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The recovery of pure ZnO (zinc oxide) nanoparticles from spent Zn–Mn dry alkaline batteries is reported. Spent batteries were dismantled to separate the contained valuable metals of the cell electrodes in the form of black powder. Treatment of this black powder with 5 mol L^–1 HCl produced leach liquor, primarily containing 2.90 g L^–1 Zn and 2.02 g L^–1 Mn. Selective and quantitative liquid–liquid extraction of Zn(II) was then carried out in three counter current steps by using Cyanex 923 (0.10 mol L^–1 in n-hexane). Zn(II) distributed in the organic phase as complex ZnCl₂·2R (R = Cyanex 923 molecule). The metal loaded organic phase was subjected to combust at 600 °C to yield pure ZnO nanoparticles (40–50 nm). Important characteristics of the synthesized nanoparticles were investigated by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction spectroscopy (XRD), and atomic force microscopy (AFM).

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The recovery of pure ZnO (zinc oxide) nanoparticles from spent Zn–Mn dry alkaline batteries is reported. Spent batteries were dismantled to separate the contained valuable metals of the cell electrodes in the form of black powder. Treatment of this black powder with 5 mol L^–1 HCl produced leach liquor, primarily containing 2.90 g L^–1 Zn and 2.02 g L^–1 Mn. Selective and quantitative liquid–liquid extraction of Zn(II) was then carried out in three counter current steps by using Cyanex 923 (0.10 mol L^–1 in n-hexane). Zn(II) distributed in the organic phase as complex ZnCl₂·2R (R = Cyanex 923 molecule). The metal loaded organic phase was subjected to combust at 600 °C to yield pure ZnO nanoparticles (40–50 nm). Important characteristics of the synthesized nanoparticles were investigated by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction spectroscopy (XRD), and atomic force microscopy (AFM).

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The widespread occurrence of pesticide residues in different agricultural and food commodities has raised concern among the environmentalists and food chemists. In order to keep a proper track of these materials, studies on their decay profiles in the various segments of ecosystem under varying environmental conditions are needed. In view of this, the metabolites of quinalphos in water and soil under controlled conditions and in plants, namely tomato and radish in field conditions have been analysed and possible pathways suggested. In order to follow the decay of the pesticide, an HPLC procedure has been developed. Studies conducted in water at different temperatures, pH and organic content reveal that the persistence of the pesticide decreases with the increase in all the three variables. In the three different types of soils studied, the effect of pH is more or less apparent on a similar line. On an average a faster decay is observed in the case of plants than in water and soil. The decay profiles in all these cases follow first order kinetics. The metabolites were identified by GC–MS. The investigations reflect that degradation occurs through hydrolysis, S-oxidation, dealkylation and thiono-thiol rearrangement. The pathways seem to be complex and different metabolites were observed with the change in the matrix. Quinalphos oxon, O-ethyl-O-quinoxalin-2-yl phosphoric acid, 2-hydroxy quinoxaline and quinoxaline-2-thiol were observed in all the matrices. Results further indicate that the metabolites, 2-hydroxy quinoxaline and oxon, which are more toxic than parent compound, persist for a longer time.

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The recovery of pure ZnO (zinc oxide) nanoparticles from spent Zn-Mn dry alkaline batteries is reported. Spent batteries were dismantled to separate the contained valuable metals of the cell electrodes in the form of black powder. Treatment of this black powder with 5 mol L-1 HCl produced leach liquor, primarily containing 2.90 g L-1 Zn and 2.02 g L-1 Mn. Selective and quantitative liquid-liquid extraction of Zn(II) was then carried out in three counter current steps by using Cyanex 923 (0.10 mol L-1 in n-hexane). Zn(II) distributed in the organic phase as complex ZnCl2.2R (R = Cyanex 923 molecule). The metal loaded organic phase was subjected to combust at 6000C to yield pure ZnO nanoparticles (40-50 nm). Important characteristics of the synthesized nanoparticles were investigated by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction spectroscopy (XRD) and atomic force microscopy (AFM).

