共查询到20条相似文献,搜索用时 484 毫秒
1.
S. Chakravarty Ashok Mohanty T. Nag Sudha A.K. Upadhyay J. Konar J.K. Sircar A. Madhukar K.K. Gupta 《Journal of hazardous materials》2010,173(1-3):502-509
Biosorption of Pb(II) on bael leaves (Aegle marmelos) was investigated for the removal of Pb(II) from aqueous solution using different doses of adsorbent, initial pH, and contact time. The maximum Pb loading capacity of the bael leaves was 104 mg g?1 at 50 mg L?1 initial Pb(II) concentration at pH 5.1. SEM and FT-IR studies indicated that the adsorption of Pb(II) occurs inside the wall of the hollow tubes present in the bael leaves and carboxylic acid, thioester and sulphonamide groups are involved in the process. The sorption process was best described by pseudo second order kinetics. Among Freundlich and Langmuir isotherms, the latter had a better fit with the experimental data. The activation energy Ea confirmed that the nature of adsorption was physisorption. Bael leaves can selectively remove Pb(II) in the presence of other metal ions. This was demonstrated by removing Pb from the effluent of exhausted batteries. 相似文献
2.
Zinab Ghasemi Ahmad Seif Temer S. Ahmadi Behroze Zargar Fatemeh Rashidi Goodarz M. Rouzbahani 《Advanced Powder Technology》2012,23(2):148-156
Titanium dioxide nanocrystals were employed, for the first time, for the sorption of Hg(II) ions from aqueous solutions. The effects of varying parameters such as pH, temperature, initial metal concentration, and contact time on the adsorption process were examined. Adsorption equilibrium was established in 420 min and the maximum adsorption of Hg(II) on the TiO2 was observed to occur at pH 8.0. The adsorption data correlated with Freundlich, Langmuir, Dubinin–Radushkevich (D–R), and Temkin isotherms. The Freundlich isotherm showed the best fit to the equilibrium data. The Pseudo-first order and pseudo-second-order kinetic models were studied to analyze the kinetic data. A second-order kinetic model fit the data with the (k2 = 2.8126 × 10?3 g mg?1min?1, 303 K). The intraparticle diffusion models were applied to ascertain the rate-controlling step. The thermodynamic parameters (ΔG°, ΔH°, and ΔS°) were calculated which showed an endothermic adsorption process. The equilibrium parameter (RL) indicated that TiO2 nanocrystals are useful for Hg(II) removal from aqueous solutions. 相似文献
3.
Xiaoli Zhao Jieming Wang Fengchang Wu Thanh Wang Yaqi Cai Yali Shi Guibin Jiang 《Journal of hazardous materials》2010,173(1-3):102-109
A novel magnetic nanosized adsorbent using hydrous aluminum oxide embedded with Fe3O4 nanoparticle (Fe3O4@Al(OH)3 NPs), was prepared and applied to remove excessive fluoride from aqueous solution. This adsorbent combines the advantages of magnetic nanoparticle and hydrous aluminum oxide floc with magnetic separability and high affinity toward fluoride, which provides distinctive merits including easy preparation, high adsorption capacity, easy isolation from sample solutions by the application of an external magnetic field. The adsorption capacity calculated by Langmuir equation was 88.48 mg g?1 at pH 6.5. Main factors affecting the removal of fluoride, such as solution pH, temperature, adsorption time, initial fluoride concentration and co-existing anions were investigated. The adsorption capacity increased with temperature and the kinetics followed a pseudo-second-order rate equation. The enthalpy change (ΔH0) and entropy change (ΔS0) was 6.836 kJ mol?1 and 41.65 J mol?1 K?1, which substantiates the endothermic and spontaneous nature of the fluoride adsorption process. Furthermore, the residual concentration of fluoride using Fe3O4@Al(OH)3 NPs as adsorbent could reach 0.3 mg L?1 with an initial concentration of 20 mg L?1, which met the standard of World Health Organization (WHO) norms for drinking water quality. All of the results suggested that the Fe3O4@Al(OH)3 NPs with strong and specific affinity to fluoride could be excellent adsorbents for fluoride contaminated water treatment. 相似文献
4.
