
Photocatalysis is a promising alternative for the decontamination of effluents. In this paper, immobilized ZnO-based photocatalysts were obtained by pressing and by slip casting. The cylindrical pieces were heat-treated at 800°C. The samples were characterized by the method based on the principle of Archimedes, XRD, FTIR, Raman, diffuse reflectance and SEM. The samples obtained by slip casting presented lower apparent density (3.12 ± 0.04 g/cm3), higher apparent porosity (44.87 ± 0.47%) and smaller grain size (0.48 ± 0.05 µm) when compared to the pressed samples, with mean apparent density of 5.37 ± 0.08 g/cm3, apparent porosity of 1.56 ± 0.10% and grain size of 0.64 ± 0.02 µm. The performances of the samples were attested by the photocatalytic degradation of Rhodamine B (RhB) under UV-C irradiation (maximum intensity at 254 nm). The samples obtained by slip casting showed photocatalytic degradation between 80% and 90%, while the pressed samples showed degradation between 40% and 60%. The reuse of the photocatalysts was evaluated over five cycles of photocatalytic degradation, in which there was no loss of performance of the samples obtained by slip casting; however, the pressed samples showed a loss of photocatalytic efficiency starting from the third-cycle. Photocatalytic assays were carried out with different dye concentrations, in which the slip casting samples showed better photocatalytic efficiency (degradation of 80% for a RhB concentration of 10 mg/L) due to higher porosity and surface area compared to pressed samples, and there was a loss of performance in higher concentrations.
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Affiliation(s)
- T M O Ruellas
- Universidade Federal de Alfenas, Instituto de Ciência e Tecnologia, Cidade Universitária, Poços de Caldas, Brasil
| | - L O O Peçanha
- Universidade Federal de Alfenas, Instituto de Ciência e Tecnologia, Cidade Universitária, Poços de Caldas, Brasil
| | - G H S Domingos
- Universidade Federal de Alfenas, Instituto de Ciência e Tecnologia, Cidade Universitária, Poços de Caldas, Brasil
| | - C R Sciena
- Departamento de Química, Universidade Federal de São Carlos, Centro de Ciências Exatas e de Tecnologia, São Carlos, Brasil
| | - J O D Malafatti
- Departamento de Química, Universidade Federal de São Carlos, Centro de Ciências Exatas e de Tecnologia, São Carlos, Brasil
| | - E C Paris
- Empresa Brasileira de Pesquisa Agropecuária, Embrapa Instrumentação, São Carlos, Brasil
| | - S C Maestrelli
- Universidade Federal de Alfenas, Instituto de Ciência e Tecnologia, Cidade Universitária, Poços de Caldas, Brasil
| | - T R Giraldi
- Universidade Federal de Alfenas, Instituto de Ciência e Tecnologia, Cidade Universitária, Poços de Caldas, Brasil
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Alaei R, Javanshir S, Behnamfard A. Treatment of gold ore cyanidation wastewater by adsorption onto a Hydrotalcite-type anionic clay as a novel adsorbent. JOURNAL OF ENVIRONMENTAL HEALTH SCIENCE & ENGINEERING 2020; 18:779-791. [PMID: 33312602 PMCID: PMC7721945 DOI: 10.1007/s40201-020-00503-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 06/22/2020] [Indexed: 06/12/2023]
Abstract
The treatment of cyanide contaminated wastewater from a gold processing plant was performed by the synthesized nanostructured Layered Double Hydroxide (LDH) which has known as a Hydrotalcite-type anionic clay. LDH was synthesized by the co-precipitation process, characterized by X-ray fluorescence (XRF), X-ray powder diffraction (XRD), scanning electron microscope (SEM) Brunauer-Emmett-Teller (BET), Fourier-transform infrared spectroscopy (FTIR) and Wavelength Dispersive X-ray analysis (WDX) and applied for removal of free cyanide from both synthetic solution and mining effluent. The maximum particle size of synthesized LDH was determined to be 4 nm based on the Scherrer's equation. The maximum loading capacity of LDH, 60 mg/g, indicates that LDH is an interesting adsorbent for cyanide removal. The data modeling showed that the kinetic and equilibrium data best fitted by FPKM and RPIM, respectively, also, rate-controlling step in the adsorption process is intra-particle diffusion based on Weber-Morris plot, and the adsorption of CN- onto LDH is a two-step process. The thermodynamic studies confirm that the adsorption of free cyanide on Mg/Al LDH is a spontaneous and endothermic process. The energy of activation for adsorption of free cyanide on Mg/Al LDH was determined to be 6.14 kJ/mol, which is in the range physicochemical sorption. The mining wastewater treatment was performed by the synthesized LDH. The adsorption experiments showed that more than 90% of free cyanide was removed from the real solution during a short period of contact time, which confirms the ability of LDH for the treatment of industrial cyanide contaminated wastewater. Graphical abstract.
