Publications by authors named "Babak Kakavandi"

16 Publications

  • Page 1 of 1

Sono-photocatalytic degradation of tetracycline and pharmaceutical wastewater using WO/CNT heterojunction nanocomposite under US and visible light irradiations: A novel hybrid system.

J Hazard Mater 2020 05 11;390:122050. Epub 2020 Jan 11.

Research Center for Health, Safety and Environment, Alborz University of Medical Sciences, Karaj, Iran; Department of Environmental Health Engineering, Alborz University of Medical Sciences, Karaj, Iran. Electronic address:

In this paper, in-situ fabrication of tungsten oxide (WO) on carbon nano-tube (CNT) was performed via sol-gel/hydrothermal method to prepare WO/CNT nanocomposites and then coupled with visible light and ultrasound (US) irradiations for sono-photocatalytic removal of tetracycline (TTC) and pharmaceutical wastewater treatment. The as-prepared catalysts were characterized by FT-IR, XRD, TEM, UV-VIS DRS, FESEM, EDS, TGA, BET, BJH, EIS, and EDX techniques. The characterization tests, indicated successful incorporation of CTNs into the WO framework and efficient reduction of charge carries recombination rate after modifying with CNT. The investigation of experimental parameters verified that 60 mg/L TTC could be perfectly degraded at optimum operational parameters (WO/CNT: 0.7 g/L, pH: 9.0, US power: 250 W/m, and light intensity: 120 W/m over 60 min treatment. Trapping experiments results verified that HO radicals and h were the main oxidative species in degradation of TTC. The as-prepared photocatalysts could be reused after six successive cycles with an approximately 8.8 % reduction in removal efficiency. Investigation of the effect of real pharmaceutical wastewater revealed that this system is able to eliminate 83.7 and 90.6 % of TOC and COD, respectively after 220 min of reaction time. Some compounds with lower toxic impact and molecular weight, compared to raw pharmaceutical wastewater, were detected after treatment by sono-photocatalysis process. The biodegradability of real pharmaceutical wastewater was improved significantly after treatment by WO/CNT sono-photocatalysis.
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http://dx.doi.org/10.1016/j.jhazmat.2020.122050DOI Listing
May 2020

Efficient clean-up of waters contaminated with diazinon pesticide using photo-decomposition of peroxymonosulfate by ZnO decorated on a magnetic core/shell structure.

J Environ Manage 2019 Nov 11;250:109472. Epub 2019 Sep 11.

College of Science and Engineering, Flinders University, Adelaide, Australia.

In the present study, ZnO nanoparticles were anchored on a magnetic core/shell structure (SiO@FeO) to perpetrate ZnO@SiO@FeO and then coupled with UV light as a heterogeneous nanocatalyst for activating peroxymonosulfate (PMS) into diazinon (DZ) degradation. Several techniques like XRD (X-ray diffraction), BET (Brunaeur, Emmett and Teller), TEM (Transmission electron microscope), FESEM (Field emission-scanning electron microscope) coupled with EDS (Energy Dispersive X-ray Spectrometer), PL (photoluminescence), VSM (Vibrating Sample Magnetometer) and UV-vis diffuse reflectance spectroscopy (DRS) were applied for identification of catalyst features. A possible mechanism for PMS activation and DZ degradation was proposed in details. The effect of solution pH, various concentrations of catalyst, PMS and DZ, quenching agents, different chemical oxidants and co-existing anions was assessed as operating factors to determine the optimum conditions. PMS decomposed effectively in coupling with ZnO@SiO@FeO and UV. At optimal conditions, over 95 and 56% of DZ and TOC were removed during 60 min reaction, respectively. The complete degradation of DZ was confirmed using its absorption peak in UV-vis spectra analysis over 60 min treatment. A wide variety of free radicals was identified during quenching tests. HO and h played a pivotal role in the degradation process of DZ. Decreasing the degradation efficiency in the presence of anions was as Cl > CO > NO > PO > SO > HCO. A negligible amount of leaching Fe (<0.2 mg/L) was found for ZnO@SiO@FeO, indicating that the catalyst possesses a high stability in oxidation systems. In addition, a significant potential was achieved in reusing of catalyst within five consecutive runs. In conclusion, ZnO@SiO@FeO/PMS/UV hybrid system can be utilized as a promising advanced oxidation process into efficient degradation of pesticides, thanks to easy recovery, high catalytic activity, co-production of different reactive species and high durability and recyclability potential.
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http://dx.doi.org/10.1016/j.jenvman.2019.109472DOI Listing
November 2019

