scholarly journals Biodegradable glucose and glucosamine grafted polyacrylamide/graphite composites for the removal of acid violet 17 from an aqueous solution

e-Polymers ◽  
2018 ◽  
Vol 18 (4) ◽  
pp. 297-311 ◽  
Author(s):  
Gayathri Kumarasamy ◽  
Palanisamy Nachimuthu

AbstractIn this work, the structural characterization and adsorption behavior of glucose and glucosamine grafted polyacrylamide/graphite composites (denoted as Gu-g-PAM/graphite and GA-g-PAM/graphite) were investigated. The grafted polymers were characterized by using Fourier transform infrared (FT-IR) spectroscopy, 1H nuclear magnetic resonance (NMR), 13C NMR and N2 sorption studies. The adsorption behavior of grafted polymers was compared by varying parameters such as pH, initial dye concentration, agitation time, adsorbent dose and temperature. The results showed that GA-g-PAM/graphite composite was an effective adsorbent for the uptake of acid violet 17 (Av-17) from an aqueous solution. The superior adsorption behavior was attributed to the presence of -NH2 and -OH groups in GA-g-PAM/graphite. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms were used to describe the adsorption isotherm. The adsorption isotherm of the adsorbents fitted well with the Langmuir model with the maximum adsorption capacity (qo) of 78.13 mg/g for GA-g-PAM/graphite. The efficiency of adsorption with time was described using pseudo first-order, pseudo second-order and intra particle diffusion kinetic models. The kinetic study revealed that the adsorption equilibrium was attained within 50 min. The thermodynamic analysis stated that the adsorption of dye is spontaneous, physical and endothermic in nature. Desorption results revealed that all the adsorbents exhibit excellent stability and remarkable regeneration ability.

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Ha Xuan Linh ◽  
Ngo Thi Thu ◽  
Tran Quoc Toan ◽  
Do Tra Huong ◽  
Bui Thanh Giang ◽  
...  

In this work, the mixture of red mud slurry and inorganic salt ((NH4)2SO4) has been used as an electrolyte for electrochemical activation of graphite. The red mud-activated graphite composite was then used as an adsorbent for removing methylene blue from aqueous solution by the batch method. The effect of pH, contact time, adsorbent dosage, and the initial concentration of methylene blue was investigated. The optimal condition was found at pH 6, contact time 120 min, and amount of adsorbent 1 mg/L. The maximum adsorption capacity was found to be 89.28 mg/g based on the Langmuir isotherm equation, suggesting that the red mud-activated graphite composite is a very potential adsorbent for removing methylene blue and is also used in other coloured wastewater treatments.


2021 ◽  
Author(s):  
Jia Lin ◽  
Yude Zhang ◽  
Qian Zhang ◽  
Jinli Shang ◽  
Fuyao Deng

Abstract A benzene sulfonate modified hydrotalcite (SO3-LDH) was synthesized by a facile one-pot hydrothermal technique, which can efficiently remove methyl orange (MO), Congo red (CR) and orange II (OII) from aqueous solution. After modified by benzene sulfonate, the microstructure of hydrotalcite changes obviously, from the cellular structure to the stacking structure formed by the face-face contact of hydrotalcite nanosheets, which resulted in much more exchangeable nitrate ions to remain in the interlayer space. The pre-insertion of benzene sulfonate as a pillar expanded the interlayer gallery, which facilitated the pollutant anions (MO, CR and OII) into the interlayer of LDH in the subsequent adsorption process. The maximum adsorption capacity of SO3-LDH for MO, CR and OII was 4200.8 mg/g, 1252.0 mg/g and 1670.6 mg/g respectively, which is approximately 1.86 times, 1.8 times and 2.32 times that of the pristine NO3-LDH, respectively. The removal mechanism of anionic dyes was determined as anion exchange between NO3− ions and dye molecules. The adsorption behavior for MO and OII is multilayer adsorption, while the adsorption behavior for CR is monolayer adsorption. The adsorption process mainly was controlled by the chemical bonding between the dye molecules and adsorbent active sites. The benzene sulfonate modified LDH has a great potential to be used as a high-efficient adsorbent to remove anionic dyes from aqueous solution.


