scholarly journals Eco-Friendly and Economic, Adsorptive Removal of Cationic and Anionic Dyes by Bio-Based Karaya Gum—Chitosan Sponge

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 251
Author(s):  
Rohith K. Ramakrishnan ◽  
Vinod V. T. Padil ◽  
Stanisław Wacławek ◽  
Miroslav Černík ◽  
Rajender S. Varma
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Organic Pollutant ◽  
Three Dimensional ◽  
Attenuated Total Reflection ◽  
Pollutant Removal ◽  
High Porosity ◽  
Anionic Dyes ◽  
Anionic Dye ◽  
Karaya Gum

A novel, lightweight (8 mg/cm3), conjugate sponge of karaya gum (Kg) and chitosan (Ch) has been synthesized with very high porosity (~98%) and chemical stability, as a pH-responsive adsorbent material for the removal of anionic and cationic dyes from aqueous solutions. Experimental results showed that Kg-Ch conjugate sponge has good adsorption capacity for anionic dye methyl orange (MO: 32.81 mg/g) and cationic dye methylene blue (MB: 32.62 mg/g). The optimized Kg:Ch composition grants access to the free and pH-dependent ionizable functional groups on the surface of the sponge for the adsorption of dyes. The studies on the adsorption process as a function of pH, adsorbate concentration, adsorbent dose, and contact time indicated that the adsorption capacity of MB was decreased with increasing pH from 5 to 10 and external mass transfer together with intra-particle diffusion. The adsorption isotherm of the anionic dye MO was found to correlate with the Langmuir model (R2 = 0.99) while the adsorption of the cationic MB onto the sponge was better described by the Freundlich model (R2 = 0.99). Kinetic regression results specified that the adsorption kinetics were well represented by the pseudo-second-order model. The H-bonding, as well as electrostatic interaction between the polymers and the adsorption interactions of dyes onto Kg-Ch sponge from aqueous solutions, were investigated using attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, and the highly wrinkled porous morphology was visualized in depth by field-emission scanning electron microscopy (FE-SEM) analysis. Moreover, the samples could be reused without loss of contaminant removal capacity over six successive adsorption-desorption cycles. The hierarchical three-dimensional sponge-like structure of Kg has not been reported yet and this novel Kg-Ch sponge functions as a promising candidate for the uninterrupted application of organic pollutant removal from water.

scholarly journals Investigation of the aqueous adsorption capacity of a 6-connected Zr-MOF for anionic and cationic dyes in comparison with other traditional porous materials

2021 ◽  
Vol 947 (1) ◽  
pp. 012032
Author(s):  
Thuyet L.D. Pham ◽  
Khanh T.M. Le ◽  
Nhi T. Vo ◽  
Khoa D. Nguyen ◽  
HaV. Le
Keyword(s):  
Porous Materials ◽  
Adsorption Capacity ◽  
Cationic Dyes ◽  
Bet Surface Area ◽  
High Porosity ◽  
X Ray Diffraction ◽  
Sunset Yellow ◽  
Anionic Dyes ◽  
Surface Areas ◽  
Quinoline Yellow

Abstract A 6-connected Zr-MOF (MOF-808) was successfully synthesized via the solvothermal method with the assistance of formic acid (HCOOH). The resulting MOF showed high crystallinity and thermal stability, which was verified by powder X-ray diffraction (PXRD) measurement, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). As can be expected, the obtained material possessed high porosity with an extremely high specific BET surface area (SABet) of 2372 m2/g. The adsorption capacity of MOF-808 for anionic dyes (i.e. sunset yellow, quinoline yellow, and methyl orange) and cationic ones (i.e. methylene blue and malachite green) in aqueous solutions was respectively investigated. For comparison purpose, the adsorption experiments were also carried out using other traditional porous materials, including commercial microporous activated carbon and synthesized mesoporous SBA-15 with BET surface areas of 1030 m2/g and approximately 800 m2/g, respectively. It was demonstrated that the efficiency of MOF-808 in trapping anionic dyes in water was significantly higher while carbon and silica materials exhibited better performances for the case of cationic dyes.

