Face-by-face growth of sucrose crystals from aqueous solutions in the presence of raffinose. I. Experiments and kinetic-adsorption model

2006 ◽  
Vol 292 (1) ◽  
pp. 92-103 ◽  
Author(s):  
G. Sgualdino ◽  
D. Aquilano ◽  
A. Cincotti ◽  
L. Pastero ◽  
G. Vaccari
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Model ◽  
Kinetic Adsorption ◽  
Sucrose Crystals

scholarly journals Determination of Phthalate Esters in Beverages and Water Samples by Solid Phase Extraction with Resin Based COFs as Filler

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3338
Author(s):  
Yunjie Ma ◽  
Xin Gao ◽  
Yang Ruan ◽  
Hang Cui ◽  
Li Zhang ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Phthalate Esters ◽  
Adsorption Behavior ◽  
Phthalate Ester ◽  
Phase Extraction ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Isothermal Adsorption ◽  
Kinetic Adsorption

Resin based covalent organic framework material was used as filler for solid phase extraction (SPE), and the solid phase extraction effect was compared with that of traditional COF material (TpBD COFs). The enrichment capacity of four phthalate esters (dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate) in beverage samples was investigated by SPE. Adsorption experiments showed that the kinetic adsorption behavior of COF materials for phthalate esters (PAEs) was more consistent with the quasi-second-order kinetic adsorption model, and the static adsorption behavior is more in line with the Freundlich isothermal adsorption model. Solid phase extraction experiments proved that the SPE column prepared with two COF materials as adsorbents had good adsorption effects, high recovery (water: 97.99–100.56% and beverage: 97.93–100.23%) and were reusable (50 cycles), which could meet the requirements for trace detection of phthalate ester. It was found that the solid phase extraction effect was better than the four types of commercial SPE columns. The new COF material reduced the cost of monomer use and provided the possibility for its industrial production. Meanwhile, it also provided a new feasible scheme for enriching trace phthalate esters in practical samples.

scholarly journals The Immobilization Effect of Natural Mineral Materials on Cr(VI) Remediation in Water and Soil

2020 ◽  
Vol 17 (8) ◽  
pp. 2832 ◽  
Author(s):  
Dading Zhang ◽  
Yanqiu Xu ◽  
Xiaofei Li ◽  
Lina Wang ◽  
Xuwen He ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Freundlich Isotherm ◽  
Soil Toxicity ◽  
Adsorption Model ◽  
X Ray Diffraction ◽  
Isothermal Adsorption ◽  
Adsorption Models ◽  
Natural Mineral ◽  
Isotherm Adsorption ◽  
Molecular Bond

The effects of sepiolite, montmorillonite, and attapulgite on the removal and immobilization of Cr(VI) in water and soil were studied. X-ray diffraction (XRD) characterizations showed that the purities of these three mineral materials decreased in the following order: montmorillonite > attapulgite > sepiolite, and that their surface molecular bond types were similar. The adsorption potential of Cr(VI) in aqueous solutions of the three mineral materials was in the following order: sepiolite > attapulgite > montmorillonite. The adsorption mechanism for attapulgite was consistent with the Freundlich isotherm adsorption model, whereas that for montmorillonite was more consistent with the Langmuir model. Sepiolite had a good fitting effect for both isothermal adsorption models. For montmorillonite and attapulgite, a lower pH corresponded to a higher removal of Cr(VI). For sepiolite, however, the removal efficiency of Cr(VI) from an aqueous solution was the lowest at a pH of approximately 5.0. The results of the soil toxicity characteristic leaching procedure showed that, following the addition of 15% sepiolite, attapulgite, or montmorillonite to the contaminated soil, Cr(VI) concentrations in the leachates decreased by 16.8%, 18.9%, and 15.9%, respectively, and the total Cr concentrations in the leachates were reduced by 21.2%, 29.2%, and 17.6%. Of the three mineral materials, attapulgite demonstrated the highest Cr(VI) immobilization efficiency in soil. This study emphasizes the effect of attapulgite on the immobilization of Cr(VI) in soil and aqueous solutions, thus providing a theoretical basis for the potential application of natural mineral material remediation of Cr(VI)-contaminated aqueous solutions and soils.

Evaluation of the marine alga Sargassum glaucescens for the adsorption of Zn(II) from aqueous solutions

2014 ◽  
Vol 49 (4) ◽  
pp. 339-345 ◽  
Author(s):  
Akbar Esmaeili ◽  
Mayam Darvish
Keyword(s):  
Aqueous Solutions ◽  
Second Order ◽  
Maximum Efficiency ◽  
Order Kinetic ◽  
Weight Retention ◽  
Adsorption Model ◽  
Solution Ph ◽  
Uptake Kinetic ◽  
Adsorption Data ◽  
Pseudo Second Order

