scholarly journals Radiochemical Studies on the Separation of Cesium, Cobalt, and Europium from Aqueous Solutions Using Zirconium Selenomolybdate Sorbent

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
H. El-Said
Keyword(s):  
Acid Solution ◽  
Aqueous Solutions ◽  
Flow Rate ◽  
Chromatographic Column ◽  
Sorption Behavior ◽  
Acid Solutions ◽  
Activation Product ◽  
Batch Equilibration

A procedure for removal and separation of Cs, Eu and activation product of Co using zirconium selenomolybdate was developed. Interactions of134Cs(I),152,154Eu(III), and60Co(II) ions from HNO3acid solutions with zirconium selenomolybdate matrix, dried at 50°C, have been individually investigated by the batch equilibration method. The sorption behavior of the three ions showed a selectivity sequence in the following order: Cs(I) > Eu(III) > Co(II). The breakthrough capacities of zirconium selenomolybdate for Cs(I), Eu(III) and Co(II) were found to be 0.82, 0.45, and 0.18 mmol/g of the sorbent, respectively. A mixture of the three radionuclides (1×10−2 M each) in 140 mL of1×10−2 M HNO3solution was passed through 1 g zirconium selenomolybdate chromatographic column. Thereafter, quantitative elution of the retained Co(II) was achieved with 14 mL of1×10−1 M HNO3acid solution leaving Eu(III) and Cs(I) strongly retained onto the column. Quantitative elution of Eu(III) was achieved by passing 22 mL2.5×10−1 M HNO3. About 89% of the retained Cs(I) was eluted with 32 mL of 2 M NH4Cl solution at a flow rate of 0.5 mL/min.

Pot Experiments on the Chemical Treatment of Soils Infected with the Potato and Oat Strains of Heterodera schachtii

1938 ◽  
Vol 16 (2) ◽  
pp. 61-66 ◽  
Author(s):  
Richard H. Hurst
Keyword(s):  
Acid Solution ◽  
Aqueous Solutions ◽  
Chemical Treatment ◽  
Laboratory Experiments ◽  
The Other ◽  
Alkaline Media ◽  
Heterodera Schachtii ◽  
Acid Solutions ◽  
Slow Process ◽  
Calcium Cyanamide

It was observed in laboratory experiments that the lethal action of dilute solutions of calcium cyanamide on the larvae of Heterodera schachtii was more rapid when these solutions were rendered slightly acid. This might be due to the rate of decomposition of calcium cyanamide in aqueous solutions of varying þH. The changes which cyanamide undergoes in acid and alkaline media have been described by Crowther & Richardson (1932). Solutions of commercial calcium cyanamide are moderately alkaline because of their lime content, and in this alkalinity any free cyanamide which is formed tends to polymerise to dicyanodiamide. Experiments with solutions of dicyanodiamide showed that this substance has very little toxic action on H. schachtii larvae. In acid solution, on the other hand, cyanamide is hydrolysed to urea. This substance becomes toxic when it decomposes to ammonia, but in the slightly acid solutions used the change would be a slow process. It is probable, therefore, that the degree of toxicity of calcium cyanamide solutions would be greatest where the cyanamide radicle could be retained unchanged for the longest period.

Absorption of oxygen into solutions of polymers

1986 ◽  
Vol 51 (10) ◽  
pp. 2127-2134 ◽  
Author(s):  
František Potůček ◽  
Jiří Stejskal
Keyword(s):  
Mass Transfer ◽  
Aqueous Solutions ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Liquid Flow ◽  
Flow Curve ◽  
Liquid Flow Rate ◽  
Polymer Concentration ◽  
Newtonian Liquids

Absorption of oxygen into water and aqueous solutions of poly(acrylamides) was studied in an absorber with a wetted sphere. The effects of changes in the liquid flow rate and the polymer concentration on the liquid side mass transfer coefficient were examined. The results are expressed by correlations between dimensionless criteria modified for non-Newtonian liquids whose flow curve can be described by the Ostwald-de Waele model.

