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Rajender S Varma - One of the best experts on this subject based on the ideXlab platform.
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Protocol encompassing ultrasound/Fe3O4 nanoparticles/Persulfate for the removal of tetracycline antibiotics from aqueous environments
Clean Technologies and Environmental Policy, 2019Co-Authors: Mahammad Malakotian, Pouria Karimi, Nima Firouzeh, Seyedeh Nastaran Asadzadeh, Mehrdad Khatami, Mohammad Ahmadian, Mohammad Reza Heidari, Rajender S VarmaAbstract:The presence of residual antibiotics in the environment is one of the major global concerns, and it is imperative to control their discharge in water bodies. The present study used a combination of Fe3O4 nanoparticles/Persulfate in conjunction with ultrasound to address this problem; the influence of effective parameters in the remediation process, Persulfate concentration, nanoparticle concentrations, initial antibiotic concentration, contact time and pH was investigated. The highest removal rate of tetracycline antibiotic was observed at pH 10, the amount of magnetic nanoparticles being (0.3 g/L), with Persulfate concentration at 4 mM for the removal of antibiotic concentration at 10 mg/L; TC and COD removal efficiency is 92.99 and 79.85%, respectively. The deployment of sonocatalytic process, along with the use of magnetite nanoparticles and Persulfates as oxidizing agents, appears to be an effective means for decreasing the high-level tetracycline concentration in water.Graphic abstract
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Protocol encompassing ultrasound/Fe_3O_4 nanoparticles/Persulfate for the removal of tetracycline antibiotics from aqueous environments
Clean Technologies and Environmental Policy, 2019Co-Authors: Mahammad Malakotian, Pouria Karimi, Nima Firouzeh, Seyedeh Nastaran Asadzadeh, Mehrdad Khatami, Mohammad Ahmadian, Mohammad Reza Heidari, Rajender S VarmaAbstract:The presence of residual antibiotics in the environment is one of the major global concerns, and it is imperative to control their discharge in water bodies. The present study used a combination of Fe_3O_4 nanoparticles/Persulfate in conjunction with ultrasound to address this problem; the influence of effective parameters in the remediation process, Persulfate concentration, nanoparticle concentrations, initial antibiotic concentration, contact time and pH was investigated. The highest removal rate of tetracycline antibiotic was observed at pH 10, the amount of magnetic nanoparticles being (0.3 g/L), with Persulfate concentration at 4 mM for the removal of antibiotic concentration at 10 mg/L; TC and COD removal efficiency is 92.99 and 79.85%, respectively. The deployment of sonocatalytic process, along with the use of magnetite nanoparticles and Persulfates as oxidizing agents, appears to be an effective means for decreasing the high-level tetracycline concentration in water. Graphic abstract
Mahammad Malakotian - One of the best experts on this subject based on the ideXlab platform.
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Protocol encompassing ultrasound/Fe3O4 nanoparticles/Persulfate for the removal of tetracycline antibiotics from aqueous environments
Clean Technologies and Environmental Policy, 2019Co-Authors: Mahammad Malakotian, Pouria Karimi, Nima Firouzeh, Seyedeh Nastaran Asadzadeh, Mehrdad Khatami, Mohammad Ahmadian, Mohammad Reza Heidari, Rajender S VarmaAbstract:The presence of residual antibiotics in the environment is one of the major global concerns, and it is imperative to control their discharge in water bodies. The present study used a combination of Fe3O4 nanoparticles/Persulfate in conjunction with ultrasound to address this problem; the influence of effective parameters in the remediation process, Persulfate concentration, nanoparticle concentrations, initial antibiotic concentration, contact time and pH was investigated. The highest removal rate of tetracycline antibiotic was observed at pH 10, the amount of magnetic nanoparticles being (0.3 g/L), with Persulfate concentration at 4 mM for the removal of antibiotic concentration at 10 mg/L; TC and COD removal efficiency is 92.99 and 79.85%, respectively. The deployment of sonocatalytic process, along with the use of magnetite nanoparticles and Persulfates as oxidizing agents, appears to be an effective means for decreasing the high-level tetracycline concentration in water.Graphic abstract
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Protocol encompassing ultrasound/Fe_3O_4 nanoparticles/Persulfate for the removal of tetracycline antibiotics from aqueous environments