Dong Nguyen Thanh Mandeep Singh Pavel Ulbrich František Štěpánek Nina Strnadová 《Materials Research Bulletin》2012,47(1):42-50
We present a novel way of enhancing the utility of low cost readily available laterite by impregnating it with the α-MnO2 nanorods, thus making a composite material suitable for the removal of As(V) from aqueous media. The composites were synthesized by two methods: (i) ball-milling of a physical blend of laterite with pre-synthesized MnO2; and (ii) in situ formation of MnO2 in the presence of laterite. The BET surface area of composites prepared by both methods was markedly higher compared to un-modified laterite, and the presence of MnO2 in the composite was also confirmed by XRD analysis and TEM microscopy. The adsorption capacity for As(V) was found to be highly pH dependent and the adsorption kinetics followed a pseudo second-order kinetic model. The Langmuir adsorption isotherm was found to be the best model to describe the adsorption equilibrium of As(V) onto un-modified laterite as well both ball-milled and in situ formed composite. The adsorption capacities at room temperature and pH 7.0 were found to be 1.50 mg g?1, 8.93 mg g?1 and 9.70 mg g?1, for un-modified laterite, ball-milled and in situ formed composite, respectively. 相似文献
5.
Hassan Ali Zamani Mitra Rohani Abbas Zangeneh-Asadabadi Mohammad Saleh Zabihi Mohammad Reza Ganjali Masoud Salavati-Niasari 《Materials science & engineering. C, Materials for biological applications》2010,30(6):917-920
A novel Lu(III) PVC membrane sensor has been constructed based on a new synthesized symmetric S–N Schiff's base, namely N-[(Z)-1-(2-thienyl)methylidene]-N-[4-(4-{[(Z)-1-(2-thienyl) methylidene]amino}benzyl)phenyl] amine (TBPA). The electrode showed a Nernstian slope of 19.8 ± 0.5 mV per decade across a wide concentration range of 1.0 × 10? 6 to 1.0 × 10? 2 mol L? 1 with a detection limit of 7.2 × 10? 7 mol L? 1. The proposed sensor showed high selectivity toward Lu(III) ion in comparison with common alkaline, alkaline earth, transition, and heavy metals specially lanthanide ions, and could be used over a pH range of 2.7–10.6. It can be used for at least 2 months without any considerable divergency in potentials and it has a relatively fast response time of < 10 s. The sensor was effectively used as an indicator electrode in the potentiometric titration of Lu(III) ions with EDTA. The constructed sensor accuracy was investigated by the monitoring of Lu(III) ion in mixtures of two and three different ions. 相似文献
6.
Hassan Ali Zamani Babak Feizyzadeh Farnoush Faridbod Mohammad Reza Ganjali 《Materials science & engineering. C, Materials for biological applications》2011,31(7):1379-1382
A thulium(III) membrane sensor was made using 2% sodium tetraphenyl borate (NaTPB), 65% dibutylphthalate (DBP), 30% poly(vinyl chloride) (PVC) and 3% 1-ethyl-3-(2,5-dihydro-4-(3,5-dimethyl-1H-pyrazol-4-yl)-5-oxo-1H-pyrazol-3-yl)thiourea (ET) as an ionophore. Conductometric study shows selectivity of the Et toward Tm3+ ions. Nernstian response of 19.6 ± 0.4 mV per decade of thulium concentration was observed, and the electrode worked well in concentration range of 1.0 × 10? 6 to 1.0 × 10? 2 mol L? 1 with a lower detection limit (LDL) of 7.2 × 10? 7 mol L? 1, in a pH range of 4.3–10.4. The selectivity of the sensor over alkaline, alkaline earth, transition and heavy metal ions was also found to be in a satisfactory range. To check the analytical applicability of the proposed Tm3+ sensor, it was successfully used as an indicator electrode in analysis of thulium in certified reference materials. 相似文献
7.
