Search results for: metal plating

Authors: Violina Angelova, Huu Q. Lee

Abstract:

A field study was conducted to evaluate the efficacy of Vetiver (Chrysopogon zizanioides L.) for phytoremediation of contaminated soils. The experiment was performed on agricultural fields contaminated by the Non-Ferrous-Metal Works near Plovdiv, Bulgaria. The experimental plots were situated at different distances (0.5, 3.5, and 15 km) from the source of pollution. The concentrations of Pb, Zn, and Cd in vetiver (roots and leaves) were determined. Correlations between the content of the heavy metal mobile forms extracted with DTPA and their content in the roots and leaves of the Vetiver have been established. The Vetiver is tolerant to heavy metals and can be grown on soils contaminated with heavy metals. Plants are characterized by low ability to absorb and accumulate Pb, Cd, and Zn and have no signs of toxicity (chlorosis and necrosis) at 36.8 mg/kg Cd, 1158.8 mg/kg Pb and 1526.2 mg/kg Zn in the soil. Vetiver plants can be classified as Pb, Cd and Zn excluder, therefore, this plant has the suitable potential for the phytostabilization of heavy metal contaminated soils. Acknowledgements: The authors gratefully acknowledge the financial support by the Bulgarian National Science Fund (Project DFNI 04/9).

Keywords: contaminated soils, heavy metals, phytoremediation, vetiver

Procedia PDF Downloads 198

Authors: W. E. Igwegbe, B. C. Okoro, J. C. Osuagwu

Abstract:

The study was aimed at assessing the effectiveness of reducing the concentrations of heavy metals in waste water using Pawpaw (Carica papaya) wood as a bio-sorbent. The heavy metals considered include; zinc, cadmium, lead, copper, iron, selenium, nickel, and manganese. The physiochemical properties of carica papaya stem were studied. The experimental sample was obtained from a felled trunk of matured pawpaw tree. Waste water for experimental use was prepared by dissolving soil samples collected from a dump site at Owerri, Imo state in water. The concentration of each metal remaining in solution as residual metal after bio-sorption was determined using Atomic absorption Spectrometer. The effects of ph, contact time and initial heavy metal concentration were studied in a batch reactor. The results of Spectrometer test showed that there were different functional groups detected in the carica papaya stem biomass. Optimum bio-sorption occurred at pH 5.9 with 5g/100ml solution of bio-sorbent. The results of the study showed that the treated wastewater is fit for irrigation purpose based on Canada wastewater quality guideline for the protection of Agricultural standard. This approach thus provides a cost effective and environmentally friendly option for treating waste water.

Keywords: biomass, bio-sorption, Carica papaya, heavy metal, wastewater

Procedia PDF Downloads 340

Authors: Manju Verma, Parag A. Deshpande

Abstract:

Electronic structure calculations of hydrogen terminated metal-porphyrin graphene were carried out to explore the catalytic activity for CO2 hydration reaction. A ruthenium atom was substituted in place of carbon atom of graphene and ruthenium chelated carbon atoms were replaced by four nitrogen atoms in metal-porphyrin graphene system. Ruthenium atom created the active site for CO2 hydration reaction. Ruthenium-porphyrin graphene followed the mechanism of carbonic anhydrase enzyme for CO2 conversion to HCO3- ion. CO2 hydration reaction over ruthenium-porphyrin graphene proceeded via the elementary steps: OH- formation from H2O dissociation, CO2 bending in presence of nucleophilic attack of OH- ion, HCO3- ion formation from proton migration, HCO3- ion desorption by H2O addition. Proton transfer to yield HCO3- ion was observed as a rate limiting step from free energy landscape.

Keywords: ruthenium-porphyrin graphene, CO2 hydration, carbonic anhydrase, heterogeneous catalyst, density functional theory

Procedia PDF Downloads 223

Authors: Dhivya Arumugam, Kaliyappan Thananjeyan

Abstract:

The monomer of (3-((4-(methacryloyloxy)phenylimino)methyl)-2-hydroxybenzoic acid) schiff base polymer was prepared by reacting methacryloyl chloride with imine compound derived from 3-formylsalisylic acid and 4- aminophenol. The monomer was polymerized in DMF at 70oC using benzoyl peroxide as free radical initiator. Polymer metal complex was obtained in DMF solution of polymer with aqueous solution of metal ions. The polymer and the polymer metal complex were characterized by elemental analysis and spectral studies. The elemental analysis data suggest that the metal to ligand ratio is 1:1 and hence, it acts as a binucleating compartmental ligand. The IR spectral data of these complexes suggest that the metals are coordinated through nitrogen of the imine group, the oxygen of carboxylate ion and the oxygen of the phenolic –OH group which also acts as the bridging ligand. The electronic spectra and magnetic moments of the polychelates shows that octahedral and square planar structure for Ni(II) and Cu(II) complexes respectively. X-ray diffraction studies revealed that polychelates are highly crystalline. The thermal and electrical properties, catalytic activity, structure property relationships are discussed. Further the synthesized polymer was used for metal uptake studies from waste water, which is one of the effective waste water treatment strategies. And also, the polymers and polychelates were investigated for antimicrobial activity with various microorganisms by using agar well diffusion method and the results have been discussed.

