scholarly journals Adsorption Studies of Antimony on Manganese Dioxide Using Radiometric Techniques

1994 ◽  
Vol 11 (1) ◽  
pp. 41-50 ◽  
Author(s):  
M.A. Rauf ◽  
M. Ikram ◽  
S.M. Hasany ◽  
S.M. Najam-ud-Din
Keyword(s):  
Metal Ions ◽  
Manganese Dioxide ◽  
Langmuir Equation ◽  
Adsorption Behaviour ◽  
Optimum Conditions ◽  
Equilibrium Time ◽  
Adsorption Studies ◽  
Foreign Ions ◽  
Sorption Energy ◽  
The Mean

The efficiency of manganese dioxide as an adsorbent for the removal of antimony has been examined using radiometric techniques. The optimum conditions for maximum adsorption were investigated. The influence of equilibrium time, the nature and composition of the electrolytes, shaking time and the effect of foreign ions and other metal ions on the adsorption behaviour of antimony was also studied. On the basis of these data, TeIV can be easily removed from antimony using manganese dioxide as an adsorbent. The adsorption was also found to obey the Langmuir equation, the mean sorption energy of Sb on MnO2 being 11.7 kJ/mol.

scholarly journals Adsorption Studies of Arsenic on Manganese Dioxide Using Radiometric Techniques

1995 ◽  
Vol 12 (2) ◽  
pp. 93-100 ◽  
Author(s):  
M.A. Rauf ◽  
S.M. Hasany ◽  
M. Ikram ◽  
M. Najam-ud-Din
Keyword(s):  
Manganese Dioxide ◽  
Time Effect ◽  
Optimum Conditions ◽  
Freundlich Equation ◽  
Sorption Energy ◽  
Adsorption Data ◽  
The Mean ◽  
High Separation Factor ◽  
Removal Of Arsenic ◽  
High Separation

Manganese dioxide has been tested as an adsorbent for the removal of arsenic using radiometric techniques. Optimum conditions for maximum adsorption in terms of equilibrium time, nature and composition of electrolytes, shaking time, effect of foreign ions and other metal ions have been investigated. On the basis of these data, high separation factor values were obtained in the case of CoII, HfIV and TeIV. The adsorption data were also found to obey the Freundlich equation, the mean sorption energy of As on MnO2 being 15.5 kJ/mol.

scholarly journals Studies on the Adsorption Behaviour of Lutetium on Sand

1996 ◽  
Vol 13 (2) ◽  
pp. 127-135
Author(s):  
M.A. Rauf ◽  
M.J. Iqbal ◽  
I. Ellahi
Keyword(s):  
Metal Ions ◽  
Distribution Coefficient ◽  
Freundlich Isotherm ◽  
Adsorption Behaviour ◽  
Foreign Ions ◽  
Adsorption Data

The adsorption behaviour of lutetium on sand samples was investigated and the conditions for maximum adsorption optimized. The effects of foreign ions, both cations and anions, were also investigated. The distribution coefficient value, KD, was compared to those for other metal ions adsorbed under similar conditions. The adsorption data seem to provide a good fit to the Freundlich isotherm and to the Dubinin–Radushkevich (D–R) equation.

scholarly journals Adsorption Studies of Europium on Manganese Dioxide from Aqueous Sulphuric Acid and 1-Propanol Mixtures

1994 ◽  
Vol 11 (3) ◽  
pp. 155-160 ◽  
Author(s):  
M.A. Rauf ◽  
S.M. Hasany ◽  
M.J. Iqbal ◽  
M.T. Hussain
Keyword(s):  
Metal Ions ◽  
Manganese Dioxide ◽  
Sulphuric Acid ◽  
Binary Mixtures ◽  
Organic Component ◽  
Adsorption Studies

The adsorption of europium on to manganese dioxide from binary mixtures of 1-propanol with aqueous sulphuric acid has been studied as a function of the concentration of the aqueous and organic component. The composition of those mixtures from which maximum and minimum adsorption could be obtained has been determined. The influence of cations and anions has also been studied. Chromate, fluoride, citrate, EDTA, CrIII, AlIII, FeIII, PbII and AgI reduce adsorption appreciably in these mixtures. The adsorption of several other metal ions has also been measured under specific conditions to determine the selectivity of manganese dioxide. Europium and some other metal ions can be separated from elements such as mercury, zinc, etc. which show very low adsorption on manganese dioxide from these binary mixtures.

