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Maria K Doula - One of the best experts on this subject based on the ideXlab platform.
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simultaneous removal of cu mn and zn from drinking water with the use of Clinoptilolite and its fe modified form
Water Research, 2009Co-Authors: Maria K DoulaAbstract:Zeolites have been widely used in water treatment and especially Clinoptilolite, due to its low cost and high abundance. It has large cation-exchange capacity and is capable of removing large quantities of heavy metals from contaminated water samples. By loading the surface of Clinoptilolite with amorphous Fe-oxide species, a total improvement in adsorption capacity could be achieved. Thus, the Clin-Fe oxide system is capable of adsorbing significantly higher heavy metal concentrations than untreated Clinoptilolite with simultaneous noticeable decrease in water hardness. Batch adsorption experiments have shown that Clin-Fe system has very large Cu, Zn and Mn adsorption capacity and for most of the cases the treated water samples were suitable for human consumption or agricultural use. New experiments were conducted to study the effectiveness of Clinoptilolite and of the Clin-Fe system in removal of Cu, Mn, Zn, present simultaneously in water samples, so that the study of metal-sorbent chemical behavior and of the adsorption selectivity would be feasible. Desorption of metals was also examined and an integrated approach of the effectiveness of such materials in drinking water treatment is presented.
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use of Clinoptilolite and an fe overexchanged Clinoptilolite in zn2 and mn2 removal from drinking water
Desalination, 2008Co-Authors: A Dimirkou, Maria K DoulaAbstract:Abstract Clinoptilolite, a natural zeolite, was used for the synthesis of a high surface area Clinoptilolite-iron oxide system (Clin–Fe system) to be used for the removal of Mn 2+ and Zn 2+ ions from drinking water samples. The new system was obtained by adding natural Clinoptilolite to an iron nitrate solution in the presence of KOH solution. The Clin–Fe system had a specific surface area equal to 151 m 2 /g and was fully iron exchanged (Fe/Al = 1.23). Batch adsorption experiments were carried out to determine the effectiveness of the Clin and of the Clin–Fe system in the removal of zinc and manganese from drinking water. For our experimental conditions, the maximum adsorbed Mn amount for Clin was 7.69 mg/g, whereas that for the Clin–Fe system was 27.1 mg/g. The respective values for the adsorption of Zn were 71.3 mg/g and 94.8 mg/g. In addition, the release of counterbalanced ions (i.e. Ca 2+ , Mg 2+ , Na + and K + ) was examined, as well as the dissolution of framework Si and Al. Desorption experiments were also carried out to determine which of the substrates is more effective in holding the adsorbed metals on its surface sites.
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synthesis of a Clinoptilolite fe system with high cu sorption capacity
Chemosphere, 2007Co-Authors: Maria K DoulaAbstract:Abstract An iron oxide–Clinoptilolite system was synthesized by adding natural Clinoptilolite in an iron nitrate solution under strongly basic condition. The newly synthesized material has a red–brown color. A combination of XRD, FTIR and EPR spectroscopies, as well as specific surface area measurements and TG/DSC thermal analyses provided information on the type of Fe species located on the zeolite surface. Clinoptilolite seems to maintain its structure, while Fe 3+ species are in a symmetric environment (Th or Oh). The new material has a noteworthy high value of specific surface area (151 m 2 g −1 ) and is fully iron exchanged (Fe/Al = 1.23). Differences in FTIR and TG/DSC spectrograms between the Fe–Clin system and untreated Clin were reported and explained. According to Cu adsorption/desorption experiments, carried out after the synthesis and characterization procedures, the Fe–Clin system is a promising new material since it adsorbs significantly larger Cu concentrations than Clinoptilolite. This fact is owed to its high specific surface area and to its high negative surface charge. Desorption of Cu was also examined and it was observed that the Fe–Clin system desorbs smaller Cu amounts than untreated Clinoptilolite.
Myroslav Sprynskyy - One of the best experts on this subject based on the ideXlab platform.
