Search results for: cation

Authors: V. Pérez-Herranz, M. Pinel, E. M. Ortega, M. García-Gabaldón

Abstract:

In the present work, Electrochemical Impedance Spectrocopy (EIS) is applied to study the transport of different metal cations through a cation-exchange membrane. This technique enables the identification of the ionic-transport characteristics and to distinguish between different transport mechanisms occurring at different current density ranges. The impedance spectra are dependent on the applied dc current density, on the type of cation and on the concentration. When the applied dc current density increases, the diameter of the impedance spectra loops increases because all the components of membrane system resistance increase. The diameter of the impedance plots decreases in the order of Na(I), Ni(II) and Cr(III) due to the increased interactions between the negatively charged sulfonic groups of the membrane and the cations with greater charge. Nyquist plots are shifted towards lower values of the real impedance, and its diameter decreases with the increase of concentration due to the decrease of the solution resistance.

Keywords: Ion-exchange Membranes, Electrochemical Impedance Espectroscopy, Multivalent Metal Cations.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1836

Authors: Ali Keshavarzi, Fereydoon Sarmadian

Abstract:

Investigation of soil properties like Cation Exchange Capacity (CEC) plays important roles in study of environmental reaserches as the spatial and temporal variability of this property have been led to development of indirect methods in estimation of this soil characteristic. Pedotransfer functions (PTFs) provide an alternative by estimating soil parameters from more readily available soil data. 70 soil samples were collected from different horizons of 15 soil profiles located in the Ziaran region, Qazvin province, Iran. Then, multivariate regression and neural network model (feedforward back propagation network) were employed to develop a pedotransfer function for predicting soil parameter using easily measurable characteristics of clay and organic carbon. The performance of the multivariate regression and neural network model was evaluated using a test data set. In order to evaluate the models, root mean square error (RMSE) was used. The value of RMSE and R2 derived by ANN model for CEC were 0.47 and 0.94 respectively, while these parameters for multivariate regression model were 0.65 and 0.88 respectively. Results showed that artificial neural network with seven neurons in hidden layer had better performance in predicting soil cation exchange capacity than multivariate regression.

Keywords: Easily measurable characteristics, Feed-forwardback propagation, Pedotransfer functions, CEC.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2163

Authors: A. Alshebani, Y. Swesi, S. Mrayed, F. Altaher, I. Musbah

Abstract:

Cs-type nanocomposite zeolite membrane was successfully synthesized on an alumina ceramic hollow fibre with a mean outer diameter of 1.7 mm; cesium cationic exchange test was carried out inside test module with mean wall thickness of 230 μm and an average crossing pore size smaller than 0.2 μm. Separation factor of n-butane/H₂ obtained indicate that a relatively high quality closed to 20. Maxwell-Stefan modeling provides an equivalent thickness lower than 1 µm. To compare the difference an application to CO₂/N₂ separation has been achieved, reaching separation factors close to (4,18) before and after cation exchange on H-zeolite membrane formed within the pores of a ceramic alumina substrate.

Keywords: MFI membrane, nanocomposite, Ceramic hollow fibre, CO2, Ion-exchange.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1968

Authors: Ahmed O. Apampa, Yinusa A. Jimoh

Abstract:

The paper examines the mechanism of pozzolan-soil reactions, using a recent study on the chemical stabilization of a Class A-2-7 (3) lateritic soil, with corn cob ash (CCA) as case study. The objectives are to establish a nexus between cation exchange capacity of the soil, the alkaline forming compounds in CCA and percentage CCA addition to soil beyond which no more improvement in strength properties can be achieved; and to propose feasible chemical reactions to explain the chemical stabilization of the lateritic soil with CCA alone. The lateritic soil, as well as CCA of pozzolanic quality Class C were separately analysed for their metallic oxide composition using the X-Ray Fluorescence technique. The cation exchange capacity (CEC) of the soil and the CCA were computed theoretically using the percentage composition of the base cations Ca²⁺, Mg²⁺ K⁺ and Na²⁺ as 1.48 meq/100 g and 61.67 meq/100 g respectively, thus indicating a ratio of 0.024 or 2.4%. This figure, taken as the theoretical amount required to just fill up the exchangeable sites of the clay molecules, compares well with the laboratory observation of 1.5% for the optimum level of CCA addition to lateritic soil. The paper went on to present chemical reaction equations between the alkaline earth metals in the CCA and the silica in the lateritic soil to form silicates, thereby proposing an extension of the theory of mechanism of soil stabilization to cover chemical stabilization with pozzolanic ash only. The paper concluded by recommending further research on the molecular structure of soils stabilized with pozzolanic waste ash alone, with a view to confirming the chemical equations advanced in the study.