Acid Attack Resistance of Magnesium Phosphate Cement

2016 ◽  
Vol 680 ◽  
pp. 392-397
Author(s):  
Zhu Ding ◽  
Meng Xi Dai ◽  
Can Lu ◽  
Ming Jie Zhang ◽  
Peng Cui
Keyword(s):  
Compressive Strength ◽  
Acid Solution ◽  
Portland Cement ◽  
Magnesium Phosphate ◽  
Acid Solutions ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Acid Attack ◽  
High Acid ◽  
Repair Materials

Magnesium phosphate cements (MPC) had been used as repair materials for deteriorated Portland cement concrete structures. In this paper a new MPC was prepared and the basic properties including workability and compressive strength were tested. The acid attack resistance of MPC was investigated by immersing the MPC mortars in solutions at pH 3, 5, and 7, for 14d, 28d and 60d respectively. The compressive strength of MPC mortars after acid attack was tested and the microstructure of MPC were examined. The results showed that the compressive strength of MPC decreased after immersion in acid solution for 14d and 28d, however the strength of MPC with suitable materials mixture can recovered again after 60d immersion. The results indicated MPC has high acid attack resistance in static acid solution. The behavior of MPC in flowing acid solutions is need to be studied further.

scholarly journals Development of the Infrared Hollow Waveguide Sampler for the Detection of Chlorophenols in Aqueous Solutions

2002 ◽  
Vol 85 (1) ◽  
pp. 163-172 ◽  
Author(s):  
Jyisy Yang ◽  
Chung-Jay Lee
Keyword(s):  
Aqueous Solutions ◽  
Flow Rate ◽  
Analytical Signal ◽  
Film Coating ◽  
Detection Sensitivity ◽  
Infrared Spectrometry ◽  
Hollow Waveguide ◽  
Fast Detection ◽  
Hydrophobic Polymers ◽  
High Degree

Abstract A method based on the infrared hollow waveguide sampler was developed for sensing chlorophenols in aqueous solutions. This sampler was constructed by coating a suitable hydrophobic film onto the inner surface of an infrared hollow waveguide. By passing the aqueous solution through the hollow waveguide sampler, analytes can be absorbed into the hydrophobic layer. The adsorbed analytes can be sensed later by using Fourier transform infrared spectrometry. Six hydrophobic polymers were investigated for their performance in conjunction with the infrared hollow waveguide sampler for the detection of chlorophenols. Results indicated that poly(acrylonitrile-co-butadiene) was a most suitable hydrophobic material for absorption of chlorophenols in aqueous solutions. To further increase the detection sensitivity, factors such as sampling flow rate, sampling time, and thickness of the hydrophobic film were also investigated. Results indicated that the infrared signals were similar in the examined flow rates (2–30 mL/min), but that a higher flow rate tended to produce a higher analytical signal. Fast detection speed was an advantage of this method for the detection of chlorophenols, and the sampling/detection time can be <10 min. In addition, analytical signals were nearly proportional to the thickness of the hydrophobic film coating the inside of the hollow waveguide. With the optimal conditions found in this work, detection limits based on 3 times the peak-to-peak noise level were around 300 ppb for the chlorophenols examined. A high degree of linearity in the standard curves was also observed for this method in the concentration range of 10–100 ppm. The typical regression coefficients were >0.994 for the chlorophenols examined.

The sorption behavior of CHA-type zeolite for removing radioactive strontium from aqueous solutions

2020 ◽  
Vol 230 ◽  
pp. 115874 ◽  
Author(s):  
Jie Liang ◽  
Jiangbo Li ◽  
Xin Li ◽  
Kaili Liu ◽  
Liu Wu ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Sorption Behavior ◽  
Type Zeolite

Absolute gas chromatography

1993 ◽  
Vol 440 (1909) ◽  
pp. 291-301 ◽  
Keyword(s):  
Gas Chromatography ◽  
Flow Rate ◽  
Experimental Test ◽  
Volumetric Flow Rate ◽  
Chromatographic Column ◽  
Theoretical Development ◽  
Chromatographic Technique ◽  
Simple Design ◽  
Molar Composition