Photo-assisted catalytic degradation of acetaminophen using peroxymonosulfate decomposed by magnetic carbon heterojunction catalyst.

Chemosphere 2019 Oct 16;232:140-151. Epub 2019 May 16.

Research Center for Environmental Determinants of Health, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran.

Catalytic oxidative degradation of acetaminophen (ACT) was evaluated using magnetic mesoporous carbon (MNPs@C) coupled with UV light and peroxymonosulfate (PMS). The performance of hybrid system (i.e., MNPs@C/UV/PMS) was assessed as a function of some operational factors (e.g., reaction time and different concentrations of catalyst, PMS and ACT) in a batch system. MNPs@C represented a high magnetic response and was easily recovered from aqueous solution via an external magnet. A significant synergistic effect was observed among the applied techniques in MNPs@C/UV/PMS system for ACT degradation. After 40 min reaction, the removal efficiencies of 97.4 and 63.5% were obtained for ACT and TOC, respectively. Both adsorption and oxidation mechanisms were responsible simultaneously for ACT removal in MNPs@C/UV/PMS system. Under optimum conditions, the removal rates of ACT and TOC were reduced slightly to 91.7 and 49.4% after five consecutive catalyst uses, which indicates the excellent reusing potential of MNPs@C. In addition, a high stability was detected for as-prepared catalyst during recycling tests, since the quantity of leached Fe was <0.2 mg/L. Methanol and tert-butyl alcohol showed a strong quenching effect on the performance of MNPs@C/UV/PMS system, demonstrating the dominant role of SO and HO radicals in ACT degradation process. MNPs@C in comparison with ferrous ions, as a homogeneous catalyst, showed a better performance in the activation of PMS and ACT degradation. Integration of MNPs@C, UV and PMS exhibited an excellent performance into ACT removal over 40 min reaction, which can be utilized as an effective and promising technique for the efficient decontamination of polluted waters.
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http://dx.doi.org/10.1016/j.chemosphere.2019.05.070DOI Listing
October 2019

Efficient treatment of saline recalcitrant petrochemical wastewater using heterogeneous UV-assisted sono-Fenton process.

Ultrason Sonochem 2019 Sep 14;56:25-36. Epub 2019 Mar 14.

Environmental Technologies Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Department of Environmental Health Engineering, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. Electronic address:

An effective hybrid system was applied as a first report for successful treatment of recalcitrant petrochemical wastewater (PCW). In this regards, magnetic powdered activated carbon (MPAC), as a heterogeneous catalyst, was coupled with ultrasound (US) and UV irradiations for activation of HO (marked as MPAC/US/UV/HO). Chemical oxygen demand (COD) removal ratio was evaluated with various influencing operating factors including solution pH, MPAC and HO concentrations, US power and quenchers. A possible mechanism for catalytic degradation and generation of reactive species was proposed. To evaluate the biodegradability of both raw and treated PCWs, the activated sludge inhibition experiments were performed based on Zahn-Wellens test. MPAC indicated high catalytic activity, reusability and stability in the studied system. Over 87% of COD was removed under optimum conditions within 80 min treatment and the residual COD concentration reached 82.9 mg/L, which was permissible to discharge surface water sources based on the environmental standards. Leaching of transition metals from catalyst textural was negligible. Compared to homogeneous system (Fe/US/UV/HO), heterogeneous system (MPAC/US/UV/HO) represented a better performance in COD removal. Identification of intermediates by GC-MS showed that a wide range of recalcitrant compounds was removed and/or degraded into small molecular compounds effectively after treatment. A biodegradability ratio of 64% and the residual COD of 28 mg/L for treated PCW, indicating that the biodegradability was improved and refractory organic matters removed effectively. As conclusion, MPAC/US/UV/HO hybrid system can be introduced as a successful advanced treatment process for efficient remediation of refractory PCWs.
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http://dx.doi.org/10.1016/j.ultsonch.2019.03.005DOI Listing
September 2019