Keywords: Cation exchange capacity, corn cob ash, lateritic soil, soil stabilization.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1292

Authors: Gemma A. Gruyal

Abstract:

Plants can contain a wide variety of substances with antioxidative properties which are associated with important health benefits. These positive health effects are of great importance at a time when the environment is laden with many toxic substances. Five selected herbal plants namely, Mimosa pudica, Phyllanthus niruri, Ceiba pentandra, Eleusine polydactyla and Trema amboinensi, were chosen for the experiment to investigate their total phenolics content and antioxidant activities using ABTS radical cation decolorization power, and ferric reducing antioxidant power. The total phenolic content of each herbal plants ranges from 0.84 to 42.59 mg gallic acid equivalent/g. The antioxidant activity in the ABTS radical cation decolorization power varies from 0.005 to 0.362 mg trolox equivalent/g and the FRAP ranges from 0.30 to 28.42 mg gallic acid equivalent/g. Among the five medicinal plants, Mimosa pudica has been an excellent performer in terms of the 3 parameters measured; it is followed by Phyllanthus niruri. The 5 herbal plants do not have equivalent antioxidant power. The relative high values for M. pudica and P. niruri supports the medicinal value of both plants. The total phenolics, ABTS and FRAP correlate strongly with one another.

Keywords: ABTS, FRAP, leaf extracts, phenol.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2435

Authors: A. Alshebani, Y. Swesi, S. Mrayed, F. Altaher

Abstract:

This paper present some preliminary work on the preparation and physicochemical caracterization of nanocomposite MFI-alumina structures based on alumina hollow fibres. The fibers are manufactured by a wet spinning process. α-alumina particles were dispersed in a solution of polysulfone in NMP. The resulting slurry is pressed through the annular gap of a spinneret into a precipitation bath. The resulting green fibres are sintered. The mechanical strength of the alumina hollow fibres is determined by a three-point-bending test while the pore size is characterized by bubble-point testing. The bending strength is in the range of 110 MPa while the average pore size is 450 nm for an internal diameter of 1 mm and external diameter of 1.7 mm. To characterize the MFI membranes various techniques were used for physicochemical characterization of MFI–ceramic hollow fibres membranes: The nitrogen adsorption, X-ray diffractometry, scanning electron microscopy combined with X emission microanalysis. Scanning Electron Microscopy (SEM) and Energy Dispersive Microanalysis by the X-ray were used to observe the morphology of the hollow fibre membranes (thickness, infiltration into the carrier, defects, homogeneity). No surface film, has been obtained, as observed by SEM and EDX analysis and confirmed by high temperature variation of N2 and CO2 gas permeances before cation exchange. Local analysis and characterise (SEM and EDX) and overall (by ICP elemental analysis) were conducted on two samples exchanged to determine the quantity and distribution of the cation of cesium on the cross section fibre of the zeolite between the cavities.

Keywords: Physicochemical characterization of MFI, Ceramic hollow fibre, CO2, Ion-exchange.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2020

Authors: Ishan Arora, Anurag S. Rathore

Abstract:

The primary objective of this work was to study the effect of resin chemistry, pH and molarity of binding and elution buffer on aggregate removal using Cation Exchange Chromatography and find the optimum conditions which can give efficient aggregate removal with minimum loss of yield. Four different resins were used for carrying out the experiments: Fractogel EMD SO3 -(S), Fractogel EMD COO-(M), Capto SP ImpRes and S Ceramic HyperD. Runs were carried out on the AKTA Avant system. Design of Experiments (DOE) was used for analysis using the JMP software. The dependence of the yield obtained using different resins on the operating conditions was studied. Success has been achieved in obtaining yield greater than 90% using Capto SP ImpRes and Fractogel EMD COO-(M) resins. It has also been found that a change in the operating conditions generally has different effects on the yields obtained using different resins.