2018 ◽  
Vol 78 (4) ◽  
pp. 837-847 ◽  
Author(s):  
Sung-Whan Yu ◽  
Hee-Jeong Choi

Abstract In this study, hybrid beads, which are made by mixing persimmon leaf and chitosan, was used to remove Pb(II) and Cd(II) from aqueous solution. According to the Fourier transform infrared spectrometry (FT-IR) analysis, the hybrid bead has a structure that enables the easy adsorption of heavy metals because it has carboxylic, carbonyl groups, O-H carboxylic acid, and bonded -OH groups. The adsorption of Pb(II) and Cd(II) by hybrid beads was more suitable with the Langmuir isothermal adsorption and showed an ion exchange reaction which occurred in the uneven adsorption surface layer. The maximum adsorption capacity of Pb(II) and Cd(II) was determined to be 278.68 mg/g and 87.91 mg/g, respectively. Furthermore, the adsorption removal process of Pb(II) and Cd(II) using hybrid beads is a spontaneous exothermic reaction and the affinity of the adsorbed material for the adsorbent is excellent. Hybrid beads are inexpensive, have a high removal efficiency of heavy metals, and are environmentally friendly.


2013 ◽  
Vol 477-478 ◽  
pp. 1331-1335
Author(s):  
Guang Fu Xu ◽  
Hui Min Jing ◽  
Rui Xin Guo

Orange peel, an agricultural waste available in large quantity in China, was utilized as low-cost adsorbent to remove furadan from aqueous solution by adsorption. Adsorption isotherms were calculated and discussed. Both Langmuir and Freundlich models fitted the adsorption data quite reasonably (R2> 0.98) and the maximum adsorption capacity was 161.29 mg.g-1. The results in this study indicated that orange peel was an attractive candidate for removing furadan from the aqueous solution.


2019 ◽  
Vol 9 (8) ◽  
Author(s):  
Somayeh Rahdar ◽  
Abbas Rahdar ◽  
Mina Khodadadi ◽  
Shahin Ahmadi

Abstract The adsorption of penicillin G (PC-G) from aqueous solution by magnesium oxide (MgO) nanoparticles has been investigated. This experimental study was conducted in a laboratory scale. The effects of various operating parameters such as pH (3–11), the dosage of MgO nanoparticles (0.3–1.5 g/L), contact time (20–150 min), and concentration of PC-G (50–200 mg/L) were studied. The results showed that under optimal conditions of concentration of 50 mg/L, pH 3, MgO nanoparticles dosage of 1.5 g/L and contact time of 60 min, the maximum adsorption capacity (qm) of PC-G adsorption on MgO nanoparticles obtained was 25.66 mg/g. The process of penicillin G adsorption on MgO nanoparticles was found to depend on Langmuir (II) and Langmuir (III) adsorption isotherm models. It could be concluded that the MgO nanoparticles can be used for PC-G removal from its aqueous solution.


2015 ◽  
Vol 737 ◽  
pp. 533-536 ◽  
Author(s):  
Dong Xue Xiao ◽  
Chang Ling Fang ◽  
Jun Zhou ◽  
Xiao Yi Lou ◽  
Jiu Hua Xiao ◽  
...  

Ferric hydrosulfate minerals are commonly byproducts of biotic oxidation of Fe (II) in acid mine drainage and biohydrometallurgy like biogenic jarosite. In this study, adsorption of Cr (VI) on jarosite was a rapid process and the optimum pH for Cr (VI) adsorption was found at 7.0. The variation of Cr (VI) adsorbed on jarosite fitted the Langmuir adsorption isotherm models and the maximum adsorption capacity was 3.23 mg/g. It was evident that anion exchange mechanism was responsible for Cr (VI) adsorption on jarosite based on the sulfate leaching data and optimum pH experiments.


2008 ◽  
Vol 26 (9) ◽  
pp. 679-686 ◽  
Author(s):  
M. Sathishkumar ◽  
J.G. Choi ◽  
C.S. Ku ◽  
K. Vijayaraghavan ◽  
A.R. Binupriya ◽  
...  