Keywords: acyclic compartmental ligands, binucleating ligand, 3-formylsalicylic acid, free radical polymerization, polluting ions, polychelate

Procedia PDF Downloads 95

Authors: J. S. Kim

Abstract:

This paper presents a 0.13-µm Complementary Metal-Oxide Semiconductor (CMOS) vector modulator for beamforming system. The vector modulator features a 360° phase and gain range of -10 dB to 10 dB with a root mean square phase and amplitude error of only 2.2° and 0.45 dB, respectively. These features make it a suitable for wireless backhaul system in the 5 GHz industrial, scientific, and medical (ISM) bands. It draws a current of 20.4 mA from a 1.2 V supply. The total chip size is 1.87x1.34 mm².

Keywords: CMOS, vector modulator, beamforming, 802.11ac

Procedia PDF Downloads 182

Authors: Chang Liu, Nuria Fiol, Isabel Villaescusa, Jordi Poch

Abstract:

Over the last decades, biosorption has been an alternative to costly wastewaters treatment for metal removal. Most of the literature on metal biosorption was devoted to studying of single metal ions but nowadays studies on multi-components biosorption are booming. Hexavalent chromium is usually found in mixtures with divalent metal ions in industries wastewaters. However, studies on the simultaneous removal of Cr(VI) and divalent metals are hardly found and the cooperative or competitive mechanism governing each metal ions sorption is still unclear. In this work, simultaneous sorption of Cr(VI) and Cu(II) from their binary mixtures by using sweet potato vine (SPV) was investigated. Sweet potato is one of the four major grain crops in China. Each year about 2000 tons of SPV are generated as by-products. SPV could be a low-cost biosorbent for metal ions due to its rich in cellulose and lignin. In this work, the sorption of Cr(VI) and Cu(II) from their binary mixtures solutions was studied by using SPV sorbent. Equilibrium studies were carried out in binary mixtures in which Cr(VI) and Cu(II) concentration was both varied between 0.1 mM and 0.3 mM, Cr(VI) and Cu(II) single solutions were also prepared as comparison. All the experiments were performed at pH 3±0.05 under 30±2°C for 7 days to make sure sorption achieved equilibrium. Results showed that (i) chromium was partially (10.93%-42.04%) eliminated under studied conditions through reduction and sorption of hexavalent and trivalent forms. The presence of Cu(II) exerts a synergistic effect on the overall sorption process in all the cases of the 0.1-0.3 mM binary mixtures concentration range. (ii) Cr(VI) removal by SPV is favoured by the presence of Cu(II) in solution, because more protons needed for Cr(VI) reduction are available due to Cu(II)-proton competition; however sorption of the formed Cr(III) is unfavoured as a result of the competition between Cr(III) and Cu(II) for protons and sorbent active sites. (iii) Copper was partially (9.26%-13.91%) sorbed onto SPV under studied conditions. The presence of Cr(VI) in binary mixtures also exerts a synergistic effect on the Cu(II) removal in all the cases of the 0.1-0.3 mM binary mixtures concentration range. The results of the present work indicate that sweet potato vine can be successfully employed for the simultaneously removal of Cr(VI) and Cu(II) in binary mixtures, taking advantage of the synergistic effect provoked by one of the metal ion to each other, even though the acquisition of higher removal yields has to be further investigated. Acknowledgements—This work has been financially supported by Ministry of Human Resources and Social Security of PRC (Anhui15), Education Department of Anhui Province (KJ2016A270) and Anhui Normal University (2015rcpy33, 2014bsqdjj53).

Keywords: sweet potato vine, chromium reduction, divalent metal, synergistic sorption

Procedia PDF Downloads 146

Authors: Hemant Upadhyay, Tarun Kumar Kundu

Abstract:

It is utmost important for a blast furnace operator to understand the mechanisms governing the liquid flow, accumulation, drainage and heat transfer between various phases in blast furnace hearth for a stable and efficient blast furnace operation. Abnormal drainage behavior may lead to high liquid build up in the hearth. Operational problems such as pressurization, low wind intake, and lower material descent rates, normally be encountered if the liquid levels in the hearth exceed a critical limit when Hearth coke and Deadman start to float. Similarly, hot metal temperature is an important parameter to be controlled in the BF operation; it should be kept at an optimal level to obtain desired product quality and a stable BF performance. It is not possible to carry out any direct measurement of above due to the hostile conditions in the hearth with chemically aggressive hot liquids. The objective here is to develop a mathematical model to simulate the variation in hot metal / slag accumulation and temperature during the tapping of the blast furnace based on the computed drainage rate, production rate, mass balance, heat transfer between metal and slag, metal and solids, slag and solids as well as among the various zones of metal and slag itself. For modeling purpose, the BF hearth is considered as a pressurized vessel, filled with solid coke particles. Liquids trickle down in hearth from top and accumulate in voids between the coke particles which are assumed thermally saturated. A set of generic mass balance equations gives the amount of metal and slag intake in hearth. A small drainage (tap hole) is situated at the bottom of the hearth and flow rate of liquids from tap hole is computed taking in account the amount of both the phases accumulated their level in hearth, pressure from gases in the furnace and erosion behaviors of tap hole itself. Heat transfer equations provide the exchange of heat between various layers of liquid metal and slag, and heat loss to cooling system through refractories. Based on all that information a dynamic simulation is carried out which provides real time information of liquids accumulation in hearth before and during tapping, drainage rate and its variation, predicts critical event timings during tapping and expected tapping temperature of metal and slag on preset time intervals. The model is in use at JSPL, India BF-II and its output is regularly cross-checked with actual tapping data, which are in good agreement.