Enhanced sono-photocatalysis of tetracycline antibiotic using TiO decorated on magnetic activated carbon (MAC@T) coupled with US and UV: A new hybrid system.

Ultrason Sonochem 2019 Jul 7;55:75-85. Epub 2019 Mar 7.

Research Center for Health, Safety and Environment, Alborz University of Medical Sciences, Karaj, Iran; Department of Environmental Health Engineering, Alborz University of Medical Sciences, Karaj, Iran.

A combined system including sonocatalysis and photocatalysis was applied for catalytic degradation of tetracycline (TC) antibiotic using TiO decorated on magnetic activated carbon (MAC@T) in coupling with ultraviolet (UV) and ultrasound (US) irradiations. MAC was fabricated via magnetization of AC using FeO nanoparticles. FESEM, EDS, TEM, BET, XRD, PL, VSM and UV-visible DRS techniques were used to characterize the catalyst features. The performance of MAC@T/UV/US system was examined under impact of different input variable such as catalyst loading, solution pH, initial TC concentration, US power, scavenging agents, chemical oxidants and co-exiting anions. The degradation rate was enhanced substantially when MAC@T coupled with US and UV irradiations. At optimal conditions, over 93% TC and 50% TOC were removed under 180 min reaction. Whereas, the complete removal of TC was obtained after 60 min treatment, when MAC@T/UV/US coupled with oxidants. Decreasing sequence of the inhibitory effect of anions was chloride > bicarbonate > phosphate > nitrate > sulfate. Both Fe leaching and loss of the decontamination were slight with reused times, indicating MAC@T has a high stability and reusability. According to trapping tests, holes, OH and O were contributed in the degradation process. In conclusion, integration of MAC@T composite and US/UV for enhancing catalytic degradation efficiency can be introduced as a successful and promising technique, owing to excellent catalytic activity, easy recovery, good adsorption capacity and high durability and recycling potential.
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http://dx.doi.org/10.1016/j.ultsonch.2019.02.026DOI Listing
July 2019

Estimation of Short-term Mortality and Morbidity Attributed to Fine Particulate Matter in the Ambient Air of Eight Iranian Cities.

Ann Glob Health 2018 08 31;84(3):408-418. Epub 2018 Aug 31.

Abadan School of Medical Sciences, Abadan, IR.

Amongst the various pollutants in the air, particulate matters (PM) have significant adverse effects on human health. The current research is based on existing epidemiological literature for quantitative estimation of the current health impacts related to particulate matters in some selected principal Iranian megacities. In order to find the influence of air pollution on human health, we used the AirQ software tool presented by the World Health Organization (WHO) European Centre for Environment and Health (ECEH), Bilthoven Division. The adverse health outcomes used in the study consist of mortality (all causes excluding accidental causes), due to cardiovascular (CVD) and respiratory (RES) diseases, and morbidity (hospital admissions for CVD and RES causes). For this purpose, hourly PM10 data were taken from the monitoring stations in eight study cities during 2011 and 2012. Results showed annual average concentrations of PM10 and PM2.5 in all megacities exceeded national and international air quality standards and even reached levels nearly ten times higher than WHO guidelines in some cities. Considering the short-term effects, PM2.5 had the maximum effects on the health of the 19,048,000 residents of the eight Iranian cities, causing total mortality of 5,670 out of 87,907 during a one-year time-period. Hence, reducing concentrations and controlling air pollution, particularly the presence of particles, is urgent in these metropolises.
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http://dx.doi.org/10.29024/aogh.2308DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6748288PMC
August 2018

Removal of vanadium and palladium ions by adsorption onto magnetic chitosan nanoparticles.