Adsorption of Methylene Blue on Starch Microsphere from Aqueous Solutions

2012 ◽  
Vol 557-559 ◽  
pp. 1109-1112 ◽  
Author(s):  
Xiao Ping Huo ◽  
Fang Wang ◽  
Deng Deng ◽  
Lei Wang
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Pore Diameter ◽  
Three Dimensional ◽  
Soluble Starch ◽  
Scanning Electronic Microscopy ◽  
Uniform Size ◽  
Starch Microsphere ◽  
Dimensional Network

In order to resolve the pollution of coloured wastewater, starch microsphere was used to absorb methylene blue from aqueous solutions in this paper. Starch microsphere is artificial starch derivative, can be synthesized by cross-linking reaction from crude starch and modified starch. The cross-linked starch microsphere was prepared from soluble starch and N, N'-methylenebisacrylamide, and starch microsphere has characteres of irregular appearance, uniform size, suitable swelling, three-dimensional network structure, suitable shell pore diameter and specific surface area, good mechanical intensity. The microporous structure of starch microsphere was determined using Scanning Electronic Microscopy (SEM). The adsorption capacity of starch microsphere to methylene blue was studied. It could be shown that the adsorption capacity increases with the increase of concentration of methylene blue. Also, the lower the temperature was, the bigger the adsorption capacity of SM was in the same concentration. So, starch microsphere could effectively absorb methylene blue from aqueous solutions and thus the influencing factors of the adsorption were discussed in detail.

scholarly journals Facile Fabrication of Superhydrophobic Cross-Linked Nanocellulose Aerogels for Oil–Water Separation

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 625
Author(s):  
Qianqian Shang ◽  
Jianqiang Chen ◽  
Yun Hu ◽  
Xiaohui Yang ◽  
Lihong Hu ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
High Porosity ◽  
Water Contact ◽  
Water Separation ◽  
Cellular Microstructure ◽  
Oil Water Separation ◽  
Facile Fabrication ◽  
Oil Water

A facile and environmental-friendly approach was developed for the preparation of the cross-linked nanocellulose aerogel through the freeze-drying process and subsequent esterification. The as-prepared aerogel had a three-dimensional cellular microstructure with ultra-low density of 6.05 mg·cm−3 and high porosity (99.61%). After modifying by chemical vapor deposition (CVD) with hexadecyltrimethoxysilane (HTMS), the nanocellulose aerogel displayed stable super-hydrophobicity and super-oleophilicity with water contact angle of 151°, and had excellent adsorption performance for various oil and organic solvents with the adsorption capacity of 77~226 g/g. Even after 30 cycles, the adsorption capacity of the nanocellulose aerogel for chloroform was as high as 170 g/g, indicating its outstanding reusability. Therefore, the superhydrophobic cross-linked nanocellulose aerogel is a promising oil adsorbent for wastewater treatment.

scholarly journals Enhanced adsorption removal of anionic dyes via a facile preparation of amino-functionalized magnetic silica

2017 ◽  
Vol 75 (6) ◽  
pp. 1399-1409 ◽  
Author(s):  
Xiao-Shui Li ◽  
Yu-Han Fan ◽  
Shou-Wen Zhang ◽  
Shi-Hua Qi
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Maximum Adsorption Capacity ◽  
Reactive Black 5 ◽  
Order Kinetic ◽  
Step Method ◽  
Anionic Dyes ◽  
Solution Ph ◽  
Experimental Conditions ◽  
Magnetic Silica

A novel amino-functionalized magnetic silica (Fe3O4@SiO2-NH2) was easily prepared via a one-step method integrating the immobilization of 3-aminopropyltriethoxysilane with a sol-gel process of tetraethyl orthosilicate into a single process. This showed significant improvement in the adsorption capacity of anionic dyes. The product (Fe3O4@SiO2-NH2) was characterized with scanning electron microscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray spectrometry, zeta potential and vibrating sample magnetometry. The adsorption performance of Fe3O4@SiO2-NH2 was then tested by removing acid orange 10 (AO10) and reactive black 5 (RB5) from the aqueous solutions under various experimental conditions including initial solution pH, initial dye concentrations, reaction time and temperature. The results indicated that the maximum adsorption capacity of AO10 and RB5 on Fe3O4@SiO2-NH2 was 621.9 and 919.1 mg g−1 at pH 2, respectively. The sorption isotherms fit the Langmuir model nicely. Similarly, the sorption kinetic data were better fitted into the pseudo-second order kinetic model than the pseudo-first order model. In addition, the thermodynamic data demonstrated that the adsorption process was endothermic, spontaneous and physical. Furthermore, Fe3O4@SiO2-NH2 could be easily separated from aqueous solutions by an external magnetic field, and the preparation was reproducible.