Keywords: blast furnace, hearth, deadman, hotmetal

Procedia PDF Downloads 157

Authors: Ipek Gunay, Efe B. Orman, Metin Ozer, Bekir Salih, Ali R. Ozkaya

Abstract:

Phthalocyanines with macrocyclic ring containing at least three heteroatoms have nine or more membered structures. Metal-free phthalocyanines react with metal salts to obtain chelate complexes. This is one of the most important features of metal-free phthalocyanine as ligand structure. Although phthalocyanines have very similar properties with porphyrins, they have some advantages such as lower cost, easy to prepare, and chemical and thermal stability. It’s known that Pc compounds have shown one-electron metal-and/or ligand-based reversible or quasi-reversible reduction and oxidation processes. The redox properties of phthalocyanines are critically related to the desirable properties of these compounds in their technological applications. Thus, Pc complexes have also been receiving increasing interest in the area of fuel cells due to their high electrocatalytic activity in dioxygen reduction and fuel cell applications. In this study, novel phthalocyanine complexes coordinated with Fe(II) and Co (II) to be used as catalyst were synthesized. Aiming this goal, a new nitrile ligand was synthesized starting from 4-hydroxy-3,5-dimethoxy benzyl alcohol and 4-nitrophthalonitrile in the presence of K2CO3 as catalyst. After the isolation of the new type of nitrile and metal complexes, the characterization of mentioned compounds was achieved by IR, H-NMR and UV-vis methods. In addition, the electrochemical behaviour of Pc complexes was identified by cyclic voltammetry, square wave voltammetry and in situ spectroelectrochemical measurements. Furthermore, the catalytic performances of Pc complexes for oxygen reduction were tested by dynamic voltammetry measurements, carried out by the combined system of rotating ring-disk electrode and potentiostat, in a medium similar to fuel-cell working conditions.

Keywords: phthalocyanine, electrocatalysis, electrochemistry, in-situ spectroelectrochemistry

Procedia PDF Downloads 292

Authors: Rachit Marwaha, Rahul Dev Gupta, Vivek Jain, Krishan Kant Sharma

Abstract:

Metal matrix hybrid composites (MMHCs) are now gaining their usage in aerospace, automotive and other industries because of their inherent properties like high strength to weight ratio, hardness and wear resistance, good creep behaviour, light weight, design flexibility and low wear rate etc. Al alloy base matrix reinforced with silicon carbide (10%) and graphite (5%) particles was fabricated by stir casting process. The wear and frictional properties of metal matrix hybrid composites were studied by performing dry sliding wear test using pin on disc wear test apparatus. Experiments were conducted based on the plan of experiments generated through Taguchi’s technique. A L9 Orthogonal array was selected for analysis of data. Investigation to find the influence of applied load, sliding speed and track diameter on wear rate as well as coefficient of friction during wearing process was carried out using ANOVA. Objective of the model was chosen as smaller the better characteristics to analyse the dry sliding wear resistance. Results show that track diameter has highest influence followed by load and sliding speed.

Keywords: Taguchi method, orthogonal array, ANOVA, metal matrix hybrid composites

Procedia PDF Downloads 298

Authors: Raphael Odoh, Obida J. Oko, Mary S. Dauda

Abstract:

The determination of Cd, Cr, Cu, Fe,Mn, Ni, Pb and Zn contents in edible oils (palm oil, ground-nut oil and soybean oil) bought from various markets of Benue and Taraba state were carried out with flame atomic absorption spectrophotometric technique. The method 3031 developed acid digestion of oils for metal analysis by atomic absorption or ICP spectrometry was used in the preparation of the edible oil samples for the determination of total metal content in this study. The overall results (µg/g) in palm oil sample ranged from 0.028-0.076, 0.035-0.092, 1.011-1.955, 2.101-4.892, 0.666-0.922, 0.054-0.095, 0.031-0.068 and 1.987-2.971 for Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn respectively, while in ground-nut oil the overall results ranged from 0.011-0.042, 0.011-0.052, 0.133-0.788, 1.789-2.511, 0.078-0.765, 0.045-0.092, 0.011-0.028 and 1.098-1.997 for Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn respectively. Of the heavy metals considered Cd and Ni showed the highest contamination in the soybean oil sample. The overall results in soybean oil samples ranged from 0.011-0.015, 0.017-0.032, 0.453-0.987, 1.789-2.511, 0.089-0.321, 0.011-0.016, 0.012-0.065 and 1.011-1.997 for Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn respectively. The concentration of Pb was the highest. The degree of contamination by each metal was estimated by the transfer factor. The transfer factors obtained for Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn in edible oils (palm oil, ground-nut oil and soybean oil) were 10.800, 16.500, 16.000, 18.813, 15.115, 14.230, 23.000 and 9.418 for Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn in palm oil, and 7.000, 12.500, 8.880, 11.333, 7.708, 10.833, 15.00 and 6.608 for Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn in ground-nut oil while for soybean oil the transfer factors were 13.000, 11.000, 7.642, 11.578, 4.486, 13.00, 12.333 and 4.412 for Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn respectively. The inter-element correlation was found among metals in edible oil samples using Pearson’s correlation co-efficient. There were positive and negative correlations among the metals determined. All Metals determined showed degree of contamination but concentrations lower than the USP specification.