Hassan Ali Zamani Majid Mohammadhosseini Saeed Haji-Mohammadrezazadeh Farnoush Faridbod Mohammad Reza Ganjali Soraia Meghdadi Abolghasem Davoodnia 《Materials science & engineering. C, Materials for biological applications》2012,32(4):712-717
According to a solution study which showed a selective complexation between N,N′-bis(methylsalicylidene)-2-aminobenzylamine (MSAB) and gadolinium ions, MSAB was used as a sensing element in construction of a gadolinium(III) ion selective electrode. Acetophenon (AP) was used as solvent mediator and sodium tetraphenyl borate (NaTPB) as an anion excluder. The electrode showed a good selectivity towards Gd(III) ions over a wide variety of cations tested. The constructed sensor displayed a Nernstian behavior (19.7 ± 0.3 mV/decade) in the concentration range of 1.0 × 10? 6 to 1.0 × 10? 2 mol L? 1 with detection limit of 5.0 × 10? 7 mol L? 1 and a short response time (< 10 s). The working pH range of the electrode was 3.5–10.1 and lifetime of the sensor was at least 10 weeks. Analysis of certified reference materials confirmed the accuracy of the proposed sensor. The electrode was successfully applied as an indicator electrode in gadolinium titration with EDTA. 相似文献
8.
Hassan Ali Zamani Mehdi Nekoei Majid Mohammadhosseini Mohammad Reza Ganjali 《Materials science & engineering. C, Materials for biological applications》2010,30(3):480-483
In this study, a new thulium(III) membrane sensor was constructed. The proposed membrane sensor was fabricated based on a membrane containing 2% sodium tetraphenyl borate (NaTPB) as an anionic additive, 65% benzyl acetate (BA) as solvent mediator, 3% 1-(2-thiazolylazo)-2-naphthol (TN) as ionophore, and 30% poly(vinyl chloride) (PVC). The proposed Tm3+ electrode exhibits a Nernstian response of 19.5 ± 0.2 mV per decade of thulium concentration, and has a lower detection limit of 8.7 × 10? 7 mol L? 1. The linear range of the sensors was 1.0 × 10? 6 to 1.0 × 10? 2 mol L? 1. It works well in the pH range of 3.2–9.5. Moreover, the recommended selective sensor revealed a comparatively satisfactory selectivity regarding most of the alkali, alkaline earth, some transition and heavy metal ions. The membrane sensor was applied to the determination of fluoride ions in mouth wash samples. 相似文献
9.
Hassan Ali Zamani Mohammad Reza Ganjali Hossien Behmadi Mohammad Ali Behnajady 《Materials science & engineering. C, Materials for biological applications》2009,29(5):1535-1539
The construction, performance characteristics, and application of a novel iron(III) membrane sensor based on a new bis-benzilthiocarbohydrazide (BBTC) are reported in this paper. The sensor is prepared by incorporating of BBTC, nitrobenzene (NB), and sodium tetraphenyl borate (NaTPB) into a plasticized poly(vinyl chloride) membrane. The electrode reveals a Nernstian behavior over a wide iron ion concentration range (1.0 × 10? 2–1.0 × 10? 7 mol L? 1), and relatively low detection limit (8.6 × 10? 8 mol L? 1). The potentiometric response is independent on the pH of the solution in the range of 1.6–4.3. The electrode shows a very short response time (< 10 s). The proposed electrode can be used for at least nine weeks without any considerable divergence in potentials. It exhibits very good selectivity relative to a wide variety of alkali, alkaline earth, transition and heavy metal ions. In fact, the selectivity of the proposed sensor shows great improvements compared to the previously reported electrodes for the iron ion. Also, the sensors accuracy was investigated in two ways: (i) with the potentiometric titration of a Fe(III) solution with EDTA and (ii) with the Fe(III) monitoring in river and wastewater samples. 相似文献
10.