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The recovery of pure ZnO (zinc oxide) nanoparticles from spent Zn-Mn dry alkaline batteries is reported. Spent batteries were dismantled to separate the contained valuable metals of the cell electrodes in the form of black powder. Treatment of this black powder with 5 mol L-1 HCl produced leach liquor, primarily containing 2.90 g L-1 Zn and 2.02 g L-1 Mn. Selective and quantitative liquid-liquid extraction of Zn(II) was then carried out in three counter current steps by using Cyanex 923 (0.10 mol L-1 in n-hexane). Zn(II) distributed in the organic phase as complex ZnCl2.2R (R = Cyanex 923 molecule). The metal loaded organic phase was subjected to combust at 6000C to yield pure ZnO nanoparticles (40-50 nm). Important characteristics of the synthesized nanoparticles were investigated by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction spectroscopy (XRD) and atomic force microscopy (AFM).

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The recovery of pure ZnO (zinc oxide) nanoparticles from spent Zn–Mn dry alkaline batteries is reported. Spent batteries were dismantled to separate the contained valuable metals of the cell electrodes in the form of black powder. Treatment of this black powder with 5 mol L^–1 HCl produced leach liquor, primarily containing 2.90 g L^–1 Zn and 2.02 g L^–1 Mn. Selective and quantitative liquid–liquid extraction of Zn(II) was then carried out in three counter current steps by using Cyanex 923 (0.10 mol L^–1 in n-hexane). Zn(II) distributed in the organic phase as complex ZnCl₂·2R (R = Cyanex 923 molecule). The metal loaded organic phase was subjected to combust at 600 °C to yield pure ZnO nanoparticles (40–50 nm). Important characteristics of the synthesized nanoparticles were investigated by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction spectroscopy (XRD), and atomic force microscopy (AFM).

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The recovery of pure ZnO (zinc oxide) nanoparticles from spent Zn–Mn dry alkaline batteries is reported. Spent batteries were dismantled to separate the contained valuable metals of the cell electrodes in the form of black powder. Treatment of this black powder with 5 mol L^–1 HCl produced leach liquor, primarily containing 2.90 g L^–1 Zn and 2.02 g L^–1 Mn. Selective and quantitative liquid–liquid extraction of Zn(II) was then carried out in three counter current steps by using Cyanex 923 (0.10 mol L^–1 in n-hexane). Zn(II) distributed in the organic phase as complex ZnCl₂·2R (R = Cyanex 923 molecule). The metal loaded organic phase was subjected to combust at 600 °C to yield pure ZnO nanoparticles (40–50 nm). Important characteristics of the synthesized nanoparticles were investigated by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction spectroscopy (XRD), and atomic force microscopy (AFM).

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A comprehensive study was conducted to evaluate the persistence of thiram in water and soil under controlled conditions and on two plants, namely tomato and radish, in field conditions. In order to follow the decay of the pesticide, an HPLC procedure was developed employing an octadecyl endcapped RP-C18 column using a mixture of acetonitrile and water as the mobile phase and an ultraviolet detector. Studies conducted in water at different temperature, pH and organic content revealed that the persistence of the pesticide decreases with the increase in all the three variables. In the three different types of soils studied, the effect of pH was more or less apparent on a similar line. On average a slower decay was observed in the case of plants than in water and soil. Copyright © 2011 John Wiley & Sons, Ltd.

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A comprehensive study was conducted to evaluate the persistence of thiram in water and soil under controlled conditions and on two plants, namely tomato and radish, in field conditions. In order to follow the decay of the pesticide, an HPLC procedure was developed employing an octadecyl endcapped RP-C18 column using a mixture of acetonitrile and water as the mobile phase and an ultraviolet detector. Studies conducted in water at different temperature, pH and organic content revealed that the persistence of the pesticide decreases with the increase in all the three variables. In the three different types of soils studied, the effect of pH was more or less apparent on a similar line. On average a slower decay was observed in the case of plants than in water and soil. Copyright © 2011 John Wiley & Sons, Ltd.

