Adsorption Science & Technology最新文献_第9页

How the Solid/Liquid Ratio Affects the Cation Exchange Process and Porosity in the Case of Dioctahedral Smectite: Structural Analysis? 在二八面体蒙脱石的情况下，固/液比如何影响阳离子交换过程和孔隙率：结构分析？

IF 2.9 4区工程技术

Adsorption Science & Technology Pub Date : 2021-10-14 DOI: 10.1155/2021/9732092

C. Mejri, W. Oueslati, A. B. H. Amara

{"title":"How the Solid/Liquid Ratio Affects the Cation Exchange Process and Porosity in the Case of Dioctahedral Smectite: Structural Analysis?","authors":"C. Mejri, W. Oueslati, A. B. H. Amara","doi":"10.1155/2021/9732092","DOIUrl":"https://doi.org/10.1155/2021/9732092","url":null,"abstract":"The performance of a clay mineral geomembrane used in the context of a geological barrier for industrial and radioactive waste confinement must pass through the understanding of its hydrous response as well as the limits of the cation exchange process which are closely related to the solid/liquid ratio constraint. The Na-rich montmorillonite is used, as starting material, to evaluate the link between the applied external constraint (variable solid/liquid ratio) and the structural response of the material. The geochemical constraint is realized at the laboratory scale, and the possible effects are investigated in the cases of Ba2+ and Ni2+ heavy metal cations. The structural analysis is achieved using the XRD profile modeling approach to quantify the interlayer space (IS) deformation. The quantitative XRD analysis, which consists of the comparison of experimental 001 reflections with the calculated ones deduced from structural models, allowed us to determine the optimal structural parameters describing IS configuration along the \u0000 \u0000 c\u0000 ∗\u0000 \u0000 axis. The obtained result showed an interstratified hydration character, for both studied exchangeable cations, regardless of the solid/liquid ratio being described probably by a partial cation exchange process. The theoretical mixed layer structure (MLS) suggests the coexistence of more one cristallite species saturated by more than one exchangeable cations, indicating a partial saturation of all exchangeable sites. The optimum structural parameter values, from the theoretical model, allowed us to follow the evolution of several intrinsic properties versus the applied constraint strength. The variable solid/liquid ratio effect on the material porosity is examined by the BET-specific surface area and BJH pore size distribution (PSD) analyses. The adsorption measurement outcomes confirm XRD results concerning mainly the link between several intrinsic clay properties and the constraint strength.","PeriodicalId":7315,"journal":{"name":"Adsorption Science & Technology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2021-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44635266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Effective and Simple NaOH-Modification Method to Remove Methyl Violet Dye via Ipomoea aquatica Roots 有效、简便的氢氧化钠改性法去除水草根甲基紫染料

IF 2.9 4区工程技术

Adsorption Science & Technology Pub Date : 2021-10-13 DOI: 10.1155/2021/5932222

YieChen Lu, M. R. R. Kooh, L. Lim, N. Priyantha

{"title":"Effective and Simple NaOH-Modification Method to Remove Methyl Violet Dye via Ipomoea aquatica Roots","authors":"YieChen Lu, M. R. R. Kooh, L. Lim, N. Priyantha","doi":"10.1155/2021/5932222","DOIUrl":"https://doi.org/10.1155/2021/5932222","url":null,"abstract":"In this study, a simple chemical modification was applied to a sustainable and abundantly available resource, kangkong root (KR), to remove methyl violet 2B (MV) dye. The chemically modified adsorbent (NaOH-KR) was obtained using NaOH solution treatment. Batch adsorption experiments were carried out to investigate the effects of pH, ionic strength, contact time, adsorbent dosage, and initial dye concentration. A regeneration experiment was also carried out to assess the potential of reusability. The adsorption process was modelled using various kinetics and isotherm models, whereby the best-fitting models were evaluated by using the coefficient of determination (\u0000 \u0000 \u0000 \u0000 R\u0000 \u0000 \u0000 2\u0000 \u0000 \u0000 \u0000 ) and error functions. The Sips (\u0000 \u0000 \u0000 \u0000 R\u0000 \u0000 \u0000 2\u0000 \u0000 \u0000 =\u0000 0.9714\u0000 \u0000 , χ2 =0.16) and pseudo-second-order (\u0000 \u0000 \u0000 \u0000 R\u0000 \u0000 \u0000 2\u0000 \u0000 \u0000 =\u0000 0.9996\u0000 \u0000 , \u0000 \u0000 \u0000 \u0000 χ\u0000 \u0000 \u0000 2\u0000 \u0000 \u0000 =\u0000 0.007\u0000 \u0000 ) models were identified to best represent the adsorption process. The Sips model predicted a maximum adsorption capacity at 551.5 mg g-1 for NaOH-KR, which is 55% improvement in performance when compared to nonmodified KR. Lastly, the regeneration experiment showed that NaOH-KR was able to maintain reasonable dye removal even after five consecutive cycles of regenerating and reusing.","PeriodicalId":7315,"journal":{"name":"Adsorption Science & Technology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2021-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44485990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 25