scholarly journals Fabrication of sponge biomass adsorbent through UV-induced surface-initiated polymerization for the adsorption of Ce(III) from wastewater

2017 ◽  
Vol 75 (12) ◽  
pp. 2755-2764 ◽  
Author(s):  
Chen Liu ◽  
Chunjie Yan ◽  
Sen Zhou ◽  
Wen Ge
Keyword(s):  
Rare Earth ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Adsorption Property ◽  
Three Dimensional ◽  
Soxhlet Extraction ◽  
Rare Earth Ions ◽  
Rare Earth Ion ◽  
Surface Initiated Polymerization ◽  
Insight Into

The recovery of rare earth ions from industrial wastewater has aroused wide concern in recent years. In present work, we synthesized a novel three-dimensional adsorbent (denoted as LF-AA) by grafting loofah fiber with acrylic acid via ultraviolet radiation. The LF-AA was washed by boiling water and subjected to soxhlet extraction with acetone and then fully characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM). Rare earth ion (Ce(III)) was selected as a model to validate its adsorption property. The saturation adsorption capacity for Ce(III) reaches 527.5 mg/g. Not only was this material highly efficient at adsorbing Ce(III) from aqueous solutions, it also proved to have ideal performance in regeneration; the total adsorption capacity of LF-AA for Ce(III) after six successive cycles decreased only 6.40% compared with the initial capacity of LF-AA. More importantly, the LF-AA can be easily separated from aqueous solutions because of its three-dimensional sponge natural structure. This study provides a new insight into the fabrication of biomass adsorbent and demonstrated that the LF-AA can be used as excellent adsorbent for the recovery of rare earth ions from wastewater.

scholarly journals Adsorption and Photodegradation of Cationic and Anionic Dyes by TiO2-Chitosan Nanocomposite

2019 ◽  
Vol 19 (2) ◽  
pp. 441
Author(s):  
Imelda Fajriati ◽  
Mudasir Mudasir ◽  
Endang Tri Wahyuni
Keyword(s):  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Maximum Adsorption Capacity ◽  
Anionic Dyes ◽  
Anionic Dye ◽  
Reaction Constant ◽  
Kinetics Of

The adsorption and photodegradation of cationic and anionic dyes by TiO2-chitosan nanocomposites have been studied. This study investigated the specific surface area, pores volume, pores size of TiO2-Chitosan nanocomposite, and determination kinetics of the reaction on the adsorption and photodegradation process. The methods were carried out by mixing TiO2-nanocomposite into cationic and anionic dyes in various contact times and initial dye concentrations. The results showed that nanocomposite adsorption capacity increased with an increase in the amount of chitosan (TiO2/Chit 0.13) even though the specific surface area (SBET) was reduced. The results indicated that the adsorption on nanocomposite was influenced by the amount of -NH2 and -OH on the chitosan surface. The maximum adsorption capacity (qm) and the observed reaction constant (kObs) for MO were also known to be higher than MB, which means that the TiO2-chitosan nanocomposites could remove anionic dye more than cationic one.