Clean Technologies and Environmental Policy, 2019Co-Authors: Mahammad Malakotian, Pouria Karimi, Nima Firouzeh, Seyedeh Nastaran Asadzadeh, Mehrdad Khatami, Mohammad Ahmadian, Mohammad Reza Heidari, Rajender S VarmaAbstract:The presence of residual antibiotics in the environment is one of the major global concerns, and it is imperative to control their discharge in water bodies. The present study used a combination of Fe_3O_4 nanoparticles/Persulfate in conjunction with ultrasound to address this problem; the influence of effective parameters in the remediation process, Persulfate concentration, nanoparticle concentrations, initial antibiotic concentration, contact time and pH was investigated. The highest removal rate of tetracycline antibiotic was observed at pH 10, the amount of magnetic nanoparticles being (0.3 g/L), with Persulfate concentration at 4 mM for the removal of antibiotic concentration at 10 mg/L; TC and COD removal efficiency is 92.99 and 79.85%, respectively. The deployment of sonocatalytic process, along with the use of magnetite nanoparticles and Persulfates as oxidizing agents, appears to be an effective means for decreasing the high-level tetracycline concentration in water. Graphic abstract
Neil R. Thomson - One of the best experts on this subject based on the ideXlab platform.
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Persulfate Interaction with Tropical Soils
Water Air & Soil Pollution, 2016Co-Authors: Fernanda De Carvalho Oliveira, Neil R. Thomson, Juliana G. Freitas, Sheila Aparecida Correia Furquim, Renata M. Rollo, Luís Reynaldo Ferracciú Alleoni, Cláudio Augusto Oller Do NascimentoAbstract:Persulfate use as a chemical oxidant for remediation of contaminated sites has increased due to its higher in situ persistence and reactivity with environmentally relevant contaminants. The interaction of Persulfate with soil materials can significantly influence treatment efficiency by either promoting activation or by decreasing its persistence. In this investigation, the interaction between Persulfate and three soils (two highly weathered and clayey Oxisols, and a sandy Psamment soil) found in tropical environments was evaluated. A series of batch tests were conducted using a high (14 g L−1) and low (1 g L−1) Persulfate concentration. Additional Persulfate mass was added after 120 days into low Persulfate concentration systems. Persulfate degradation generally followed a first-order kinetic model; however, the reaction rate coefficients varied with initial concentration and with the addition of Persulfate at 120 days. A kinetic model that accounts for the presence of a finite mass of oxidizable material was shown to capture all experimental conditions. In all systems, the pH decreased significantly, causing favorable conditions for the dissolution of clay minerals such as kaolinite, as supported by mineralogical analyses. This dissolution resulted in an increase in exchangeable aluminum and iron, as well as conversion of iron associated with amorphous oxides to crystalline oxides. The increased availability of these species resulted in accelerated Persulfate degradation. Based on the data set assembled, a conceptual model was developed that represents the interaction between Persulfate and soils that have clay minerals containing iron that are susceptible to dissolution.
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Treatment of Organic Compounds by Activated Persulfate Using Nanoscale Zerovalent Iron
Industrial & Engineering Chemistry Research, 2013Co-Authors: Mohammed A. Al-shamsi, Neil R. ThomsonAbstract:Recently, Persulfate has caught the attention of groundwater remediation practitioners as a promising oxidant for in situ chemical oxidation. In this study, a method was applied to treat a selection of hazardous organic compounds using nanoscale zerovalent iron (nZVI) particles as activators for Persulfate. The results show that degradation of these organic compounds using nZVI-activated Persulfate is more effective than nZVI alone. For example, the degradation of naphthalene by nZVI-activated Persulfate was >99% compared to
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treatment of organic compounds by activated Persulfate using nanoscale zerovalent iron
Industrial & Engineering Chemistry Research, 2013Co-Authors: Mohammed A Alshamsi, Neil R. ThomsonAbstract:Recently, Persulfate has caught the attention of groundwater remediation practitioners as a promising oxidant for in situ chemical oxidation. In this study, a method was applied to treat a selection of hazardous organic compounds using nanoscale zerovalent iron (nZVI) particles as activators for Persulfate. The results show that degradation of these organic compounds using nZVI-activated Persulfate is more effective than nZVI alone. For example, the degradation of naphthalene by nZVI-activated Persulfate was >99% compared to <10% by nZVI alone. Despite the higher effectiveness, the nZVI particles were passivated quickly following exposure to Persulfate, causing the reaction rate to reduce to a magnitude representative of an unactivated Persulfate system. X-ray photoelectron spectroscopy analyses indicated that an iron sulfate layer was formed on the nZVI particle surfaces following exposure to Persulfate compared to the FeOOH layer that was present on the fresh nZVI surfaces. Although the nZVI particle su...
