Carboxylated carbon nanotubes-graphene oxide aerogels as ultralight and renewable high performance adsorbents for efficient adsorption of glyphosate

2020 ◽  
Vol 17 (1) ◽  
pp. 6 ◽  
Author(s):  
Hao Liu ◽  
Xueying Wang ◽  
Chaofan Ding ◽  
Yuxue Dai ◽  
Yuanling Sun ◽  
...  

Environmental contextGlyphosate is a highly effective and widely used organophosphorus pesticide, but its residues can harm the environment and human health. We report a carboxylated carbon nanotubes-graphene oxide aerogel that can efficiently remove glyphosate from water. This technology has great application prospects in dealing with water contaminated with glyphosate. AbstractGlyphosate, an organophosphorus pesticide, has received considerable attention in recent years owing to its carcinogenic potency. The technologies that remove glyphosate in the environment, especially in water, are important. In this work, we prepare a carboxylated carbon nanotubes-graphene oxide aerogel (cCNTs-GA) by the freeze-drying method for the adsorption of glyphosate. The prepared aerogel exhibits an ultra-low density (7.30mgcm−3), good morphology and strong mechanical strength. Meanwhile, a NaOH solution (0.5molL−1) is selected as an eluent and the adsorption parameters for the adsorption of glyphosate are optimised. The properties of the adsorbents after multiple repetitions and the adsorption mechanism of the cCNTs-GA are also studied. The results show that the adsorbent can be recycled more than 20 times and maintains a good adsorption performance. The maximum adsorption capacity of glyphosate at pH 3 is calculated from the Langmuir isotherm model (546mgg−1 at the temperature of 298K), and the cCNTs-GA exhibits a high adsorption affinity and adsorption capacity for glyphosate, as determined by the partition coefficient (PC). The pseudo-second-order kinetic model fits well to the dynamic behaviour. The equilibrium adsorption process follows the Langmuir isotherm model and the adsorption process is mainly controlled by the intraparticle diffusion model. Furthermore, thermodynamic analysis indicates that the adsorption of glyphosate on the cCNTs-GA is exothermic and spontaneous. The adsorbent is used to remove glyphosate from waste water and the adsorption capacity of the cCNTs-GA for glyphosate is higher than other adsorbents, which indicates that the developed adsorbent has a great potential application in environmental pollution treatment.

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 942 ◽  
Author(s):  
Huo-Xi Jin ◽  
Hong Xu ◽  
Nan Wang ◽  
Li-Ye Yang ◽  
Yang-Guang Wang ◽  
...  

The ability to remove toxic heavy metals, such as Pb(II), from the environment is an important objective from both human-health and ecological perspectives. Herein, we describe the fabrication of a novel carboxymethylcellulose-coated metal organic material (MOF-5–CMC) adsorbent that removed lead ions from aqueous solutions. The adsorption material was characterized by Fourier-transform infrared spectroscopy, X-ray diffractometry, scanning electron microscopy, and X-ray photoelectron spectroscopy. We studied the functions of the contact time, pH, the original concentration of the Pb(II) solution, and adsorption temperature on adsorption capacity. MOF-5–CMC beads exhibit good adsorption performance; the maximum adsorption capacity obtained from the Langmuir isotherm-model is 322.58 mg/g, and the adsorption equilibrium was reached in 120 min at a concentration of 300 mg/L. The adsorption kinetics is well described by pseudo-second-order kinetics, and the adsorption equilibrium data are well fitted to the Langmuir isotherm model (R2 = 0.988). Thermodynamics experiments indicate that the adsorption process is both spontaneous and endothermic. In addition, the adsorbent is reusable. We conclude that MOF-5–CMC is a good adsorbent that can be used to remove Pb(II) from aqueous solutions.


