Preparation of composite cathode material by using the extracted lead (Pb) of waste lead acid battery for LT-SOFC

The extraction of Pb from the waste lead acid batteries offers the conservation of energy resources and reduction of pollution load in the environment. The recycling of waste lead acid batteries than discarding by conventional methods is the best way. In the present studies, for LT-SOFC, three composite cathode materials (Pb_0.1Fe_0.4Co_0.5O_4-δ, Pb_0.2Fe_0.3Co_0.5O_4-δ and Pb_0.3Fe_0.2Co_0.5O_4-δ) were produced by extracting Pb from the waste lead acid batteries, cobalt nitrate [Co(NO₃)₃.6H₂O] and iron nitrate [Fe(NO₃)₃.9H₂O] using standard solid state reaction method. Thermal stability, morphological and structural characteristics were studied by TGA, SEM and XRD analyses. FTIR spectra were used to investigate the types of metal oxide bonding in the prepared ceramic composite cathode materials. Fuel cell testing and DC four probes were used to investigate electrochemical properties. The measurement of average crystalline size of the composites was found to be in the range of 12–37 nm.Scanning electron microscopy (SEM) images showed that composite materials are porous and suitable to diffuse the gases. The maximum conductivities of 1.6 Scm^?1, 2.05 Scm^?1 and 2.6 Scm^?1 have been obtained for Pb_0.1Fe_0.4Co_0.5O_4-δ, Pb_0.2Fe_0.3Co_0.5O_4-δ and Pb_0.3Fe_0.2Co_0.5O_4-δ, respectively. At 600 °C, the high OCV (0.95V) and the maximum power density (439 mW/cm²) have been achieved using hydrogen as the fuel. Lower value of activation energy (0.36ev) of Pb_0.3Fe_0.2Co_0.5O_4-δ confirms that it is the efficient material to convert electrochemically hydrogen fuel into valuable electricity.     

Derivation and verification of an aerosol dynamics expression for the below-cloud scavenging process using the moment method

An aerosol dynamics equation for the below-cloud scavenging process considering phoretic and electric charging effects in addition to the conventional mechanisms (the Brownian diffusion, interception, and impaction) is developed by using the moment method. Then, the dynamics of particle size distribution by the below-cloud scavenging process is calculated by using the developed equation and verified with the measurement data. The calculated particle size distribution changes are quite small compared to the measured changes. The calculated removal rate is smaller by 10^?2–10^?3 than the measured data when only the conventional mechanisms are considered. With the extended mechanisms, the scavenging coefficient increases upto 20 times, mainly for the particle size range of 0.1 μm<d_p<3.0 μm. However, the difference between the calculated and measured scavenging coefficient is still large, especially, for d_p<0.1 μm. Other possible scavenging mechanisms that might affect the below-cloud scavenging process such as coagulation and condensational growth of hygroscopic particles, turbulence, and updraft into cloud are discussed. It is recommended that further studies on wet scavenging process are needed.     

In situ polarized total-reflection fluorescence X-ray absorption near-edge structure spectroscopy for the analysis of oriented structure of vanadium oxides on ZrO2(100)

The oriented structure of the exposed V=O bond of vanadium oxides on ZrO₂(100) was studied by in situ polarized total-reflection fluorescence X-ray absorption near-edge structure (XANES) spectroscopy. The pre-edge peak intensity of s-polarized XANES was half the intensity of the p-polarized one. Moreover, both pre-edge peaks decreased in a similar way and eventually became zero by the reaction of V=O bonds with NH₃ at 423 K, suggesting that all of the observed V=O bonds behaved as active sites. The present technique suggests that the exposed V=O bonds are oriented to a 45°-direction from the normal to the ZrO₂(100) surface.     

Preparation of carbon micro-coils involving the decomposition of hydrocarbons using PACT (plasma and catalyst technology) reactor

Carbon micro-coils as well as carbon fibers with various morphologies were prepared by the decomposition of hydrocarbons, such as acetylene, methane, propane, ethylene, etc., at 770°C using a PACT (plasma and catalyst technology) reactor. The preparation conditions, growth mechanism and morphology of the carbon micro-coils were examined. The Ni electrode of the PACT reactor was used as the catalyst as well as a plasma source electrode. It was found that hydrocarbons, such as methane, propane and ethylene, decomposed under the plasma and catalyst atmosphere to form acetylene as the main decomposition product, and then this acetylene was further decomposed to form carbon micro-coils. Using a Ni powder catalyst dispersed on the substrate, the carbon micro-coils with a double helix structure, in which two pieces of carbon coils entwine each other in the same coiling direction, grew among the single straight carbon fibers and paired straight fibers. On the other hand, the carbon micro-coils with a single helix structure and wide coil pitch were obtained by the indirect decomposition of acetylene using the N₂ plasma formed by the PACT reactor.     