Keywords: Benue State, contamination, edible oils, heavy metals, markets, Taraba State

Procedia PDF Downloads 280

Authors: Saleh H. Abud, Z. Hassan, F. K. Yam

Abstract:

Characteristics of MSM photodetector based on a porous In0.08Ga0.92N thin film were reported. Nanoporous structures of n-type In0.08Ga0.92N/AlN/Si thin films were synthesized by photoelectrochemical (PEC) etching at a ratio of 1:4 of HF:C2H5OH solution for 15 min. The structural and optical properties of pre- and post-etched thin films were investigated. Field emission scanning electron microscope and atomic force microscope images showed that the pre-etched thin film has a sufficiently smooth surface over a large region and the roughness increased for porous film. Blue shift has been observed in photoluminescence emission peak at 300 K for porous sample. The photoluminescence intensity of the porous film indicated that the optical properties have been enhanced. A high work function metals (Pt and Ni) were deposited as a metal contact on the porous films. The rise and recovery times of the devices were investigated at 390 nm chopped light. Finally, the sensitivity and quantum efficiency were also studied.

Keywords: porous InGaN, photoluminescence, SMS photodetector, atomic force microscopy

Procedia PDF Downloads 464

Authors: Cristina Diaz, Lucia Perez, Simone Visigalli, Giuseppe Di Florio, Gonzalo Fuentes, Roberto Canziani, Paolo Gronchi

Abstract:

During the last 50 years, the selection of materials is one of the main decisions in machine design for different industrial applications. It is due to numerous physical, chemical, mechanical and technological factors to consider in it. Corrosion effects are related with all of these factors and impact in the life cycle, machine incidences and the costs for the life of the machine. Corrosion affects the deterioration or destruction of metals due to the reaction with the environment, generally wet. In food industry, dewatering industry, concrete industry, paper industry, etc. corrosion is an unsolved problem and it might introduce some alterations of some characteristics in the final product. Nowadays, depending on the selected metal, its surface and its environment of work, corrosion prevention might be a change of metal, use a coating, cathodic protection, use of corrosion inhibitors, etc. In the vast majority of the situations, use of a corrosion resistant material or in its defect, a corrosion protection coating is the solution. Stainless steels are widely used in machine design, because of their strength, easily cleaned capacity, corrosion resistance and appearance. Typical used are AISI 304 and AISI 316. However, their benefits don’t fit every application, and some coatings are required against corrosion such as some paintings, galvanizing, chrome plating, SiO₂, TiO₂ or ZrO₂ coatings, etc. In this work, some coatings based in a bilayer made of Titanium-Tantalum, Titanium-Niobium, Titanium-Hafnium or Titanium-Zirconium, have been developed used magnetron sputtering configuration by PVD (Physical Vapor Deposition) technology, for trying to reduce corrosion effects on AISI 304, AISI 316 and comparing it with Titanium alloy substrates. Ti alloy display exceptional corrosion resistance to chlorides, sour and oxidising acidic media and seawater. In this study, Ti alloy (99%) has been included for comparison with coated AISI 304 and AISI 316 stainless steel. Corrosion tests were conducted by a Gamry Instrument under ASTM G5-94 standard, using different electrolytes such as tomato salsa, wine, olive oil, wet compost, a mix of sand and concrete with water and NaCl for testing corrosion in different industrial environments. In general, in all tested environments, the results showed an improvement of corrosion resistance of all coated AISI 304 and AISI 316 stainless steel substrates when they were compared to uncoated stainless steel substrates. After that, comparing these results with corrosion studies on uncoated Ti alloy substrate, it was observed that in some cases, coated stainless steel substrates, reached similar current density that uncoated Ti alloy. Moreover, Titanium-Zirconium and Titanium-Tantalum coatings showed for all substrates in study including coated Ti alloy substrates, a reduction in current density more than two order in magnitude. As conclusion, Ti-Ta, Ti-Zr, Ti-Nb and Ti-Hf coatings have been developed for improving corrosion resistance of AISI 304 and AISI 316 materials. After corrosion tests in several industry environments, substrates have shown improvements on corrosion resistance. Similar processes have been carried out in Ti alloy (99%) substrates. Coated AISI 304 and AISI 316 stainless steel, might reach similar corrosion protection on the surface than uncoated Ti alloy (99%). Moreover, coated Ti Alloy (99%) might increase its corrosion resistance using these coatings.

Keywords: coatings, corrosion, PVD, stainless steel

Procedia PDF Downloads 124

Authors: Sukhwinder Singh Jolly

Abstract:

Metal spinning is one such process in which the stresses are localized to a small area and the material is made to flow or move over the mandrel with the help of spinning tool. Spinning of tubular products can be performed by two techniques, forward spinning and backward spinning. Many researchers have studied the process both experimentally and analytically. An effort has been made to apply the process to the spinning of thin wall, highly precision, small bore long tube in hard-to-work materials such as titanium.

Keywords: metal spinning, hard-to-work materials, roller diameter, power consumption

Procedia PDF Downloads 367

Authors: S. Ramesh, A. S. Sasiraaju, K. Sidhaarth, N. Sudhan Rajkumar, V. Manivel Muralidaran

Abstract:

This work presents the result of investigations aimed at determining the hardness of the welded Chromoly (A 4130) steel plate of 2” thickness. Multi pass welding for the thick sections was carried out and analyzed for the Chromoly alloy steel plates. The study of hardness at the weld metal reveals that there is the presence of different micro structure products which yields diverse properties. The welding carried out using GMAW with ER70s-2 electrode. Single V groove design was selected for the butt joint configuration. The presence of hydrogen has been suppressed by selecting low hydrogen electrode. Preheating of the plate prior to welding reduces the cooling rate which also affects the weld metal microstructure. The shielding gas composition used in this analysis is 80% Ar-20% CO2. The experimental analysis gives the detailed study of the hardness of the material.