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Affiliation(s)
- Rasool Alaei
- Mining engineering Department, Faculty of Engineering, University of Birjand, Birjand, Iran
| | - Sepideh Javanshir
- Mining engineering Department, Faculty of Engineering, University of Birjand, Birjand, Iran
| | - Ali Behnamfard
- Mining engineering Department, Faculty of Engineering, University of Birjand, Birjand, Iran
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Photocatalytic degradation of a typical agricultural chemical: metalaxyl in water using TiO2 under solar irradiation. SN APPLIED SCIENCES 2020. [DOI: 10.1007/s42452-020-2722-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Kadi MW, Hameed A, Mohamed R, Ismail IM, Alangari Y, Cheng HM. The effect of Pt nanoparticles distribution on the removal of cyanide by TiO2 coated Al-MCM-41 in blue light exposure. ARAB J CHEM 2019. [DOI: 10.1016/j.arabjc.2016.02.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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8
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Ghasemi N, Rohani S. Optimization of cyanide removal from wastewaters using a new nano-adsorbent containing ZnO nanoparticles and MOF/Cu and evaluating its efficacy and prediction of experimental results with artificial neural networks. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.04.085] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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9
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Ojaghi A, Shafaie Tonkaboni SZ, Shariati P, Doulati Ardejani F. Novel cyanide electro-biodegradation using Bacillus pumilus ATCC 7061 in aqueous solution. JOURNAL OF ENVIRONMENTAL HEALTH SCIENCE & ENGINEERING 2018; 16:99-108. [PMID: 30728983 PMCID: PMC6277327 DOI: 10.1007/s40201-018-0289-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Accepted: 01/10/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Electro-biodegradation is a novel technique for cyanide degradation in aqueous solutions. Many physical, chemical, and biological methods have been developed and used to treat cyanide degradation. The biological methods are more environmentally-friendly and economically cost-effective when compared to other techniques, however, the process reaction time period is much longer and the efficiency is lower. METHODS In this research, the bacterial strain, Bacillus pumilus ATCC 7061, was tested for the first time to introduce the Cyanide Electro-biodegradation technique. By using a direct current power supply, electrons were generated in an electro-biodegradation cell containing culture media at free cyanide concentrations of 100 to 500 mg/l, under alkaline conditions. RESULTS Experimental tests showed that when electrons were added and bacteria were inoculated into the aqueous media containing 100, 200, 300, 400 and 500 mg/l of free cyanide, the cyanide degradation efficiency increased from 16.2, 21.6, 29.5, 38.7 and 44.5% to 98.6, 99.3, 99.7, 99.8 and 99.7%, in 36, 72, 137, 233 and 301 h, respectively. The results show that by adding electrons, the process reaction time decreases and cyanide degradation efficiency increases significantly. CONCLUSIONS The results presented here demonstrate for the first time the importance and the significance of the electro-biodegradation technique in the efficient degradation and removal of cyanide present in aqueous solutions.
