COMPARATIVE EXTRACTION OF Mn AND Pb USING EDTA AND CITRATE TO ASSESS THEIR MOBILITY FROM TWO DUMPSITES IN ZARIA METROPOLIS

2021 ◽  
Vol 5 (1) ◽  
pp. 558-565
Author(s):  
Comfort Samuel-Okey ◽  
V. O. Ajibola
Keyword(s):  
Soil Washing ◽  
Metal Extraction ◽  
Complexing Agents ◽  
Complexing Agent ◽  
High Permeability ◽  
Time Intervals ◽  
Extraction Capacity ◽  
Physiochemical Parameters ◽  
Low Levels ◽  
Target Metal

An estimate of the labile fractions of different trace metals (Mn and Pb) in soil from two dumpsites with complexing agents (EDTA and Citrate) was carried out. The dump sites used for this study receives both commercial and domestic wastes. Physiochemical parameters and the total metal concentrations of the soil was determined, extraction with EDTA and Citrate were used to study the potential metal extraction capacity at different time intervals and the extraction rates of  metal released as a function of time (between 0 to 24 hr). The relatively low levels of silt, clay, organic matter and CEC indicates high permeability, hence leachability of heavy metals in the soil and suggest that it might be amenable to remediation by soil washing. The removal efficiency showed that complete solubilization of metals did not occur, as not all the complexing agents added to the soil, was bound to the target metal. This might be due to the presence of other ions such as Ca and Fe which form relatively high stable complexes. EDTA yielded much more than citrate for both metals under consideration. Lead was extracted more than Manganese, which suggest Lead has been more labile in solution than Manganese and EDTA as a stronger complexing agent than citrate. The level of extraction was constant for the period of 60 min to 720 min after which it increased considerably

The Structural, Magnetic and Optical Properties of Ni-Mg-Zn Ferrite Prepared With Different Complexing Agents via Sol-Gel Method

2021 ◽  
Author(s):  
Yanchun Zhang ◽  
Aimin Sun ◽  
Zhaxi Suonan
Keyword(s):  
Optical Properties ◽  
Electron Microscope ◽  
Sol Gel ◽  
Complexing Agents ◽  
Complexing Agent ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Zn Ferrite ◽  
Vis Spectroscopy

Abstract Different complexing agents were used to prepare Ni-Mg-Zn ferrite with the composition formula Ni0.2Mg0.2Zn0.6Fe2O4 via sol-gel method, which included citric acid, oxalic acid, egg white and EDTA. The Ni0.2Mg0.2Zn0.6Fe2O4 ferrite with no complexing agent was also prepared as a comparison. The chemical phases of samples were analyzed by the X-ray diffraction (XRD), which indicated that samples had spinel phase structure. The lattice constants of samples are in the range of 8.3980 ~ 8.4089 Å. The composition and structure were further studied by fourier transform infrared spectroscopy (FTIR). There were two typical characteristic bands related to the stretching vibrations of spinel ferrite in FTIR spectra. Scanning electron microscope (SEM) micrographs and transmission electron microscope (TEM) images showed that the particles have the shape of spherical cube. Energy dispersive spectrometer (EDS) analyzed the elements and ingredients of samples, which included Ni, Mg, Zn, Fe and O. X-ray photoelectron spectroscopy (XPS) is used to examine further the elemental composition and chemical state of sample prepared with EDTA as complexing agent. The optical properties of samples were investigated by photoluminescence spectra and UV-Vis spectroscopy. Vibrating sample magnetometer (VSM) was used to characterize magnetic properties, hysteresis loops revealed the ferrimagnetism behavior of prepared samples.

An Assessment of Olmesartan Medoxomil Tablet by Inclusion Complex Technique

2021 ◽  
pp. 193-197
Author(s):  
Deepak Sarangi ◽  
Subhashree Mallick ◽  
Anjum Ara ◽  
Sanjeeb Kumar Sahoo ◽  
Rabinarayan Rana
Keyword(s):  
Inclusion Complex ◽  
Water Solubility ◽  
Olmesartan Medoxomil ◽  
Complexing Agents ◽  
Complexing Agent ◽  
Angiotensin Ii Receptor ◽  
Current Effort ◽  
Ir Studies ◽  
Beta Cyclodextrin ◽  
Ft Ir

Olmesartan Medoxomil is an AT1 subtype selected angiotensin-II receptor antagonist approved for the treatment of hypertension. It has low water solubility, so the current effort is being made to enhance the solubility of the Olmesartan by inclusion complex and to incorporate them into tablets by direct compression. Complexing agent like Beta cyclodextrin and polyvinyalpyrrolidone has been used for complexation method. FT-IR studies have shown that there is no link between drugs and complexing agents. Among all methods, the inclusion complex (OLBCD 3) containing the drug: Beta cyclodextrin in a 1: 3 ratio showed rapid drug release (87.41% within 30 minutes) and post compression parameters are within limits. All the values obtained from pre compression and post compression parameters meets the legal requirements for tablets. Stability studies of batch no OLBCD 3 shows no significant change. Therefore, it can be concluded that the structure was stable.