Keywords: Aggregates, cation exchange chromatography, design of experiments, monoclonal antibodies.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2874

Authors: Yusuke Ayato, Takashi Itahashi, Akiko Takatsu, Kenji Kato, Naoki Matsuda

Abstract:

In situ observation of absorption spectral change of heptil viologen cation radical (HV+.) was performed by slab optical waveguide (SOWG) spectroscopy utilizing indium-tin-oxide (ITO) electrodes. Synchronizing with electrochemical techniques, we observed the adsorption process of HV+.on the ITO electrode. In this study, we carried out the ITO-SOWG observations using KBr aqueous solution containing different concentration of HV to investigate the concentration dependent spectral change. A few specific absorption bands, which indicated HV+.existed as both monomer and dimer on ITO electrode surface with a monolayer or a few layers deposition, were observed in UV-visible region. The change in the peak position of the absorption spectra from adsorption species of HV+. were correlated with the concentration of HV as well as the electrode potential.

Keywords: absorption phenomena, heptil viologen, indium-tin-oxide (ITO) electrode, in situ, slab optical waveguide(SOWG) spectroscopy,

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1485

Authors: Ren Jian-min, Wu Si-wei, Jin Wei

Abstract:

CTMA-bentonite and BTEA-Bentonite prepared by Na-bentonite cation exchanged with cetyltrimethylammonium(CTMA) and benzyltriethylammonium (BTEA). Products were characterized by XRD and IR techniques.The d001 spacing value of CTMA-bentonite and BTEA-bentonite are 7.54Å and 3.50Å larger than that of Na-bentonite at 100% cation exchange capacity, respectively. The IR spectrum showed that the intensities of OH stretching and bending vibrations of the two organoclays decreased greatly comparing to untreated Na-bentonite. Batch experiments were carried out at 303 K, 318 K and 333 K to obtain the sorption isotherms of Crystal violet onto the two organoclays. The results show that the sorption isothermal data could be well described by Freundlich model. The dynamical data for the two organoclays fit well with pseudo-second-order kinetic model. The adsorption capacity of CTMA-bentonite was found higher than that of BTEA-Bentonite. Thermodynamic parameters such as changes in the free energy (ΔG°), the enthalpy (ΔH°) and the entropy (ΔS°) were also evaluated. The overall adsorption process of Crystal violet onto the two organoclays were spontaneous, endothermic physisorption. The CTMA-bentonite and BTEA-Bentonite could be employed as low-cost alternatives to activated carbon in wastewater treatment for the removal of color which comes from textile dyes.

Keywords: Characterization, Adsorption, Crystal violet, Bentonite, BTEA, CTMA

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2109

Authors: N. Hoosain, S. Nene, B. Pearce, C. Jacobs, M. Du Plessis, M. Benjeddou

Abstract:

Organic cation transporter (OCT) 1could influence an individual’s response to various treatments and increase their susceptibility to diseases.Genotypic and allelic frequencies of nineteen non-synonymous and one intronic Single Nucleotide Polymorphism (SNP) from the OCT1 gene were determined in 101 unrelated healthy Zulu participants, using a SNaPshot^® multiplex assay. Minor allele frequencies (MAF)were compared to representative populations of Africa, Asia and Europe, from Ensembl. MAFs for S14F, V519F, rs622342 and P341L were 2.0%, 6.0%, 6.0% and 1.0%, respectively. Sixteen of nineteen investigated non-synonymous SNPs were monomorphic. No study participant harbored variant alleles for S189L, G220V, P283L, G401S, M420V, M440I, G465R, I542V, R61C, R287G, C88S, A306T, A413V, I421F, C436F and V501E. Haplotype, CGTCGCCGCGCAAGAGGTGA, was most frequently observed (81.23%).Further investigations are encouraged to evaluate potential roles these SNPs could play in the therapeutic efficacy of clinically important drugs and in the development of various diseases in the Zulu population.

Keywords: OCT1, PCR, SNaPshot assay, Zulu population.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2228

Authors: Ashish R. Tanna, Hiren H. Joshi

Abstract:

The mineral having chemical compositional formula MgAl2O4 is called “spinel". The ferrites crystallize in spinel structure are known as spinel-ferrites or ferro-spinels. The spinel structure has a fcc cage of oxygen ions and the metallic cations are distributed among tetrahedral (A) and octahedral (B) interstitial voids (sites). The X-ray diffraction (XRD) intensity of each Bragg plane is sensitive to the distribution of cations in the interstitial voids of the spinel lattice. This leads to the method of determination of distribution of cations in the spinel oxides through XRD intensity analysis. The computer program for XRD intensity analysis has been developed in C language and also tested for the real experimental situation by synthesizing the spinel ferrite materials Mg0.6Zn0.4AlxFe2- xO4 and characterized them by X-ray diffractometry. The compositions of Mg0.6Zn0.4AlxFe2-xO4(x = 0.0 to 0.6) ferrites have been prepared by ceramic method and powder X-ray diffraction patterns were recorded. Thus, the authenticity of the program is checked by comparing the theoretically calculated data using computer simulation with the experimental ones. Further, the deduced cation distributions were used to fit the magnetization data using Localized canting of spins approach to explain the “recovery" of collinear spin structure due to Al3+ - substitution in Mg-Zn ferrites which is the case if A-site magnetic dilution and non-collinear spin structure. Since the distribution of cations in the spinel ferrites plays a very important role with regard to their electrical and magnetic properties, it is essential to determine the cation distribution in spinel lattice.