Removal of Heavy Metal Ions from Aqueous Solution by Manganese Dioxide-Coated Polypropylene Granules: An Implication of Rainwater Runoff Treatment

2007 ◽  
Vol 544-545 ◽  
pp. 131-134
Author(s):  
Sardor Abdukakharovich Mavlyankariev ◽  
Dong Seok Rhee
Keyword(s):  
Metal Ions ◽  
Manganese Dioxide ◽  
Surface Area ◽  
Mercury Porosimetry ◽  
Surface Characteristics ◽  
Metal Species ◽  
Adsorption Model ◽  
Rainwater Runoff ◽  
Flow Through ◽  
Fast Removal

Modified polypropylene granules (MDPG) were coated by manganese dioxide and their surface and adsorptive characteristics were studied. Surface characteristics of the adsorbent were investigated by B.E.T. surface area and mercury porosimetry. Coating has significantly increased the surface area of granules from 0.12 m 2 /g B.E.T. N 2 to 15.42 m 2 /g. Gas pycnometry measurements resulted in low density of 0.13 g/cm 3 for uncoated granules, the fact ascribed to 0.65 porosity measured. Coating increased micro pore volume of raw granules by a factor of 58. Adsorption experiments were conducted in column flow-through reactors at pH 6.0 and 10 g/L sorbent dosage for mixture of four metal species, each having 5 mg/L initial concentration. More than 60 % of Pb and Cu was removed within first 20 min, whereas just over 29 and 13 % for Cd and Zn respectively. Furthermore, more than 99, 84, 40, 16 % of Pb, Cu, Cd, and Zn was removed within 1 h. Adsorption efficiencies for 5 ppm of initial metal concentration at pH 5.0 and 10 g/L sorbent/solute ratio resulted in 4.9, 3.9 mg of Pb and Cu sorbed per gram of sorbent. And these ratios for separate metal ions were substantially higher than those for the mixture of the four metal ions. For 5 g/L of sorbent under the same parameters, removal efficiencies of Cd and Zn were respectively 0.98, 0.75 mg/g, correlating well with Freundlich adsorption model. Adsorption kinetics showed relatively fast removal rates within first 5 h of sorption. Desorption resulted in eluting 57, 70, 76, 78 % of the initial feeding concentrations for Pb, Cu, Cd, Zn, respectively.

Incorporation of Impurity Metal Ions in Electrolytic Manganese Dioxide

1994 ◽  
Vol 141 (8) ◽  
pp. 2035-2040 ◽  
Author(s):  
Hiroki Tamura ◽  
Kenji Ishizeki ◽  
Masaichi Nagayama ◽  
Ryusaburo Furuichi
Keyword(s):  
Metal Ions ◽  
Manganese Dioxide ◽  
Electrolytic Manganese Dioxide ◽  
Electrolytic Manganese ◽  
Impurity Metal

scholarly journals OPTIMIZATION OF REFLUX EXTRACTION FOR CAESALPINIA SAPPAN LINN. WOOD BY USING RESPONSE SURFACE METHODOLOGY

2020 ◽  
Vol 83 (1) ◽  
pp. 85-92
Author(s):  
Mohd Azahar Mohd Ariff ◽  
Muhammad Syafiq Abd Jalil ◽  
Noor ‘Aina Abdul Razak ◽  
Jefri Jaapar
Keyword(s):  
Particle Size ◽  
Response Surface Methodology ◽  
Drinking Water ◽  
Response Surface ◽  
Extraction Time ◽  
Percentage Error ◽  
Optimum Conditions ◽  
Caesalpinia Sappan ◽  
The Mean ◽  
Repeated Runs