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Clinoptilolite in study of lindane and aldrin sorption processes from water solution
Journal of Hazardous Materials, 2008Co-Authors: Myroslav Sprynskyy, Tomasz Ligor, Boguslaw BuszewskiAbstract:Abstract The scope of this study was adsorption of lindane and aldrin from water solution onto Clinoptilolite rock with the following desorption using n -hexane. Both kinetic and equilibrium tests were conducted. During kinetic experiment the most part of aldrin and a half part of lindane were sorbed during the first hours. The sorption equilibria with removal of 95% of aldrin amount and about 68% of lindane amount have been set in for 48 h. The pseudo-second-order kinetics model gives somewhat better fit to the both pesticides’ sorption data that may testify to the complicated and heterogeneous nature of interaction between active zeolite surface and the pesticides polar-dipole centers. OH − -groups and the coordinated exchangeable cations are probably the main active positions for the pesticide sorption on the Clinoptilolite surface. Equilibrium experiment results show that adsorption isotherms for the low concentrations of lindane and aldrin (10–200 and 3–100 μg/L, respectively) fit well to the Freundlich and the Liner models. Only 10% of lindane sorbed and about 60% of aldrin sorbed were desorbed from the Clinoptilolite using n -hexane under static conditions.
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study of the selection mechanism of heavy metal pb2 cu2 ni2 and cd2 adsorption on Clinoptilolite
Journal of Colloid and Interface Science, 2006Co-Authors: Myroslav Sprynskyy, Artur P. Terzyk, Boguslaw Buszewski, Jacek NamieśnikAbstract:Abstract The study was carried out on the sorption of heavy metals (Ni2+, Cu2+, Pb2+, and Cd2+) under static conditions from single- and multicomponent aqueous solutions by raw and pretreated Clinoptilolite. The sorption has an ion-exchange nature and consists of three stages, i.e., the adsorption on the surface of microcrystals, the inversion stage, and the moderate adsorption in the interior of the microcrystal. The finer Clinoptilolite fractions sorb higher amounts of the metals due to relative enriching by the zeolite proper and higher cleavage. The slight difference between adsorption capacity of the Clinoptilolite toward lead, copper, and cadmium from single- and multicomponent solutions may testify to individual sorption centers of the zeolite for each metal. The decrease of nickel adsorption from multicomponent solutions is probably caused by the propinquity of its sorption forms to the other metals and by competition. The maximum sorption capacity toward Cd2+ is determined as 4.22 mg/g at an initial concentration of 80 mg/L and toward Pb2+, Cu2+, and Ni2+ as 27.7, 25.76, and 13.03 mg/g at 800 mg/L. The sorption results fit well to the Langmuir and the Freundlich models. The second one is better for adsorption modeling at high metal concentrations.
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ammonium sorption from aqueous solutions by the natural zeolite transcarpathian Clinoptilolite studied under dynamic conditions
Journal of Colloid and Interface Science, 2005Co-Authors: Myroslav Sprynskyy, Artur P. Terzyk, Jacek Namieśnik, Mariya Lebedynets, Pio Kowalczyk, Oguslaw UszewskiAbstract:The scope of this study is ammonium-ion uptake from synthetic aqueous solutions onto raw and pretreated forms of the natural zeolite Transcarpathian Clinoptilolite under dynamic conditions. Hydrogen ions displaced exchangeable cations on the Clinoptilolite in distilled water (sodium ions) and hydrochloric acid (sodium, potassium, and calcium ions) and destroyed the zeolite framework structure in the last case. Ammonium uptake onto the zeolite occurs by exchange with Na(+), Ca(2+), and K(+) ions. Although Na(+) ions were observed to be more easily exchanged for both hydrogen and ammonium ions, the role of Ca(2+) ions increased with zeolite saturation by NH(+)(4) ions. The maximum sorption capacity of the Clinoptilolite toward NH(+)(4) ions, estimated under dynamic conditions, is significantly higher than that measured under static conditions; proximity of the values of a distribution coefficient and a retardation factor for different conditions (215-265 dm(3)/kg and 979-1107, respectively) allows us to use these parameters to model ammonium uptake onto the Clinoptilolite. Slowing down or interruption in filtration resulted in the improvement of ammonium sorption properties of the zeolite. The ammonium removal improves with use of the finer fractions of the Clinoptilolite up to 0.35 mm. A recycling study results confirmed the importance of external diffusion for ammonium sorption by the Clinoptilolite. Preliminary treatment of the sorbent confirmed the predominant importance of the ion-exchange mechanism. The advantage of prior NaCl treatment of the Clinoptilolite in improvement of ammonium removal over the other techniques was shown.