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Waste rubber tire has been used for the removal of pesticides from waste water by adsorption phenomenon. By applying successive chemical and thermal treatment, a basically cabonaceous adsorbent is prepared which has not only a higher mesopore, macropore content but also has a favorable surface chemistry. Presence of oxygen functional groups as evidenced by FTIR spectra along with excellent porous and surface properties were the driving force for good adsorption efficiency observed for the studied pesticides: methoxychlor, methyl parathion and atrazine. Batch adsorption studies revealed maximum adsorption of 112.0 mg g⁻¹, 104.9 mg g⁻¹ and 88.9 mg g⁻¹ for methoxychlor, atrazine and methyl parathion respectively occurring at a contact time of 60 min at pH 2 from an initial pesticide concentration of 12 mg/L. These promising results were confirmed by column experiments; thereby establishing the practicality of the developed system. Effect of various operating parameters along with equilibrium, kinetic and thermodynamic studies reveal the efficacy of the adsorbent with a higher adsorption capacity than most other adsorbents. The adsorption equilibrium data obey Langmuir model and the kinetic data were well described by the pseudo-first-order model. Applicability of Bangham’s equation indicates that diffusion of pesticide molecules into pores of the adsorbent mainly controls the adsorption process. Spontaneous, exothermic and random characteristics of the process are confirmed by thermodynamic studies. The developed sorbent is inexpensive in comparison to commercial carbon and has a far better efficiency for pesticide removal than most other adsorbents reported in literature.

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The extraction of In(III) from HCl, H₂SO₄, and HNO₃ media using a 0.20moll⁻¹ Cyanex 923 solution in toluene is investigated. In(III) is quantitatively extracted over a fairly wide range of HCl molarity while from H₂SO₄ and HNO₃ media the extraction is quantitative at low acid concentration. The extracted metal ion has been recovered by stripping with 1.0moll⁻¹ H₂SO₄. The stoichiometry of the In(III): Cyanex 923 complex is observed to be 1:2. The extraction of In(III) is insignificantly changed in diluents namely toluene, n-hexane, kerosene (160–200°C), cyclohexane, and xylene having more or less the same dielectric constants, whereas, it decreases with increasing polarity of diluents such as cyclohexanone and chloroform. The extractant is stable towards prolonged acid contact and there is a negligible loss in its extraction efficiency even after recycling for 20 times. The extraction behavior of some commonly associated metal ions namely V(IV), Ti(IV), Al(III), Cr(III), Fe(III), Ga(III), Sb(III), Tl(III), Mn(II), Fe(II), Cu(II), Zn(II), Cd(II), Pb(II), and Tl(I) has also been investigated. Based on the partition data the conditions have been identified for attaining some binary separations of In(III). These conditions are extended for the recovery of pure indium from zinc blend, zinc plating mud, and galena. The recovery of the metal ions is around 95% with purity approximately 99%.

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A method for the extraction-spectrophotometric determination of palladium with 3,4,4a,5-tetrahydro-3,3,4a-trimethyl-7-(substituted)-pyrimido(1,6-a)benzimidazole-1-thiol (PBT) is described. PBT-Pd(II) complex is extracted from an acidic aqueous solution (0.01-0.5 M HClO₄) into a chloroform layer. The absorbance is measured at 438 nm and the molar absorptivity found to be 1.033 × 10⁴ M⁻¹ cm⁻¹. The complex system conforms to Beer's law over the range 1.9-28.5 μg/ml palladium(II). The effects of pH (2-6), HClO₄ concentration, PBT concentration and shaking time were studied. The ratio of metal ion to ligand molecules in the coloured complex was found to be 1:4. The tolerance limit for many metals have been determined. Finally, the method has been applied successfully to the determination of palladium in synthetic mixtures and in the standard palladium carbon powder (palladium catalyst).