Keywords: Spinel ferrites, Localized canting of spins, X-ray diffraction, Programming in Borland C.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3732

Authors: Xiangjun Li, Huaiyuan Tian, Wujie Zhang, Dianhua Liu

Abstract:

Polyoxymethylene dimethyl ethers (PODE_n) as clean diesel additive can improve the combustion efficiency and quality of diesel fuel and alleviate the problem of atmospheric pollution. Considering synthetic routes, PODE production from methanol and formaldehyde is regarded as the most economical and promising synthetic route. However, methanol used for synthesizing PODE can produce water, which causes the loss of active center of catalyst and hydrolysis of PODE_n in the production process. Macroporous strong acidic cation exchange resin catalyst was prepared, which has comparative advantages over other common solid acid catalysts in terms of stability and catalytic efficiency for synthesizing PODE. Catalytic reactions were carried out under 353 K, 1 MPa and 3mL·g_cat^-1·h^-1 in a fixed bed reactor. Methanol conversion and PODE_3-6 selectivity reached 49.91% and 23.43%, respectively. Catalyst lifetime evaluation showed that resin catalyst retained its catalytic activity for 20 days without significant changes and catalytic activity of completely deactivated resin catalyst can basically return to previous level by simple acid regeneration. The acid exchange capacities of original and deactivated catalyst were 2.5191 and 0.0979 mmol·g^-1, respectively, while regenerated catalyst reached 2.0430 mmol·g^-1, indicating that the main reason for resin catalyst deactivation is that Brønsted acid sites of original resin catalyst were temporarily replaced by non-hydrogen ion cations. A separation process consisting of extraction and distillation for PODE_3-6 product was designed for separation of water and unreacted formaldehyde from reactive mixture and purification of PODE_3-6, respectively. The concentration of PODE_3-6 in final product can reach up to 97%. These results indicate that the scale-up production of PODE_3-6 from methanol and formaldehyde solution is feasible.

Keywords: Inactivation, polyoxymethylene dimethyl ethers, separation process, sulfonic cation exchange resin.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 834

Authors: H. R. Moghadamzadeh, M. Naimi, H. Rahimzadeh, M. Ardjmand, V. M. Nansa, A. M. Ghanadi

Abstract:

The Iranian bentonite was first characterized by Scanning Electron Microscopy (SEM), Inductively Coupled Plasma mass spectrometry (ICP-MS), X-ray fluorescence (XRF), X-ray Diffraction (XRD) and BET. The bentonite was then treated thermally between 150°C-250°C at 15min, 45min and 90min and also was activated chemically with different concentration of sulphuric acid (3N, 5N and 10N). Although the results of thermal activated-bentonite didn-t show any considerable changes in specific surface area and Cation Exchange Capacity (CEC), but the results of chemical treated bentonite demonstrated that such properties have been improved by acid activation process.

Keywords: Acid activation, Bentonite, CEC, Thermal activation.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2792

Authors: Ilija Plecas, Uranija Kozmidis-Luburic, Radojica Pesic

Abstract:

The leaching rate of 137Cs from spent mix bead (anion and cation) exchange resins in a cement-bentonite matrix has been studied. Transport phenomena involved in the leaching of a radioactive material from a cement-bentonite matrix are investigated using three methods based on theoretical equations. These are: the diffusion equation for a plane source an equation for diffusion coupled to a firstorder equation and an empirical method employing a polynomial equation. The results presented in this paper are from a 25-year mortar and concrete testing project that will influence the design choices for radioactive waste packaging for a future Serbian radioactive waste disposal center.

Keywords: bentonite, cement , radioactive waste, composite, disposal, diffusion

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2244

Authors: Jaromír Marek, Jakub Wiener, Yan Wang

Abstract:

The main goal of this study was to find simple and industrially applicable production of ion exchangers based on nanofibrous polystyrene matrix and characterization of prepared material. Starting polystyrene nanofibers were sulfonated and crosslinked under appropriate conditions at the same time by sulfuric acid. Strongly acidic cation exchanger was obtained in such a way. The polymer matrix was made from polystyrene nanofibers prepared by Nanospider^TM technology.

