scholarly journals Cyclodextrin modified filter paper for removal of cationic dyes/Cu ions from aqueous solutions

2018 ◽  
Vol 78 (12) ◽  
pp. 2553-2563 ◽  
Author(s):  
Yaoyue Li ◽  
Yanbo Zhou ◽  
Yi Zhou ◽  
Juying Lei ◽  
Shengyan Pu

Abstract A filter paper was functionalized with β-cyclodextrin and citric acid via esterification reaction for the removal of dyes and Cu ions from aqueous solutions. The adsorption capacity and removal performance of the modified filter paper (MFP) was investigated using static and dynamic adsorption experiments. The static adsorption data fit well the Langmuir and pseudo-second-order models, and the adsorption capacity of Methylene Blue (MB), Brilliant Green (BG), Rhodamine-B (RB) and Cu(II) over the MFP were 124.6 mg/g, 130.4 mg/g, 99.7 mg/g and 39.1 mg/g, respectively, which are much higher than the unmodified filter paper (below 2 mg/g). Even better, the decolorization performance and Cu(II) removal of MFP are remarkable in dynamic adsorption. The effluent can reach the National Standard for dyeing and finishing of textile industry of China after three cycles in a continuous filtration-adsorption system. This method provides a new pathway to achieve high efficiency removal of dyes and metal ions from wastewater.

2018 ◽  
Vol 5 (5) ◽  
pp. 172382 ◽  
Author(s):  
Wei Guo ◽  
Shujuan Wang ◽  
Yunkai Wang ◽  
Shaoyong Lu ◽  
Yue Gao

A magnetically modified rice husk biochar (MBC) was successfully prepared by a hydrothermal method from original biochar (BC) and subsequently used to remove phenanthrene (PHE) from aqueous solutions. The porosity, specific surface area and hydrophobicity of BC were significantly improved (approx. two times) after magnetic modification. The adsorption data fitted well to pseudo-second-order kinetic and Langmuir models. Compared with BC, MBC had a faster adsorption rate and higher adsorption capacity of PHE. The adsorption equilibrium for PHE on MBC was achieved within 1.0 h. The maximum adsorption capacity of PHE on MBC was 97.6 mg g −1 based on the analysis of the Sips model, which was significantly higher than that of other sources of BCs. The adsorption mechanism of the two BCs was mainly attributed to the action of surface functional groups and π–π-conjugated reactions. The adsorption of PHE on MBC mainly occurred in the functional groups of C–O and Fe 3 O 4 , but that on BC was mainly in the functional groups of –OH, N–H, C=C and C–O.


2017 ◽  
Vol 13 ◽  
pp. 323-329 ◽  
Author(s):  
Anastasiya E. Kucherova ◽  
Irina V. Romantsova ◽  
Alexandr E. Burakov ◽  
Nariman R. Memetov ◽  
Mikhail N. Krasnyansky

The present paper describes an investigation of the adsorption of lead ions (Pb2+) on graphene-based nanocomposites obtained via exfoliation of hydrolyzed expanded graphite intercalation compound. Three types of these nanocomposites - suspension of graphene nanoplatelets (SGN), paste of multi-layered oxidized graphene (PMOG), and paste of few-layered oxidized graphene (PFOG) - were used to extract Pb2+ from 1,040 mg L-1 aqueous solutions of Pb (NO3)2, and the kinetic of the Pb2+ adsorption was studied. It was found that the kinetic data are best fitted by the pseudo-second-order model. The adsorption equilibrium was achieved within 30 min under normal conditions. The maximum Pb2+ adsorption capacity of SGN, PMOG and PFOG was found to be 457, 103 and 38 mg g-1, respectively. Considering the obtained results, it can be assumed that the phenolic and hydroxyl oxygen-containing functional groups located at the surface of the adsorption materials under study play an important role in the Pb2+ removal process.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Shaojun Huang ◽  
Chengzhang Ma ◽  
Yaozu Liao ◽  
Chungang Min ◽  
Ping Du ◽  
...  