Determination of Molybdenum in Fertilizers by Atomic Absorption Spectrophotometry

1967 ◽  
Vol 50 (6) ◽  
pp. 1269-1273
Author(s):  
William L Hoover ◽  
Sonja C Dtjren
Keyword(s):  
Atomic Absorption ◽  
Isoamyl Alcohol ◽  
Potassium Thiocyanate ◽  
Atomic Absorption Spectrophotometry ◽  
Water Soluble ◽  
Complexing Agent ◽  
Alcohol Fraction ◽  
Low Levels ◽  
High Concentrations

Abstract A procedure for determining low levels of molybdenum in fertilizers by atomic absorption is proposed. With potassium thiocyanate as complexing agent, molybdenum is extracted in an isoamyl alcohol fraction to separate the fraction containing molybdenum from the water-soluble fraction containing materials that would interfere in the atomic absorption procedure. However, the procedure cannot be used with samples that have high concentrations of iron. Tests on the recovery of molybdenum in four fertilizers indicate that the procedure is reliable to levels as low as 2.5 ppm of molybdenum

Chemical Mechanical Polishing of Cu Pattern Wafer Based Alkaline Slurry in GLSI with R(NH2)n as Complexing Agent

2011 ◽  
Vol 236-238 ◽  
pp. 3020-3023 ◽  
Author(s):  
Yan Gang He ◽  
Xiao Wei Gan ◽  
Wei Hong ◽  
Yi Hu ◽  
Yu Ling Liu
Keyword(s):  
Reaction Mechanism ◽  
Chemical Mechanical Polishing ◽  
Mechanical Polishing ◽  
Complexing Agents ◽  
Complexing Agent ◽  
Mechanism Analysis ◽  
Slurry Stability ◽  
Cu Cmp ◽  
Better Than

Chemical mechanical polishing (CMP) of Cu pattern wafer based alkaline slurry in GLSI with R(NH2)n as complexing agent was investigated. In Cu CMP procedure, it is necessary to minimize the surface dishing and erosion while maintaining good planarity. This requirements are met through the complexing agents. Based on the reaction mechanism analysis of Cu in alkaline slurry with R(NH2)n as complexing agent in CMP, the performance of Cu dishing and erosion were discussed. The results showed that the slurry stability can be improved obviously by the addition of R(NH2)n as complexing agent, both Cu1 and Cu2 have good dishing and erosion performance. Furthermore, the dishing condition of Cu2 (180-230nm) is better than that of Cu1 (280-370nm), and the erosion condition of Cu2 (230-260nm) is also better than that of Cu1 (450-500nm).

Effect of complexing agents on desulphurization and deashing of coal by H2O2/H2SO4 leaching

2018 ◽  
Vol 29 (7) ◽  
pp. 1142-1154
Author(s):  
Hafiza Sana ◽  
Rizwan Haider ◽  
Muhammad Usman Rahim ◽  
Shahid Munir
Keyword(s):  
Hydrogen Peroxide ◽  
Citric Acid ◽  
Phosphoric Acid ◽  
Removal Efficiency ◽  
Coal Sample ◽  
Complexing Agents ◽  
Complexing Agent ◽  
Chemical Leaching ◽  
Optimized Conditions

The present study was aimed at investigating the effect of the addition of complexing agents on the removal efficiency of sulphur and ash contents during chemical leaching by acidified hydrogen peroxide. Representative coal sample from Lakhra was subjected to chemical leaching under various conditions of the parameters including time (60 and 120 min), temperature (25 and 50°C), complexing agents (citric acid and phosphoric acid) and the concentration of complexing agents (100 and 1000 ppm). The addition of complexing agents, i.e. citric acid and phosphoric acid imparted significant effects on improving the removal efficiency of sulphur and ash contents. Under optimized conditions, it was found out that the addition of citric acid improved the removal efficiency for sulphur from 63.88 to 83.47% and from 33.12 to 66.25% for ash. In case of phosphoric acid, the removal in sulphur and ash contents was increased from 63.77 to 80.77% and from 33.12 to 59.18%, respectively. Apparently, citric acid happened to be the most effective complexing agent, as compared to phosphoric acid. These results warrant subsequent detailed studies for further optimization of the process, including the use of some other complexing agents, as well.