A world-wide program for the continuous monitoring of solar UV radiation using poly(phenylene oxide) film,and a consideration of results

The use of poly(phenylene oxide) film to monitor UV radiation is demonstrated, and the results from the continuous monitoring of solar UV radiation at 24 sites throughout the world are presented. The global and diffuse measurements from a temperate and from a tropical site are analyzed in detail, and the effects of season and weather conditions on the UV contribution to solar radiation and the relative importance of the diffuse and direct components of solar UV are discussed.     

Comparison of Two Solvent Extraction Systems for the Separation of V(V) and Cr(VI) from an Industrial Leaching Solution

Two solvent extraction systems for V (V) and Cr (VI) separation in leaching solution were investigated in order to select the suitable separation method for the disposing of chromium-bearing vanadium slag. The best/suitable system was determined by extraction yield (E_V,%) and the separation factor of V(V) and Cr(VI) (β_V/Cr). On the condition of 1:1 molar ratio of H⁺ to vanadium (V), the E_V values were 99.8% and 95.1%, while the β_V/Cr values were 546.58 and 29.53 using the two different systems, respectively. The extraction reactions for system 1 were determined by the slope method, and the chemical equilibrium constants were obtained.     

Preparation of liposomes using the supercritical anti-solvent (SAS) process and comparison with a conventional method

Two methods to produce liposomes encapsulating a fluorescent marker were compared: the supercritical anti-solvent (SAS) method and a conventional one (Bangham). Liposome size and encapsulation efficiency were measured to assess the methods. Micronized lecithin produced by the SAS process was characterized in terms of particle size, morphology and residual solvent content in order to investigate the influence of experimental parameters (pressure, CO₂/solvent molar ratio and solute concentration). It appears that when the lecithin concentration increases from 15 to 25 wt.%, at 9 MPa and 308 K, larger (20-60 μm) and less aggregated lecithin particles are formed. As concerns liposomes formed from SAS processed lecithin, size distribution curves are mainly bimodal, spreading in the range of 0.1-100 μm. Liposome encapsulation efficiencies are including between 10 and 20%. As concerns the Bangham method, more dispersed liposomes were formed; encapsulation efficiencies were about 20%, and problems of reproducibility have been raised.     

Preparation and characterization of silanized silica gel‐supported poly(acrylic acid) network polymer and study of its analytical application as selective extractor for lead ion

A novel silanized silica gel (SSG)‐supported poly(acrylic acid) network polymer (ion exchanger) has been synthesized and characterized for the study of its analytical applications. The chemical nature of the ion exchanger has been elucidated with the help of FTIR, NMR, TGA, DSC, and SEM. The immobilization of the polymer network on SSG has been studied. The optimum pH range for quantitative extraction of lead was found to be 4.5–6.0. The effects of pH and stripping agent on extraction and elution of Pb(II), respectively, have been investigated. Ion exchange and break through capacity of the exchanger have been determined at room temperature. Pb(II) has been extracted quantitatively from various environmental samples. A plausible mechanism for lead ion exchange has been suggested. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Oviposition and feeding preferences of the southern pine coneworm (Lepidoptera: Pyralidae) for different host-plant materials and observations on monoterpenes as an oviposition stimulant

Bioassays were conducted with first-stage larvae and newly emerged females of the southern pine coneworm,Dioryctria amatella (Hulst), to detect feeding and ovipositional preferences for different host-plant materials collected between April and August. Correlations between measures of insect preferences and estimates of wood parameters indicated that larvae preferred to feed on host-plant materials with high moisture contents, low wood densities, and low monoterpene contents. Female moths, however, did not necessarily select those plant materials preferred by larvae for feeding, but tended to oviposit more frequently on materials with high monoterpene contents. A synthetic mixture of monoterpenes similar in composition to those present in fusiform rust galls of slash pine (Pinus elliottii) Englem. var.elliottii) elicited mating and oviposition behavior.Mention of proprietary products does not necessarily imply endorsement by USDA.     