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Batch experiments on the uptake of (Hg(II)) from nitric acid medium by coated inert support have been conducted. The effect of different variables like equilibration time, concentration of acid, metal ion and extractant has been studied. Binary separations of Hg(II) from other metal ions have been carried out. Experiments to evaluate the recycling capacity of the columns reveal a practically insignificant change in the extraction efficiency of the extractant. The practical utility of the columns has been demonstrated by decontaminating mercury containing waste effluent.

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The paper examines the ethical conception of the most well-known and much discussed Hindu text, the Bhagavad Gītā, in the context of the Western distinction between duty ethics and virtue ethics. Most of the materials published on the Gītā make much of its conception of duty; however, there is no systematic investigation of the notion of virtue in the Gītā. The paper begins with a discussion of the fundamental characteristics of virtue ethics, before undertaking a discussion of the conceptions of duty and virtue in the Gītā. The paper clearly demonstrates that (1) both duty and virtue coexist in the Gītā, and (2) the Gītā accords virtue an important place.

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The present study aims to decontaminate arsenic from metallurgical processing solutions. The extraction profile of As(V)/(III) along with some associated metal ions like Se(IV), Ga(III), Sb(III), Bi(III), Ni(II), Cu(II), Hg(II) and Pb(II) in bis(2,4,4-trimethylpentyl)dithiophsophinic acid (Cyanex 301) has been investigated. As(V) remains unextracted whereas As(III) is quantitatively extracted into 0.1molL⁻¹ Cyanex 301 by a solvating mechanism. The influence of various parameters, such as equilibration time, temperature, nature of diluent and mineral acid, concentration of hydrogen ion, chloride ion, metal ion and extractant on the distribution of As(III), was examined. The extracted species has been identified and loading capacity determined. The extractant has good hydrolytic stability and regeneration power, confirming its commercial viability. Conditions for the binary separation of arsenic from metal ions like Se(IV), Ga(III), Sb(III), Bi(III), Ni(II), Cu(II), Hg(II) and Pb(II) have been optimized. The proposed separation conditions were successfully applied to galena, copper pyrite and to a synthetic copper electrolyte bath solution. This resulted in the quantitative recovery of impurity-free Pb and Cu solutions. The developed procedure can be employed for the removal of impurities from metallurgical effluents before discharge.

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The extraction of indium(III) and gallium(III) along with the associated metal ions from hydrochloric acid medium by bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272) has been studied. The extraction profiles of indium(III) and gallium(III) have been investigated as a function of type and molarity of the acid, nature of organic diluent and concentration of the metal ion and the extractant. The extracting species have been identified as In(OH)R₂, Ga(OH)R₂ and H⁺GaCl₄·2R. It has been possible to strip In(III) and Ga(III) from the organic phase by appropriate molarity of HCl. Conditions for a number of binary and ternary separations of analytical interest have been optimized. The developed conditions have been extended to recover pure In(III) from sphalerite and galena and Ga(III) from bottom ash and electronic waste. Loading capacity of the extractant was evaluated and the results reveal that Cyanex 272 can hold indium(III) up to one-fifteenth and gallium(III) up to one-twentieth of its molar concentration. The hydrolytic stability and regeneration capacity of the extractant has been assessed.

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The extraction of Ga(III) from HCl, HNO₃ and H₂SO₄ media using 0.50 mol/L Cyanex 923 in toluene is investigated. Ga(III) is quantitatively extracted over a wide range of HCl at high concentration while the extraction is poor over the entire concentration range of HNO₃ and H₂SO₄. The extracted Ga(III) is recovered by stripping with 0.10 mol/L HCl. The extracted species is identified as GaCl₃.3Cyanex 923. The extraction behaviour of some commonly associated metal ions is also investigated. Based on the partition data, conditions have been identified for attaining some binary and ternary separations involving Ga(III) and V(IV), Al(III), Fe(III), In(III), Ti(IV), Ni(II), Mn(II), Cu(II), Zn(II), and Hg(II). The conditions are extended for the recovery of pure gallium from light emitting diode (LED) waste and bottom ash. The extractant is stable towards prolonged acid contact and there is a negligible loss in its extraction efficiency even after recycling ten times.

