SORPTION OF Au(III) BY <i>Saccharomyces cerevisiae</i> BIOMASS

Au(III) sorption by S. cerevisiae biomass extracted from beer waste industry was investigated. Experimentally, the sorption was conducted in batch method. This research involved five steps: 1) identification the functional groups present in the S. cerevisiae biomass by infrared spectroscopic technique, 2) determination of optimum pH, 3) determination of the sorption capacity and energy, 4) determination of the sorption type by conducting desorption of sorbed Au(III) using specific eluents having different desorption capacity such as H2O (van der Waals), KNO3 (ion exchange), HNO3 (hydrogen bond), and tiourea (coordination bond), 5) determination of effective eluents in Au(III) desorption by partial desorption of sorbed Au(III) using thiourea, NaCN and KI. The remaining Au(III) concentrations in filtrate were analyzed using Atomic Absorption Spectrophotometer. The results showed that: 1) Functional groups of S. cerevisiae biomass that involved in the sorption processes were hydroxyl (-OH), carboxylate (-COO-) and amine (-NH2), 2) maximum sorption was occurred at pH 4, equal to 98.19% of total sorption, 3) The sorption capacity of biomass was 133.33 mg/g (6.7682E-04 mol/g) and was involved sorption energy 23.03 kJ mol-1, 4) Sorption type was dominated by coordination bond, 5) NaCN was effective eluent to strip Au(III) close to 100%. Keywords: sorption, desorption, S. cerevisiae biomass, Au(III)

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Use of aminated hulls of sunflower seeds for the removal of anionic dyes from aqueous solutions

International Journal of Environmental Science and Technology ◽

10.1007/s13762-019-02536-8 ◽

2019 ◽

Vol 17 (3) ◽

pp. 1211-1224 ◽

Cited By ~ 4

Author(s):

T. Jóźwiak ◽

U. Filipkowska ◽

S. Brym ◽

L. Kopeć

Keyword(s):

Sorption Capacity ◽

Textile Industry ◽

Sunflower Seed ◽

Freundlich Isotherm ◽

Sorption Kinetics ◽

Reactive Black 5 ◽

Anionic Dyes ◽

Maximum Sorption Capacity ◽

Maximum Sorption

Abstract In this study, we analyzed the effectiveness of sorption of dyes popular in the textile industry (Reactive Black 5, Reactive Yellow 84, Acid Yellow 23, and Acid Red 18) on aminated and non-aminated seed hulls of common sunflower (Helianthus annuus L.). The scope of the study included: determination of the effect of pH on dye sorption effectiveness, sorption kinetics analyses (sorption equilibrium time, pseudo-first-order/pseudo-second-order model, intramolecular diffusion model), and determination of the maximum sorption capacity against dyes (Langmuir/Freundlich isotherm). The sorbent was subjected to the FTIR analysis. The sorption capacity of the aminated sunflower seed hulls against reactive dyes RB5 and RY84 accounted for 51.02 mg/g and 63.27 mg/g, respectively, and was higher by 1665% (17.6 times higher) and 1425% (15.3 times higher) compared to that of non-modified hulls. In the case of acidic dyes, Acid Yellow 23 and Acid Red 18, the sorption capacity of the aminated sunflower seed hulls reached 44.78 mg/g and 42.19 mg/g, respectively, and was higher by 1881% (19.8 times higher) and 2284% (23.8 times higher), respectively, compared to the non-modified hulls.

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Determination of optimal adsorption-desorption conditions for selective removal of Ni(II) from petrochemical samples using ion imprinted nanosorbent

European Journal of Chemistry ◽

10.5155/eurjchem.9.1.57-62.1685 ◽

2018 ◽

Vol 9 (1) ◽

pp. 57-62 ◽

Cited By ~ 2

Author(s):

Azizallah Nezhadali ◽

Maryam Pirouzmand ◽

Mahmood Payehghadr

Keyword(s):

Limit Of Detection ◽

Modified Electrodes ◽

Imprinted Polymer ◽

Cyclic Voltammetric ◽

Relative Standard ◽

Ion Imprinted ◽

Optimum Ph ◽

Maximum Sorption ◽

Adsorption Desorption

Nanoporous particles Ni(II) ion imprinted polymer (IIP), and non-imprinted polymer (NIP) in the absence of Ni(II) ion, with 18-70 nm dimensions were synthesized, and characterized by Fourier transform infrared, energy dispersive X-ray and nuclear magnetic resonance spectroscopic methods. Then, the surface area, pore size and structural composition of the products were characterized by Brunauer-Emmett-Teller and scanning electron microscope methods. Then, modified electrodes by the IIP for Ni(II) sensing and determination, were constructed and their catalytic activity were investigated by cyclic voltammetric method. Some parameters like desorption solvent, amount of sorbent, pH and contact time were optimized, and the measurements were all conducted under optimal conditions. The optimum pH for maximum sorption was obtained 7.8. In the optimum conditions, the maximum sorbent capacity of the IIP was obtained 371.9 µM/g. The limit of detection and relative standard deviation (n = 5) were obtained 1.3 ng/mLand 1.47%, respectively. The pre-concentration procedure revealed a linear curve within the concentration range of 10-6000 ng/mL and a good linearity with squared correlation coefficient of r2 0.9991 was achieved. The method was applied successfully for determination of Ni(II) ion in petrochemical samples.