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adsorption of ammonium ions onto a natural zeolite transcarpathian Clinoptilolite
Adsorption Science & Technology, 2004Co-Authors: Mariya Lebedynets, Myroslav Sprynskyy, Iryna Sakhnyuk, Radoslaw Zbytniewski, Roma Golembiewski, Oguslaw UszewskiAbstract:A study was carried out of ammonium ion sorption from synthetic aqueous solutions by Transcarpathian Clinoptilolite, a natural zeolite, under static conditions. The main physical properties of the Clinoptilolite and the basic parameters of its porous structure were determined. Values of the specific surface area and of the pore volume occupied by sorbed substances were calculated using the relative moisture content established and the maximum sorption capacity exhibited towards ammonium ions as well as a nitrogen adsorption/desorption method. Ammonium ion sorption by the zeolite appeared to be complete within 24 h for all fraction sizes, initial NH4+ ion concentration and adsorbate volumes. The amounts of NH4+ ions sorbed increased with increasing initial NH4+ concentration and decreasing adsorbate volumes, with the maximum sorption capacity exhibited by the Clinoptilolite being 0.64 mequiv/g. The sorption effectiveness decreased somewhat with increasing fraction size. The Langmuir and Freundlich models w...
Alireza Nezamzadehejhieh - One of the best experts on this subject based on the ideXlab platform.
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investigation of photocatalytic effect of zno sno2 nano Clinoptilolite system in the photodegradation of aqueous mixture of 4 methylbenzoic acid 2 chloro 5 nitrobenzoic acid
Journal of Molecular Catalysis A-chemical, 2015Co-Authors: Zahra Khodami, Alireza NezamzadehejhiehAbstract:Abstract The photocatalytic degradation of 4-methylbenzoic acid (MBA) and 2-chloro-5-nitro benzoic acid (CNBA) as aqueous solution mixture was studied using ZnO–SnO 2 /nano-Clinoptilolite under UV irradiation. The Clinoptilolite nano-particles (CNP) were obtained via ball-mill method and ion exchanged in Zn 2+ –Sn 4+ aqueous solutions with different concentrations. The ion exchanged samples (Zn(II)–Sn(IV)/CNP) were calcined at 450 °C for 12 h to obtain ZnO–SnO 2 /CNP catalysts. XRD, DRS, FT-IR and TEM techniques were applied for characterization of samples. The experimental parameters which influenced degradation process were optimized and the optimum values were obtained as: 1 g L −1 of the photocatalyst, pH 5 and 5 mg L −1 of MBA and CNBA in the mixture. The degradation/ mineralization extents were confirmed by COD and HPLC.
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enhancement of the photocatalytic activity of ferrous oxide by doping onto the nano Clinoptilolite particles towards photodegradation of tetracycline
Chemosphere, 2014Co-Authors: Alireza Nezamzadehejhieh, Arezoo ShirzadiAbstract:Abstract Photodegradation of tetracycline (TC) aqueous solution by FeO doped onto nano-Clinoptilolite particles was investigated using a high pressure Hg lamp as radiation source. Nano-particles of Clinoptilolite were prepared using ball-milling of micro crystals of zeolite. The pretreated nano-particles ion exchanged in a ferrous solution and the Fe(II)-exchanged form was calcined at 450 °C. All samples were characterized by FT-IR, DRS, SEM and XRD. The degradation extent was determined via UV–Vis absorption spectroscopy and COD. Based on the study of the effect of key operating parameters, the optimal conditions were determined to reach the higher efficiency of the process. The best photocatalytic activity was obtained in presence of the catalyst containing 5.4% FeO.
