The current study was to examine the reliability and effectiveness of using most abundant, inexpensive waste in the form of scrap raw zero valent aluminum ZVAI and zero valent iron ZVI for the capture, retard, and removal of one of the most serious and hazardous heavy metals cadmium dissolved in water. Batch tests were conducted to examine contact time (0-250) min, sorbent dose (0.25-1 g ZVAI/100 mL and 2-8 g ZVI/100 mL), initial pH (3-6), pollutant concentration of 50mg/L initially, and speed of agitation (0-250) rpm . Maximum contaminant removal efficiency corresponding to (90 %) for cadmium at 250 min contact time, 1g ZVAI/ 6g ZVI sorbent mass ratio, pH 5.5, pollutant concentration of 50 mg/L initially, and 250 rpm agitation speed were obtained. Langmuir and Freundlich isotherms were presumed to fit the batch kinetics data for the sorption of Cd(II) onto ZVAI and/or ZVI and found that Langmuir (I) was the most representative model type with coefficient of determination R2 greater than 0.9115. Kinetics data for the sorption of Cd(II) onto ZVAI/ZVI mixture and due to the good agreement between the fitted and the experimental results; the data was found to obey the pseudo second order model. The scanning electron microscopy (SEM) for the ZVI and ZVAI was conducted before and after the sorbent-liquid reaction and revealed distinct morphological changes in the sorbent surface due to the contaminant saturation and pore channel blockages that ceased the sorption process.
A new chelate polymer (2-5-hydroxy-3-methyl-2- (3-nonyl benzene) imino) methyl) benzyl) 4-6-dimethyphenol] (K4) was prepared by using the condensation reaction method and identified by several techniques, including FT-IR, NMR, and atomic absorption spectroscopy, as well as TG-DTA thermal analysis. The kinetic equilibrium for the sorption of lead and cadmium ions on the chelate polymer surface was also investigated. The results showed that the sorption of both ions followed the pseudo-first-order and pseudo-second-order kinetic equilibrium. The rate constant values of pseudo-first-order reaction were equal to 0.062 and 0.057 min-1 , while the values of pseudo-second-order were 0.0103 and 0.053 L.m
... Show MoreFor extraction chloro anion complexes of Cd2+ and Hg2+ used many organic agents as extractant according to liquid ion exchange method such as α-Naphthyl amine (α-NA), 4-Amino benzoic acid (4-ABA), 2-[(4-Carboxy methyl phenyl) azo]-4,5-diphenyl imidazole (4CMePADPI) and Cryptand (C222). This study includes definition hydrochloric acid concentration in aqueous phase and shaking with organic phase necessary for extraction as well as shaking time, organic solvent effect, interferences and alkaline salt effect. Thermodynamic showed the ion exchange reaction was exothermic for α-NA, C222 and endothermic for 4-ABA, 4-CMePADPI for extraction CdCl4=, but for extraction HgCl4= was exothermic with 4-ABA, 4CMePADPI and C222 but
... Show MoreFriction stir welding (FSW) of Tee-joints is obtained by inserting a specially designed rotating pin into the clamped blanks, through top plate (skin) to bottom plate (stringer), and then moving it along the joint, limiting the contact between the tool shoulder and the skin. The present work aims to investigate the defects occur for Tee-joint of an Aluminum alloy (Al 5456) with dimensions (180mm x 70mm) for the skin plate, (180mm x 30mm) for stringer plate and thickness of (4mm).
