Synthesis, Characterization and Sorption Capacity Examination for a Novel Hydrogel Composite Based on Gellan Gum and Graphene Oxide (GG/GO)

A novel hydrogel composite based on gellan gum and graphene oxide (GG/GO) was synthesized, characterized and tested for sorption capacity in this work. The microstructural, thermogravimetric and spectroscopic analysis confirmed the formation of the GG/GO composite. Comparative batch sorption experiments revealed a sorption capacity of the GG/GO composite for Zn (II) ions of approximately 2.3 higher than that of pure GG. The GG/GO composite exhibits a maximum sorption capacity of 272.57 mg/g at a pH of Zn (II) initial solution of 6. Generally, the sorption capacity of the sorbents is approximately 1.5 higher in slightly acidic conditions (pH 6) comparative with that for strong acidic conditions (pH 3). The sorption isotherms revealed that the sorption followed a monolayer/homogenous behavior. The sorption kinetic data were well fitted by the pseudo-second-order kinetic model, and were consistent with those derived from sorption isotherms. The intraparticle diffusion was considered to be the rate-determining step. Two main sorption mechanisms for Zn (II) were identified namely, ion exchange at low pH values, and both ion exchange and chemisorption in weekly acidic conditions.

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Phosphate removal from aqueous solutions using (vinylbenzyl)trimethylammonium chloride grafted onto polyester fibers

Water Science & Technology ◽

10.2166/wst.2015.173 ◽

2015 ◽

Vol 71 (12) ◽

pp. 1875-1883 ◽

Cited By ~ 3

Author(s):

HyunJu Park ◽

Duc Canh Nguyen ◽

Choo-Ki Na

Keyword(s):

Free Energy ◽

Ion Exchange ◽

Aqueous Solutions ◽

Sorption Capacity ◽

Phosphate Removal ◽

Trimethylammonium Chloride ◽

Order Kinetic ◽

Phosphate Sorption ◽

Maximum Sorption Capacity ◽

Competing Anions

In this study, we investigated the removal of phosphate from aqueous solutions using (vinylbenzyl)-trimethylammonium chloride (VBTAC) grafted onto poly(ethylene terephthalate) (PET) fibers (PET-g-VBTAC). Batch-mode experiments were conducted using various contact times, initial phosphate concentrations, temperatures, pH values, and competing anions, to understand phosphate sorption onto PET-g-VBTAC. The phosphate sorption capacity of PET-g-VBTAC increased with increasing solution pH and was highest near pH 7. The equilibrium data fitted the Langmuir isotherm model well. The maximum sorption capacity (qm) of PET-g-VBTAC for phosphate was 55.6–56.0 mg/g at 25–45 °C. The sorption process followed a pseudo-second-order kinetic model. The obtained values of the mean free energy indicated that sorption of phosphate on PET-g-VBTAC occurs via ion exchange. Thermodynamic parameters, enthalpy change, entropy change, and Gibb's free energy, confirmed that phosphate sorption was spontaneous and endothermic. The adverse effects of competing anions on phosphate removal by PET-g-VBTAC were insignificant. These results demonstrate that PET-g-VBTAC effectively removes phosphate from aqueous solutions by ion exchange.

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Contribution of Cross-Linker and Silica Morphology on Cr(VI) Sorption Performances of Organic Anion Exchangers Embedded into Silica Pores

Molecules ◽

10.3390/molecules25051249 ◽

2020 ◽

Vol 25 (5) ◽

pp. 1249 ◽

Cited By ~ 4

Author(s):

Ecaterina Stela Dragan ◽

Doina Humelnicu

Keyword(s):