Environ Sci Pollut Res Int 2018 Dec 6;25(34):34262-34276. Epub 2018 Oct 6.

Environmental Technologies Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.

Chitosan (CS), synthesized from chitin chemically extracted from shrimp shells, was used for the synthesis of magnetic chitosan nanoparticles (FeO-CSN), which makes the adsorbent easier to separate. FeO-CSN was used for the removal of toxic metals such as vanadium (V(V)) and palladium (Pd(II)) ions from aqueous solutions. Influencing factors on the adsorption process such as pH, contact time, adsorbent dosage, and agitation speed were investigated. A competitive adsorption of V(V) and Pd(II) ions for the active sites was also studied. The monolayer maximum adsorption capacities (Q) of 186.6 and 192.3 mg/g were obtained for V(V) and Pd(II) ions, respectively. The pseudo-second-order equation gave the best fit for the kinetic data, implying that chemisorption was the determining step. Freundlich model yielded a much better fit than the other adsorption models assessed (Langmuir, Temkin and Dubinin-Radushkevich). Thus, the adsorption of V(V) and Pd(II) ions onto FeO-CSN is a combination of physical and chemical adsorption, as based on the kinetics and equilibrium study. Generally, physical adsorption is the mechanism that governs the system, while chemical adsorption is the slowest adsorption step that takes place. Thermodynamic studies displayed that the adsorption process was exothermic and spontaneous. Removal efficiencies of 99.9% for V(V) and 92.3% for Pd(II) ions were achieved, implying that FeO-CSN adsorbent had an excellent ability for the removal of the metal ions from real industrial wastewaters without remarkable matrix effect. Graphical abstract ᅟ.
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http://dx.doi.org/10.1007/s11356-018-3137-1DOI Listing
December 2018

Photocatalytic activation of peroxymonosulfate by TiO anchored on cupper ferrite (TiO@CuFeO) into 2,4-D degradation: Process feasibility, mechanism and pathway.

J Hazard Mater 2018 10 8;359:325-337. Epub 2018 Jul 8.

Department of Environmental Health Engineering, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.

A thorough study of photo-oxidation efficiency of TiO@CuFeO dissociating peroxymonosulfate (PMS) is reported in detail. The origin of high catalytic activity was discussed as evidence by numerous controlled trials and several operational parameters. Based on quenching tests, possible mechanism and pathway of degradation were proposed. 2,4-dichlorophenoxyacetic acid (2,4-D) degradation in TiO@CuFeO/UV/PMS system could abide pseudo-first-order kinetics. Moreover, reaction rate constant (K) showed a linear increasing trend as PMS and catalyst concentrations increased. Over 97.2% of 2,4-D (20 mg/L) was degraded within 60 min at 0.3 mM PMS and 0.1 g/L TiO@CuFeO. However, the water matrix species inhibited 2,4-D degradation to different amounts and the inhibiting effect was as follows: HCO- > NO-  > Cl- > SO. As-prepared catalyst showed a high ability of PMS activation, compared to other studied oxidants. Particularly, sulfate radicals were accounted for 2,4-D degradation in the catalytic oxidation reaction. TiO@CuFeO catalyst displayed the excellent recyclability and durability. Identification of intermediates and end-products brought about the conclusion that enhanced degradation involving dechlorination, dehydrogenation, hydroxylation, and ring cleavage, through SO, OH, O and holes attack during TiO@CuFeO/PMS photocatalysis of 2,4-D. As conclusion, integration of TiO, CuFeO and UV light to efficient activation of PMS can be proposed as a successful and promising method to wastewater treatment effectively, because of the cogeneration of different reactive oxidizing species, simple and easy recovery of catalyst and good catalytic activity.
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http://dx.doi.org/10.1016/j.jhazmat.2018.06.069DOI Listing
October 2018

Modeling and optimization of nonylphenol removal from contaminated water media using a magnetic recoverable composite by artificial neural networks.