Capacitive Deionization for the Removal of Paraquat Herbicide from Aqueous Solution 电容去离子法去除水溶液中的百草枯除草剂

IF 2.9 4区工程技术

Adsorption Science & Technology Pub Date : 2021-10-08 DOI: 10.1155/2021/9601012

T. Alfredy, Joyce Elisadiki, Y. Jande

{"title":"Capacitive Deionization for the Removal of Paraquat Herbicide from Aqueous Solution","authors":"T. Alfredy, Joyce Elisadiki, Y. Jande","doi":"10.1155/2021/9601012","DOIUrl":"https://doi.org/10.1155/2021/9601012","url":null,"abstract":"In comparison to other conventional methods like adsorption and reverse osmosis (RO), capacitive deionization (CDI) has only been investigated extensively for the removal of inorganic pollutants from water, demonstrating limited practicality. Herein, the study investigated the use of CDI for the removal of paraquat (PQ) herbicide from water by using commercial activated carbon (AC) electrodes. The CDI performance was examined as a function of the initial PQ concentration, applied voltage, flowrate, treatment time, and cycle stability testing in the batch mode approach. The applied voltage had a beneficial effect on the removal efficiency, whereas the removal efficiency of PQ declined as the initial PQ concentration increased. However, the electrosorption capacity gradually increased with the increase of initial feed solutions’ concentration. The maximum removal efficiency and electrosorption capacity achieved at 5 mg/L and 20 mg/L PQ initial concentrations, an applied voltage of 1.2 V, and 5 mL/min flowrate were 100% and 0.33 mg/g and 52.5% and 0.7 mg/g, respectively. Washing the electrodes with distilled water achieved sequential desorption of PQ, and the process produces a waste stream that can be disposed of or treated further. Therefore, the CDI method is considered a promising and efficient method for removing organic pollutants from water including pesticides.","PeriodicalId":7315,"journal":{"name":"Adsorption Science & Technology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2021-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44429946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Improved Adsorption Capacity of Nannochloropsis sp. through Modification with Cetyltrimethylammonium Bromide on the Removal of Methyl Orange in Solution 十六烷基三甲基溴化铵改性提高Nannochloropsis sp.对溶液中甲基橙的吸附性能

IF 2.9 4区工程技术

Adsorption Science & Technology Pub Date : 2021-10-07 DOI: 10.1155/2021/1641074

Buhani, Suharso, Nurul Miftahza, D. Permatasari, Sumadi

{"title":"Improved Adsorption Capacity of Nannochloropsis sp. through Modification with Cetyltrimethylammonium Bromide on the Removal of Methyl Orange in Solution","authors":"Buhani, Suharso, Nurul Miftahza, D. Permatasari, Sumadi","doi":"10.1155/2021/1641074","DOIUrl":"https://doi.org/10.1155/2021/1641074","url":null,"abstract":"In this research, biomass modification of Nannochloropsis sp. with surfactant cetyltrimethylammonium bromide (CTAB) through a cation exchange reaction to produce adsorbent Nannochloropsis sp.-cetyltrimethylammonium bromide (AlgN-CTAB) has been carried out. Biomass modification of Nannochloropsis sp. by CTAB has been successfully carried out through confirmation from the analysis data produced by Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDX). AlgN-CTAB adsorbent has been tested for its adsorption ability against anionic dye of methyl orange (MO) in solution by way of a sequence of experiments by the batch method. The optimum conditions for MO removal from the solution occurred at an adsorbent quantity of 0.1 g, pH of 5, and an interaction time of 60 min. MO adsorption kinetic data by AlgN and AlgN-CTAB tended to take the kinetic model of pseudo-second-order (PSO) with PSO rate constant (\u0000 \u0000 \u0000 \u0000 k\u0000 \u0000 \u0000 2\u0000 \u0000 \u0000 \u0000 ) values of 0.56 and 2.17 g mg-1 min-1, serially. The MO adsorption isotherm pattern by AlgN tends to take the Freundlich adsorption isotherm, whereas in AlgN-CTAB it follows the Langmuir and Dubinin-Radushkevich adsorption isotherms. The results of the adsorption-desorption of MO by AlgN-CTAB with 4 repetition cycles resulted in % removal of \u0000 \u0000 MO\u0000 >\u0000 80\u0000 %\u0000 \u0000 . The AlgN-CTAB adsorbent can be used repeatedly and is very effective in absorbing MO in water.","PeriodicalId":7315,"journal":{"name":"Adsorption Science & Technology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2021-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49589107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Facile Synthesis of Silica Composites with Oil Sorption Efficiency from a Vital Agricultural Waste of Corn Stalk Cultivated in Bishoftu, Ethiopia 从埃塞俄比亚比绍夫图种植的玉米秸秆的重要农业废弃物中方便合成具有吸油效率的二氧化硅复合材料