Sorption Capacity ◽

Organic Anion ◽

Isotherm Models ◽

Order Kinetic ◽

Anion Exchangers ◽

Fast Kinetics ◽

Strong Base ◽

Maximum Sorption Capacity ◽

Composite Sorbents ◽

Cross Linker

Removal of Cr(VI) from the environment represents a stringent issue because of its tremendous effects on living organisms. In this context, design of sorbents with high sorption capacity for Cr(VI) is getting a strong need. For this purpose, poly(vinylbenzyl chloride), impregnated into porous silica (PSi), was cross-linked with either N,N,N’,N’-tetramethyl-1,2-ethylenediamine (TEMED) or N,N,N’,N’-tetramethyl-1,3-propanediamine, followed by the reaction of the free -CH2Cl groups with N,N-diethyl-2-hydroxyethylamine to generate strong base anion exchangers (ANEX) inside the pores. The PSi/ANEX composite sorbents were deeply characterized by FTIR spectroscopy, SEM-energy dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), and water uptake. The sorption performances of composites against Cr(VI) were investigated as a function of pH, contact time, initial concentration of Cr(VI), and temperature. It was found that the cross-linker structure and the silica morphology are the key factors controlling the sorption capacity. The adsorption process was spontaneous and endothermic and well described by pseudo-second-order kinetic and Sips isotherm models. The maximum sorption capacity of 311.2 mg Cr(VI)/g sorbent was found for the composite prepared with mesoporous silica using TEMED as cross-linker. The PSi/ANEX composite sorbents represent an excellent alternative for the removal of Cr(VI) oxyanions, being endowed with fast kinetics, equilibrium in about 60 min, and a high level of reusability in successive sorption/desorption cycles.

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Graphene Oxide/Polyvinyl Alcohol/Fe3O4 Nanocomposite: An Efficient Adsorbent for Co(II) Ion Removal

Journal of Analytical Methods in Chemistry ◽

10.1155/2021/6670913 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Thu Dieu Le ◽

Luyen Thi Tran ◽

Hue Thi Minh Dang ◽

Thi Thu Huyen Tran ◽

Hoang Vinh Tran

Keyword(s):

Graphene Oxide ◽

Polyvinyl Alcohol ◽

Order Kinetic ◽

Maximum Sorption Capacity ◽

Ion Removal ◽

Maximum Sorption ◽

Order Kinetic Model ◽

Metal Treatment ◽

Pseudo Second Order ◽

Adsorption Of Co2

In this work, an effective nanocomposite-based adsorbent directed to adsorb cobalt (Co2+) ion was successfully synthesized from graphene oxide (GO), polyvinyl alcohol (PVA), and magnetite (Fe3O4) nanoparticles via a coprecipitation technique. The synthesized GO/PVA/Fe3O4 nanocomposite was applied for Co2+ ion removal with the optimized working conditions including 100 min of contact time, 0.01 g of adsorbent dosage, pH of 5.2, and 50°C of temperature. The investigation of adsorption kinetics showed that the adsorption of Co2+ ion onto the GO/PVA/Fe3O4 nanocomposite followed the pseudo-second-order kinetic model with the rate constant k2 being 0.0026 (g mg−1·min−1). The Langmuir model is suitable to describe the adsorption of Co2+ ion onto the GO/PVA/Fe3O4 nanocomposite with the maximum sorption capacity (qmax) reaching 373.37 mg·g−1. The obtained results also indicated that the GO/PVA/Fe3O4 nanocomposite can adsorb/regenerate for at least 5 cycles with a little reduction in removal efficiency. Therefore, we believe that the GO/PVA/Fe3O4 nanocomposite could be used as a potential adsorbent for heavy metal treatment in terms of high adsorption capacity, fast adsorption rate, and recyclability.

