scholarly journals 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

2016 ◽  
Vol 35 (1) ◽  
pp. 122-144 ◽  
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.

scholarly journals Removal of Salicylic and Ibuprofen by Hexadecyltrimethylammonium-Modified Montmorillonite and Zeolite

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 898
Author(s):  
Jiyeon Choi ◽  
Won Sik Shin
Keyword(s):  
Sorption Isotherms ◽  
Organic Carbon Content ◽  
Sorption Data ◽  
Maximum Sorption Capacity ◽  
Ideal Adsorbed Solution Theory ◽  
Modified Montmorillonite ◽  
Maximum Sorption ◽  
Competitive Model ◽  
Sorption Mechanisms ◽  
Positively Charged

The removal of salicylic acid (SA) and ibuprofen (IB) by sorption onto HDTMA-modified montmorillonite (HM) and zeolite (HZ) was investigated at pH 7. The single sorption data were fitted well by the Freundlich, Langmuir, Dubinin−Radushkevich (DR), and Polanyi−Dubinin−Manes (PDM) models (R2 > 0.94). The sorption affinity of Freundlich and the maximum sorption capacity of Langmuir and PDM models of pharmaceuticals onto HM were consistently higher than that of HZ mainly owing to the higher organic carbon content. In addition, the KF, qmL, and qm values were in the order of IB > SA owing to higher hydrophobicity and molar volume. Since the predominant speciation of SA and IB is anionic at pH 7 (>pKa), sorption onto HM occurs mainly by the two-dimensional surface adsorption onto the pseudo-organic medium in the HM, whereas the interaction of anionic pharmaceuticals with the positively charged “head” of HDTMA is responsible for HZ. Sorption isotherms were fitted well by the PDM model, which indicated that pore-filling was one of the dominating sorption mechanisms. The extended Langmuir model, modified Langmuir competitive model, and ideal adsorbed solution theory employed with Freundlich and Langmuir sorption models were applied to predict binary sorption. The effect of competition between the solutes was clearly evident in the characteristic curves; the maximum sorbed volume (qv.m) was reduced, and the sorbed volume (qv) had a wider distribution toward the sorption potential density.

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

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.

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

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.

scholarly journals Phosphate Removal Using Polyethylenimine Functionalized Silica-Based Materials

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.

Use of bentonite to control the release of copper from contaminated soils

Soil Research ◽  
2007 ◽  
Vol 45 (8) ◽  
pp. 618 ◽  
Author(s):  
Wanting Ling ◽  
Qing Shen ◽  
Yanzheng Gao ◽  
Xiaohong Gu ◽  
Zhipeng Yang
Keyword(s):  
Heavy Metals ◽  
Sorption Capacity ◽  
Contaminated Soils ◽  
Montmorillonite Clay ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Wide Ph Range ◽  
Ph Dependent ◽  
Ph Range ◽  
Soil Ageing

A decrease in release and availability of heavy metals in soil has been of worldwide interest in recent years. Bentonite is a type of expandable montmorillonite clay, and has strong sorption for heavy metals. In this work, the control of amended bentonite on the release of copper (Cu2+) from spiked soils was investigated using a batch equilibrium technique. Sorption of Cu by bentonite was pH-dependent, and could be well described using the Langmiur model. Maximum sorption capacity of the bentonite used in this study was 5.4 mg/g, which was much greater than soils reported in the literature. The extent of Cu2+ release from spiked soils was correlated with slurry concentrations, pH, and soil ageing process. In all cases, the amendment of bentonite was observed to effectively decrease the release of Cu2+ from soils. The apparent aqueous concentrations of Cu2+ released from soils devoid of bentonite treatment were 113–1160% higher than those from the soils amended with bentonite. Moreover, the magnitude of Cu2+ release decreased with increasing amount of bentonite added to soils. The bentonite added was more effective in retaining Cu2+ in sorbents for aged contaminated soils. Such enhanced retention resulting from the presence of bentonite was observed within a wide pH range from 2.5 to 7.0. Bentonite, as one of the most abundant minerals in soils, is regarded to improve the soil overall quality. The results obtained from this work provide useful information on utilisation of bentonite to control the release of heavy metals from contaminated soils.