IF 2.9 4区工程技术

Adsorption Science & Technology Pub Date : 2021-10-06 DOI: 10.1155/2021/7205135

M. Kamaraj, Sudarshan Kamble, S. Sonia

引用次数: 3

Simple and Rapid Synthesis of Calcium Acetate from Scallop Shells to Reduce Environmental Issues 从扇贝壳中简单快速合成醋酸钙以减少环境问题

IF 2.9 4区工程技术

Adsorption Science & Technology Pub Date : 2021-10-06 DOI: 10.1155/2021/6450289

Montree Thongkam, Jinnaput Saelim, B. Boonchom, S. Seesanong, Kittichai Chaiseeda, N. Laohavisuti, K. Bunya-atichart, W. Boonmee, D. Taemchuay

{"title":"Simple and Rapid Synthesis of Calcium Acetate from Scallop Shells to Reduce Environmental Issues","authors":"Montree Thongkam, Jinnaput Saelim, B. Boonchom, S. Seesanong, Kittichai Chaiseeda, N. Laohavisuti, K. Bunya-atichart, W. Boonmee, D. Taemchuay","doi":"10.1155/2021/6450289","DOIUrl":"https://doi.org/10.1155/2021/6450289","url":null,"abstract":"The search for sustainable resources remains a subject of global interest. Calcium acetate used in many fields was prepared using waste scallop shell as a raw material, and its physicochemical properties were investigated. The waste scallop shells were transformed to calcium acetate compounds by reactions with four acetic acid concentrations at ambient temperature until the completely dried powder is obtained. The maximum yield of 87% with short reaction time at a low temperature was observed in the reaction of 60%w/w acetic acid with scallop shells. Thermal transformation reactions of all prepared calcium acetate samples revealed temperature conditions for heating to produce other advanced materials. FTIR and XRD results confirmed the purity and solid phase of all prepared calcium acetate samples, and they were compared with those of literatures and found to be well consistent. The obtained timber-like particles have different sizes depending on the acetic acid concentration. This work reports an easy and low-cost method with no environmental effect to produce cheap calcium products to be used in the industry.","PeriodicalId":7315,"journal":{"name":"Adsorption Science & Technology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2021-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42272786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Evolution of Pore Characteristics for Bentonite Modified by an Ionic Soil Stabilizer during Hydration Processes 离子土壤稳定剂改性膨润土水化过程中孔隙特性的演化