Wei Chen Xiaoping Zhang Mairambek Mamadiev Chunhu Zhao Zihao Wang Hanjiang Xu 《Advanced Powder Technology》2017,28(2):521-533
Layers from two different delaminated dispersions of 3-aminopropyltriethoxysilane (APTES)-intercalated montmorillonite (Mts) and octylamine (OA)-intercalated graphene oxide (GO) could be co-stacked to obtain APTES-intercalated Mts (Mts-APTES)/OA-intercalated GO (GO-OA) interstratified composites (MAGO). The synthesized composites were characterized by XRD, FTIR, BET, TGA, TEM and XPS, which showed that MAGO had been prepared successfully. The optimal concentration of APTES was 8% in anhydrous toluene which avoided self-polymerization of APTES while facilitating the nucleophilic attack of APTES amine groups and the protic character of ethanol to compete with silane for the intimal hydroxyl groups by H-bonding. The MAGO demonstrated an extremely fast Cr(VI) removal from aqueous solution with a high removal efficiency at low pH. Data from batch studies of the adsorption process followed pseudo-second-order kinetics. The results fit a Langmuir model of adsorption, with maximum adsorption capacities of MAGO composites at pH 3.0 being 44.25 mg g?1, 47.46 mg g?1, 49.58 mg g?1 under 30 °C, 40 °C, 50 °C, respectively, which were much higher than capacities of some conventional adsorbents. The reusability of the MAGO composite was also determined through adsorption-desorption studies, providing evidence for the potential use of MAGO composite in the removal of Cr(VI) from acidic wastewater. 相似文献
11.
Hassan Ali Zamani Fatemeh Naghavi-Reyabbi Farnoush Faridbod Majid Mohammadhosseini Mohammad Reza Ganjali Azadeh Tadjarodi Maryam Rad 《Materials science & engineering. C, Materials for biological applications》2013,33(2):870-874
A new ion-selective electrode for Sm3 + ion is described based on the incorporation of N,N′,N″-tris(4-pyridyl)trimesic amide (TPTA) in a poly(vinylchloride) (PVC) matrix. The membrane sensor comprises nitrobenzene (NB) as a plasticizer, and oleic acid (OA) as an anionic additive. The sensor with the optimized composition shows a Nernstian potential response of 19.8 ± 0.5 mV decade? 1 over a wide concentration range of 1.0 × 10? 2 and 1 × 10? 6 mol L? 1, with a lower detection limit of 4.7 × 10? 7 mol L? 1 and satisfactor applicable pH range of 3.6–9.2. Having a short response time of less than 10 s and a very good selectivity towards the Sm3 + over a wide variety of interfering cations (e.g. alkali, alkaline earth, transition and heavy metal ions) the sensor seemed to be a promising analytical tool for determination of the Sm3 +. Hence, it was used as an indicator electrode in the potentiometric titration of samarium ion with EDTA. It was also applied to the direct samarium recovery in binary mixtures. 相似文献
12.
Sheng-Yu Liu Jin Gao Yi-Jin Yang Ying-Chun Yang Zhi-Xiang Ye 《Journal of hazardous materials》2010,173(1-3):558-562
Batch experiments were carried out to investigate the kinetics of adsorption of lead ions by steel slag on the basis of the external diffusion, intra-particle diffusion and adsorption reaction model (pseudo-first-order, pseudo-second-order). The results showed that the controlling step for the adsorption kinetics changed with the varying experimental parameters. When the particle size of steel slag was larger than 120 mesh, intra-particle diffusion of Pb2+ was the controlling step, and when the initial concentration of Pb2+ was less than 150 mg L?1 or the shaking rate was lower than 150 rpm, external diffusion of Pb2+ was promoted. Contrary to the former experimental conditions the adsorption reaction was the controlling step, and the adsorption followed second-order kinetics, with an adsorption rate constant of 13.26 g mg?1 min?1. The adsorption isotherm of Pb2+ with steel slag followed the Langmuir model, with a correlation coefficient of 0.99. 相似文献
13.