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Studies have been carried out in the extraction of Cd(II) along with Al(III), Fe(III), In(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Hg(II) and Pb(II) from hydrochloric acid medium using Cyanex 923. The effect of different variables influencing the extraction of Cd(II) such as the concentration of acid, metal ion and extractant and the nature of the diluent has been investigated. The extracting species of Cd(II) is proposed. Based on the partition data, some binary separations of topical interest from Cd(II) have been achieved. The potential of the extractant for the recovery of pure cadmium from some zinc and copper matrices is assessed.

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The paper describes a process for the recovery of pure Co(II), Ni(II), and Cu(II) from a hydrochloric acid solution of polymetallic sea nodules. An overnight contact of the nodule powder with 4 M HCl almost quantitatively leaches these metal ions. From the leachate, Co(II) and Cu(II) were recovered by their extraction with Cyanex 923 and Ni(II) by extraction with Cyanex 301. Co(II) and Cu(II) are partitioned in the organic phase as H₂CoCl₄·2 Cyanex 923 and CuCl₂·2 Cyanex 923, whereas Ni(II) is extracted in the form of NiR₂ (HR=Cyanex 301). A solution of 0.001 M H₂SO₄ is used for the stripping of Co(II) and Cu(II) and 5% NH₄Cl in 75% NH₃ for Ni(II). Both extractants are found to be stable toward prolonged contact with HCl and show negligible loss in their extraction capacity even after recycling them for 20 cycles. The partition data have been utilized in developing conditions for the separation of Co(II), Ni(II), and Cu(II) mutually and from other metal ions, namely Ti(IV), Al(III), Fe(III), Mn(II), and Zn(II). The procedure of separation thus developed has been extended for the recovery of around 90% Co(II), Ni(II), and Cu(II) from sea nodules. The purity of the metal ions thus obtained is around 99%.

▼ Stabilization of solvent impregnated resins was achieved by the formation of a surface coating with the absorptive layer of poly(vinyl alcohol) and cross-linking with the protective layer of vinyl sulphone (VS). Amberlite XAD-4 and vinyl sulphone proved to be effective matrix and cross-linking agents, respectively, in the preparation of a protective layer of SIRs containing Cyanex 923 as extractant. The stabilized SIRs were characterized by the amount of vinyl sulphone contributing to the N and S content in the stabilized resin as well as to its operational stability. Optical and single electron microscope pictures were used to examine the appearance and the morphology, respectively, of the external protective barrier of SIR. Batch and column mode of sorption/elution studies for the removal of mercury from aqueous solution at pH 4 were carried out with Cyanex 923 containing SIR coated with PVA cross-linked with VS. Stabilized SIR was found to be effective for the mercury removal and showed great stability during the batch recycle runs. Elution of mercury from SIR was quantitatively achieved with 3M HNO₃. Kinetic and column performances were influenced by the degree of cross-linking of resin coating. Chemical stability and sorption capacity of stabilized SIR remained almost constant after several recycle runs whilst uncoated SIRs lose extractant with time as confirmed by efficiency studies.

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This paper deals with the dynamics of chromium, nickel, copper and lead among the different components namely water, surface sediments, submerged and free floating macrophytes and fish of the twin manmade lakes, Upper and Lower lakes, of Bhopal (M.P., India). Some basic parameters of water and sediment have also been studied. The basin of the lake system is densely populated and the water is used for various purposes including drinking. Ni and Pb along with nitrate in both lakes are significantly higher than the drinking water quality criteria of USEPA. The concentration of the metals in the sediments is noticeably higher than that present in the adjoining rock, particularly Ni and Pb. There is a significant uptake of metals by the macrophytes (Eichhornia crassipes and Hydrilla verticillata) and fish (Labeo rohita and Oreochromis niloticus) mainly in summer. The fish of Lower lake (O. niloticus) is unfit for human consumption. The data have been statistically treated. Principle component analysis and cluster analysis were performed to define the origin of metals and to assess the relationship among the sites. Overall the Lower lake is more polluted than the Upper lake. In aggregate, the lake system is under an environmental stress due to certain practices.