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Природные материалы для сорбционной очистки хром- и кадмийсодержащих инфильтратов полигонов ТБО

Vodosnabzhenie i sanitarnaia tehnika ◽

10.35776/mnp.2019.12.02 ◽

2019 ◽

pp. 13-19

Author(s):

A. Safonov ◽

N. Andriushchenko ◽

N. Popova ◽

K. Boldyrev

Keyword(s):

Sorption Capacity ◽

Electron Acceptors ◽

Bacterial Cells ◽

Maximum Sorption Capacity ◽

Sorption Material ◽

Maximum Sorption ◽

Properties Of Materials ◽

Solid Waste Landfills ◽

Sorption Characteristics

Проведен анализ сорбционных характеристик природных материалов (вермикулит, керамзит, перлит, цеолит Трейд ) при очистке кадмий- и хромсодержащих сточных вод с высокой нагрузкой по ХПК. Установлено, что цеолит обладает максимальными сорбционными характеристиками для Cd и Cr и наименьшим биологическим обрастанием. При использовании вермикулита и керамзита или смесей на их основе можно ожидать увеличения сорбционной емкости для Cd и Сr при микробном обрастании, неизбежно происходящем в условиях контакта с водами, загрязненными органическими соединениями и биогенами. При этом биообрастание может повысить иммобилизационную способность материалов для редоксзависимых металлов за счет ферментативных ресурсов бактериальных клеток, использующих их в качестве акцепторов электронов. Эффект микробного обрастания разнонаправленно изменял параметры материалов: для Cr в большинстве случаев уменьшение и для Cd значительное увеличение. При этом дополнительным эффектом иммобилизации Cr является его биологическое восстановление биопленками. Варьируя состав сорбционного материала, можно подбирать смеси, оптимально подходящие для очистки вод инфильтратов с полигонов твердых бытовых отходов с высокой нагрузкой по ХПК и биогенным элементам как при использовании in situ, так и в системах на поверхности.The analysis of the sorption characteristics of natural materials (vermiculite, expanded clay, perlite, Trade zeolite) during the purification of cadmium and chromium-containing leachate with a high COD load was carried out. It was determined that zeolite had the maximum sorption capacity for Cd and Cr and the lowest biological fouling. When using vermiculite and expanded clay or mixtures on their basis, one can expect an increase in the sorption capacity for Cd and Cr during microbial fouling that inevitably occurs during contacting with water polluted with organic compounds and nutrients. In this case biofouling can increase the immobilization properties of materials for redox-dependent metals due to the enzymatic resources of bacterial cells that use them as electron acceptors. The effect of microbial fouling changed the parameters of materials in different directions: for Cr, in most cases, downward, and for Cd, significantly upward. Moreover, chromium biological recovery by biofilms is an additional effect of immobilization. Varying the composition of the sorption material provides for selecting mixtures that are optimally suitable for the purification of leachates from solid waste landfills with high COD and nutrients load, both when used in situ and in surface systems.

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Sorption of Lead by the Selective Ion Exchanger Ostsorb DETA

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19921393 ◽

1992 ◽

Vol 57 (7) ◽

pp. 1393-1404 ◽

Cited By ~ 3

Author(s):

Ladislav Svoboda ◽

Jan Uhlíř ◽

Zdeněk Uhlíř

Keyword(s):

Phosphoric Acid ◽

Aqueous Solutions ◽

Functional Groups ◽

Ion Exchanger ◽

Preconcentration Procedure ◽

Bead Cellulose

The properties of Ostsorb DETA, a selective ion exchanger based on modified bead cellulose with chemically bonded diethylenetriamine functional groups, were studied, and its applicability to the preconcentration of trace amounts of lead from aqueous solutions was verified. The conditions of the preconcentration procedure in the column and batch modes were optimized for this purpose. The results obtained were applied to the determination of lead in phosphoric acid.

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Phosphate Removal Using Polyethylenimine Functionalized Silica-Based Materials

Sustainability ◽

10.3390/su13031502 ◽

2021 ◽

Vol 13 (3) ◽

pp. 1502

Author(s):

Maria Xanthopoulou ◽

Dimitrios Giliopoulos ◽

Nikolaos Tzollas ◽

Konstantinos S. Triantafyllidis ◽

Margaritis Kostoglou ◽

...