Keywords: chromoly, gas metal arc weld (GMAW), hardness, multi pass weld, shielding gas composition

Procedia PDF Downloads 191

Authors: Mahmoud H. Aboul-Ela, Riham R. Mohamed, Magdy W. Sabaa

Abstract:

Synthesis of cross-linked hydrogels composed of trimethyl chitosan (TMC) and poly(vinyl alcohol) (PVA) in different weight ratios in presence of glutaraldehyde as cross-linking agent. Characterization of the prepared hydrogels was done using FTIR, XRD, SEM and TGA. The prepared hydrogels were investigated as adsorbent materials for some transition metal ions from their aqueous solutions. Moreover, the swell ability of the prepared hydrogels was also investigated in both acidic and alkaline pHs, as well as in simulated body fluid (SBF).

Keywords: trimethyl chitosan, hydrogels, metal uptake, superabsorbent materials

Procedia PDF Downloads 356

Authors: Rui Tu, Yakui Bai, Huailin Li

Abstract:

The lead-bismuth eutectic (LBE) alloy is a promising candidate of coolant in the fast neutron reactors and accelerator-driven systems (ADS) because of its good properties, such as low melting point, high neutron yields and high thermal conductivity. Although the corrosion of the structure materials caused by the liquid metal (LM) coolant is a challenge to the safe operating of a lead-bismuth eutectic nuclear reactor. Thermodynamic theories, experiential formulas and experimental data can be used for explaining the maintenance of the protective oxide layers on stainless steels under satisfaction oxygen concentration, but the atomic scale insights of such anti-corrosion mechanisms are little known. In the present work, the first-principles calculations are carried out to study the effects of oxygen partial pressure on the formation energies of the liquid metal coolant relevant impurity defects in the anti-corrosion oxide films on the surfaces of the structure materials. These approaches reveal the microscope mechanisms of the corrosion of the structure materials, especially for the influences from the oxygen partial pressure. The results are helpful for identifying a crucial oxygen concentration for corrosion control, which can ensure the systems to be operated safely under certain temperatures.

Keywords: oxygen partial pressure, liquid metal coolant, TDDFT, anti-corrosion layer, formation energy

Procedia PDF Downloads 98

Authors: Omoruyi Gold Idemudia, Alexander P. Sadimenko

Abstract:

The synthesis of N-heterocycles with novel properties, having broad spectrum biological activities that may become alternative medicinal drugs, have been attracting a lot of research attention due to the emergence of medicinal drug’s limitations such as disease resistance and their toxicity effects among others. Acylpyrazolones have been employed as pharmaceuticals as well as analytical reagent and their application as coordination complexes with transition metal ions have been well established. By way of a condensation reaction with amines acylpyrazolone ketones form a more chelating and superior group of compounds known as azomethines. 4-propyl-3-methyl-1-phenyl-2-pyrazolin-5-one was reacted with phenylhydrazine to get a new phenylhydrazone which was further reacted with aqueous solutions of palladium and platinum salts, in an effort towards the discovery of transition metal based synthetic drugs. The compounds were characterized by means of analytical, spectroscopic, thermogravimetric analysis TGA, as well as x-ray crystallography. 4-propyl-3-methyl-1-phenyl-2-pyrazolin-5-one phenylhydrazone crystallizes in a triclinic crystal system with a P-1 (No. 2) space group based on x-ray crystallography. The bidentate ON ligand formed a square planar geometry on coordinating with metal ions based on FTIR, electronic and NMR spectra as well as magnetic moments. Reported compounds showed antibacterial activities against the nominated bacterial isolates using the disc diffusion technique at 20 mg/ml in triplicates. The metal complexes exhibited a better antibacterial activity with platinum complex having an MIC value of 0.63 mg/ml. Similarly, ligand and complexes also showed antioxidant scavenging properties against 2, 2-diphenyl-1-picrylhydrazyl DPPH radical at 0.5mg/ml relative to ascorbic acid (standard drug).

Keywords: acylpyrazolone, antibacterial studies, metal complexes, phenylhydrazone, spectroscopy

Procedia PDF Downloads 225

Authors: Justina I. R. Udotong, Essien U. Essien

Abstract:

Diagnostic enzymes like aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) were determined as indices of heavy metal pollution in Tilapia guinensis. Three different sets of fishes treated with lead (Pb), iron (Fe) and copper (Cu) were used for the study while a fourth group with no heavy metal served as a control. Fishes in each of the groups were exposed to 2.65 mg/l of Pb, 0.85 mg/l of Fe and 0.35 mg/l of Cu in aerated aquaria for 96 hours. Tissue fractionation of the liver tissues was carried out and the three diagnostic enzymes (AST, ALT, and ALP) were estimated. Serum levels of the same diagnostic enzymes were also measured. The mean values of the serum enzyme activity for ALP in each experimental group were 19.5±1.62, 29.67±2.17 and 1.15±0.27 IU/L for Pb, Fe and Cu groups compared with 9.99±1.34 IU/L enzyme activity in the control. This result showed that Pb and Fe caused increased release of the enzyme into the blood circulation indicating increased tissue damage while Cu caused a reduction in the serum level as compared with the level in the control group. The mean values of enzyme activity obtained in the liver were 102.14±6.12, 140.17±2.06 and 168.23±3.52 IU/L for Pb, Fe and Cu groups, respectively compared to 91.20±9.42 IU/L enzyme activity for the control group. The serum and liver AST and ALT activities obtained in Pb, Fe, Cu and control groups are reported. It was generally noted that the presence of the heavy metal caused liver tissues damage and consequent increased level of the diagnostic enzymes in the serum.