Caesalpinia sappan linn. (CSL) is a plant which is also known as Sepang tree contains various medicinal values such as to treat diarrhea, skin rashes, syphilis, jaundice, drinking water for blood purifying, diabetes, and to improve skin complexion. The aim of this study is to obtain the most optimum condition in terms of the ratio of sample to solvent, particle size, and extraction time to get the highest amount of concentration of the CSL extract. In this study, the ranges of each parameters used were: ratio sample to solvent: 1.0:20, 1.5:20, 2.0:20, 2.5:20, 3.0:20, particle size: 1 mm, 500 um, 250 um, 125 um, 63 um, and extraction time: 1 hr, 2 hr, 3 hr, 4 hr, 5 hr. The concentration was analyzed using a UV-vis spectrophotometer. The optimum conditions were obtained by response surface methodology. From the design, 20 samples were run throughout this experiment. The optimized value from the RSM were 2.0:20 for ratio sample to solvent, 125 µm of particle size and 2.48 hours with the concentration of 37.1184 ppm. The accuracy of the predictive model was validated with 2 repeated runs and the mean percentage error was less than 3%. This confirmed the model’s capability for optimizing the conditions for the reflux extraction of CSL’s wood.

A Versatile Radioimmunoassay for the Determination of Serum Oestriol in Pregnancy

1973 ◽  
Vol 10 (1-6) ◽  
pp. 159-166 ◽  
Author(s):  
J. E. H. Stafford
Keyword(s):  
Normal Pregnancy ◽  
Optimum Conditions ◽  
Random Series ◽  
The Mean ◽  
Hydrolysis Of ◽  
Selection Of ◽  
In Pregnancy

A versatile radioimmunoassay for serum oestriol in pregnancy has been developed which requires 10 μ| of serum (for total) or 50 μ| (for unconjugated). Selection of the optimum conditions for the hydrolysis of serum oestriol conjugates, the isolation of free oestriol, the displacement of tritiated oestriol by cold oestriol and the separation of the free and bound fractions is described. Total oestriol levels doubled between weeks 34 and 38 of normal pregnancy, very little change occurring in the mean level after the 38th week of gestation. In a random series of pregnancy sera there was a significant correlation between total and unconjugated oestriol.

Optimized atomic absorption spectrophotometry of calcium in erythrocytes.

1987 ◽  
Vol 33 (11) ◽  
pp. 2004-2007 ◽  
Author(s):  
S Nomoto ◽  
S Shoji
Keyword(s):  
Hydrochloric Acid ◽  
Atomic Absorption ◽  
Atomic Absorption Spectrophotometry ◽  
Graphite Tube ◽  
Optimum Conditions ◽  
Absorption Spectrophotometry ◽  
Flame Atomic Absorption ◽  
Flame Atomic Absorption Spectrophotometer ◽  
The Mean ◽  
Mean Concentration

Abstract We sought to establish optimum conditions for measuring calcium in erythrocytes by atomic absorption spectrophotometry. The conditions we selected are as follows. Wash one volume of fresh heparin-treated packed cells once with 30 volumes of isotonic buffered saline (pH 7.4) at a temperature somewhat exceeding 25 degrees C. Dilute the washed packed cells 10-fold with 12 mmol/L hydrochloric acid, and analyze the supernate for calcium. Measure the hematocrit of the washed packed cells, then analyze an aliquot of them for calcium, using a computer-readout type of flame or a non-flame atomic absorption spectrophotometer equipped with a pyrocoated graphite tube. The temperature program is 1000 degrees C for ashing [corrected] and 1800 degrees C for the atomizing cycle. Intraday and day-to-day reproducibility of the assay was 6.55% and 8.19%, respectively, at the mean concentration of calcium in the erythrocytes of healthy adults, which is 4.30 mumol/L.

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