Various types postpolymerization reactions and other methods of crosslinking were studied. Greatly different behavior between nano- and microsize materials was observed. The final nanofibrous material was characterized and compared to common granular ion exchangers and available microfibrous ion exchangers. The sorption properties of nanofibrous ion exchangers were compared with the granular ion exchangers. For nanofibrous ion exchangers of comparable ion exchange capacity was observed considerably faster adsorption kinetics.

Keywords: Electrospinning, ion exchangers, nanofibers, polystyrene.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1933

Authors: Z. H. Shi, T. J. Dou, H. Zhang, H. X. Huang, N. Zeng

Abstract:

The contamination of significant quantities of soils and sediments with uranium and other actinide elements as a result of nuclear activity poses many environmental risks. The electrokinetic process is one of the most promising remediation techniques for sludge, sediment, and saturated or unsaturated soils contaminated with heavy metals and radionuclides. However, secondary waste is a major concern for soil contaminated with nuclides. To minimize the generation of secondary wastes, this study used the anion and cation exchange membranes to improve the performance of the experimental apparatus. Remediation experiments of uranium-contaminated soil were performed with different agents. The results show that using acetic acid and EDTA as chelating agents clearly enhances the migration ability of the uranium. The ion exchange membranes (IEMs) used in the experiments not only reduce secondary wastes, but also, keep the soil pH stable.

Keywords: Electrokinetic remediation, ion exchange membranes, soil, uranium.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1337

Authors: Nidal H. Abu-Zahra, Subhashini Gunashekar

Abstract:

Polyurethane foam is functionalized with Sulfonic acid groups to remove lead ions (Pb²⁺) from drinking water through a cation exchange process. The synthesis is based on addition polymerization of the -NCO groups of an isocyanate with the –OH groups of a polyol to form the urethane. Toluene-diisocyanateis reacted with Polypropylene glycol to form a linear pre-polymer, which is further polymerized using a chain extender, N, N-bis(2-hydorxyethyl)-2-aminoethane-sulfonic acid (BES). BES acts as a functional group site to exchange Pb²⁺ ions. A set of experiments was designed to study the effect of various processing parameters on the performance of the synthesized foam. The maximum Pb²⁺ ion exchange capacity of the foam was found to be 47ppb/g from a 100ppb Pb²⁺ solution over a period of 60 minutes. A multistage batch filtration process increased the lead removal to 50-54ppb/3g of foam over a period of 90 minutes.

Keywords: Adsorption, Functionalized, Ion exchange, Polyurethane, Sulfonic.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3001

Authors: M.M. Jafarpour, Ar. Foolad, M.K. Mansouri, Z. Nikbakhsh, H. Saeedizade

Abstract:

Ammonia nitrogen is one of the most hazardous water pollutants, discharging into water receptors through industrial effluents. Negative environmental impacts of such chemical species in hydrosphere include accelerated eutrophication, water toxicity and harming the aquatics. Natural zeolite clinoptilolite has very high selectivity & capacity for ammonium cation sorption. It occurs in high abundances and rich mines of this zeolite exist in different parts of Iran and thus are available more cheaply and with different sizing. The aim of this study is to investigate ammonia nitrogen removal over this natural sorbent from real samples of high polluted wastewater discharging from a fertilizer producing plant. The experimental results showed that this natural sorbent without even any pre treatment system & with the same particle size available in Iranian markets has still high capability & selectivity in ammonia nitrogen removal both in batch and continuous tests.

Keywords: Ammonia nitrogen removal, Clinoptilolite, Naturalzeolite, Waste water.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3333

Authors: Mohammad Sadeghi, Behrouz Heidari, Korush Montazeri

Abstract:

A novel thermo-sensitive superabsorbent hydrogel with salt- and pH-responsiveness properties was obtained by grafting of mixtures of acrylic acid (AA) and N-isopropylacrylamide (NIPAM) monomers onto kappa-carrageenan, kC, using ammonium persulfate (APS) as a free radical initiator in the presence of methylene bisacrylamide (MBA) as a crosslinker. Infrared spectroscopy was carried out to confirm the chemical structure of the hydrogel. Moreover, morphology of the samples was examined by scanning electron microscopy (SEM). The effect of MBA concentration and AA/NIPAM weight ratio on the water absorbency capacity has been investigated. The swelling variations of hydrogels were explained according to swelling theory based on the hydrogel chemical structure. The hydrogels exhibited salt-sensitivity and cation exchange properties. The temperature- and pH-reversibility properties of the hydrogels make the intelligent polymers as good candidates for considering as potential carriers for bioactive agents, e.g. drugs.