Water Sci Technol 2017 Apr;75(7-8):1761-1775

Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.

Herein, activated carbon impregnated iron oxide nanoparticles (FeO/AC) were synthesized to determine their potentials for the adsorption of nonylphenol (NP) in aqueous solution with different experimental variables, namely the pH of the solution, contact time, adsorbent dosage and the initial NP concentration. Additionally, an artificial neural network system was used to find the relative importance of each of the aforementioned input variables on NP adsorption efficiency. Experimental findings indicated that the optimum solution pH for NP adsorption was 3.0. The equilibrium time of the adsorption process was 30 min. According to the results of isotherm and kinetic studies, among all applied models, the Liu and pseudo-first-order models showed the best fit with the experimental data. The pH of the solution, compared to other input variables, had the maximum impacts on NP adsorption efficiency. Under optimum conditions, the adsorption percentage decreased insignificantly from 99.6 to 92.6% after the fifth cycle. Also, the adsorption efficiencies of 70.7, 73.5 and 67.3% were observed for river water, tap water and wastewater effluent, respectively. Ultimately, from the findings of this study, it can be postulated that FeO/AC nanoparticles can be recommended as a promising and novel adsorbent to remove NP from polluted groundwater.
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http://dx.doi.org/10.2166/wst.2016.523DOI Listing
April 2017

A systematic review on the efficiency of cerium-impregnated activated carbons for the removal of gas-phase, elemental mercury from flue gas.

Environ Sci Pollut Res Int 2017 May 21;24(13):12092-12103. Epub 2017 Mar 21.

Center for Water Quality Research (CWQR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.

In the present systematic review, we aimed to collect and analyze all the relevant evidence on the efficiency of cerium-impregnated versus virgin-activated carbons (ACs) for the removal of gas-phase elemental mercury (Hg) from the flue gas of coal-fired power plants and to assess the effect of different calcination and operational parameters on their efficiency. A total of eight relevant papers (out of 1193 hits produced by the search) met the eligibility criteria and were included in the study. Results indicated that the Hg adsorption capacity of cerium-impregnated ACs is significantly higher than that of virgin ACs, depending highly on the impregnation and operational parameters. It was noticed that although cerium-impregnated ACs possessed smaller surface areas and pore volumes, their Hg removal efficiencies were still higher than their virgin counterparts. An increased Hg removal efficiency was in general found by increasing the operational adsorption temperature as high as 150-170 °C. Studies also indicated that NO, SO, and HCl have promoting impacts on the Hg removal efficiency of Ce-impregnated ACs, while HO has an inhibitory effect.
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http://dx.doi.org/10.1007/s11356-017-8559-7DOI Listing
May 2017

Performance, kinetic, and biodegradation pathway evaluation of anaerobic fixed film fixed bed reactor in removing phthalic acid esters from wastewater.

Sci Rep 2017 02 20;7:41020. Epub 2017 Feb 20.

Department of Environmental Health Engineering, Faculty of Health, Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran.

Emerging and hazardous environmental pollutants like phthalic acid esters (PAEs) are one of the recent concerns worldwide. PAEs are considered to have diverse endocrine disrupting effects on human health. Industrial wastewater has been reported as an important environment with high concentrations of PAEs. In the present study, four short-chain PAEs including diallyl phthalate (DAP), diethyl phthalate (DEP), dimethyl phthalate (DMP), and phthalic acid (PA) were selected as a substrate for anaerobic fixed film fixed bed reactor (AnFFFBR). The process performances of AnFFFBR, and also its kinetic behavior, were evaluated to find the best eco-friendly phthalate from the biodegradability point of view. According to the results and kinetic coefficients, removing and mineralizing of DMP occurred at a higher rate than other phthalates. In optimum conditions 92.5, 84.41, and 80.39% of DMP, COD, and TOC were removed. DAP was found as the most bio-refractory phthalate. The second-order (Grau) model was selected as the best model for describing phthalates removal.
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http://dx.doi.org/10.1038/srep41020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5316953PMC
February 2017

Silica-coated magnetite nanoparticles core-shell spheres (FeO@SiO) for natural organic matter removal.