Preparation of amidoxime‐modified polyacrylonitrile nanofibrous adsorbents for the extraction of copper(II) and lead(II) ions and dye from aqueous media

Amidoxime‐modified polyacrylonitrile nanofibrous films (AOPAN NFs) were prepared via an electrospinning technique. The traditional preparation methods for amidoximated polyacrylonitrile (AOPAN) solution were changed and improved. First, the PAN solution was modified by hydroxylamine hydrochloride to produce an AOPAN solution, and then, a small amount of inhibitor was added to the AOPAN solution for electrospinning. We found that the crosslinking of the AOPAN solution was inhibited by the addition of a small amount of inhibitor; at the same time, the storage time of the AOPAN solution was prolonged. In addition, the prepared AOPAN solution was electrospun into nanofibrous films, which could be used as excellent adsorption materials for Cu(II), Pb(II), and methyl orange (MO) after drying. The maximal adsorption capacities for Cu(II), Pb(II), and MO were 143.47, 178.57, and 68.07 mg/g, respectively. The adsorption capacities of the nanofibrous films were more than 50% that of the first adsorption after four recycling runs; this indicated the reusability of the nanofibrous films for water treatment. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45697.     

X-ray powder diffraction-based method for the determination of the glass content and mineralogy of coal (co)-combustion fly ashes

The relevance of Al-Si glass in a number of fly ash applications, such as use as a pozzolanic material, zeolite synthesis, and geopolymer production, necessitated research towards investigation of methods for an easy and consistent determination of the glass content in this coal (co)-combustion by-products. A glass standard-addition X-ray powder diffraction (XRD)-based method is proposed in this study as an alternative to the non straightforward procedure of conventional methods for determining the amorphous components, mainly by difference of the total mass and the addition of quantified crystalline species. A >99% Al-Si glass slag sample was selected as a standard for glass. A number of glass standard/fly ash mixtures were performed on Fluidized Bed Combustion (FBC) and pulverized coal combustion (PCC) fly ashes and subsequently analyzed by XRD. The method provides results closer to quantitative proportions of the Al-Si amorphous material of this (co)-combustion by-product, with a range of values <3% when compared with those obtained by the conventional Reference Intensity Method (RIM) method, demonstrating suitability and consistence of the procedure. Furthermore, by the proposed method, the requirement of previous determination of the mineral phases of conventional techniques is avoided. Coupled with the easy calculations, this allowed a fast determination of the glass content of (co)-combustion fly ash. The mineralogy of FBC and PCC fly ash was also investigated using the RIM method. The occurrence and proportions of the crystalline components in fly ash are in line with the combustion technology and their inherent operational parameters, especially the (co)-combustion temperature. The FBC fly ash shows the highest content of relic phases from feed coal (quartz, illite, calcite, and feldspars) and lower contents of amorphous components. The PCC fly ash are characterized by the highest proportions of mullite and Al-Si glass and low contents of quartz an other relict phases. The occurrence and distribution of anhydrite and Fe-oxide species appears to be related to the content of Ca and Fe in the feed fuels, showing slightly higher contents in FBC than in PCC fly ash.     

Self-assembly of thiourea intercalated graphene oxide based dual IIP for the SPE coupled FAAS method development of Cu(II) and Pb(II) determination

A new dual-template surface imprinted polymer for Cu(II) and Pb(II) was synthesized in one pot. Magnetic graphene oxide was self-assembled with low cost and environmentally benign thiourea. Presence of sulfur and nitrogen donor atoms provide hooks for coordination and partial reduction of graphene oxide matrix. It was used as an solid-phase extraction adsorbent for extraction, preconcentration, and coupled with flame atomic absorption spectrometry to manifest performance comparable with inductively coupled plasma atomic emission spectrometry (ICPAES) both in terms of quantification limit as well as interference. The critical experimental parameters such as pH; 4.6, contact time of 15 min and initial concentration of 777 (Q_e; 227 mg g⁻¹) and 800 μg L⁻¹ (Q_e; 273 mg g⁻¹) for Cu(II) and Pb(II), respectively, were optimized using RSM-CCD and artificial neural network. The adsorption process was kinetically faster (50% adsorption in 5 min), following fractal-like-pseudo-second-order (FLPSO) kinetics and Brouers–Sotolongo isotherm model owing to the heterogenous energy landscape. The imprinting factors were in the range of 4–7 in the presence of all coexisting ions. The proposed method was robust in the determination and removal of Cu(II) and Pb(II) from food, ground water, and industry effluents with low limit of detection (Cu(II); 1.03 μg L⁻¹ & Pb(II); 1.79 μgL⁻¹). Spiking and recovery tests were used to assess the method's accuracy. Cu(II)/Pb(II) loaded dual template IIP (DIIP) was utilized to remove anionic dyes with >95% efficiency. Thorough examination of the method and material selectivity (in binary, ternary, and multielement system), multi fold applications of determination, removal of Cu(II), Pb(II), and removal of anionic dyes makes DIIP a promising candidate for environmental remediation.     