Keywords: diagnostic enzymes, enzyme activity, heavy metals, tissues investigations

Procedia PDF Downloads 267

Authors: Shaher Bano, Samia Fida, Asif Israr

Abstract:

The synergistic effect of properties of metals and fibers reinforced laminates has diverted attention of the world towards use of robust composite materials known as fiber-metal laminates in many high performance applications. In this study, modification of an adhesively bonded joint as a single lap joint of carbon fibers based CARALL FML has done to increase interlaminar shear strength of the joint. The effect of different configurations of joint designs such as spews, stepped and modification in adhesive by addition of nano-fillers was studied. Both experimental and simulation results showed that modified joint design have superior properties as maximum force experienced stepped joint was 1.5 times more than the simple lap joint. Addition of carbon nano-tubes as nano-fillers in the adhesive joint increased the maximum force due to crack deflection mechanism.

Keywords: adhesive joint, Carbon Reinforced Aluminium Laminate (CARALL), fiber metal laminates, spews

Procedia PDF Downloads 204

Authors: F. Fakheri Raof, F. Zobeidizadeh

Abstract:

The present study examined the potential capability of Spirogyra algae remove heavy metals Zn, Pb, Cu, and Cr from the water. For this purpose, the water treatment No. 3 of Ahvaz County in Khuzestan Province of Iran was selected as a case study. From 8 sampling stations, 4 stations were dedicated to the water samples and 4 stations to the algae samples. According to the obtained results, the concentration of the heavy metals Cr, Cu, Pb, and Zn in water samples were within the ranges of 1.98-19.53, 0.67-13.45, 1-23.18, and 2.12-83.04 µg/L. Besides, the concentration of heavy metal Cr, Pb, Cu, and Zn in spirogyra algae samples varied between the ranges 2.30-3.61, 2.06-3.43, 2.29-2.56, and 9.88-10.84 µg/L. The highest amount of metal absorption in spirogyra algae samples was related to the zinc. The obtained results also indicated that the last spirogyra algae sample which was at the inlet of Tank 4 absorbed the lowest concentration of metals. This would be due to the treatment process along the course of ponds resulted in completely pure water at the outlet without the existence of algae on the sides. The paper also provides some useful recommendations on this issue.

Keywords: absorption, Ahvaz, heavy metal, spirogyra algae, water treatment plants

Procedia PDF Downloads 236

Authors: Rizwan Ahmad, Soomin Chang, Daeun Kwon, Jeonghwan Kim

Abstract:

Interests in an inorganic membrane are growing rapidly for industrial wastewater treatment due to its excellent chemical and thermal stability over polymeric membrane. Nevertheless, understanding of the membrane rejection and fouling rate caused by the deposit of contaminants on membrane surface and within membrane pores through inorganic porous membranes still requires much attention. Microfiltration alumina membranes were developed and applied for the industrial wastewater treatment to investigate rejection efficiency of organic contaminant and membrane fouling at various operational conditions. In this study, organic rejection and membrane fouling were investigated by using the alumina flat-tubular membrane developed for the treatment of industrial wastewaters. The flat-tubular alumina membranes were immersed in a fluidized membrane reactor added with granular activated carbon (GAC) particles. Fluidization was driven by recirculating a bulk industrial wastewater along membrane surface through the reactor. In the absence of GAC particles, for hazardous anionic dye contaminants, functional group characterized by the organic contaminant was found as one of the main factors affecting both membrane rejection and fouling rate. More fouling on the membrane surface led to the existence of dipolar characterizations and this was more pronounced at lower solution pH, thereby improving membrane rejection accordingly. Similar result was observed with a real metal-plating wastewater. Strong correlation was found that higher fouling rate resulted in higher organic rejection efficiency. Hydrophilicity exhibited by alumina membrane improved the organic rejection efficiency of the membrane due to the formation of hydrophilic fouling layer deposited on it. In addition, less surface roughness of alumina membrane resulted in less fouling rate. Regardless of the operational conditions applied in this study, fluidizing the GAC particles along the surface of alumina membrane was very effective to enhance organic removal efficiency higher than 95% and provide an excellent tool to reduce membrane fouling. Less than 0.1 bar as suction pressure was maintained with the alumina membrane at 25 L/m²hr of permeate set-point flux during the whole operational periods without performing any backwashing and chemical enhanced cleaning for the membrane.

Keywords: alumina membrane, fluidized membrane reactor, industrial wastewater, membrane fouling, rejection

Procedia PDF Downloads 139

Authors: E. E. Tereshatov, M. Yu. Boltoeva, V. Mazan, M. F. Volia, C. M. Folden III

Abstract:

Room temperature ionic liquids (RTILs) are a class of liquid organic salts with melting points below 20 °C that are considered to be environmentally friendly ‘designers’ solvents. Pure hydrophobic ILs are known to extract metallic species from aqueous solutions. The closest analogues of ionic liquids are deep eutectic solvents (DESs), which are a eutectic mixture of at least two compounds with a melting point lower than that of each individual component. DESs are acknowledged to be attractive for organic synthesis and metal processing. Thus, these non-volatile and less toxic compounds are of interest for critical metal extraction. The US Department of Energy and the European Commission consider indium as a key metal. Its chemical homologue, thallium, is also an important material for some applications and environmental safety. The aim of this work is to systematically investigate In and Tl extraction from aqueous solutions into pure fluorinated ILs and hydrophobic DESs. The dependence of the Tl extraction efficiency on the structure and composition of the ionic liquid ions, metal oxidation state, and initial metal and aqueous acid concentrations have been studied. The extraction efficiency of the TlXz3–z anionic species (where X = Cl– and/or Br–) is greater for ionic liquids with more hydrophobic cations. Unexpectedly high distribution ratios (> 103) of Tl(III) were determined even by applying a pure ionic liquid as receiving phase. An improved mathematical model based on ion exchange and ion pair formation mechanisms has been developed to describe the co-extraction of two different anionic species, and the relative contributions of each mechanism have been determined. The first evidence of indium extraction into new quaternary ammonium- and menthol-based hydrophobic DESs from hydrochloric and oxalic acid solutions with distribution ratios up to 103 will be provided. Data obtained allow us to interpret the mechanism of thallium and indium extraction into ILs and DESs media. The understanding of Tl and In chemical behavior in these new media is imperative for the further improvement of separation and purification of these elements.