2014 ◽  
Vol 1056 ◽  
pp. 16-19
Author(s):  
Shu Li Ding ◽  
Dan Dan Hou ◽  
Bo Hui Xu ◽  
Yu Zhuang Sun

The Bentonite from Yongnian is Ca-Bentonite, Montmorillonite Content 52%, Colloidal Value 57ml/15g, Eca2+/CEC 53.60%. the Adsorption Characteristics of Pb2+, Cu2+ and Cr3+ onto Bentonite under Conditions of Constant Temperature and Ph have been Studied. the Results Show that the Adsorption Capacities of Heavy Metal Ions onto Bentonite from Yongnian Follow the Order of Pb2+> Cu2+> Cr3+. it is Found that the Adsorption Process of Bentonite Accords with the Langmuir Isotherm Model. the Maximum Adsorption of 3 Kinds of Metal Ions onto Bentonite is in Order of Cr3+>Cu2+>Pb2+.


2018 ◽  
Vol 6 (1) ◽  
pp. 44-50
Author(s):  
Matheis F.J.D.P. Tanasale ◽  
Adriani Bandjar ◽  
Natasya Sewit

Chitosan isolated from mushroom (Vollariella volvaceae) as adsorbent of lead (Pb) metal has been done.  The isolation of chitosan was obtained 2.94% from total weight of mushroom.  Fungtional groups of chitin and chitosan were indentified by using FTIR spectrophotometry.  The chitosan had 74.66% degree of deacetylation and 2.09 x 104 g/mol viscosity molecular weight.  The experimental data of the chitosan as adsorbent for Pb metal were correlated with the Langmuir and Freundlich isotherm model.  The maximum adsorption capacity of Pb based on the Langmuir isotherm model was 2.66 mg/g.


Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5690
Author(s):  
Changkun Liu ◽  
Hui Wen ◽  
Kaili Chen ◽  
Yanni Chen

Removing toxic heavy metal species from aqueous solutions is a point of concern in our society. In this paper, a promising biomass adsorbent, the modified waste shrimp shell (MS), for Cu (II) removal was successfully prepared using a facile and simple one-step modification, making it possible to achieve high-efficiency recycling of the waste NaOH solution as the modification agent. The outcome shows that with the continuous increase in pH, temperature and ion concentration, the adsorption effect of MS on Cu (II) can also be continuously improved. Adsorption isotherm and adsorption kinetics were fitted with the Langmuir isotherm model and the pseudo-second-order model, respectively, and the maximum adsorption capacity of Cu (II) as obtained from the Langmuir isotherm model fitting reached 1.04 mmol/g. The systematic desorption results indicated that the desorption rate of Cu (II) in the MS could reach 100% within 6 min, where HNO3 is used as the desorption agent. Moreover, experiments have proven that after five successive recycles of NaOH as a modifier, the adsorption capacity of MS on Cu (II) was efficient and stable, maintaining tendency in 0.83–0.85 mmol/g, which shows that waste NaOH solution can be used as a modification agent in the preparation of waste shrimp shell adsorbent, such as waste NaOH solution produced in industrial production, thereby making it possible to turn waste into renewable resources and providing a new way to recycle resources.


2021 ◽  
Author(s):  
CI Chemistry International

Development of a sustainable route for preparation Fe(OH)3/kaolinite nanoplatelets from Batin El-Ghoul clay deposits, south Jordan with uniform plate-like morphology. Fe(OH)3/kaolinite nanoplatelets is an efficient adsorbent for the removal of Pb(II) ions from aqueous solutions. Effects of pH solution, adsorbent dose, initial metal ion concentration, contact time, and temperature on the adsorption process were examined. The Langmuir isotherm model is the best fit model to predict the experimental data and the adsorption capacity. Maximum adsorption capacity on Langmuir isotherm was 370.37 mg/g. Thermodynamic parameters revealed that the negative values of ΔGo and the positive value of ΔHo, the adsorption process was spontaneous and endothermic. Results revealed that Fe(OH)3/kaolinite is promising for the removal of metal ions from effluents.