超重力法制备CNT负载MnFe2O4纳米材料及吸附Pb(II)应用

为改善MnFe2O4纳米颗粒在实际应用中的团聚问题,结合多壁碳纳米管(CNT)原位负载,提出超重力法制备CNT负载MnFe2O4纳米材料(MnFe2O4/CNT)。以典型的重金属污染Pb(II)作为研究对象,对其吸附性能进行研究。首先考察了MnFe2O4负载量对Pb(II)吸附容量的影响,确定最佳MnFe2O4负载量为83.3wt%。采用XRD, SEM, N2吸附-脱附比表面分析仪和VSM对最佳MnFe2O4负载量条件下的MnFe2O4/CNT进行表征。MnFe2O4/CNT展现出优异的磁性,其饱和磁化强度为35.85 emu/g,因而可应用于水体中污染物的磁性分离。吸附实验结果表明在初始Pb(II)浓度300 mg/L和溶液pH=6的条件下,Pb(II)在MnFe2O4/CNT上180 min达到吸附平衡,吸附平衡容量为80.7 mg/g,远高于单独的CNT (28.4 mg/g)。动力学研究表明Pb(II)在MnFe2O4/CNT上的吸附符合Elvoch动力学模型,说明吸附机理中存在化学吸附。Freundlich等温线模型能够很好地描述Pb(II)在MnFe2O4/CNT上的吸附过程,其代表发生在非均匀表面的多分子层吸附。另外,吸附等温线实验中获得的MnFe2O4/CNT最大吸附容量为106.2 mg/g,展现出了对重金属Pb(II)优异的吸附性能,在去除溶液中重金属中具有较大的应用潜力。根据X射线光电子能谱分析,表明吸附机理涉及到Pb(II)与MnFe2O4表面羟基的络合。     

A new method for the simultaneous determination of Fe(III), Cu(II), Pb(II), Zn(II), Cd(II), and Ni(II) in wine using differential pulse polarography

A new and simple differential pulse polarographic method for the analysis of wine has been established. With this method, it was possible to determine simultaneously six trace elements in wine. There was no need for time consuming extraction and separation procedures with danger of contamination. The polarogram of wet digested wine was taken initially in pH 2 acetate buffer and Pb, Cd, and Zn were determined by standard additions. Ethylene diamine tetraacetic acid (EDTA) was added and pH was increased to six by addition of NaOH. Fe and Cu were determined subsequently. The ammonia buffer, pH 9.5, was identified as the best medium for separation and determination of Ni and Zn. The quantities of trace elements were found as Cu 290 ± 20 μg L⁻¹, Fe 8960 ± 50 μg L⁻¹, Pb 148 ± 17 μg L⁻¹, Cd 16 ± 8 μg L⁻¹, Zn 460 ± 25 μg L⁻¹, and Ni 78 ± 17 μg L⁻¹.     

Preparation of a poly(L-lactide-co-caprolactone) copolymer using a novel tin(II) alkoxide initiator and its fiber processing for potential use as an absorbable monofilament surgical suture

A poly(L-lactide-co-caprolactone) copolymer, P(LL-co-CL), of composition 75:25 mol% was synthesized via the bulk ring-opening copolymerization of L-lactide and ε-caprolactone using a novel bis[tin(II) monooctoate] diethylene glycol coordination-insertion initiator, OctSn-OCH₂CH₂OCH₂CH₂O-SnOct. The P(LL-co-CL) copolymer obtained was characterized by a combination of analytical techniques, namely nuclear magnetic resonance spectroscopy, gel permeation chromatography, dilute-solution viscometry, differential scanning calorimetry, and thermogravimetric analysis. For processing into a monofilament fiber, the copolymer was melt spun with minimal draw to give a largely amorphous and unoriented as-spun fiber. The fiber's oriented semicrystalline morphology, necessary to give the required balance of mechanical properties, was then developed via a sequence of controlled offline hot-drawing and annealing steps. Depending on the final draw ratio, the fibers obtained had tensile strengths in the region of 200–400 MPa.     