Poly(1-amino-5-chloroanthraquinone) (PACA) nanofibrils were applied as novel nanoadsorbents for highly toxic mercury removal from aqueous solutions. A series of batch adsorption experiments were conducted to study the effect of adsorbent dose, pH, contact time, and metal concentration on Hg(II) uptake by PACA nanofibrils. Kinetic data indicated that the adsorption process of PACA nanofibrils for Hg(II) achieved equilibrium within 2 h following a pseudo-second-order rate equation. The adsorption mechanism of PACA nanofibrils for Hg(II) was investigated by Fourier transform-infrared (FT-IR) spectra and X-ray photoelectron spectroscopy (XPS) analyses. The adsorption isotherm of Hg(II) fitted well the Langmuir model, exhibiting superb adsorption capacity of 3.846 mmol of metal per gram of adsorbent. Lastly, we found out that the as-synthesized PACA nanofibrils are efficient in Hg(II) removal from real wastewater. Furthermore, five consecutive adsorption-desorption cycles demonstrated that the PACA nanofibrils were suitable for repeated use without considerable changes in the adsorption capacity.


2011 ◽  
Vol 347-353 ◽  
pp. 281-284
Author(s):  
Peng Ge ◽  
Li Juan Wan ◽  
Ya Jing Xu

Among the investigated clays and minerals (kaolinite, natural zeolite, manual zeolite, bentonite, sepiolite, sepiolite amianthus, tremolite amianthus, vermiculite and baritite), the baritite clay was selected as the optimal adsorbent for aqueous Cr (VI). The Cr (VI) adsorption capacity on baritite clay reached as high as 39.01 mg∙g−1 at 20°C. Then the adsorption kinetics of Cr (VI) by the baritite clay were investigated in details. Results showed that the pseudo-second-order model was a suitable description for the adsorption kinetics and fitted well with the experimental data.


2016 ◽  
Vol 73 (9) ◽  
pp. 2132-2142 ◽  
Author(s):  
F. Ferrarini ◽  
L. R. Bonetto ◽  
Janaina S. Crespo ◽  
M. Giovanela

Adsorption has been considered as one of the most effective methods to remove dyes from aqueous solutions due to its ease of operation, high efficiency and wide adaptability. In view of all these aspects, this study aimed to evaluate the adsorption capacity of a halloysite-magnetite-based composite in the removal of Congo red dye from aqueous solutions. The effects of stirring rate, pH, initial dye concentration and contact time were investigated. The results revealed that the adsorption kinetics followed the pseudo-second-order model, and equilibrium was well represented by the Brunauer–Emmett–Teller isotherm. The thermodynamic data showed that dye adsorption onto the composite was spontaneous and endothermic and occurred by physisorption. Finally, the composite could also be regenerated at least four times by calcination and was shown to be a promising adsorbent for the removal of this dye.


Author(s):  
E.S. Mkrtchyan ◽  
◽  
E.A. Neskoromnaya ◽  
I.V. Burakova ◽  
O.A. Ananyeva ◽  
...  

The comparative adsorption capacity of graphene aerogel and activated coconut carbon in the process of removing the main cationic synthetic dye, methylene blue (MB), from aqueous solutions with an initial concentration of 150 mg/l was investigated. The characteristics of the new material have been determined using scanning electron microscopy, thermogravimetry, and Raman spectroscopy. The values of the adsorption capacity of graphene aerogel – 420 mg/g and activated carbon – 205 mg/g were established. The saturation time in the presence of graphene aerogel was 7 min. The experimental data were processed using kinetic models – pseudo-first and pseudo-second order, Elovich and intraparticle diffusion. According to the results obtained, graphene aerogel is a promising sorption material in the extraction of molecular organic pollutants, namely, synthetic dyes, demonstrating a high efficiency of the target pollutant removal.


RSC Advances ◽  
2019 ◽  
Vol 9 (50) ◽  
pp. 29015-29022 ◽  
Author(s):  
Yanjie Dong ◽  
Dashen Sang ◽  
Chengdong He ◽  
Xinfeng Sheng ◽  
Longwen Lei

Studies on Mxene/alginate composite adsorption have opened up a new avenue for designing adsorbents possessing high adsorption capacity and high efficiency.