Keyword(s):

Sorption Capacity ◽

Removal Rate ◽

Phosphate Concentration ◽

Phosphate Removal ◽

Equilibrium Studies ◽

Maximum Sorption Capacity ◽

Algae Blooms ◽

Maximum Sorption ◽

Phosphate Anions ◽

Adsorbent Dose

In water and wastewater, phosphate anions are considered critical contaminants because they cause algae blooms and eutrophication. The present work aims at studying the removal of phosphate anions from aqueous solutions using silica particles functionalized with polyethylenimine. The parameters affecting the adsorption process such as pH, initial concentration, adsorbent dose, and the presence of competitive anions, such as carbonate, nitrate, sulfate and chromate ions, were studied. Equilibrium studies were carried out to determine their sorption capacity and the rate of phosphate ions uptake. The adsorption isotherm data fitted well with the Langmuir and Sips model. The maximum sorption capacity was 41.1 mg/g at pH 5, which decreased slightly at pH 7. The efficiency of phosphate removal adsorption increased at lower pH values and by increasing the adsorbent dose. The maximum phosphate removal was 80% for pH 5 and decreased to 75% for pH 6, to 73% for pH 7 and to 70% for pH 8, for initial phosphate concentration at about 1 mg/L and for a dose of adsorbent 100 mg/L. The removal rate was increased with the increase of the adsorbent dose. For example, for initial phosphate concentration of 4 mg/L the removal rate increased from 40% to 80% by increasing the dose from 0.1 to 2.0 g/L at pH 7. The competitive anions adversely affected phosphate removal. Though they were also found to be removed to a certain extent. Their co-removal provided an adsorbent which might be very useful for treating waters with low-level multiple contaminant occurrence in natural or engineered aquatic systems.

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Bichromatic Photoassociation Spectroscopy for the Determination of Rotational Constants of Cs2 0 u + Long-Range State below the 6S1/2 + 6P1/2 Asymptote

Molecules ◽

10.3390/molecules25173963 ◽

2020 ◽

Vol 25 (17) ◽

pp. 3963

Author(s):

Jizhou Wu ◽

Jie Ma ◽

Yuqing Li ◽

Wenliang Liu ◽

Peng Li ◽

...

Keyword(s):

Long Range ◽

Spectroscopic Technique ◽

Rigid Rotor ◽

Simple Analysis ◽

Rotational Constants ◽

Vibrational Levels ◽

Photoassociation Spectroscopy ◽

Rotor Model ◽

Good Agreement

This article demonstrates new observation of the high-resolution ro-vibrational bichromatic photoassociation spectra (BPAS) of Cs2 in the 0u+ long-range state below the asymptotes 6S1/2 + 6P1/2. By combining with a modulation spectroscopic technique, precise references of the frequency differences have been engineered through the BPAS, with which the rotational constants of low-lying vibrational levels of the Cs20u+ long-range state have been accurately determined by fitting the frequency differences to the non-rigid-rotor model. The rotational constants for the newly observed seven ro-vibrational levels are summarized and disagreement for the level ῦ = 498 is clarified. The rotational constants of different vibrational levels demonstrate strong perturbations of the related energy structures. A simple analysis is performed and shows good agreement with experimental results.

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A Purely Spectroscopic Technique for Determining Energy Band Offsets in Quantum Wells

MRS Proceedings ◽

10.1557/proc-240-99 ◽

1991 ◽

Vol 240 ◽

Cited By ~ 1

Author(s):

Emil S. Koteies

Keyword(s):

Quantum Wells ◽

Valence Band ◽

Accurate Determination ◽

Energy Difference ◽

Spectroscopic Technique ◽

Band Offsets ◽

Band Energy ◽

Semiconductor Quantum Wells ◽

Sensitive Function

ABSTRACTWe have developed a novel experimental technique for accurately determining band offsets in semiconductor quantum wells (QW). It is based on the fact that the ground state heavy- hole (HH) band energy is more sensitive to the depth of the valence band well than the light-hole (LH) band energy. Further, it is well known that as a function of the well width, Lz, the energy difference between the LH and HH excitons in a lattice matched, unstrained QW system experiences a maximum. Calculations show that the position, and more importantly, the magnitude of this maximum is a sensitive function of the valence band offset, Qy, which determines the depth of the valence band well. By fitting experimentally measured LH-HH splittings as a function of Lz, an accurate determination of band offsets can be derived. We further reduce the experimental uncertainty by plotting LH-HH as a function of HH energy (which is a function of Lz ) rather than Lz itself, since then all of the relevant parameters can be precisely determined from absorption spectroscopy alone. Using this technique, we have derived the conduction band offsets for several material systems and, where a consensus has developed, have obtained values in good agreement with other determinations.

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