Keywords: deep eutectic solvents, indium, ionic liquids, thallium

Procedia PDF Downloads 214

Authors: L. Khalfa, M. Bagane, M. L. Cervera, S. Najjar

Abstract:

The aim of this work is to present a low cost adsorbent for removing toxic heavy metals from aqueous solutions. Therefore, we are interested to investigate the efficiency of natural clay minerals collected from south Tunisia and their modified form using sulfuric acid in the removal of toxic metal ions: Zn(II) and Pb(II) from synthetic waste water solutions. The obtained results indicate that metal uptake is pH-dependent and maximum removal was detected to occur at pH 6. Adsorption equilibrium is very rapid and it was achieved after 90 min for both metal ions studied. The kinetics results show that the pseudo-second-order model describes the adsorption and the intraparticle diffusion models are the limiting step. The treatment of natural clay with sulfuric acid creates more active sites and increases the surface area, so it showed an increase of the adsorbed quantities of lead and zinc in single and binary systems. The competitive adsorption study showed that the uptake of lead was inhibited in the presence of 10 mg/L of zinc. An antagonistic binary adsorption mechanism was observed. These results revealed that clay is an effective natural material for removing lead and zinc in single and binary systems from aqueous solution.

Keywords: heavy metal, activated clay, kinetic study, competitive adsorption, modeling

Procedia PDF Downloads 193

Authors: Swarna Shikha, Pammi Gauba

Abstract:

Heavy metal pollution in water bodies and soil is a major and ever increasing environmental issue nowadays, and most conventional remediation approaches do not provide appropriate solutions. By using specially selected and engineered metal-accumulating plants for environmental clean-up is an emerging technology called as phytoremediation. The aim of this study was to find the effect of phytoextraction of Chromium in hydroponics culture by using Vigna mungo, Vigna radiata and Cicer arietinum. The plants were allowed to grow in static hydroponic culture at 0, 50, 250, 500 and 750 ppm concentrations of Chromium dichromate. The germination percentage was determined. It was found that the germination percentage of the seeds decreased with an increase in the concentration of the heavy metals. The maximum permissible limit of Cr for Vigna radiate and Cicer arietinum was 500 ppm and toxicity was observed whereas at even at 750 ppm no toxicity was observed in Vigna mungo. The main aim of our experiment was to study the impact of Chromium on all the three selected plants.

Keywords: phytoremediation, phytoextraction metal-accumulation, heavy metals, pollutants

Procedia PDF Downloads 317

Authors: Khaled Alshammari

Abstract:

A facile approach to synthesizing highly active and stable Au/NiO catalysts for the hydrogenation of nitro-aromatics is reported. Preformed gold nanoparticles have been immobilized onto NiO using a colloidal method. In this article, the reduction of 4-nitrophenol with NaBH4 has been used as a model reaction to investigate the catalytic activity of synthesized Au/NiO catalysts. In addition, we report a systematic study of the reduction kinetics and the influence of specific reaction parameters such as (i) temperature, (ii) stirring rate, (iii) sodium borohydride concentration and (iv) substrate/metal molar ratio. The reaction has been performed at a substrate/metal molar ratio of 7.4, a ratio significantly higher than previously reported. The reusability of the catalyst has been examined, with little to no decrease in activity observed over 5 catalytic cycles. Systematic variation of Au loading reveals the successful synthesis of low-cost and efficient Au/NiO catalysts at very low Au content and using high substrate/metal molar ratios.

Keywords: nonochemistry, catalyst, nanoparticles supported, characterization of materials, colloidal nanoparticles

Procedia PDF Downloads 24

Authors: Francisco Espinosa, Juan Chavarría

Abstract:

Glycerol is a byproduct of biodiesel production that can be used for aqueous-phase reforming to obtain hydrogen. Iridium is a material that has high activity and hydrogen selectivity for steam phase reforming. Nevertheless, a drawback for the use of iridium in aqueous-phase reforming is the low activity in water-gas shift reaction. Therefore, in this work, it is proposed the use of nickel and copper as a second metal in the catalyst to reach a synergetic effect. Iridium, iridium-nickel and iridium-copper catalysts were prepared by incipient wetness impregnation and evaluated in the aqueous-phase reforming of glycerol using CeO₂ or La₂O₃ as support. The catalysts were characterized by XRD, XPS, and EDX. The reactions were carried out in a fixed bed reactor feeding a solution of glycerol 10 wt% in water at 270°C, and reaction products were analyzed by gas chromatography. It was found that IrNi/CeO₂ reached highest glycerol conversion and hydrogen production, slightly above 70% and 43 vol% respectively. In terms of conversion, iridium is a promising metal, and its activity for hydrogen production can be enhanced when adding a second metal.