J Environ Health Sci Eng 2016 25;14:21. Epub 2016 Nov 25.

Research Center for Environmental Health Technology (RCEHT), Iran University of Medical Sciences, Tehran, Iran ; Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.

Background: In this work, the magnetite (FeO) nanoparticles (MNPs) and silica-coated magnetite nanoparticles (SMNPs) were synthesized as adsorbents for removing humic acid (HA) from water resources.

Methods: The adsorption processes were performed in batch experiments with which the influence of pH, reaction time, adsorbent dosage, initial concentrations of HA and temperature were investigated. Specific techniques were applied to characterize the features of both adsorbents (i. e. TECHNIQUES) (SEM, XRD, TEM, BET, EDX and VSM).

Results: The maximum saturation magnetization for SMNPs was 30.2 emu/g, which made its separation from the solution by a magnetic field to be easier and faster. The HA adsorption process onto the both adsorbents were best described by the Freundlich isotherm and pseudo-second-order kinetic models. Highest adsorption efficiency of HA by MNPs an d SMNPs occurred at acidic conditions (pH ≈ 3). The mechanisms of adsorption process involved with a physisorption process such as (i. e. hydrogen bonding and electrostatic interaction). The predicted maximum monolayer adsorption capacities obtained by Langmuir isotherm model for MNPs and SMNPs were 96.15 and 196.07 mg/g, respectively.

Conclusion: Higher amount of HA adsorption onto the surfaces of SMNPs than MNPs surfaces was observed, reflecting that silica impregnated on MNPs enhances the efficiency of the adsorbent in removing HA.
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http://dx.doi.org/10.1186/s40201-016-0262-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5123275PMC
November 2016

Enhanced removal of nitrate from water using nZVI@MWCNTs composite: synthesis, kinetics and mechanism of reduction.

Water Sci Technol 2015 ;72(11):1988-99

Department of Environmental Health Engineering, School of Public Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran E-mail:

Herein, multi-wall carbon nanotubes (MWCNTs) were used as the carrier of nano-zero valent iron (nZVI) particles to fabricate a composite known as nZVI@MWCNTs. The composite was then characterized and applied in the nitrate removal process in a batch system under anoxic conditions. The influential parameters such as pH, various concentrations of nitrate and composite were investigated within 240 min of the reaction. The mechanism, kinetics and end-products of nitrate reduction were also evaluated. Results revealed that the removal nitrate percentage for nZVI@MWCNTs composite was higher than that of nZVI and MWCNTs alone. Experimental data from nitrate reduction were fitted to the Langmuir-Hinshelwood kinetic model. The values of observed rate constant (kobs) decreased with increasing the initial concentration of nitrate. Our experiments proved that the nitrate removal efficiency was favorable once both high amounts of nZVI@MWCNTs and low concentrations of nitrate were applied. The predominant end-products of the nitrate reduction were ammonium (84%) and nitrogen gas (15%). Our findings also revealed that ZVI@MWCNTs is potentially a good composite for removal/reduction of nitrate from aqueous solutions.
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http://dx.doi.org/10.2166/wst.2015.417DOI Listing
February 2016

Enhanced chromium (VI) removal using activated carbon modified by zero valent iron and silver bimetallic nanoparticles.

J Environ Health Sci Eng 2014 21;12(1):115. Epub 2014 Aug 21.

Department of Environmental Health Engineering, School of Public Health, Shahrood University of Medical Sciences, Semnan, Iran.