Trace determination of gadolinium by conductivity-based approach

2020 ◽  
Vol 98 (10) ◽  
pp. 652-658
Author(s):  
R. Ananthanarayanan ◽  
M. Sivaramakrishna ◽  
B.S. Panigrahi
Keyword(s):  
Heavy Water ◽  
Ethylenediaminetetraacetic Acid ◽  
Limit Of Detection ◽  
Nuclear Industry ◽  
Complexing Agents ◽  
Complexing Agent ◽  
High Performing ◽  
New Class ◽  
Water Reactors

A conductivity-based technique is developed for the determination of Gd3+ in the heavy water moderators of pressurized heavy water reactors (PHWRs). The method involves monitoring extremely small shifts in conductivity, in the order of few nS/cm, due to the continuous addition of a suitable complexing agent to Gd3+ in aqueous medium. The resulting plot gives two distinct regions with vastly differing slopes. Two multidentate ligands, ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaaceticacid (DTPA), as complexing agents are compared. A high performing conductivity detector based on a new class of sensors called pulsating sensors that works entirely in the digital domain is deployed to monitor the conductivity shifts. Titration plots are studied in both H2O and D2O, and the observed difference between the plots in the two matrices is discussed in detail. Boron did not interfere in the analysis. The method was validated using the UV–vis spectrophotometric technique. The method is sensitive and rapid, as each analysis takes 3 min. The limit of detection in H2O and D2O are 1.27×10−7 mol/L and 5.1×10−7 mol/L, respectively. The precision in analysis lies between 1.9% and 5.3%. This method has important application in the nuclear industry for the routine analysis of gadolinium.

scholarly journals Effect of Soil Washing Solutions on Simultaneous Removal of Heavy Metals and Arsenic from Contaminated Soil

2020 ◽  
Vol 17 (9) ◽  
pp. 3133 ◽  
Author(s):  
Kanghee Cho ◽  
Eunji Myung ◽  
Hyunsoo Kim ◽  
Cheonyoung Park ◽  
Nagchoul Choi ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Sulfuric Acid ◽  
Phosphoric Acid ◽  
Contaminated Soil ◽  
Contaminated Soils ◽  
Soil Washing ◽  
Metal Extraction ◽  
Simultaneous Removal ◽  
Removal Of Heavy Metals ◽  
Removal Efficiencies

In this study, we investigated the feasibility of using a solution of sulfuric acid and phosphoric acid as an extraction method for soil-washing to remove Cu, Pb, Zn, and As from contaminated soil. We treated various soil particles, including seven fraction sizes, using sulfuric acid. In addition, to improve Cu, Pb, Zn, and As removal efficiencies, washing agents were compared through batch experiments. The results showed that each agent behaved differently when reacting with heavy metals (Cu, Pb, and Zn) and As. Sulfuric acid was more effective in extracting heavy metals than in extracting As. However, phosphoric acid was not effective in extracting heavy metals. Compared with each inorganic acid, As removal from soil by washing agents increased in the order of sulfuric acid (35.81%) < phosphoric acid (62.96%). Therefore, an enhanced mixture solution using sulfuric acid and phosphoric acid to simultaneously remove heavy metals and As from contaminated soils was investigated. Sulfuric acid at 0.6 M was adopted to combine with 0.6 M phosphoric acid to obtain the mixture solution (1:1) that was used to determine the effect for the simultaneous removal of both heavy metals and As from the contaminated soil. The removal efficiencies of As, Cu, Pb, and Zn were 70.5%, 79.6%, 80.1%, and 71.2%, respectively. The combination of sulfuric acid with phosphoric acid increased the overall As and heavy metal extraction efficiencies from the contaminated soil samples. With the combined effect of dissolving oxides and ion exchange under combined washings, the removal efficiencies of heavy metals and As were higher than those of single washings.

scholarly journals On the Spatial Dimension of the Circular Economy

Resources ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 32 ◽  
Author(s):  
T. Graedel ◽  
Barbara Reck ◽  
Luca Ciacci ◽  
Fabrizio Passarini
Keyword(s):  
Circular Economy ◽  
Spatial Dimension ◽  
Metal Extraction ◽  
Extraction Capacity ◽  
Resource Network ◽  
Carbon Neutrality ◽  
Nickel Copper ◽  
Product Manufacturing ◽  
Copper Zinc ◽  
Conservation Of Natural Resources