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Persulfate treatment of gasoline-range organics
IAHS-AISH publication, 2011Co-Authors: Kanwartej S. Sra, Neil R. Thomson, James F. BarkerAbstract:Persulfate is a strong chemical oxidant with a higher oxidation potential on activation to the sulfate free radical and has been shown to be capable of destroying a wide range of organic compounds. The potential for Persulfate to oxidize gasoline compounds was assessed in a series of bench-scale trials. The comprehensive data set assembled demonstrated that Persulfate activated by peroxide or chelated-iron resulted in almost complete oxidation (>99%) of selected gasoline compounds; however, the associated reaction rate coefficients were practically similar to those observed using inactivated Persulfate. Based on the results from this reactivity study, a pilot-scale field trial was conducted to understand the ability of inactivated Persulfate to treat a well characterized gasoline source zone. The performance data collected (organic compounds, sodium, sulfate, carbon dioxide, Persulfate, carbon isotope, pH, and EC) indicated that the source zone strength was significantly reduced following treatment, although partial rebound was evident in the late-time data collected 140 days following treatment.
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Persistence of Persulfate in uncontaminated aquifer materials.
Environmental science & technology, 2010Co-Authors: Kanwartej S. Sra, Neil R. Thomson, James F. BarkerAbstract:Batch and stop-flow column experiments were performed to estimate Persulfate decomposition kinetic parameters in the presence of seven well-characterized aquifer materials. Push-pull tests were conducted in a sandy aquifer to represent Persulfate decomposition under in situ conditions. The decomposition of Persulfate followed a first-order rate law for all aquifer materials investigated. Reaction rate coefficients (k(obs)) increased by an order of magnitude when Persulfate concentration was reduced from 20 g/L to 1 g/L, due to ionic strength effects. The column experiments yielded higher k(obs) than batch experiments due to the lower oxidant to solids mass ratio. The kinetic model developed from the batch test data was able to reproduce the observed Persulfate temporal profiles from the push-pull tests. The estimated k(obs) indicate that unactivated Persulfate is a persistent oxidant for the range of aquifer materials explored with half-lives ranging from 2 to 600 d.
Chenju Liang - One of the best experts on this subject based on the ideXlab platform.
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Treatment of Trichloroethylene by Adsorption and Persulfate Oxidation in Batch Studies
Industrial & Engineering Chemistry Research, 2009Co-Authors: Chenju Liang, Ya-ting Lin, Wu-hang ShihAbstract:For remediation of trichloroethylene (TCE) contaminated groundwater, activated carbon (AC) has been used to adsorb and reduce the TCE concentration and to manage contaminant migration. Additionally, AC may also act as an activator of the electron-transfer mediator in activating Persulfate anion (S2O82−) to generate sulfate radical (SO4−·) for contaminant destruction. The objective of the present research was to examine the combined use of AC and Persulfate to treat TCE. The degradation of Persulfate in the presence of AC follows a first-order kinetic behavior, and the faster Persulfate degradation is observed when elevated AC dosage is used. Higher initial Persulfate concentration results in a decrease of the Persulfate degradation rate. Upon Persulfate oxidation, the AC surface properties are altered including: an increase in acidity of surface concentration, a decrease in pHzpc, and a slight decrease in the surface area. The results of a study of adsorption kinetics and isotherms suggest that the adsorp...