IF 2.9 4区工程技术

Adsorption Science & Technology Pub Date : 2021-10-04 DOI: 10.1155/2021/7777091

Wei Huang, Zili Feng, Huanran Fu, W. Xiang

{"title":"Evolution of Pore Characteristics for Bentonite Modified by an Ionic Soil Stabilizer during Hydration Processes","authors":"Wei Huang, Zili Feng, Huanran Fu, W. Xiang","doi":"10.1155/2021/7777091","DOIUrl":"https://doi.org/10.1155/2021/7777091","url":null,"abstract":"An ionic soil stabilizer (ISS) is used to reinforce clay soils because the ISS can regulate the hydration processes and microstructures of clays. To evaluate the regulation of ISS, natural bentonite was modified by ISS at different concentrations in this research. Water vapour adsorption and X-ray diffraction (XRD) were carried out to interpret the hydration mechanism of bentonite. Meanwhile, an associated analysis between hydration pore structures and hydration mechanisms was implemented through variation of pore characteristic tests at different relative humidities (RHs) to distinguish multiscale pore adsorption of water during the corresponding hydration process. In addition, the pore characteristics were studied via XRD, nitrogen adsorption, and mercury injection tests. Finally, the origins that adsorbed water and pore structures changed by adding ISS were discussed. The results showed that for calcium bentonite, the cations hydrated first in the range of \u0000 \u0000 0\u0000 <\u0000 RH\u0000 <\u0000 0.45\u0000 ~\u0000 0.55\u0000 \u0000 , accompanied by the expansion of micropores. Then, adsorption occurred on the basal surface of the crystal layer in the range of \u0000 \u0000 0.45\u0000 ~\u0000 0.55\u0000 <\u0000 RH\u0000 <\u0000 0.8\u0000 ~\u0000 0.9\u0000 \u0000 , with water mainly adsorbed into the mesopores. With further hydration when \u0000 \u0000 RH\u0000 >\u0000 0.8\u0000 ~\u0000 0.9\u0000 \u0000 , diffused double layer (DDL) water ceaselessly entered the macropores. Both adsorbed water and multiscale pore size decreased when ISS was added to bentonite. The origins of the reduction were the regulation of ISS to exchangeable cations and the basal surface of the crystal layer.","PeriodicalId":7315,"journal":{"name":"Adsorption Science & Technology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41976341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Improving SERS Sensing Efficiency and Catalytic Reduction Activity in Multifunctional Ternary Ag-TiO2-GO Nanostructures: Roles of Electron Transfer Process on Performance Enhancement 提高多功能三元Ag-TiO2-GO纳米结构SERS传感效率和催化还原活性：电子转移过程对性能增强的作用

IF 2.9 4区工程技术

Adsorption Science & Technology Pub Date : 2021-10-01 DOI: 10.1155/2021/1169599

Mai Quan Doan, Nguyen Ha Anh, Hoang Van Tuan, N. C. Tu, N. H. Lam, Nguyen Tien Khi, Vu Ngoc Phan, P. D. Thang, Anh-Tuan Le

{"title":"Improving SERS Sensing Efficiency and Catalytic Reduction Activity in Multifunctional Ternary Ag-TiO2-GO Nanostructures: Roles of Electron Transfer Process on Performance Enhancement","authors":"Mai Quan Doan, Nguyen Ha Anh, Hoang Van Tuan, N. C. Tu, N. H. Lam, Nguyen Tien Khi, Vu Ngoc Phan, P. D. Thang, Anh-Tuan Le","doi":"10.1155/2021/1169599","DOIUrl":"https://doi.org/10.1155/2021/1169599","url":null,"abstract":"Multifunctional nanocomposites have received great attention for years; electron transfer (ET) is considered as an explanatory mechanism for enhancement of performance of these nanostructures. The existence of this ET process has been proved in many studies using either experimental or computational approaches. In this study, a ternary nanocomposite system of Ag/TiO2/GO was prepared to evaluate the performance enhancement in two experimental models: a physical model (i.e., surface-enhanced Raman scattering (SERS) sensor) and a chemical one (i.e., catalytic reduction reaction). The metal/semiconductor heterojunction between Ag and TiO2, as well as Ti-O-C bonds, has allowed plasmonic hot electrons to be transferred in the internal structure of the material. An investigation on the role of Ag content on the SERS sensing and catalytic reduction efficiency of Ag/TiO2/GO was performed in both models. Interestingly, they all resulted in the same optimal Ag content of 50 wt%. It was then further discussed to provide a convincing evidence for the plasmon-induced electron transfer phenomena in the Ag/TiO2/GO nanostructure. These findings also suggest a pathway to design and develop high-performance, cost-effective, facile-preparation, and eco-friendly multifunctional nanostructures for detecting and removing contaminants in environment.","PeriodicalId":7315,"journal":{"name":"Adsorption Science & Technology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46774222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Effect of Nitrogen-Doped Carbon Dots (NCDs) on the Characteristics of NCD/MIL-53(Fe) Composite and Its Photocatalytic Performance for Methylene Blue Degradation under Visible Light 氮掺杂碳点（NCDs）对NCD/MIL-53（Fe）复合材料特性及其在可见光下降解亚甲基蓝的光催化性能的影响