Polymer‐grafted banana (Musa paradisiaca) stalk as an adsorbent for the removal of lead(II) and cadmium(II) ions from aqueous solutions: kinetic and equilibrium studies

This study examined the effectiveness of a new adsorbent prepared from banana (Musa paradisiaca) stalk, one of the abundantly available lignocellulosic agrowastes, in removing Pb(II) and Cd(II) ions from aqueous solutions. The adsorbent (PGBS‐COOH) having a carboxylate functional group at its chain end was synthesized by graft copolymerization of acrylamide on to banana stalk, followed by functionalization. Batch adsorption experiments were carried out as a function of solution pH, ionic strength, contact time, metal concentration, adsorbent dose and temperature. A pH range of 5.5–8.0 was found to be effective for the maximum removal for both Pb(II) and Cd(II). Metal uptake was found to decrease with increase in ionic strength due to the expansion of the diffuse double layer and, more importantly, the formation of some chloro complexes (since NaCl was used in the adjustment of ionic strength), which do not appear to be adsorbed to the same extent as cations [M²⁺ and M(OH)⁺]. The kinetic studies showed that an equilibrium time of 3 h was needed for the adsorption of Pb(II) and Cd(II) on PGBS‐COOH and adsorption processes followed a pseudo‐second‐order equation. The Langmuir isotherm model fitted the experimental equilibrium data well. The maximum sorption capacity for Pb(II) and Cd(II) ions was 185.34 and 65.88 mg g^?1, respectively, at 30 °C. The thermodynamic parameters such as changes in free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) were derived to predict the nature of adsorption. The isosteric heat of adsorption was found to be independent of surface coverage. Adsorption experiments were also conducted using a commercial cation exchanger, Ceralite IRC‐50, for comparison. Synthetic wastewater samples were treated with the adsorbent to demonstrate its efficiency in removing Pb(II) and Cd(II) ions from industrial wastewaters. Acid regeneration was tried for several cycles with a view to recovering the sorbed metal ions and also restoring the sorbent to its original state. Copyright © 2005 Society of Chemical Industry     

Study of the structure and transport of asymmetric polyamide membranes for reverse osmosis using the electron spin resonance (ESR) method

The electron spin resonance technique (ESR) was used to study the structure and transport of asymmetric aromatic polyamide membranes. TEMPO (2,2,6,6-tetramethyl-1-piperridinyloxy free radical) was used as a spin probe that was brought into the membrane either by (a) immersion ofthe membranes in aqueous TEMPO solutions, (b) reverse osmosis (RO) experiments with feed solutions involving TEMPO or (c) blending TEMPO in casting solutions. The membranes were further tested for the separation of sodium chloride and TEMPO from water by RO. It was concluded that aromatic polyamide membranes contain water channels in the polymer matrix like cellulose acetate membranes. The presence of such water channels allows aromatic polyamide membranes to be used as RO membranes. The diffusion of organic solutes through the water channels seems much slower in aromatic polyamide membranes than in cellular acetate membranes, which probably causes a higher separation of organic solutes by aromatic polyamide membranes than cellulose acetate membranes. A comparison was made with other RO membranes (cellulose acetate, CA) and ultrafiltration membranes (polyethersulphone, PES). It was observed that the ESR technique can be used to study the structure of OF and RO membranes. The presence of water channels in the polymer matrix seems indispensable for the RO membrane.     

Simple,selective and sensitive voltammetric method for the determination of herbicide (paraquat) using a bare boron-doped diamond electrode

A simple, selective and sensitive electroanalytical method for detection of paraquat on a bare boron-doped diamond electrode (BDDE) using square-wave voltammetry is demonstrated. It was found that paraquat provided a highly reproducible and well-defined reduction peak in aqueous media (ammonia buffer, pH 9.0) using BDDE. Excellent linear response of peak current on the paraquat concentration in the range from 5 × 10^− 9 to 1 × 10^− 6 mol L^− 1, good repeatability (RSD 3.2%) and low detection limit of 1.5 × 10^− 9 mol L^− 1 without any chemical modifications and electrochemical pretreatment of the electrode surface were evaluated. The effect of possible interferences appeared to be negligible which proved very good selectivity. The proposed method was successfully applied to paraquat determination in natural water samples collected from a Polish river and sea.     

Simple and efficient method for the oxidation of sulfides to sulfones using hydrogen peroxide and a Mo(VI) based catalyst

A simple and efficient method for the oxidation of sulfides to sulfones at room temperature using ammonium heptamolybdate and 30% H₂O₂ is developed. The reactions provide excellent yields within short time, also sensitive functional groups such as allyl, vinyl, propargyl, alcohol, ketone, ester, pyridine and nitrile are found to be tolerated.