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ph dependence of Persulfate activation by edta fe iii for degradation of trichloroethylene
Journal of Contaminant Hydrology, 2009Co-Authors: Chenju Liang, Chingping Liang, Chichin ChenAbstract:Abstract The ability of free ferrous ion activated Persulfate (S 2 O 8 2− ) to generate sulfate radicals (SO 4 − ) for the oxidation of trichloroethylene (TCE) is limited by the scavenging of SO 4 − with excess Fe 2+ and a quick conversion of Fe 2+ to Fe 3+ . This study investigated the applicability of ethylene-diamine-tetra-acetic acid (EDTA) chelated Fe 3+ in activating Persulfate for the destruction of TCE in aqueous phase under pH 3, 7 and 10. Fe 3+ and EDTA alone did not appreciably degrade Persulfate. The presence of TCE in the EDTA/Fe 3+ activated Persulfate system can induce faster Persulfate and EDTA degradation due to iron recycling to activate Persulfate under a higher pH condition. Increasing the pH leads to increases in pseudo-first-order-rate constants for TCE, S 2 O 8 2− and EDTA degradations, and Cl generation. Accordingly, the experiments at pH 10 with different EDTA/Fe 3+ molar ratios indicated that a 1/1 ratio resulted in a remarkably higher degradation rate at the early stage of reaction as compared to results by other ratios. Higher Persulfate dosage under the EDTA/Fe 3+ molar ratio of 1/1 resulted in greater TCE degradation rates. However, increases in Persulfate concentration may also lead to an increase in the rate of Persulfate consumption.
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pH dependence of Persulfate activation by EDTA/Fe(III) for degradation of trichloroethylene.
Journal of Contaminant Hydrology, 2009Co-Authors: Chenju Liang, Chingping Liang, Chichin ChenAbstract:Abstract The ability of free ferrous ion activated Persulfate (S 2 O 8 2− ) to generate sulfate radicals (SO 4 − ) for the oxidation of trichloroethylene (TCE) is limited by the scavenging of SO 4 − with excess Fe 2+ and a quick conversion of Fe 2+ to Fe 3+ . This study investigated the applicability of ethylene-diamine-tetra-acetic acid (EDTA) chelated Fe 3+ in activating Persulfate for the destruction of TCE in aqueous phase under pH 3, 7 and 10. Fe 3+ and EDTA alone did not appreciably degrade Persulfate. The presence of TCE in the EDTA/Fe 3+ activated Persulfate system can induce faster Persulfate and EDTA degradation due to iron recycling to activate Persulfate under a higher pH condition. Increasing the pH leads to increases in pseudo-first-order-rate constants for TCE, S 2 O 8 2− and EDTA degradations, and Cl generation. Accordingly, the experiments at pH 10 with different EDTA/Fe 3+ molar ratios indicated that a 1/1 ratio resulted in a remarkably higher degradation rate at the early stage of reaction as compared to results by other ratios. Higher Persulfate dosage under the EDTA/Fe 3+ molar ratio of 1/1 resulted in greater TCE degradation rates. However, increases in Persulfate concentration may also lead to an increase in the rate of Persulfate consumption.
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A rapid spectrophotometric determination of Persulfate anion in ISCO
Chemosphere, 2008Co-Authors: Chenju Liang, Chiu-fen Huang, Nihar Mohanty, Rama Mohan KurakalvaAbstract:Due to a gradual increase in the use of Persulfate as an in situ chemical oxidation (ISCO) oxidant, a simple measurement of Persulfate concentration is desirable to analyze Persulfate distribution at designated time intervals on/off a site. Such a distribution helps evaluate efficacy of ISCO treatment at a site. This work proposes a spectrophotometric determination of Persulfate based on modification of the iodometric titration method. The analysis of absorption spectra of a yellow color solution resulting from the reaction of Persulfate and iodide in the presence of sodium bicarbonate reveals an absorbance at 352 nm, without significant interferences from the reagent matrix. The calibration graph was linear in the range of Persulfate solution concentration of 0-70 mM at 352 nm. The proposed method is validated by the iodometric titration method. The solution pH was at near neutral and the presence of iron activator does not interfere with the absorption measurement. Also, analysis of Persulfate in a groundwater sample using the proposed method indicates a good agreement with measurements by the titration method. This proposed spectrophotometric quantification of Persulfate provides a simple and rapid method for evaluation of ISCO effectiveness at a remediation site.