Keywords: superabsorbent, carrageenan, acrylic acid, Nisopropylacrylamide, hydrogel, swelling

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1629

Authors: Qiying Zhang, Panpan Xu, Hui Qian

Abstract:

Groundwater is an important water resource in the world, especially in arid and semi-arid regions. In the present study, 141 groundwater samples were collected and analyzed for various physicochemical parameters to assess the irrigation water quality using six indicators (sodium percentage (Na%), sodium adsorption ratio (SAR), magnesium hazard (MH), residual sodium carbonate (RSC), permeability index (PI), and potential salinity (PS)). The results show that the patterns for the average cation and anion concentrations were in decreasing orders of Na^＋ > Mg^2＋ > Ca^2＋ > K^＋and SO₄^2－ > HCO₃^－ > Cl^－ > NO₃^－ > CO₃^2－ > F^－, respectively. The values of Na%, MH, and PS show that most of the groundwater samples are not suitable for irrigation. The same conclusion is drawn from the USSL and Wilcox diagrams. PS values indicate that Cl^－and SO₄^2－have a great influence on irrigation water in Jiaokou Irrigation District. RSC and PI values indicate that more than half of groundwater samples are suitable for irrigation. The finding is beneficial for the policymakers for future water management schemes to achieve a sustainable development goal.

Keywords: Irrigation water quality evaluation, groundwater chemistry, Jiaokou Irrigation District, Guanzhong Basin.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 899

Authors: Bahareh Aghasi, Ahmad Jalalian, Naser Honarjoo

Abstract:

Land use change, if not based on proper scientific investigation affects other physical, chemical, and biological properties of soil and leading to increased destruction and erosion. It was imperative to study the effects of changing rangelands to farmlands on some Soil quality indexes. Undisturbed soil samples were collected from the depths of 0-10 and 10-30 centimeter in pasture with good vegetation cover(GP), pasture with medium vegetation cover(MP), abandoned dry land farming(ADF) and degraded dry land farming(DDF) land uses in Ghareh Aghaj watershed of Isfahan province. The results revealed that organic matter(OM), cation exchange capacity(CEC) and available potassium(AK) decreasing in the depth of 0-10 centimeter were 66.6, 38.8 and 70 percent and in the depth of 10-30 centimeter were 58, 61.4 and 83.5 percent respectively in DDF comparison with GP. Concerning to the results, it seems that land use change can decrease soil quality and increase soil degradation and lead in undesirable consequences.

Keywords: Land use change, Soil degradation, Soil quality

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1620

Authors: Galina Mamardashvili, Nugzar Mamardashvili, Win Dehaen

Abstract:

The processes of complexation of the Zn-tetraarylporphyrins with eight 4-(4-(3,6-bis(t-butyl)carbazol-9-yl-phenyl)-1,2,3-triazole (ZnP1) and eight 4-(4-(3,6-di-tert-butyl-9-H-carbazol-9-yl)phenoxy)methyl)-2,4,6-trimethylphenyl (ZnP2)with the 1,10-diaza-4,7,13,18tetraoxabicyclo[8.5.5]eicosane (L1),1,10-diaza-4,7,13,16,21,24-hexaoxabicyclo[8.8.8]hexacosane (L2)and 1,10-diaza-5,6,14,15-dibenzo-4,7,13,16,21,24 hexaoxabicyclo[8.8.8] hexacosane (L3) were investigated by the method of spectrophotometric titration and ¹H NMR-spectroscopy. We determined the structures of the host-guest complexes, and their stability constants in toluene were calculated. It was found out that the ZnP1 interacts with the guest molecules L1, L2 with the formation of stable "nest" type complexes and does not form similar complexes with the L3 (presumably due to the fact that the L3 does not match the size of the porphyrin ZnP(1) cavity). On the other hand, the porphyrin ZnP2 binds all of the ligands L1-L3, however complexes thus formed are less stable than complexes ZnP1-L1, ZnP1-L2. In the report, we will also discuss the influence of the alkali cations additives on the stability of the complexes between the porphyrin ZnP1, ZnP2 hosts and guest molecules of the ligands L1-L3.