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Affiliation(s)
- Aghil Ojaghi
- School of Mining, College of Engineering, University of Tehran, Tehran, Iran
| | | | - Parvin Shariati
- Department of Industrial and Environmental Biotechnology, Bioprocess Engineering Research Group, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
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10
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Jonidi-Jafari A, Gholami M, Farzadkia M, Esrafili A, Shirzad-Siboni M. Application of Ni-doped ZnO nanorods for degradation of diazinon: Kinetics and by-products. SEP SCI TECHNOL 2017. [DOI: 10.1080/01496395.2017.1303508] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Ahmad Jonidi-Jafari
- Research Center for Environmental Health Technology, Iran University of Medical Sciences, Tehran, Iran
- Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
| | - Mitra Gholami
- Research Center for Environmental Health Technology, Iran University of Medical Sciences, Tehran, Iran
- Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
| | - Mahdi Farzadkia
- Research Center for Environmental Health Technology, Iran University of Medical Sciences, Tehran, Iran
- Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
| | - Ali Esrafili
- Research Center for Environmental Health Technology, Iran University of Medical Sciences, Tehran, Iran
- Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
| | - Mehdi Shirzad-Siboni
- Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
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11
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Pueyo N, Miguel N, Mosteo R, Ovelleiro JL, Ormad MP. Synergistic effect of the presence of suspended and dissolved matter on the removal of cyanide from coking wastewater by TiO 2 photocatalysis. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2017; 52:182-188. [PMID: 27791477 DOI: 10.1080/10934529.2016.1240493] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This study assesses the influence of the presence of suspended and dissolved matter on the efficiency of TiO2 photocatalysis for the removal of cyanide from coking wastewater. Photocatalytic processes were carried out at basic pH (pH 9) with titanium dioxide (1 g/L), artificial radiation (290-800 nm) and during different time periods (20-100 min). The first assays applied in aqueous solutions achieved promising results in terms of removing cyanide. The maximum cyanide removal obtained in coking wastewater was 89% after 80 min of irradiation in the presence of suspended and dissolved matter. The presence of suspended matter composed of coal improves the efficiency of the photocatalytic process due to the synergistic effect between carbon and TiO2. The absence of dissolved matter also improves the process due to the minimization of the hydroxyl radical scavenging effect produced by carbonate and bicarbonate ions. On the other hand, the presence of certain species in the real matrix such as silicon increases the activity of the titanium dioxide catalyst. In consequence, the improvement achieved by the photocatalytic process for the removal of cyanide in the absence of dissolved matter is counteracted.
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Affiliation(s)
- Noelia Pueyo
- a Department of Chemical Engineering and Environmental Technologies , University of Zaragoza , Zaragoza , Spain
| | - Natividad Miguel
- a Department of Chemical Engineering and Environmental Technologies , University of Zaragoza , Zaragoza , Spain
| | - Rosa Mosteo
- a Department of Chemical Engineering and Environmental Technologies , University of Zaragoza , Zaragoza , Spain
| | - José L Ovelleiro
- a Department of Chemical Engineering and Environmental Technologies , University of Zaragoza , Zaragoza , Spain
| | - María P Ormad
- a Department of Chemical Engineering and Environmental Technologies , University of Zaragoza , Zaragoza , Spain
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12
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Wahab R, Khan F, Lutfullah, Al-Khedhairy AA. Photocatalytic activity and statistical determination of ball-shaped zinc oxide NPs with methylene blue dye. INORG NANO-MET CHEM 2016. [DOI: 10.1080/15533174.2016.1186082] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Rizwan Wahab
- Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
- Al-Jeraisy, Chair for DNA Research, Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Farheen Khan
- Department of Chemistry, Aligarh Muslim University (AMU), Aligarh, India
| | - Lutfullah
- Department of Chemistry, Aligarh Muslim University (AMU), Aligarh, India
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Samarghandi MR, Yang JK, Giahi O, Shirzad-Siboni M. Photocatalytic reduction of hexavalent chromium with illuminated amorphous FeOOH. ENVIRONMENTAL TECHNOLOGY 2015; 36:1132-1140. [PMID: 25367257 DOI: 10.1080/09593330.2014.982718] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this study, photocatalytic reduction of hexavalent chromium [Cr(VI)] by amorphous FeOOH was investigated with variations in FeOOH dosage, pH, initial Cr(VI) concentration, purging gas, organic compounds and initial hydrogen peroxide concentration. Reduction and adsorption were identified as important processes for the removal of Cr(VI). FeOOH dosage was also an important parameter for the removal of Cr(VI). As the FeOOH dosage increased up to 0.5 g/L, the removal of Cr(VI) was continuously enhanced and then decreased above 0.5 g/L due to increased blockage of the incident UV light. The removal efficiency of Cr(VI) decreased with increasing pH, initial Cr(VI) concentration and initial hydrogen peroxide concentration. While the removal efficiency of Cr(VI) increased with purging of nitrogen gas compared to that of oxygen gas because of less competition between dissolved oxygen and Cr(VI) with the electron in the conduction band of FeOOH. The photocatalytic reduction of Cr(VI) was increased in the presence of citric acid and phenol, while it was decreased in the presence of EDTA and oxalic acid. The reaction rate constant (kobs) was decreased from 0.2141 to 0.0026 1/min and the value of electrical energy per order (EEo) was increased from 22.41 to 1846.15 (kWh/m3) with increasing initial Cr(VI) concentration from 10 to 50 mg/L, respectively. Finally, proper photocatalytic activity was maintained even after five successive cycles.