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Trichloroethylene Degradation by Zero Valent Iron Activated Persulfate Oxidation
Environmental Engineering Science, 2008Co-Authors: Chenju Liang, Ming-chun LaiAbstract:The present study describes the use of zero valent iron (Fe0 ) as a source for ferrous ion activated Persulfate (PS) oxidation of trichloroethylene (TCE). The experimental results indicated that in the absence of TCE there was a lag time for Persulfate decomposition when the reaction was activated by Fe0 . An initial pH drop in the Fe0 /PS system to acidic conditions was accompanied by the Persulfate decomposition and a decrease in oxidation-reduction potential (ORP) values. Furthermore, in the TCE/Fe0 /PS system, the rapid TCE degradation was accompanied by the rapid Persulfate decomposition and chloride ion formation as evidence of TCE mineralization. SEM images of Fe0 before and after Persulfate oxidation exhibited significant corrosions of Fe0 . Acicular aggregate formation in the absence of TCE and coarse aggregate formation in the presence of TCE were observed. Moreover, the XRD spectrum revealed the formation of magnetite over the surface of Fe0 after contact with Persulfate. Thus, Fe0 activated pe...
Mohammad Reza Heidari - One of the best experts on this subject based on the ideXlab platform.
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Protocol encompassing ultrasound/Fe3O4 nanoparticles/Persulfate for the removal of tetracycline antibiotics from aqueous environments
Clean Technologies and Environmental Policy, 2019Co-Authors: Mahammad Malakotian, Pouria Karimi, Nima Firouzeh, Seyedeh Nastaran Asadzadeh, Mehrdad Khatami, Mohammad Ahmadian, Mohammad Reza Heidari, Rajender S VarmaAbstract:The presence of residual antibiotics in the environment is one of the major global concerns, and it is imperative to control their discharge in water bodies. The present study used a combination of Fe3O4 nanoparticles/Persulfate in conjunction with ultrasound to address this problem; the influence of effective parameters in the remediation process, Persulfate concentration, nanoparticle concentrations, initial antibiotic concentration, contact time and pH was investigated. The highest removal rate of tetracycline antibiotic was observed at pH 10, the amount of magnetic nanoparticles being (0.3 g/L), with Persulfate concentration at 4 mM for the removal of antibiotic concentration at 10 mg/L; TC and COD removal efficiency is 92.99 and 79.85%, respectively. The deployment of sonocatalytic process, along with the use of magnetite nanoparticles and Persulfates as oxidizing agents, appears to be an effective means for decreasing the high-level tetracycline concentration in water.Graphic abstract
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Protocol encompassing ultrasound/Fe_3O_4 nanoparticles/Persulfate for the removal of tetracycline antibiotics from aqueous environments
Clean Technologies and Environmental Policy, 2019Co-Authors: Mahammad Malakotian, Pouria Karimi, Nima Firouzeh, Seyedeh Nastaran Asadzadeh, Mehrdad Khatami, Mohammad Ahmadian, Mohammad Reza Heidari, Rajender S VarmaAbstract:The presence of residual antibiotics in the environment is one of the major global concerns, and it is imperative to control their discharge in water bodies. The present study used a combination of Fe_3O_4 nanoparticles/Persulfate in conjunction with ultrasound to address this problem; the influence of effective parameters in the remediation process, Persulfate concentration, nanoparticle concentrations, initial antibiotic concentration, contact time and pH was investigated. The highest removal rate of tetracycline antibiotic was observed at pH 10, the amount of magnetic nanoparticles being (0.3 g/L), with Persulfate concentration at 4 mM for the removal of antibiotic concentration at 10 mg/L; TC and COD removal efficiency is 92.99 and 79.85%, respectively. The deployment of sonocatalytic process, along with the use of magnetite nanoparticles and Persulfates as oxidizing agents, appears to be an effective means for decreasing the high-level tetracycline concentration in water. Graphic abstract