Recently, adsorption process has been introduced as a favorable and effective technique for the removal of metal ions from aqueous solutions. In the present study, bimetallic nanoparticles consisting of zero valent iron and silver were loaded on the activated carbon powder for the preparation of a new adsorbent (PAC-Fe(o)/Ag). The above adsorbent was characterized by using XRD, SEM and TEM techniqes. Experimental data were exploited for kinetic, equilibrium and thermodynamic evaluations related to the adsorption processes. The Cr(VI) adsorption process was found to be favorable at pH 3 and it reached equilibrium state within 60 min. The stirring rate did not have a significant effect on the adsorption efficiency. Furthermore, the monolayer adsorption capacity of Cr(VI) based on the Langmuir model was measured to be 100 mg/g. The experimental equilibrium data were fitted to the Freundlich adsorption and pseudo second-order models. According to the thermodynamic study, the adsorption process was spontaneous and endothermic in nature, indicating the adsorption capacity increases with increasing the temperature. The results also revealed that the synthesized composite can be potentially applied as a magnetic adsorbent to remove Cr(VI) contaminants from aqueous solutions.
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http://dx.doi.org/10.1186/s40201-014-0115-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4147180PMC
September 2014

Magnetic Fe3O4@C nanoparticles as adsorbents for removal of amoxicillin from aqueous solution.

Water Sci Technol 2014 ;69(1):147-55

Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran E-mail: Center for Water Quality Research (CWQR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.

In the present study, powder activated carbon (PAC) combined with Fe(3)O(4) magnetite nanoparticles (MNPs) were used for the preparation of magnetic composites (MNPs-PAC), which was used as an adsorbent for amoxicillin (AMX) removal. The properties of magnetic activated carbon were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Brunaeur, Emmett and Teller and vibrating sample magnetometer. The operational factors affecting adsorption such as pH, contact time, adsorbent dosage, initial AMX concentration and temperature were studied in detail. The high surface area and saturation magnetization for the synthesized adsorbent were found to be 671.2 m(2)/g and 6.94 emu/g, respectively. The equilibrium time of the adsorption process was 90 min. Studies of adsorption equilibrium and kinetic models revealed that the adsorption of AMX onto MNPs-PAC followed Freundlich and Langmuir isotherms and pseudo-second-order kinetic models. The calculated values of the thermodynamic parameters, such as ΔG°, ΔH° and ΔS° demonstrated that the AMX adsorption was endothermic and spontaneous in nature. It could be concluded that MNPs-PAC have a great potential for antibiotic removal from aquatic media.
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http://dx.doi.org/10.2166/wst.2013.568DOI Listing
April 2014

Synthesis and properties of Fe3O4-activated carbon magnetic nanoparticles for removal of aniline from aqueous solution: equilibrium, kinetic and thermodynamic studies.

Iranian J Environ Health Sci Eng 2013 17;10(1):19. Epub 2013 Feb 17.

Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.

In this study, powder activated carbon (PAC) and magnetic nanoparticles of iron (III) oxide were used for synthesis of Fe3O4-activated carbon magnetic nanoparticles (AC-Fe3O4 MNPs) as an adsorbent for the removal of aniline. The characteristics of adsorbent were evaluated by SEM, TEM, XRD and BET. Also, the impact of different parameters such as pH, contact time, adsorbent dosage, aniline initials concentration and solution temperature were studied. The experimental data investigated by Langmuir and Freundlich adsorption isotherms and two models kinetically of pseudo first-order and pseudo second-order. The results indicated that the adsorption followed Langmuir and pseudo second-order models with correlation r(2) > 0.98 and r(2) > 0.99, respectively. The equilibrium time was obtained after 5 h. According to Langmuir model, the maximum adsorption capacity was 90.91 mg/g at pH = 6, and 20°C. The thermodynamic parameters indicated that adsorption of aniline on magnetic activated carbon was exothermic and spontaneous. This synthesized AC-Fe3O4 MNPs due to have advantages such as easy and rapid separation from solution could be applied as an adsorbent effective for removal of pollutants such as aniline from water and wastewater.
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http://dx.doi.org/10.1186/1735-2746-10-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3606349PMC
October 2015