2018 ◽  
Vol 15 (2) ◽  
pp. 6296-6305
Author(s):  
Yong Pyo Hong ◽  
Keon Sang Ryoo

In this study, adsorption of NO3- -N and PO43--P on granular activated charcoal (GAC) was investigated depending on pH, agitation time, GAC dosage, adsorption capacity and adsorption isotherms by employing batch adsorption type. The GAC was characterized by thermogravimetric analysis (TG-DTA), scanning electron micrograph coupled with energy-dispersive X-ray spectroscopy (SEM-EDX) and BET surface area analyzer. The GAC exhibited nearly similar adsorption equilibrium time. Both NO3--N and PO43—P appeared to approach equilibrium after approximately 4 h of agitation time. In the adsorption equilibrium, the removal efficiencies of NO3- -N and PO43--P were found to be 14.6-66.0 % and 52.4-99.0 %, respectively. The adsorption data for NO3--N and PO43--P was correlated to Freundlich and Langmuir isotherm model and the equilibrium data was fitted well to the Langmuir isotherm model due to their higher correlation coefficient (R2) value. The Langmuir adsorption capacity was 1.54 and 2.56 mg g-1 for NO3--N and PO43--P, respectively, which suggests that the GAC is a good adsorbent for removal of NO3--N and PO43—P from water.


2009 ◽  
Vol 620-622 ◽  
pp. 555-558
Author(s):  
Yi Li ◽  
Xue Gang Luo ◽  
Zhao Liu ◽  
Yan Huang ◽  
Xiao Yan Long

The modified valonian tannin was prepared through sulfonated-mannich reaction and used to adsorb Cu (II) from the aqueous solutions. The adsorption capacity rapidly reached equilibrium within 2 hours. The effect of pH on adsorption was apparent, the amount of adsorption increased significantly as the pH increased from 2.0 to 4.0 and then leveled off at pH 4.0-6.0. Equilibrium data fitted well with Freundlich isotherm model compared to Langmuir isotherm model, indicating that adsorption takes place on heterogeneous surface of the modified valonia tannin. The adsorption capacity was increased by increasing initial concentrations. The maximum adsorption capacity of cooper ion was determined to be 56.200 mg/g at 100 mg/L concentration.


2020 ◽  
Vol 18 (1) ◽  
pp. 843-849
Author(s):  
Mirza Nadeem Ahmad ◽  
Arif Hussain ◽  
Muhammad Naveed Anjum ◽  
Tajamal Hussain ◽  
Adnan Mujahid ◽  
...  

AbstractChitosan was grafted with polyorthoethylaniline through oxidative polymerization using ammonium persulfate as oxidant, resulting in the formation of a biocomposite of chitosan-grafted-polyorthoethylaniline (CH-g-POEA). The synthesized biocomposite (CH-g-POEA) was characterized by FTIR, SEM, and TGA. Adsorption of methyl orange (MO) dye by CH-g-POEA was studied, wherein the Langmuir isotherm model with a R2 of 0.9979 and adsorption capacity of 45.7 mg/g was evaluated.


2018 ◽  
Vol 69 (5) ◽  
pp. 1233-1239
Author(s):  
Raluca Madalina Senin ◽  
Ion Ion ◽  
Ovidiu Oprea ◽  
Rusandica Stoica ◽  
Rodica Ganea ◽  
...  

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.


2012 ◽  
Vol 9 (4) ◽  
pp. 1823-1834 ◽  
Author(s):  
P. N. Palanisamy ◽  
A. Agalya ◽  
P. Sivakumar

Poly Pyrrle saw dust composite was prepared by reinforcement of natural wood saw dust (obtained fromEuphorbia Tirucalli Lwood) and Poly Pyrrole matrix phase. The present study investigates the adsorption behaviour of Poly Pyrrole Saw dust Composite towards reactive dye. The batch adsorption studies were carried out by varying solution pH, initial dye concentration, contact time and temperature. The kinetic study showed that adsorption of Reactive Red by PPC was best represented by pseudo-second order kinetics with ion exchange adsorption. The equilibrium data were analyzed by Freundlich and Langmuir isotherm model. The equilibrium isotherm data were fitted well with Langmuir isotherm model. The maximum monolayer adsorption capacities calculated by Langmuir model were 204.08 mg/g for Reactive Red at 303 K. The thermodynamic parameters suggest the spontaneous, endothermic nature of ion exchange adsorption with weak Vader walls force of attraction. Activation energy for the adsorption of Reactive by Poly Pyrrole Composite was 11.6387 kJ/mole, Isosteric Heat of adsorption was 48.5454 kJ/mole also supported the ion exchange adsorption process in which forces of attraction between dye molecules and PPC is weak.


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