IF 2.9 4区工程技术

Adsorption Science & Technology Pub Date : 2021-09-28 DOI: 10.1155/2021/5906248

N. Nguyen, Xuan-Truong Nguyen, Duc-Trung Nguyen, H. Tran, Thi May Nguyen, T. Tran

{"title":"Effect of Nitrogen-Doped Carbon Dots (NCDs) on the Characteristics of NCD/MIL-53(Fe) Composite and Its Photocatalytic Performance for Methylene Blue Degradation under Visible Light","authors":"N. Nguyen, Xuan-Truong Nguyen, Duc-Trung Nguyen, H. Tran, Thi May Nguyen, T. Tran","doi":"10.1155/2021/5906248","DOIUrl":"https://doi.org/10.1155/2021/5906248","url":null,"abstract":"Metal-organic framework composites, which are combined from metal-organic framework and advanced carbon material, have drawn great attention in many fields of application such as environmental remediation and catalysts. Within this paper, the carbon/MIL-53(Fe) composite was fabricated via an in situ synthesis, in which N-containing carbon dots (NCDs) were mixed with MOF precursors’ solutions under various ratios before going through the solvothermal stage. It was showed that the introduction of a certain amount of NCDs would affect characteristic features and improve the photocatalytic performance of final products. The optimal doping content of NCDs in NCD/MIL-53(Fe) composite was determined. SEM images showed that the M-140 appeared as hexagonal bipyramid-shaped crystals with an average size of 700 nm. Compared with pristine MIL-53(Fe), the M-140 was more visibly light-responsive, and its calculated band gap energy was approximately 2.3 eV. In addition, M-140 catalyst also displayed more excellent photocatalytic activity for Methylene Blue degradation in a pH range from 5 to 7. Under optimal conditions, MB was achieved within 60 minutes and the removal rate was nearly 100% after 5 cycles. The photocatalytic mechanism of the obtained NCD/MIL-53(Fe) composite was discussed.","PeriodicalId":7315,"journal":{"name":"Adsorption Science & Technology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2021-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46415766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Preparation and Characterization of Chitosan/Bentonite Composites for Cr (VI) Removal from Aqueous Solutions 壳聚糖/膨润土复合材料去除Cr (VI)的制备与表征

IF 2.9 4区工程技术

Adsorption Science & Technology Pub Date : 2021-09-21 DOI: 10.1155/2021/6681486

J. Jia, Yanjun Liu, Shujuan Sun

{"title":"Preparation and Characterization of Chitosan/Bentonite Composites for Cr (VI) Removal from Aqueous Solutions","authors":"J. Jia, Yanjun Liu, Shujuan Sun","doi":"10.1155/2021/6681486","DOIUrl":"https://doi.org/10.1155/2021/6681486","url":null,"abstract":"Chitosan/bentonite composites (CSBT) prepared by physical gelation were tested for the adsorption of Cr (VI) from aqueous solutions in this work. The composites were prepared at a mass ratio from 2 : 1 to 1 : 2, and a composite of 1 : 1 was found to be most suitable for efficient Cr (VI) removal. The influencing parameters, including temperature, adsorbent dose, and pH, were statistically optimized using response surface methodology (RSM) for the removal of Cr (VI). The pH was found to be the limiting factor during the adsorption process, and under the optimal conditions, namely, adsorbent dose of 400 mg/L, \u0000 \u0000 pH\u0000 =\u0000 3\u0000 \u0000 , and temperature of 298 K, 87.61% Cr (VI) would be removed expectantly. The mechanism of Cr (VI) removal by CSBT was discussed, and the protonation of amino groups on chitosan followed by the combination of -NH3+ and anionic hexavalent chromium was the primary driving force. In addition, the removal of Cr (VI) onto CSBT was monolayer adsorption with a maximum adsorption capacity of 133.85 mg/g by the Langmuir isotherm. CSBT follows a pseudosecond-order kinetic model, and within 1.5 h, adsorption was observed to reach equilibrium. The calculated thermodynamic functions clarified that the adsorption process was exothermic and spontaneous below 312.60 K. CSBT could be regenerated after desorption by 0.5 mol/L NaOH solutions and exhibited superior reusability after six cycles. This study demonstrated composites of chitosan/bentonite as eco-friendly bioadsorbents for the removal of Cr (VI) from aqueous environments.","PeriodicalId":7315,"journal":{"name":"Adsorption Science & Technology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47706377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5