This paper reports the adsorption ability of banana pith activated carbon, with ZnCl2 as the porogen, towards carbaryl (1-naphthyl- N-methylcarbamate) from aqueous solution. The pH-edge experiments revealed that carbaryl adsorption onto ZnCl2-treated banana pith activated carbon (ZTC) was a pH-dependent process with maximum adsorption occurring at pH 11. The adsorption isotherm obtained at pH 11 revealed that ZTC possessed a maximum adsorption capacity of 45.9 mg/g. The adsorption isotherms were well described by the Langmuir and Freundlich models. The kinetic data obtained at different initial carbaryl concentrations were modelled using pseudo-first- and -second-order models. Acetone successfully desorbed carbaryl with a 99.8% elution efficiency.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Johnatan D. Castro-Castro ◽  
Iván F. Macías-Quiroga ◽  
Gloria I. Giraldo-Gómez ◽  
Nancy R. Sanabria-González

Clay minerals can be modified organically by a cationic surfactant resulting in materials known as organoclays. The organoclays have been used as adsorbents of most of the organic contaminants in the aqueous solution and oxyanions of the heavy metal. In this study, a Colombian bentonite was modified with hexadecyltrimethylammonium bromide to obtain an organobentonite, and its capacity to adsorb Cr(VI) oxyanions in the aqueous solution was evaluated. The effect of pH, stirring speed, adsorbent amount, contact time, and ionic strength were investigated at 25°C. Stirring speeds above 200 rpm, contact times greater than 120 min, and the addition of NaCl (0.1 to 2.0 mM) did not have a significant effect on Cr(VI) removal. The influence of the adsorbent amount and pH on Cr(VI) adsorption was studied by the response surface methodology (RSM) approach based on a complete factorial design 32. Results proved that the Cr(VI) adsorption follows a quadratic model with high values of coefficient of determination (R2 = 95.1% and adjusted R2 = 93.9%). The optimal conditions for removal of Cr(VI) from an aqueous solution of 50 mg/L were pH of 3.4 and 0.44 g amount of the adsorbent. The adsorption isotherm data were fitted to the Langmuir and Freundlich adsorption isotherm models, and the model parameters were evaluated. The maximum adsorption capacity of Cr(VI) onto organobentonite calculated from the Langmuir model equation was 10.04 ± 0.34 mg/g at 25°C. The results suggest that organobentonite is an effective adsorbent for Cr(VI) removal, with the advantage of being a low-cost material.


Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 2
Author(s):  
Pawan Kumar ◽  
Meenu Saini ◽  
Maninder Singh ◽  
Nidhi Chhillar ◽  
Brijnandan S. Dehiya ◽  
...  

Herein, we report a micro-plasma assisted solvothermal synthesis and characterization of zinc oxide nanosheets (ZnO-NSs) and their application for the removal of Cr6+ ion from aqueous solution. The morphological investigations by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) confirmed the high-density growth of nanosheets with the typical sizes in the range of 145.8–320.25 nm. The typical surface area of the synthesized ZnO-NSs, observed by Brunauer-Emmett-Teller (BET), was found to be 948 m2/g. The synthesized ZnO-NSs were used as efficient absorbent for the removal of Cr6+ ion from aqueous solution. Various parameters such as pH, contact time, amount of adsorbate and adsorbent on the removal efficiency of Cr6+ ion was optimized and presented in this paper. At optimized conditions, the highest value for removal was 87.1% at pH = 2 while the calculated maximum adsorption capacity was ~87.37 mg/g. The adsorption isotherm data were found to be best fitted to Temkin adsorption isotherm and the adsorption process followed the pseudo-first-order kinetics. Furthermore, the toxicity of ZnO-NSs were also examined against fibroblast cells, which show favorable results and proved that it can be used for wastewater treatment.


2020 ◽  
Vol 71 (1) ◽  
pp. 1-12
Author(s):  
Salman H. Abbas ◽  
Younis M. Younis ◽  
Mohammed K. Hussain ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor ◽  
...  

The biosorption performance of both batch and liquid-solid fluidized bed operations of dead fungal biomass type (Agaricusbisporus ) for removal of methylene blue from aqueous solution was investigated. In batch system, the adsorption capacity and removal efficiency of dead fungal biomass were evaluated. In fluidized bed system, the experiments were conducted to study the effects of important parameters such as particle size (701-1400�m), initial dye concentration(10-100 mg/L), bed depth (5-15 cm) and solution flow rate (5-20 ml/min) on breakthrough curves. In batch method, the experimental data was modeled using several models (Langmuir,Freundlich, Temkin and Dubinin-Radushkviechmodels) to study equilibrium isotherms, the experimental data followed Langmuir model and the results showed that the maximum adsorption capacity obtained was (28.90, 24.15, 21.23 mg/g) at mean particle size (0.786, 0.935, 1.280 mm) respectively. In Fluidized-bed method, the results show that the total ion uptake and the overall capacity will be decreased with increasing flow rate and increased with increasing initial concentrations, bed depth and decreasing particle size.


Sign in / Sign up

Export Citation Format

Share Document