Keywords: Porphyrin, cryptand, cation, complex guest-host.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 715

Authors: M. Michael Gromiha, Kiyonobu Yokota, Kazuhiko Fukui

Abstract:

We have developed an energy based approach for identifying the binding sites and important residues for binding in protein-protein complexes. We found that the residues and residuepairs with charged and aromatic side chains are important for binding. These residues influence to form cation-¤Ç, electrostatic and aromatic interactions. Our observation has been verified with the experimental binding specificity of protein-protein complexes and found good agreement with experiments. The analysis on surrounding hydrophobicity reveals that the binding residues are less hydrophobic than non-binding sites, which suggests that the hydrophobic core are important for folding and stability whereas the surface seeking residues play a critical role in binding. Further, the propensity of residues in the binding sites of receptors and ligands, number of medium and long-range contacts, and influence of neighboring residues will be discussed.

Keywords: Protein-protein interactions, energy based approach;binding sites, propensity, long-range contacts, hydrophobicity

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1354

Authors: M. B. Limooei, Hadi Ebrahimifar, Sh. Hosseini

Abstract:

Protective coatings that resist oxide scale growth and decrease chromium evaporation are necessary to make stainless steel interconnect materials for long-term durable operation of solid oxide fuel cells (SOFCs). In this study a layer of cobalt was electroplated on the surface of AISI 441 ferritic stainless steel which is used in solid oxide fuel cells for interconnect applications. The oxidation behavior of coated substrates was studied as a function of time at operating conditions of SOFCs. Cyclic oxidation has been also tested at 800ºC for 100 cycles. Cobalt coating during isothermal oxidation caused to the oxide growth resistance by limiting the outward diffusion of Cr cation and the inward diffusion of oxygen anion. Results of cyclic oxidation exhibited that coated substrates demonstrate an excellent resistance against the spallation and cracking.

Keywords: Oxidation resistance, full cell, Cobalt coating, ferritic stainless steel.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1982

Authors: May Zin Lwin., Mya Mya Oo

Abstract:

In the first part of the research work, an electrolyzer (10.16 cm dia and 24.13 cm height) to produce hydrogen and oxygen was constructed for single slice O2/H2 fuel cell using cation exchange membrane. The electrolyzer performance was tested with 23% NaOH, 30% NaOH, 30% KOH and 35% KOH electrolyte solution with current input 4 amp and 2.84 V from the rectifier. Rates of volume of hydrogen produced were 0.159 cm3/sec, 0.155 cm3/sec, 0.169 cm3/sec and 0.163 cm3/sec respectively from 23% NaOH, 30% NaOH, 30% KOH and 35% KOH solution. Rates of volume of oxygen produced were 0.212 cm3/sec, 0.201 cm3/sec, 0.227 cm3/sec and 0.219 cm3/sec respectively from 23% NaOH, 30% NaOH, 30% KOH and 35% KOH solution (1.5 L). In spite of being tested the increased concentration of electrolyte solution, the gas rate does not change significantly. Therefore, inexpensive 23% NaOH electrolyte solution was chosen to use as the electrolyte in the electrolyzer. In the second part of the research work, graphite serpentine flow plates, fiberglass end plates, stainless steel screen electrodes, silicone rubbers were made to assemble the single slice O2/H2 polymer electrolyte membrane fuel cell (PEMFC).

Keywords: electrolyzer, electrolyte solution, fuel cell, rectifier

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2032

Authors: R. Ziaie Moayed, H. Keshavarz Hedayati

Abstract:

Over recent years, due to increased population and increased waste production, groundwater protection has become more important, therefore, designing engineered barrier systems such as landfill liners to prevent the entry of leachate into groundwater should be done with greater accuracy. These measures generally involve the application of low permeability soils such as clays. Bentonite is a natural clay with low permeability which makes it a suitable soil for using in liners. Also zeolite with high cation exchange capacity can help to reduce of hazardous materials risk. Bentonite expands when wet, absorbing as much as several times its dry mass in water. This property may effect on some structural properties of soil such as shear strength. In present study, shear strength parameters are determined by both leachates polluted and not polluted bentonite-amended zeolite soil with mixing rates (B/Z) of 5%-10% and 20% with unconfined compression test to obtain the differences. It is shown that leachate presence causes reduction in resistance in general.