The objective of this research was to study the efficacy of the marine brown alga Sargassum glaucescens in batch removal of Zn(II) from wastewater and seawater. For these experiments, a dried biomass was used to adsorb Zn(II) from aqueous solutions. The effects of varying pH, biomass weight, retention time and initial concentration of Zn(II) were studied. The maximum efficiency of Zn(II) removal obtained was 90.00%. The experimental adsorption data were fitted to the Freundlich adsorption model. A pseudo-second-order model was found to offer the best analysis of Zn(II) uptake. Kinetic studies showed that a biomass formed of marine-dried S. glaucescens exhibited high biosorption capacity. A solution pH of 5.0 was found to be optimal for adsorption. Results showed that removal of Zn(II), increased to 90.00% with increasing contact time, increasing pH (to 5.0) and decreasing adsorbent amount. The equilibrium adsorption data are fitted to the Freundlich isotherm model and pseudo-second-order kinetic models. Therefore, brown algae Sargassum glaucescens was an economical adsorbent.

scholarly journals Removal of lead, cadmium and copper ions from aqueous solutions by using ion exchange resin C 160

2016 ◽  
Vol 32 (4) ◽  
pp. 129-140 ◽  
Author(s):  
Agnieszka Bożęcka ◽  
Monika Orlof-Naturalna ◽  
Stanisława Sanak-Rydlewska
Keyword(s):  
Ion Exchange ◽  
Aqueous Solutions ◽  
Sorption Capacity ◽  
Exchange Resin ◽  
Copper Ions ◽  
Exchange Process ◽  
Cation Exchange Resin ◽  
Ion Exchange Resin ◽  
Adsorption Model ◽  
Ion Exchange Process

Abstract Industrial waste solutions may contain toxic Pb, Cu, Cd and other metal ions. These ions may also be components of leachates in landfills of ores. The toxicity of the ionic forms of these metals is high. For this reason the paper presents the results of studies on one of the methods to reduce their concentration in aqueous solutions. The article presents the results of studies on the removal of Pb2+, Cd2+ and Cu2+ ions from model aqueous solutions with synthetic ion exchange resin C 160 produced by Purolite. The investigated ion exchanger contains sulfonic acid groups (-SO3H) in its structure and is a strongly acidic cation-exchange resin. The range of the studied initial concentrations of the Pb2+, Cd2+ and Cu2+ ions in the solutions was from 6.25 mg/L to 109.39 mg/L. The results confirmed that the used ion exchange resin C160 efficiently removes the above-mentioned ions from the studied solutions. The highest degree of purification was achieved in lead solutions for the assumed range of concentrations and conditions of the ion exchange process. It reached 99.9%. In the case of other solutions, the ion exchange process occurs with lower efficiency, however it remains high and amounts to over 90% for all the ions. The results of research were interpreted on the basis of the Langmuir adsorption model. For each studied ion, sorption capacity of the ion exchange resin increases until the saturation and equilibrium state is reached. Based on the interpretation of the Langmuir equation coefficients, an indication can be made that the studied ion exchange resin has a major sorption capacity towards the copper ions. In their case, the highest value of constant qmax was obtained in the Langmuir isotherm. For Cu2+ ions it was 468.42 mg/g. For Pb2+ and Cd2+ ions, this parameter reached the values of 112.17 mg/g and 31.76 mg/g, respectively. Ion exchange resin C 160 shows the highest affinity for the Pb2+ ions. In this case, the achieved value of coefficient b is highest and equals 1.437 L/mg.

Adsorption Characteristics of Pb(II) from Aqueous Solution onto Na-Bentonite/Poly AMPS Composite

2012 ◽  
Vol 503-504 ◽  
pp. 658-661
Author(s):  
Hai Yan Xiao ◽  
Kai Sha Gao ◽  
Qiu Rong Li
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Correlation Coefficient ◽  
Adsorption Model ◽  
Adsorption Characteristics ◽  
Optimum Ph

Na-bentonite/poly AMPS composite were prepared as an adsorbent for the removal of Pb (Ⅱ) from aqueous solutions. Pb (Ⅱ) adsorption experiments show the optimum pH and the bentonite content are pH 4.0 and 5g Na-bentonite /10g AMPS, respectively. Experimental data were described by Langmuir and Freundlih isotherms, and the correlation coefficient (R2) shows that the adsorption follows the Freundlich adsorption model.

Growth kinetics, adsorption and morphology of sucrose crystals from aqueous solutions in the presence of raffinose

2005 ◽  
Vol 40 (10-11) ◽  
pp. 1087-1093 ◽  
Author(s):  
G. Sgualdino ◽  
D. Aquilano ◽  
R. Fioravanti ◽  
G. Vaccari ◽  
L. Pastero
Keyword(s):  
Aqueous Solutions ◽  
Growth Kinetics ◽  
Sucrose Crystals

Sucrose crystal growth. I. Rate of crystal growth in pure solutions

1967 ◽  
Vol 20 (6) ◽  
pp. 1087 ◽  
Author(s):  
BM Smythe
Keyword(s):  
Crystal Growth ◽  
Aqueous Solutions ◽  
Growth Rates ◽  
Relative Velocity ◽  
Rate Process ◽  
Step Rate ◽  
Rate Of Growth ◽  
Controlled Conditions ◽  
Sucrose Solutions ◽  
Sucrose Crystals

A method is described for the measurement of rate of growth of sucrose crystals from aqueous solutions under controlled conditions of temperature, super-saturation, and relative velocity of the solution with respect to the crystal. The effects of these parameters on sucrose crystal growth rates in pure sucrose solutions are reported. The results can be explained qualitatively in terms of a two-step rate process, the two steps of which are interdependent and neither solely rate-controlling under the conditions studied.

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