The effects of welding parameters such as rotational speed, linear speed, plunging depth, tool tilting, and die radii of welding fixture on the welding quality of Aluminum Alloy will be studied. Weld defects had been summarized and studied, and then the best
In humans, Pseudomonas aeruginosa is the second most frequent gram negative nosocomial pathogen in hospitals and has the highest case-fatality rate of all hospital-acquired bacteremia because of the hardy resistance of these bacteria to mechanical cleansing as well as to disinfectant, and many antibiotics. The susceptibility of bacteria against the antibiotics is modulated by several local factors such as temperature which modified drug efficacy, so this study was carried out to evaluate the effect of different temperature (20,42,45)Ċon the susceptibility of Pseudomonas aeruginosa to the minimum inhibitory concentrations (MIC) of the antimicrobial agents before and after irradiation. The samples collected from 150 persons suffering from
... Show MorePhenotypic And genotypic characteristics of Salmonella enterica serotype Typhi have been determined for 29 isolates, from Baghdad in 2007. Conventional typing methods were performed by biochemical tests, and antimicrobial susceptibility test. Molecular typing performed by analysis plasmid DNA beside using the Random Amplified Polymorphic DNA (RAPD-PCR). For the latter, two universal primers that have selected for the high discriminatory power were used for RAPD analysis. All isolates were belong one biotype according to the differention by their ability to decarboxylat lysine, 29(100%) were lysine (+). All the isolates were susceptible to the Antibiotics used. However, all the strains free of plasmids. RAPD was capable of grouping the strai
... Show MoreBackground: Metal ions can be released from metallic orthodontic appliances due to corrosion in the oral cavity; prophylactic mouthwashes may have an effect on ion release from orthodontic wires. Materials and Methods: Thirty six orthodontic sets of half maxillary fixed appliance with 2 types of arch wires SS and NiTi(Morelli) were constructed and immersed in 2 types of mouthwashes; Claradone (non-fluoridated) and Silver Care (fluoridated) for 28 days at 37°C, then the released Ni and Cr ionswere measured using atomic absorption spectrophotometer and compared statistically. Results: Ni ion release was higher from NiTi wire group than SS wire group for both mouthwashes and also was higher for Silver Care group than for Claradone group.
... Show MoreA series of adsorption laboratory experiments were conducted to study the sorption efficiency of bentonite in removal Cd from aqueous solutions. The bentonite was found to be a good receptive to the adsorption of Cd under specific laboratory conditions. The sorption capacity for Cd onto bentonite was investigated through the variation in pH and initial Cd2+ concentration. The sorption efficiency onto bentonite was examined as a function of pH, initial ion concentration, equilibrium reaction time and solid mass/ liquid volume ratio. The maximum sorption (%) of Cd from solutions were determined when solid to liquid ratio is 2 gm of bentonite versus 50 ml solution, the equilibrium reaction time is 50 minute at pH ranges from 5-7. The sorpti
... Show MoreBecause of the contaminants represented by heavy metals in the aquatic
environment have an adverse effects need to be addressed, therefore, a laboratory
simulation was conducted on Cd using kaolinite that collected from Ga’ara Formation
as considered as a natural sorbent material that can be used to remove heavy metals
from aqueous environments. Mineralogical study was conducted on kaolinite using
X-Ray diffraction (XRD), Scanning Electron Microscope (ESM) and Energy-
Dispersive X-ray Spectroscopy (EDS) for the purpose of investigating the microtexture.
It was found that kaolinite has pure phase of very fine grains with a very little
quantity of quartz and has a number of active sites for adsorption. Chemical an
The aim of present study is to determine the optimum parameters of friction stir welding process and known the most important parameter along with percentage contribution of each parameter which effect on tensile strength and joint efficiency of FS welded joint of dissimilar aluminum alloys AA2024-T3 and AA7075-T73 of 3 mm thick plates by applied specific number of experiments using Taguchi method .AA2024 was placed on the advancing side and AA7075 on the retreating side. FSW was achieved under three different rotation speeds (898, 1200 and 1710) rpm, three different welding speeds (20, 45 and 69) mm\min , three different pin profiles (cylindrical, threaded cylindrical and cone) and tool tilt angle 2◦. Taguchi method w
... Show MoreIn this study, carbon nanotubes were prepared using a pure chemical method modified similar to the Hummers method with simple changes in the work steps. The carbon nanotubes were then coated and reduced on copper and aluminum metals using the electrodeposition method (EDP) for corrosion protection application in seawater medium (NaCl 3.5%) at four different temperatures: 20, 30, 40, and 50 °C, which were studied using three electrode potentiostats. All corrosion measurements, thermodynamics, and kinetics parameters were nominated from Tafel plots. The films deposited by the carbon nanotubes were examined by the SEM technique, and this technique showed the formation of carbon nanotubes.