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Studies on chromium(III) removal from aqueous solutions by sorption on Sphagnum moss peat

Journal of the Serbian Chemical Society ◽

10.2298/jsc0909953b ◽

2009 ◽

Vol 74 (8-9) ◽

pp. 953-964 ◽

Cited By ~ 13

Author(s):

Catalin Balan ◽

Doina Bilba ◽

Matei Macoveanu

Keyword(s):

Aqueous Solutions ◽

Metal Ion ◽

Sorption Isotherms ◽

Second Order ◽

Ion Concentration ◽

Sphagnum Moss ◽

Order Kinetic ◽

Maximum Sorption Capacity ◽

Maximum Sorption ◽

Pseudo Second Order

Batch sorption experiments were performed for the removal of chromium(III) ions from aqueous solutions using Romanian Sphagnum moss peat (untreated and treated with NaCl solution) as sorbent. In order to establish the best conditions for the sorption of chromium(III), the influence of initial pH, contact time, peat dose and metal ion concentration was investigated. The Freundlich, Langmuir and Dubinin-Radushkevich models were applied to describe the sorption isotherms and to calculate its constants. The experimental data fitted well to the Langmuir model with a maximum sorption capacity of 18.6 mg Cr(III)/g of peat. The mean free energy of sorption suggests that the binding of Cr(III) on peat occurred through an ion exchange mechanism. The kinetic data evaluated by pseudo-first order and pseudo-second order kinetic models showed that the sorption of chromium onto the peat followed a pseudo-second order rate equation. The chromium(III) could be easily eluted from the loaded peat using 0.10 M HCl and the peat may be reused in several sorption/ desorption cycles. The experimental results indicated the potential of Sphagnum moss peat for removal of Cr(III) from wastewaters.

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Application of Langmuir and Dubinin–Radushkevich models to estimate methane sorption capacity on two shale samples from the Upper Triassic Chang 7 Member in the southeastern Ordos Basin, China

Energy Exploration & Exploitation ◽

10.1177/0144598716684309 ◽

2016 ◽

Vol 35 (1) ◽

pp. 122-144 ◽

Cited By ~ 15

Author(s):

Lei Chen ◽

Zhenxue Jiang ◽

Keyu Liu ◽

Wenming Ji ◽

Pengfei Wang ◽

...

Keyword(s):

Sorption Capacity ◽

Ordos Basin ◽

Sorption Isotherms ◽

Upper Triassic ◽

Organic Carbon Content ◽

Maximum Sorption Capacity ◽

Maximum Sorption ◽

Methane Sorption ◽

Temperature And Pressure ◽

Increasing Temperature

A series of methane sorption isotherms were measured at 303 K, 313 K, 323 K, 333 K, and 343 K at pressures up to 12.0 MPa for two shale samples from the Upper Triassic Chang 7 Member in the southeastern Ordos Basin with total organic carbon content values of 5.15% and 4.76%, respectively. Both the Langmuir- and Dubinin–Radushkevich-based excess sorption models were found to well represent the excess sorption isotherms within the experimental pressure range. The maxima of absolute methane sorption capacity fitted by both models are not significantly different. In the current study, the effects of temperature and pressure on methane sorption capacity support the findings that under isothermal condition, methane sorption capacity of organic shale goes up with increasing pressure and under isobaric condition, while it goes down with increasing temperature. Good negative linear relationships between temperature and maximum sorption capacity exist both in the Langmuir and the Dubinin–Radushkevich models. In addition, a good positive linear relation exists between the reciprocal of temperature and the natural logarithm of Langmuir pressure, which indicate that temperature and pressure are really important for methane sorption capacity. The extended Langmuir and Dubinin–Radushkevich models have been improved to calculate the methane sorption capacity of shales, which can be described as a function of temperature and pressure. By means of using the two estimation algorithms established in this study, we may draw the conclusion methane sorption capacity can be obtained as a function of depth under geological reservoir. Due to the dominant effect of pressure, methane sorption capacity increases with depth initially, till it reaches a maximum value, and then decrease as a result of the influence of increasing temperature at a greater depth. Approximately, the maximum sorption capacity ranges from 400 m to 800 m.