Adsorptive removal of congo red dye from aqueous solutions using Mo-doped CoFe2O4 magnetic nanoparticles

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ibrahim A. Amar ◽  
Jawaher O. Asser ◽  
Amina S. Mady ◽  
Mabroukah S. Abdulqadir ◽  
Fatima A. Altohami ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Aqueous Solutions ◽  
Congo Red ◽  
Organic Pollutant ◽  
Point Of Zero Charge ◽  
Solution Temperature ◽  
Anionic Dyes ◽  
Content Type ◽  
Kinetics And Isotherms ◽  
Nano Adsorbent

Purpose The main purpose of this paper is to investigate the adsorption properties of CoFe1.9Mo0.1O4 magnetic nanoparticles (CFMo MNPs) using, anionic dye “congo red (CR)” as a model of water pollutants. Design/methodology/approach The magnetic nano-adsorbent was synthesized via sol-gel process. Different techniques including; Fourier transform infrared spectroscopy, point of zero charge, scanning electron microscope and X-ray powder diffraction were used to characterize the prepared adsorbent. Adsorption experiments were conducted in batch mode under various conditions (contact time, shaking speed, initial dye concentration, initial solution pH, solution temperature and adsorbent amount) to investigate the adsorption capability of CFMo MNPs for CR. Findings The results showed that, CFMo MNPs could successfully remove more than 90% of CR dye within 20 min. Adsorption kinetics and isotherms were better described using pseudo-second-order (PSO) and Langmuir models, respectively. The maximum adsorbed amount (qmax) of CR dye was 135.14 mg/g. The adsorption process was found to be endothermic and spontaneous in nature as demonstrated by the thermodynamics ( ΔGo, ΔHoand ΔSo). Practical implications This study provided a good example of using an easily separated magnetic nano-adsorbent for fast removal of a very toxic organic pollutant, congo red, from the aquatic environment Originality/value The employment of Mo-doped cobalt ferrite for the first time for removing hazardous anionic dyes such as congo red from their aqueous solutions.

scholarly journals Clay–graphene oxide liquid crystals and their aerogels: synthesis, characterization and properties

2019 ◽  
Vol 6 (2) ◽  
pp. 181439 ◽  
Author(s):  
Sisi Ye ◽  
Zhihong Yang ◽  
Jianmei Xu ◽  
Zehao Shang ◽  
Jing Xie
Keyword(s):  
Graphene Oxide ◽  
Liquid Crystals ◽  
Adsorption Capacity ◽  
Sol Gel ◽  
Three Dimensional ◽  
Anionic Dyes ◽  
Porous Network ◽  
Mass Fractions ◽  
Sol Gel Transition ◽  
Gel Transition

The dispersions containing two kinds of layered solids—graphene oxide (GO) and exfoliated montmorillonite (MMT) were mainly prepared, following which the binary aerogels were synthesized. The results indicate that the formation of liquid crystals (LCs) occurs at lower GO concentration and the birefringence becomes stronger when MMT is introduced into GO dispersion. Sol–gel transition forms in the binary suspensions with different mass fractions of MMT and GO. LCs with highly ordered alignment are observed in the gel and the fraction of LCs obviously increases with the increase in GO concentration. Moreover, the birefringence is observed in MMT–GO binary aerogels with the interconnected three-dimensional porous network, which is attributed to the ordered arrangement of MMT and GO nanosheets in pore walls. Among the aerogels with different MMT/GO ratios, the samples at the ratio of 10 : 1 show better adsorption capacity and removal percentage of cationic and anionic dyes.

Sorption of Bisphenol A in Aqueous Solutions on Irradiated and as-Grown Multiwalled Carbon Nanotubes

2018 ◽  
Vol 69 (5) ◽  
pp. 1233-1239
Author(s):  
Raluca Madalina Senin ◽  
Ion Ion ◽  
Ovidiu Oprea ◽  
Rusandica Stoica ◽  
Rodica Ganea ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Bisphenol A ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Multiwalled Carbon Nanotubes ◽  
Adsorption Process ◽  
Sorption Process ◽  
Multiwalled Carbon ◽  
Before And After ◽  
Kinetic Sorption

In this study, non-irradiated and weathered multiwalled carbon nanotubes (MWCNTs) obtained through irradiation, were studied as adsorbents for BPA, both nanomaterials being characterized before and after the adsorption process. The objectives of our investigation were to compare the characteristics of non-irradiated and irradiated MWCNTs, to evaluate the adsorption capacity of BPA by pristine and irradiated MWCNTs and to determine the variation of the kinetic, sorption and thermodynamic parameters during sorption process using both sorbents.

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