Katarzyna Kazimierska-Drobny Mariusz Kaczmarek 《Materials science & engineering. C, Materials for biological applications》2013,33(8):4533-4538
In this paper the identification of diffusion coefficient, retardation factor and surface distribution coefficient for selected salts in poly(vinyl alcohol) hydrogels is performed. The identification of the transport parameters is based on the previously developed inverse problem technique using experimental data from the reservoir test and the solution of the diffusive transport equation with linear equilibrium sorption. The estimated values of diffusion coefficient are: for physiological fluid (6.30 ± 0.10) × 10? 10 m2/s, for 1 M NaCl (6.42 ± 0.39) × 10? 10 m2/s, and for 1 M KCl (7.94 ± 0.38) × 10? 10 m2/s. The retardation factor for all tested materials and salts is equal or close to one. The average value of the effective surface distribution coefficient is equal to 0.5. 相似文献
14.
A selective method for the determination of thorium (IV) using an optical sensor is described. The sensing membrane is prepared by immobilization of thorin–methyltrioctylammonium ion pair on triacetylcellulose polymer. The sensor produced a linear response for thorium (IV) concentration in the range of 6.46 × 10?6 to 9.91 × 10?5 mol L?1 with detection limit of 1.85 × 10?6 mol L?1. The regeneration of optode was accomplished completely at a short time (less than 20 s) with 0.1 mol L?1 of oxalate ion solution. The relative standard deviation for ten replicate measurements of 2.15 × 10?5 and 8.62 × 10?5 mol L?1 of thorium was 2.71 and 1.65%, respectively. The optode membrane exhibits good selectivity for thorium (IV) over several other ionic species and are comparable to those obtained in case of spectrophotometric determination of thorium using thorin in solution. A good agreement with the ICP-MS and spiked method was achieved when the proposed optode was applied to the determination of thorium (IV) in dust and water samples. 相似文献
15.
Ida Tiwari Manorama Singh Mandakini Gupta S.K. Aggarwal 《Materials Research Bulletin》2012,47(7):1697-1703
We herein report a simple, low cost and green preparation of nanowires of (anthraquinone-2-carboxylic acid/amino functionalized) multiwalled carbon nanotubes (HOOC-2-AQ/AMWCNTs) which has been further employed for the development of highly sensitive oxygen sensor. The prepared composite has been characterized by TEM and electrochemical studies. The glassy carbon electrode modified with composite shows an irreversible and good electrocatalytic activity for the reduction of oxygen. The reduction potential of the oxygen was shifted 460 mV towards the positive potential with this modified electrode as compared to bare glassy carbon electrode. The prepared material was stable with no leaching observed of the mediator. A linear response range of 0.2–6.8 mg L?1, with a sensitivity of 5.0 μA L mg?1 and a detection limit of 0.02 mg L?1 were obtained with this sensor. 相似文献
16.
Wen-Tien Tsai Mei-Kuei Lee Ting-Yi Su Yuan-Ming Chang 《Journal of hazardous materials》2009,168(1):269-275
In this work, the photocatalytic behaviors of bisphenol-A (BPA), which has been listed as one of endocrine disrupting chemicals, were carried out in a batch TiO2 suspension reactor. The photodegradation efficiency has been investigated under the controlled process parameters including initial BPA concentration (i.e., 1–50 mg L?1), TiO2 dosage (i.e., 5–600 mg/200 cm3), initial pH (i.e., 3–11), and temperature (i.e., 10–70 °C). It was found that the optimal conditions in the photoreaction process could be coped with at initial BPA concentration = 20 mg L?1, TiO2 dosage = 0.5 g L?1 (100 mg/200 cm3), initial pH = 7.0, and temperature = 25 °C. According to the Langmuir–Hinshelwood model, the results showed that the photodegradation kinetics for the destruction of BPA in water also followed the first-order model well. The apparent first-order reaction constants (kobs), thus obtained from the fittings of the model, were in line with the destruction-removal efficiencies of BPA in all the photocatalytic experiments. Based on the intermediate products identified in the study, the possible mechanisms for the photodegradation of BPA in water were also proposed in the present study. 相似文献
17.