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photocatalytic degradation of 4 nitrophenol with zno supported nano Clinoptilolite zeolite
Journal of Industrial and Engineering Chemistry, 2014Co-Authors: Alireza Nezamzadehejhieh, Setareh KhorsandiAbstract:Abstract Photocatalytic degradation of 4-nitrophenol aqueous solution was investigated using ZnO/nano-Clinoptilolite zeolite under UV irradiation. Nano-powders of Clinoptilolite were prepared using a planetary ball mill mechanically method. The photocatalyst was prepared by ion exchanging of nano-Clinoptilolite in a 0.1 M zinc nitrate aqueous solution for 24 h followed by calcination at 450 °C for 12 h. Samples were characterized by XRD, FT-IR, DRS, AAS, TG/DTG, SEM, TEM and BET. Effects of various key operating parameters on the degradation rate were studied. The COD and HPLC tests were also used to confirm the degradation extent of the pollutant.
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cuo supported Clinoptilolite towards solar photocatalytic degradation of p aminophenol
Powder Technology, 2013Co-Authors: Alireza Nezamzadehejhieh, Mehdi AmiriAbstract:Abstract CuO as a semiconductor as incorporated onto an Iranian natural Clinoptilolite zeolite, was prepared by calcination of Cu(II)-ion exchanged Clinoptilolite. The obtained composite was used as a photocatalyst to degrade a p-aminophenol aqueous solution. All raw and modified samples were characterized using XRD, FT-IR, BET and SEM methods. The degradation and mineralization extents were performed by UV–vis spectrophotometry, COD and HPLC. The optimum values of the experimental parameters which affect the degradation efficiency were obtained as: 2.0 gL− 1 of the photocatalyst, 20 ppm of p-aminophenol and pH 6.0. Hydrogen peroxide and potassium bromate considerably increased the rate of degradation. Zeolite bed had considerable role in the photodegradation efficiency, so the proposed catalyst significantly increased the efficiency with respect to CuO and especially Clinoptilolite alone.
Oguslaw Uszewski - One of the best experts on this subject based on the ideXlab platform.
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ammonium sorption from aqueous solutions by the natural zeolite transcarpathian Clinoptilolite studied under dynamic conditions
Journal of Colloid and Interface Science, 2005Co-Authors: Myroslav Sprynskyy, Artur P. Terzyk, Jacek Namieśnik, Mariya Lebedynets, Pio Kowalczyk, Oguslaw UszewskiAbstract:The scope of this study is ammonium-ion uptake from synthetic aqueous solutions onto raw and pretreated forms of the natural zeolite Transcarpathian Clinoptilolite under dynamic conditions. Hydrogen ions displaced exchangeable cations on the Clinoptilolite in distilled water (sodium ions) and hydrochloric acid (sodium, potassium, and calcium ions) and destroyed the zeolite framework structure in the last case. Ammonium uptake onto the zeolite occurs by exchange with Na(+), Ca(2+), and K(+) ions. Although Na(+) ions were observed to be more easily exchanged for both hydrogen and ammonium ions, the role of Ca(2+) ions increased with zeolite saturation by NH(+)(4) ions. The maximum sorption capacity of the Clinoptilolite toward NH(+)(4) ions, estimated under dynamic conditions, is significantly higher than that measured under static conditions; proximity of the values of a distribution coefficient and a retardation factor for different conditions (215-265 dm(3)/kg and 979-1107, respectively) allows us to use these parameters to model ammonium uptake onto the Clinoptilolite. Slowing down or interruption in filtration resulted in the improvement of ammonium sorption properties of the zeolite. The ammonium removal improves with use of the finer fractions of the Clinoptilolite up to 0.35 mm. A recycling study results confirmed the importance of external diffusion for ammonium sorption by the Clinoptilolite. Preliminary treatment of the sorbent confirmed the predominant importance of the ion-exchange mechanism. The advantage of prior NaCl treatment of the Clinoptilolite in improvement of ammonium removal over the other techniques was shown.