2005 ◽  
Vol 23 (5) ◽  
pp. 367-380 ◽  
Author(s):  
A. Hashem ◽  
E.S. Abdel-Halim ◽  
Kh.F. El-Tahlawy ◽  
A. Hebeish

Peanut hulls were modified chemically by esterification with citric acid under conditions which yielded hulls rich in carboxyl content. The esterified products thus obtained were used in the removal of Co(II) and Ni(II) ions from aqueous solutions. The factors affecting the esterification reaction and the adsorption of the metal cations onto the peanut hulls before and after esterification were thoroughly investigated. The results obtained highlighted the following conclusions. The optimum conditions for esterification involve the treatment of peanut hulls (1 g) with 12.4 mmol citric acid in the presence of a very small amount of water for 2 h at 140°C. Similarly, the optimum pH for the adsorption of cobalt(II) ions onto the peanut hulls citrate was 7.0. The adsorption capacity, qe (mg/g), of Co(II) ions onto the peanut hulls citrate increased on increasing the extent of esterification, expressed as mequiv. —COOH/100 g sample. The maximum values for the adsorption capacity, qmax, were 28.7 mg/g and 270.3 mg/g on native and peanut hulls citrate, respectively. The qmax values for of Ni(II) ion adsorption were 5 mg/g and 175.4 mg/g on native and peanut hulls citrate, respectively. The equilibrium data were well fitted by the Langmuir and Freundlich adsorption models and showed the large capacity of peanut hulls citrate in the removal of Co(II) and Ni(II) ions from aqueous solutions.


2013 ◽  
Vol 67 (5) ◽  
pp. 1129-1136 ◽  
Author(s):  
Z. Ioannou ◽  
Ch. Karasavvidis ◽  
A. Dimirkou ◽  
V. Antoniadis

Zeolite, hematite, modified zeolite and commercial activated charcoal were examined for their ability to remove methylene blue (MB) and methyl red (MR) from their aqueous solutions. Modified zeolite and hematite were produced according to the Schwertmann and Cornell method while zeolite and commercial activated charcoal were obtained from S&B and Fluka AG companies, respectively. Adsorption experiments were conducted at three different adsorbent-to-solution ratios, namely 8, 16 and 24 g/L under environmental conditions and continuous stirring. Equilibrium isotherms of MB and MR were studied at different initial concentrations (from 5 × 10−4 to 5 × 10−3 g/L). MB adsorption kinetics were also studied. The maximum adsorption of MB and MR from their aqueous solutions was achieved at 24 g/L (adsorbent-to-dye solution ratio) after 1 h and was equal to 100% (MB) on modified zeolite and 99% (MR) on commercial activated charcoal, respectively. All the other materials achieved intermediate values of dye adsorption. From the applied kinetic models, the pseudo-second-order equation best described the adsorption of MB and MR. Consequently, modified zeolite showed the highest adsorption capacity for MB, while commercial activated charcoal showed the highest adsorption capacity of MR. The studied adsorbents can be used as filters to remove dyes from wastewaters.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zheng Liu ◽  
Yuling Wei

Activated carbons (ACs) were prepared from pomelo peels by K2CO3 activation and used as an adsorbent (PAC) for the removal of Cu(II) from aqueous solutions. BET, SEM, and FT-IR were employed for the characterization of the obtained ACs. The optimum ACs were reported at activation temperature of 850°C, activation time of 60 min, and impregnation ratio of 3, which had a high surface area (1213 m2/g) and total pore volume (0.57 cm3/g). The resulting ACs were used for the adsorption of Cu(II) from aqueous solutions in the batch mode and yielded a superior adsorption capacity of 139.08 mg/g. The pH of optimum adsorption was determined as 5. Pseudo first-order model, pseudo second-order model, and intraparticle diffusion model were applied to describe the adsorption processes. The adsorption kinetic data were found to follow the pseudo second-order model. The adsorption isotherms data were analyzed using Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich models. The Langmuir model was found to provide the best fit, and the calculated adsorption capacity was 151.35 mg/g.


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