The concept of a “circular economy”, in which material in society is regarded as “a transient phase in anthropogenic resource utilization”, is a growing topic for discussion. The primary motivations for supporting a circular economy include a reduction of environmental impacts and conservation of natural resources. Australia is a vivid example of a country whose large metal extraction capacity is not balanced as it has neither an extensive product manufacturing capability nor a large domestic market. Consequently, Australia must rely on the global resource network to achieve circularity and carbon neutrality. This work illustrates this situation with quantitative material flow cycles for Australian aluminum, nickel, copper, zinc, and stainless steel, and comments on the implications of the results for Australia and for circular economy prospects more generally.

scholarly journals Bacterially Induced Weathering of Ultramafic Rock and Its Implications for Phytoextraction

2013 ◽  
Vol 79 (17) ◽  
pp. 5094-5103 ◽  
Author(s):  
Cristina Becerra-Castro ◽  
Petra Kidd ◽  
Melanie Kuffner ◽  
Ángeles Prieto-Fernández ◽  
Stephan Hann ◽  
...  
Keyword(s):  
Ultramafic Rock ◽  
Production Capacity ◽  
Metal Extraction ◽  
Limiting Factor ◽  
Bacterial Strains ◽  
Time Intervals ◽  
Content Type ◽  
Ultramafic Soil ◽  
Serpentine Minerals ◽  
Improve Metal

ABSTRACTThe bioavailability of metals in soil is often cited as a limiting factor of phytoextraction (or phytomining). Bacterial metabolites, such as organic acids, siderophores, or biosurfactants, have been shown to mobilize metals, and their use to improve metal extraction has been proposed. In this study, the weathering capacities of, and Ni mobilization by, bacterial strains were evaluated. Minimal medium containing ground ultramafic rock was inoculated with either of twoArthrobacterstrains: LA44 (indole acetic acid [IAA] producer) or SBA82 (siderophore producer, PO4solubilizer, and IAA producer). Trace elements and organic compounds were determined in aliquots taken at different time intervals after inoculation. Trace metal fractionation was carried out on the remaining rock at the end of the experiment. The results suggest that the strains act upon different mineral phases. LA44 is a more efficient Ni mobilizer, apparently solubilizing Ni associated with Mn oxides, and this appeared to be related to oxalate production. SBA82 also leads to release of Ni and Mn, albeit to a much lower extent. In this case, the concurrent mobilization of Fe and Si indicates preferential weathering of Fe oxides and serpentine minerals, possibly related to the siderophore production capacity of the strain. The same bacterial strains were tested in a soil-plant system: the Ni hyperaccumulatorAlyssum serpyllifoliumsubsp.malacitanumwas grown in ultramafic soil in a rhizobox system and inoculated with each bacterial strain. At harvest, biomass production and shoot Ni concentrations were higher in plants from inoculated pots than from noninoculated pots. Ni yield was significantly enhanced in plants inoculated with LA44. These results suggest that Ni-mobilizing inoculants could be useful for improving Ni uptake by hyperaccumulator plants.

Formation and characterization of the CuIn(S,Se)2/buffer layer interface in electrodeposited solar cells

2005 ◽  
Vol 865 ◽  
Author(s):  
N. Naghavi ◽  
C. Hubert ◽  
O. Roussel ◽  
L. Sapin ◽  
M. Lamirand ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Fill Factor ◽  
Open Circuit ◽  
Solution Chemistry ◽  
Complexing Agents ◽  
Complexing Agent ◽  
Main Role ◽  
Near Surface

AbstractThis paper presents the influence of the solution chemistry of chemical bath deposition (pH and complexing agents) on the performance of CuIn(S,Se)2 cells after an initial CN treatment. It is shown that it is possible to modify the deposition conditions of the CdS by increasing the pH of the solution and by replacing the complexing agent (ammonia) by citrate ions. Both NH3 based and citrate based process give very homogenous and covering thin films. However, in the case of the citrate based process a decrease of open circuit voltage (Voc) and fill factor (FF) and thus of the cell efficiencies is observed. This points out that the main role of the buffer layer is not only related to the specific properties of the CdS itself but also to the near surface modifications of the CuIn(S,Se)2 caused by the presence of the complexing agent in the bath.

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