Keywords: Bentonite, zeolite, leachate, shear strength parameters, unconfined compression tests.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 505

Authors: Gomaa N. Abdel-Rahman, Nadia R. A. Nassar, Yehia A. Heikal, Mahmoud A. M. Abou-Donia, Mohamed M. Naguib, Mohamed Fadel

Abstract:

Cane molasses is used as a raw material for the production of baker’s yeast (Saccharomyces cerevisiae) in Egypt. The high levels of heavy metals in molasses cause a critical problem during fermentation and cause various kinds of technological difficulties (yield and quality of yeast become lower). The aim of the present study was to determine heavy metal concentrations (cadmium, nickel, lead, and copper) in crude and treated molasses obtained from the storage tanks of the baker’s yeast factory through four seasons. Also, the effect of crude molasses treatment by different methods (at laboratory scale) on heavy metals reduction and its comparison with factory treated molasses were conducted. The molasses samples obtained at autumn season had the highest values of all the studied heavy metals. The molasses treated by cation exchange resin then sulfuric acid had the lowest concentrations of heavy metals compared with other treatments.

Keywords: Molasses, baker’s yeast, heavy metals, treatment.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2409

Authors: B. A. Lawal, A. G. Ojanuga, P. A. Tsado, A. Mohammed

Abstract:

This work assessed some properties of three pedons on a toposequence in Ijah-Gbagyi district in Niger State, Nigeria. The pedons were designated as JG1, JG2 and JG3 representing the upper, middle and lower slopes respectively. The surface soil was characterized by dark yellowish brown (10YR3/4) color at the JG1 and JG2 and very dark grayish brown (10YR3/2) color at JG3. Sand dominated the mineral fraction and its content in the surface horizon decreased down the slope, whereas silt content increased down the slope due to sorting by geological and pedogenic processes. Although organic carbon (OC), total nitrogen (TN) and available phosphorus (P) were rated high, TN and available P decreased down the slope. High cation exchange capacity (CEC) was an indication that the soils have high potential for plant nutrients retention. The pedons were classified as Typic Haplustepts/ Haplic Cambisols (Eutric), Plinthic Petraquepts/ Petric Plinthosols (Abruptic) and Typic Endoaquepts/ Endogleyic Cambisols (Endoclayic).

Keywords: Ecological region, landscape positions, soil characterization, soil classification.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 4266

Authors: Hamad N. Altalyan, Brian G. Jones, John Bradd

Abstract:

A comprehensive study was conducted to examine the removal of inorganic contaminants that exist in surface and groundwater in the Illawarra and Sydney regions. The ability of multi-walled carbon nanotubes (MWCNT), as a generation of membrane technology, was examined using a dead-end filtration cell setup. A set of ten compounds were examined in this study that represent the significant inorganic cations and anions commonly found in contaminated surface and groundwater. The performance of MWCNT buckypaper membranes in excluding anions was found to be better than that of its cation exclusion. This phenomenon can be attributed to the Donnan exclusion mechanism (charge repulsion mechanism). Furthermore, the results revealed that phosphate recorded the highest exclusion value reaching 69.2%, whereas the lowest rejection value was for potassium where no removal occurred (0%). The reason for this is that the molecular weight of phosphate (95.0 g/mol) is greater than the molecular weight of potassium (39.10 g/mol).

Keywords: Nanotechnology, buckypaper, carbon nanotube, CNT, multi-walled carbon nanotube, MWCNT, Botany Bay, Russell Vale.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 533

Authors: A. Goodarzian, A. Ghasemipanah, R. Ziaie Moayed, H. Niroumand

Abstract:

The problem of soil stabilization has been one of the important issues in geotechnical engineering. Nowadays, nanomaterials have revolutionized many industries. In this research, improvement of the Kerman fine-grained soil by nanozeolite and nanobentonite additives separately has been investigated using Atterberg Limits and unconfined compression test. In unconfined compression test, the samples were prepared with 3, 5 and 7% nano additives, with 1, 7 and 28 days curing time with strain control method. Finally, the effect of different percentages of nanozeolite and nanobentonite on the geotechnical behavior and characteristics of Kerman fine-grained soil was investigated. The results showed that with increasing the amount of nanozeolite and also nanobentonite to fine-grained soil, the soil exhibits more compression strength. So that by adding 7% nanozeolite and nanobentonite with 1 day curing, the unconfined compression strength is 1.18 and 2.1 times higher than the unstabilized soil. In addition, the failure strain decreases in samples containing nanozeolite, whereas it increases in the presence of nanobentonite. Increasing the percentage of nanozeolite and nanobentonite also increased the elasticity modulus of soil.

Keywords: Nanozeolite particles, nanobentonite particles, clayey soil, unconfined compression stress, specific surface area, cation exchange capacity, Atterberg limits.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 799