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The Influences of the Rank of Coal on Methane Sorption Capacity in Coals/Wpływ Rzędu Węgla Na Pojemność Sorpcyjną Metanu W Węglach

Archives of Mining Sciences ◽

10.2478/amsc-2014-0037 ◽

2014 ◽

Vol 59 (2) ◽

pp. 509-516

Author(s):

Andrzej Olajossy

Keyword(s):

Sorption Capacity ◽

Coalbed Methane ◽

Vitrinite Reflectance ◽

Sorption Isotherms ◽

Volatile Matter ◽

Low Rank ◽

Hard Coal ◽

Petrographic Composition ◽

Methane Sorption ◽

Indian Coals

Abstract Methane sorption capacity is of significance in the issues of coalbed methane (CBM) and depends on various parameters, including mainly, on rank of coal and the maceral content in coals. However, in some of the World coals basins the influences of those parameters on methane sorption capacity is various and sometimes complicated. Usually the rank of coal is expressed by its vitrinite reflectance Ro. Moreover, in coals for which there is a high correlation between vitrinite reflectance and volatile matter Vdaf the rank of coal may also be represented by Vdaf. The influence of the rank of coal on methane sorption capacity for Polish coals is not well understood, hence the examination in the presented paper was undertaken. For the purpose of analysis there were chosen fourteen samples of hard coal originating from the Upper Silesian Basin and Lower Silesian Basin. The scope of the sorption capacity is: 15-42 cm3/g and the scope of vitrinite reflectance: 0,6-2,2%. Majority of those coals were of low rank, high volatile matter (HV), some were of middle rank, middle volatile matter (MV) and among them there was a small number of high rank, low volatile matter (LV) coals. The analysis was conducted on the basis of available from the literature results of research of petrographic composition and methane sorption isotherms. Some of those samples were in the form (shape) of grains and others - as cut out plates of coal. The high pressure isotherms previously obtained in the cited studies were analyzed here for the purpose of establishing their sorption capacity on the basis of Langmuire equation. As a result of this paper, it turned out that for low rank, HV coals the Langmuire volume VL slightly decreases with the increase of rank, reaching its minimum for the middle rank (MV) coal and then increases with the rise of the rank (LV). From the graphic illustrations presented with respect to this relation follows the similarity to the Indian coals and partially to the Australian coals.

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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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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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Doxorubicin loaded magnetism nanoparticles based on cyclodextrin dendritic-graphene oxide inhibited MCF-7 cell proliferation

BioMolecular Concepts ◽

10.1515/bmc-2021-0002 ◽

2021 ◽

Vol 12 (1) ◽

pp. 8-15

Author(s):

Ainaz Mihanfar ◽

Niloufar Targhazeh ◽

Shirin Sadighparvar ◽

Saber Ghazizadeh Darband ◽

Maryam Majidinia ◽

...

Keyword(s):

Graphene Oxide ◽

Cancer Cells ◽

Breast Cancer Cells ◽

Anticancer Drug Delivery ◽

Release Studies ◽

Anti Cancer ◽

Acidic Conditions ◽

Mcf 7

Abstract Doxorubicin (DOX) is an effective chemotherapeutic agent used for the treatment of various types of cancer. However, its poor solubility, undesirable side effects, and short half-life have remained a challenge. We used a formulation based on graphene oxide as an anticancer drug delivery system for DOX in MCF-7 breast cancer cells, to address these issues. In vitro release studies confirmed that the synthesized formulation has an improved release profile in acidic conditions (similar to the tumor microenvironment). Further in vitro studies, including MTT, uptake, and apoptosis assays were performed. The toxic effects of the nanocarrier on the kidney, heart and liver of healthy rats were also evaluated. We observed that the DOX-loaded carrier improved the cytotoxic effect of DOX on the breast cell line compared to free DOX. In summary, our results introduce the DOX-loaded carrier as a potential platform for in vitro targeting of cancer cells and suggest further studies are necessary to investigate its in vivo anti-cancer potential.

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