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adsorption of ammonium ions onto a natural zeolite transcarpathian Clinoptilolite
Adsorption Science & Technology, 2004Co-Authors: Mariya Lebedynets, Myroslav Sprynskyy, Iryna Sakhnyuk, Radoslaw Zbytniewski, Roma Golembiewski, Oguslaw UszewskiAbstract:A study was carried out of ammonium ion sorption from synthetic aqueous solutions by Transcarpathian Clinoptilolite, a natural zeolite, under static conditions. The main physical properties of the Clinoptilolite and the basic parameters of its porous structure were determined. Values of the specific surface area and of the pore volume occupied by sorbed substances were calculated using the relative moisture content established and the maximum sorption capacity exhibited towards ammonium ions as well as a nitrogen adsorption/desorption method. Ammonium ion sorption by the zeolite appeared to be complete within 24 h for all fraction sizes, initial NH4+ ion concentration and adsorbate volumes. The amounts of NH4+ ions sorbed increased with increasing initial NH4+ concentration and decreasing adsorbate volumes, with the maximum sorption capacity exhibited by the Clinoptilolite being 0.64 mequiv/g. The sorption effectiveness decreased somewhat with increasing fraction size. The Langmuir and Freundlich models w...
Venceslav Kaucic - One of the best experts on this subject based on the ideXlab platform.
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removal of nickel ii ions from aqueous solutions using the natural Clinoptilolite and preparation of nano nio on the exhausted Clinoptilolite
Applied Surface Science, 2010Co-Authors: Nevenka Rajic, Djordje Stojakovic, Mina Jovanovic, Natasa Zabukovec Loga, Matjaz Mazaj, Venceslav KaucicAbstract:Abstract The natural zeolite tuff (Clinoptilolite) from a Serbian deposit has been studied as adsorbent for Ni(II) ions from aqueous solutions. Its sorption capacity at 298 K varies from 1.9 mg Ni g−1 (for the initial solution concentration of 100 mg Ni dm−3) to 3.8 mg Ni g−1 (for C0 = 600 mg Ni dm−3) and it increases 3 times at 338 K. The sorption is best described by the Sips isotherm model. The sorption kinetics follows the pseudo-second-order model, the activation energies being 7.44, 5.86, 6.62 and 6.63 kJ mol−1 for C0 = 100, 200, 300 and 400 mg Ni dm−3, respectively. The sorption involves a film diffusion, an intra-particle diffusion, and a chemical cation-exchange between the Na+ ions of Clinoptilolite and the Ni2+ ions. The sorption is endothermic (ΔH° being 37.9, 33.4, 30.0, 27.7 and 24.3 kJ mol−1 for C0 = 100, 200, 300, 400 and 600 mg Ni dm−3, respectively) and spontaneous in the 298–338 K temperature range. Thermal treatment of the Ni(II)-loaded Clinoptilolite results in the formation of spherical nano-NiO particles of approx. 5 nm in diameter which are randomly dispersed in the Clinoptilolite lattice.
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removal of aqueous manganese using the natural zeolitic tuff from the vranjska banja deposit in serbia
Journal of Hazardous Materials, 2009Co-Authors: Nevenka Rajic, Djordje Stojakovic, Natasa Zabukovec Loga, Sanja Jevtic, Janez Kovac, Venceslav KaucicAbstract:Abstract The natural zeolite tuff from the Vranjska Banja deposit (Serbia) has been studied as sorbent for Mn(II) ions from aqueous solutions. The zeolite sample containing mainly Clinoptilolite (more than 70%) removes Mn(II) ions by ion-exchange process, which was confirmed by X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray analysis (EDXS). XPS showed that there is no surface accumulation of Mn but an almost uniform distribution inside the sorbent; EDXS confirmed that Mn(II) replaced the Clinoptilolite Na counter ions. The sorption isotherms were studied at 298 K by batch experiments showing that the Mn(II) removal is best described by the Langmuir–Freundlich or Sips model. The kinetics followed the pseudo-second-order model, the activation energy being 128 kJ mol −1 . The intra-particle diffusion is not the rate-controlling step in the sorption of Mn(II) on Clinoptilolite. Thermodynamic data suggest spontaneity of the endothermic ion-exchange process in the 298–338 K range.