A gas chromatographic technique is reported that is absolute in the sense that the molar composition of a sample can be determined without the need for calibration. It functions by measuring the volumetric flow rate of the stream leaving a chromatographic column: the flow rate changes temporarily when a peak emerges. Because volumetric flow rate is measured, the resulting chromatogram is much more closely related to quantities of material than is a conventional chromatogram. The simple theoretical development and equally simple design refinement that make the method absolute are described here together with a severe experimental test of the method.

Study on Properties of Extraction Palladium(II) with the New Synthesized Material

2013 ◽  
Vol 774-776 ◽  
pp. 1342-1345 ◽  
Author(s):  
Shao Ping Feng ◽  
Zhao Long Huang ◽  
Wei Liu ◽  
Zi Jing Li ◽  
Yan Jiang ◽  
...  
Keyword(s):  
Solvent Extraction ◽  
Hydrochloric Acid ◽  
Acid Solution ◽  
Contact Time ◽  
Acid Solutions ◽  
Quantitative Extraction ◽  
Hydrochloric Acid Solutions ◽  
Thiourea Concentration ◽  
Extraction Parameters ◽  
Hcl Concentration

In this study, the solvent extraction of Pd(II) from hydrochloric acid solutions was investigated using the new synthesized material, 2-ethylhexyl benzothiazolyl sulfide (EHBTS) which was dissolved in xylene. Pd(II) was strongly extracted by 7% EHBTS in a lower concentration hydrochloric acid solution. Extraction parameters of Pd(II), including EHBTS concentration in different diluents, contact time of aqueous and organic phases, organic/aqueous (O/A) phase ratio and HCl concentration of aqueous phase, were studied. Quantitative extraction of Pd(II) occurred at 0.1 mol.L-1 of HCl concentration, 7% of EHBTS concentration, 1.0 of O/A, 40 min of contact time. In addition，the percentage stripping of Pd(II) could be more than 98% when thiourea concentration was 0.8 mol.L-1. EHBTS can be used more than 8 as extractant to extract of Pd(II) from hydrochloric acid solutions.

scholarly journals Removal of Methylene Blue from Waste Water Using Activated Carbon Prepared from Rice Husk

2012 ◽  
Vol 60 (2) ◽  
pp. 185-189 ◽  
Author(s):  
Mohammad Arifur Rahman ◽  
S. M. Ruhul Amin ◽  
A. M. Shafiqul Alam
Keyword(s):  
Waste Water ◽  
Methylene Blue ◽  
Activated Carbon ◽  
Aqueous Solutions ◽  
Rice Husk ◽  
Flow Rate ◽  
Activated Carbons ◽  
Low Cost ◽  
Waste Water Treatment ◽  
Blue Dye

The possible utilization of rice husk activated carbon as an adsorbent for the removal of methylene blue dye from aqueous solutions has been investigated. In this study, activated carbons, prepared from low-cost rice husk by sulfuric acid and zinc chloride activation, were used as the adsorbent for the removal of methylene blue, a basic dye, from aqueous solutions. Effects of various experimental parameters, such as adsorbent dosage and particle size, initial dye concentration, pH and flow rate were investigated in column process. The maximum uptakes of methylene blue by activated rice husk carbon at optimized conditions (particle sizes: 140 ?m; Flow rate: 1.4 mL/min; pH: 10.0; initial volume of methylene blue: 50 mL and initial concentration of methylene blue: 4.0 mg/L etc.) were found to 97.15%. The results indicate that activated carbon of rice husk could be employed as low-cost alternatives to commercial activated carbon in waste water treatment for the removal of basic dyes. This low cost and effective removal method may provide a promising solution for the removal of crystal violet dye from wastewater.DOI: http://dx.doi.org/10.3329/dujs.v60i2.11491 Dhaka Univ. J. Sci. 60(2): 185-189, 2012 (July)

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