Yuan-Zhi Song An-Feng Zhu Hui Zhong Yang Song Fei-Yue Wu Wen-lan Yang Hui Huang 《Materials Letters》2011,65(23-24):3612-3614
A sensor based on gold nanoparticle/single-walled carbon nanotube film on the surface of glassy carbon electrode is prepared. Electrochemical behavior of adrenaline hydrochloride (AH) on the surface of gold nanoparticle/single-walled carbon nanotube modified glassy carbon electrode is investigated. A simple, sensitive, and inexpensive method for determination of AH is proposed. The oxidation peak currents is proportional to adrenaline hydrochloride concentrations in the range of 0.20 mg L? 1 to 1.80 mg L? 1 in 0.1 M phosphate buffer solution of pH 7.3, the detection limit for AH is 0.06 mg L? 1, and the recoveries are in the range from 100.0 to 110.0% with RSD of 1.2–1.9% (n = 6). 相似文献
18.
Konstantinos Dermentzis 《Journal of hazardous materials》2010,173(1-3):647-652
Electrostatic shielding zones made of electrode graphite powder were used as a new type of ionic and electronic current sinks. Because of the local elimination of the applied electric field, voltage and current within the zones, ions are led inside them and accumulate there. The current sinks were implemented in electrostatic shielding electrodialysis of a simulated nickel plating rinse water containing 100 mg L?1 nickel and electrodeionization of a 0.001 M NiSO4 solution with simultaneous electrochemical regeneration of the ion exchange resin beds. Pure water was obtained with a Ni2+ ion concentration of less than 0.1 mg L?1 at a flow rate of 2.02 × 10?4 dm3 s?1 diluate stream and a current density of 30 A m?2. 相似文献
19.
Hassan Ali Zamani Farnoush Faridbod Mohammad Reza Ganjali 《Materials science & engineering. C, Materials for biological applications》2013,33(2):608-612
A novel Dy(III) ion-selective PVC membrane sensor was made using a new synthesized organic compound, 3,4-diamino-N′-((pyridin-2-yl)methylene)benzohydrazide (L) as an excellent sensing element. The electrode showed a Nernstian slope of 19.8 ± 0.6 mV per decade in a wide concentration range of 1.0 × 10? 6–1.0 × 10? 2 mol L? 1, a detection limit of 5.5 × 10? 7 mol L? 1, a short conditioning time, a fast response time (< 10 s), and high selectivity towards Dy(III) ion in contrast to other cations. The proposed sensor was successfully used as an indicator electrode in the potentiometric titration of Dy(III) ions with EDTA. The membrane sensor was also applied to the F– ion indirect determination of some mouth washing solutions and to the Dy3 + determination in binary mixtures. 相似文献
20.
Hassan Ali Zamani Mohammad Taghi Hamed-Mosavian Elham Hamidfar Mohammad Reza Ganjali Parviz Norouzi 《Materials science & engineering. C, Materials for biological applications》2008,28(8):1551-1555
This work introduces a unique ionophore for the selective determination of Fe(III) ions. This ionophore was N-(2-hydroxyethyl)ethylenediamine-N,N′,N″-triacetic acid (NTA), presenting a high affinity towards the trivalent iron cations. The designed sensor exhibited a wide linear response with a slope of 19.5 ± 0.4 mV per decade over the concentration range of 1.0 × 10− 9–1.0 × 10− 2 mol L− 1, while the illustrated detection limit was 3.0 × 10− 10 mol L− 1 of the Fe(III) ions concentration. It was concluded that the sensor response was pH independent in the range of 1.8–4.5. The sensor possessed the advantages of short conditioning time, fast response time (10 s) and, especially, good selectivity towards the transition and heavy metal ions as well as some mono, di and trivalent cations. Concerning the electrode lifetime, no considerable potential divergence was noticed for at least 10 weeks. The sensor accuracy was investigated in the potentiometric titration of a Fe(III) solution with EDTA. 相似文献