CuO nanorods: a potential and efficient adsorbent in water purification

RSC Advances ◽  
2014 ◽  
Vol 4 (76) ◽  
pp. 40580-40587 ◽  
Author(s):  
Prasanta Kumar Raul ◽  
Samarpita Senapati ◽  
Ashish K. Sahoo ◽  
Iohborlang M. Umlong ◽  
Rashmi R. Devi ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Sorption Capacity ◽  
Water Purification ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Efficient Adsorbent ◽  
Cuo Nanorods

CuO nanorods can remove Pb(ii) from aqueous solution with a maximum sorption capacity of 3.31 mg g−1at 298 K.

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

2019 ◽  
Vol 17 (3) ◽  
pp. 1211-1224 ◽  
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.

scholarly journals Quaternization of Composite Algal/PEI Beads for Enhanced Uranium Sorption—Application to Ore Acidic Leachate

Gels ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 12 ◽  
Author(s):  
Mohammed F. Hamza ◽  
Amal E. Mubark ◽  
Yuezou Wei ◽  
Thierry Vincent ◽  
Eric Guibal
Keyword(s):  
Ph Effect ◽  
Sorption Isotherms ◽  
Environmental Safety ◽  
Sorption Properties ◽  
Yellow Cake ◽  
Maximum Sorption Capacity ◽  
Copper Precipitation ◽  
Protonated Amine ◽  
Maximum Sorption ◽  
Pre Treatment

The necessity to recover uranium from dilute solutions (for environmental/safety and resource management) is driving research towards developing new sorbents. This study focuses on the enhancement of U(VI) sorption properties of composite algal/Polyethylenimine beads through the quaternization of the support (by reaction with glycidyltrimethylammonium chloride). The sorbent is fully characterized by FTIR, XPS for confirming the contribution of protonated amine and quaternary ammonium groups on U(VI) binding (with possible contribution of hydroxyl and carboxyl groups, depending on the pH). The sorption properties are investigated in batch with reference to pH effect (optimum value: pH 4), uptake kinetics (equilibrium: 40 min) and sorption isotherms (maximum sorption capacity: 0.86 mmol U g−1). Metal desorption (with 0.5 M NaCl/0.5 M HCl) is highly efficient and the sorbent can be reused for five cycles with limited decrease in performance. The sorbent is successfully applied to the selective recovery of U(VI) from acidic leachate of uranium ore, after pre-treatment (cementation of copper, precipitation of rare earth elements with oxalate, and precipitation of iron). A pure yellow cake is obtained after precipitation of the eluate.

Effective uranium(vi) sorption from alkaline media using bi-functionalized silica-coated magnetic nanoparticles

RSC Advances ◽  
2015 ◽  
Vol 5 (70) ◽  
pp. 56658-56665 ◽  
Author(s):  
X. T. Chen ◽  
L. F. He ◽  
R. Z. Liu ◽  
C. Zhang ◽  
B. Liu ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Sorption Capacity ◽  
Alkaline Media ◽  
Functionalized Silica ◽  
Magnetic Iron Oxide ◽  
Maximum Sorption Capacity ◽  
Oxide Composite ◽  
Maximum Sorption

A bi-functionalized magnetic iron oxide composite has been employed for uranium(vi) sorption from alkaline media. The maximum sorption capacity was observed at pH 9.0 with a capacity of 70.7 mg g−1atcU(vi)initial= 21.7 mg L−1.

Adsorption of CuCl2 on Mg-Al HTlc: Effect of EDTA and Addition Sequences

2012 ◽  
Vol 573-574 ◽  
pp. 150-154
Author(s):  
Yun Bo Zang ◽  
Nai Ying Wu
Keyword(s):  
Aqueous Solutions ◽  
Sorption Capacity ◽  
Contact Time ◽  
Room Temperature ◽  
Copper Ions ◽  
Sorption Process ◽  
Langmuir Model ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Pseudo Second Order

In this study, removal of copper ions from aqueous solutions by synthetic Mg-Al-HTlc was investigated as a function of contact time, EDTA and addition sequences at room temperature. It is found that HTlc could reduced copper ions concentration effectively. The kinetics closely fit pseudo-second order kinetics with necessary time 9 h to reach equilibrium. The sorption process followed langmuir model. The maximum sorption capacity calculated was found to be 39.4 mg/g. The presence of EDTA and addition sequences could affect sorption of Cu(II) onto HTlc.

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