Keywords: aqueous-phase reforming, glycerol, hydrogen production, iridium

Procedia PDF Downloads 293

Authors: Isil Kerti, Onur Okur, Sibel Daglilar, Recep Calin

Abstract:

Particulate reinforced aluminium matrix composites have gained more importance in automotive, aeronautical and defense industries due to their specific properties like as low density, high strength and stiffness, good fatigue strength, dimensional stability at high temperature and acceptable tribological properties. In this study, 2014 Aluminium alloy used as a matrix material and B₄C and SiC were selected as reinforcements components. For production of composites materials, vacuum infiltration method was used. In the experimental studies, the reinforcement volume ratios were defined by mixing as totally 10% B₄C and SiC. Aging treatment (T6) was applied to the specimens. The effect of T6 treatment on hardness was determined by using Brinell hardness test method. The effects of the aging treatment on microstructure and chemical structure were analysed by making XRD, SEM and EDS analysis on the specimens.

Keywords: metal matrix composite, vacumm infiltration method, aluminum metal matrix, mechanical feature

Procedia PDF Downloads 285

Authors: Przemyslaw J. Jodlowski, Roman J. Jedrzejczyk, Damian K. Chlebda, Anna Dziedzicka, Lukasz Kuterasinski, Anna Gancarczyk, Maciej Sitarz

Abstract:

The aim of this study was to obtain highly active catalysts based on non-noble metal oxides supported on zirconia prepared via a sonochemical method. In this study, the influence of the stabilizers addition during the preparation step was checked. The final catalysts were characterized by using such characterization methods as X-ray Diffraction (XRD), nitrogen adsorption, X-ray fluorescence (XRF), scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectrometer (EDS), transmission electron microscopy (TEM) and µRaman. The proposed preparation method allowed to obtain uniformly dispersed metal-oxide nanoparticles at the support’s surface. The catalytic activity of prepared catalyst samples was measured in a methane combustion reaction. The activity of the catalysts prepared by the sonochemical method was considerably higher than their counterparts prepared by the incipient wetness method.

Keywords: methane catalytic combustion, nanoparticles, non-noble metals, sonochemistry

Procedia PDF Downloads 187

Authors: Aida Safiera, Andika Dwi Rubyantoro, Muhammad Bagus Prakasa

Abstract:

Indonesia’s needs of diesel oil each year are increasing and getting urge. However, that problems are not supported by the amount of oil production that still low and also influenced by the fact of oil reserve is reduced. Because of that, the government prefers to import from other countries than fulfill the needs of diesel. To anticipate that problem, development of fuel based on renewable diesel is started. Renewable diesel is renewable alternative fuel that is hydrocarbon derivative from decarbonylation of non-edible oil. Indonesia is rich with natural resources, including nyamplung oil (Calophyllum inophyllum oil) and zeolite. Nyamplung oil (Calophyllum inophyllum oil) has many stearic acids which are useful on renewable diesel synthesis meanwhile zeolite is cheap. Zeolite is many used on high temperature reaction and cracking process on oil industry. Zeolite also has advantages which are a high crystallization, surface area and pores. In this research, the main focus that becomes our attention is on preparation and characterization of metal nanocrystal. Active site that used in this research is Nickel Molybdenum (NiMo). The advantage of nanocrystal with nano scale is having larger surface area. The synthesis of metal nanocrystal will be done with conventional preparation modification method that is called simple heating. Simple heating method is a metal nanocrystal synthesis method using continuous media which is polymer liquid. This method is a simple method and produces a small particles size in a short time. Influence of metal nanocrystal growth on this method is the heating profile. On the synthesis of nanocrystal, the manipulated variables are temperature and calcination time. Results to achieve from this research are diameter size on nano scale (< 100 nm) and uniform size without any agglomeration. Besides that, the conversion of synthesis of renewable diesel is high and has an equal specification with petroleum diesel. Catalyst activities are tested by FT-IR and GC-TCD on decarbonylation process with a pressure 15 bar and temperature 375 °C. The highest conversion from this reaction is 35% with selectivity around 43%.

Keywords: renewable diesel, simple heating, metal nanocrystal, NiMo, zeolite

Procedia PDF Downloads 203

Authors: Kusuma Urs M. B., Navakant Bhat, Vinayak B. Kamble

Abstract:

Metal oxide semiconductors (MOS) are known to be excellent candidates for solid-state gas sensor devices. However, in spite of high sensitivities, their high operating temperatures and lack of selectivity is a big concern limiting their practical applications. A lot of research has been devoted so far to enhance their sensitivity and selectivity, often empirically. Some of the promising routes to achieve the same are reducing dimensionality and formation of heterostructures. These heterostructures offer improved sensitivity, selectivity even at relatively low operating temperatures compared to bare metal oxides. Thus, a combination of n-type and p-type metal oxides leads to the formation of p-n junction at the interface resulting in the diffusion of the carriers across the barrier along with the surface adsorption. In order to achieve this and to study their sensing mechanism, we have designed and lithographically fabricated a suspended nanobeam of NiO, which is a p-type semiconductor. The response of the same has been studied for various gases and is found to exhibit selective response towards hydrogen gas at room temperature. Further, the same has been radially coated with TiO₂ shell of varying thicknesses, in order to study the effect of radial p-n junction thus formed. Subsequently, efforts have been made to study the effect of shell thickness on the space charge region and to shed some light on the basic mechanism involved in gas sensing of MOS sensors.

Keywords: gas sensing, heterostructure, metal oxide semiconductor, space charge region

Procedia PDF Downloads 103