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Affiliation(s)
- Mohammad-Reza Samarghandi
- a Department of Environmental Health and Research Center for Health Sciences , Hamadan University of Medical Sciences , Hamadan , Iran
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14
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Jonidi-Jafari A, Shirzad-Siboni M, Yang JK, Naimi-Joubani M, Farrokhi M. Photocatalytic degradation of diazinon with illuminated ZnO–TiO2 composite. J Taiwan Inst Chem Eng 2015. [DOI: 10.1016/j.jtice.2014.12.020] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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15
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Farzadkia M, Bazrafshan E, Esrafili A, Yang JK, Shirzad-Siboni M. Photocatalytic degradation of Metronidazole with illuminated TiO2 nanoparticles. JOURNAL OF ENVIRONMENTAL HEALTH SCIENCE & ENGINEERING 2015; 13:35. [PMID: 25908992 PMCID: PMC4407879 DOI: 10.1186/s40201-015-0194-y] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 04/15/2015] [Indexed: 05/22/2023]
Abstract
Metronidazole (MNZ) is a brand of nitroimidazole antibiotic, which is generally used in clinical applications and extensively used for the treatment of infectious diseases caused by anaerobic bacteria and protozoans. The aim of this investigation was to degrade MNZ with illuminated TiO2 nanoparticles at different catalyst dosage, contact time, pH, initial MNZ concentration and lamp intensity. Maximum removal of MNZ was observed at near neutral pH. Removal efficiency was decreased by increasing dosage and initial MNZ concentration. The reaction rate constant (k obs ) was decreased from 0.0513 to 0.0072 min(-1) and the value of electrical energy per order (EEo) was increased from 93.57 to 666.67 (kWh/m(3)) with increasing initial MNZ concentration from 40 to 120 mg/L, respectively. The biodegradability estimated from the BOD5/COD ratio was increased from 0 to 0.098. The photocatalyst demonstrated proper photocatalytic activity even after five successive cycles. Finally, UV/TiO2 is identified as a promising technique for the removal of antibiotic with high efficiency in a relatively short reaction time.
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Affiliation(s)
- Mahdi Farzadkia
- />Department of Environmental Health Engineering, School of public Health, Iran University of Medical Sciences, Tehran, Iran
| | - Edris Bazrafshan
- />Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Ali Esrafili
- />Department of Environmental Health Engineering, School of public Health, Iran University of Medical Sciences, Tehran, Iran
| | - Jae-Kyu Yang
- />Divisions of General Education, Kwangwoon University, Seoul, 139-701 South Korea
| | - Mehdi Shirzad-Siboni
- />Department of Environmental Health Engineering, School of public Health, Iran University of Medical Sciences, Tehran, Iran
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Li M, Zhong V, Chen G. Gold nanoparticles-coated chemically-reactive polymer colloids and the study of their catalytic kinetics. ACTA ACUST UNITED AC 2014. [DOI: 10.1557/opl.2014.318] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTRaspberry-like composite spheres based on chemically-reactive poly(glycidyl methacrylate) (PGMA) colloids as the cores coated with tunable size of gold nanoparticles were synthesized via a controlled assembly method. Kinetic study of 4-nitrophenol reduction by NaBH4 in the presence of poly(allylamine hydrochloride)-modified PGMA composite with tunable size of AuNPs (PGMA@PAH@AuNPs) was demonstrated. Effects of gold nanoparticles size and PGMA colloid diameter on the reaction time, average reaction rate and average turnover frequency (TOF), order of reaction (n) and apparent rate constant (kapp) were systematically investigated. Experimental results of our study showed composites with 3.4 ± 0.9 nm AuNPs have the best catalytic efficiency with the highest reaction order and apparent rate constant. The poisoning of product 4-aminophenol on PAH-modified PGMA colloid-supported gold nanocatalysts was evaluated using 4-nitrophenol/NaBH4 reduction reaction for the reaction time, average reaction rate, average TOF, order of reaction and apparent rate constant.
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