Fe3O4-CS-L: a magnetic core-shell nano adsorbent for highly efficient methyl orange adsorption

2017 ◽  
Vol 77 (3) ◽  
pp. 628-637 ◽  
Author(s):  
Shuangzhen Guo ◽  
Jian Zhang ◽  
Xianlong Li ◽  
Fan Zhang ◽  
Xixi Zhu

Abstract A novel core-shell bio-adsorbent was fabricated by using biological materials for removing methyl orange (MO) from aqueous solution. The structure characteristics results of scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FT-IR), thermo-gravimetric analysis (TGA), vibrating sample magnetometer (VSM), and Brunauer–Emmett–Teller (BET) shows that Fe3O4-CS-L has been successfully prepared. The effects of contact time, pH, temperature and initial concentration were explored. The results suggested pH was a negligible factor in adsorption progress. Kinetic studies showed that the experiment data followed pseudo-second-order model. Boyd mode suggested that external mass transfer showed a rather weak rate control for MO adsorption onto Fe3O4-CS-L. Equilibrium studies showed that isotherm data were the best described by Langmuir model. The maximum adsorption capacity of MO estimated to be 338.98 mg/g at 298 K. Moreover, the adsorption capacity of Fe3O4-CS-L can keep about 74% in the fifth adsorption–regeneration cycle. Thus, the Fe3O4-CS-L could be a kind of promising material for removing MO from wastewater.

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 962
Author(s):  
Kuo-Yu Chen ◽  
Wei-Yu Zeng

Poly-γ-glutamate/apatite (PGA-AP) nanoparticles were prepared by chemical coprecipitation method in the presence of various concentrations of poly-γ-glutamate (γ-PGA). Powder X-ray diffraction pattern and energy-dispersive spectroscopy revealed that the main crystal phase of PGA-AP was hydroxyapatite. The immobilization of γ-PGA on PGA-AP was confirmed by Fourier transform infrared spectroscopy and the relative amount of γ-PGA incorporation into PGA-AP was determined by thermal gravimetric analysis. Dynamic light scattering measurements indicated that the particle size of PGA-AP nanoparticles increased remarkably with the decrease of γ-PGA content. The adsorption of aqueous Cu(II) onto the PGA-AP nanoparticles was investigated in batch experiments with varying contact time, solution pH and temperature. Results illustrated that the adsorption of Cu(II) was very rapid during the initial adsorption period. The adsorption capacity of PGA-AP nanoparticles for Cu(II) was increased with the increase in the γ-PGA content, solution pH and temperature. At a pH of 6 and 60 °C, a higher equilibrium adsorption capacity of about 74.80 mg/g was obtained. The kinetic studies indicated that Cu(II) adsorption onto PGA-AP nanoparticles obeyed well the pseudo-second order model. The Langmuir isotherm model was fitted well to the adsorption equilibrium data. The results indicated that the adsorption behavior of PGA-AP nanoparticles for Cu(II) was mainly a monolayer chemical adsorption process. The maximum adsorption capacity of PGA-AP nanoparticles was estimated to be 78.99 mg/g.


2021 ◽  
Vol 36 (1) ◽  
pp. 16-24
Author(s):  
O. A. Ajayi ◽  
S Nanbyen ◽  
A. A Oladipo ◽  
F. U. Nwafulugo

MIL-53(Fe)/Cow bone char composite, prepared via the sol-gel method was used for the removal of chromium from real tannery effluent having an initial concentration of 40mg/l. The characteristics of MIL-53(Fe)/Cow bone char were studied using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA) Boehm titration and scanning electron microscopy (SEM-EDX). Adsorption capacity of MIL-53(Fe)/Cow bone char composite for chromium was 19.61 mg/g with a removal efficiency of 87.8% at an optimal bed height of 2.4cm (2.0g) for MIL-53(Fe)/Cow bone char composite, time of 2 minutes and pHpzc=5.4.The kinetic studies showed that the adsorption data were well fitted to the pseudo second-order model with high correlation coefficient R2=0.9911. Furthermore, the adsorption isotherm equilibrium studies confirmed that the Langmuir model best described the adsorption process of chromium onto MIL-53(Fe)/Cow bone char composite. Analysis of data with Dubinin–Radushkevich and Temkin isotherms showed that adsorption of chromium onto MIL-53(Fe)/Cow bone char composite is physical in nature.


2021 ◽  
Author(s):  
Adeel Mustafa ◽  
Nazia Yaqoob ◽  
Maheen Almas ◽  
Shagufta Kamal ◽  
Khalid Mahmood Zia ◽  
...  

Abstract In this study graphene oxide (GO) reinforced polyvinyl alcohol (PVA) composites hydrogels were synthesized and used as efficient adsorbents for Drimarene Brilliant Blue K-4BL. GO nanoparticles (NPs) were synthesized by modified Hummer’s method. The composites were characterized by Fourier transform infrared spectroscopy (FT-IR), Thermo-gravimetric analysis (TGA), Scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed homogeneous dispersion of reinforcement in the synthesized composites. Moreover thermal stability of the composites was significantly enhanced by the addition of graphene oxide nanoparticles. The synthesized composites were used for the removal of Drimarene brilliant Blue from model waste water. The effect of pH, content of GONPs and initial concentration of Drimarene Brilliant Blue K-4BL on the adsorption capacity of synthesized GO/PVA composites were investigated. The equilibrium isothermal data were studied by applying Langmuir and Freundlich isotherm models. Results demonstrated that the adsorption process is well described by the Langmuir adsorption isotherm. According to the Langmuir model, maximum adsorption capacity i.e. 32mg/g was obtained at 0.7% GO/PVA composite. From the kinetic study it was concluded that pseudo-second-order model is the best fitted. Synthesized composites showed excellent reusability (almost 95 %) for the adsorption of Drimarene Brilliant Blue K-4BL after four successive cycles of adsorption and desorption. Thus, the GO/PVA composites demonstrated a great potential in terms of cost effectiveness, efficiency and reusability for the removal of Drimarene Brilliant Blue K-4BL dye.


2019 ◽  
Vol 801 ◽  
pp. 304-310
Author(s):  
Jirah Emmanuel T. Nolasco ◽  
Elaine Nicole O. Cañeba ◽  
Karl Michael V. Edquila ◽  
Joel Ian C. Espita ◽  
Jem Valerie D. Perez

Nanocomposite beads containing 2% chitosan (CS), 2% polyethyleneimine (PEI), and 1,500 ppm graphene oxide (GO) were synthesized for the removal of methyl orange (MO) from water. Characterization of the CS-PEI-GO beads using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) showed favorable adsorbent properties as given by the presence of numerous surface functional groups and a porous structure. Effects of different parameters such as pH, contact time, and initial concentration on the percentage removal of MO and adsorption capacity of the beads were investigated by performing batch adsorption experiments. MO removal of more than 85% was achieved by the beads across a wide pH range. Kinetic studies were performed and a pseudo-second order kinetic equation with R2 of 0.9999 was obtained. Furthermore, adsorption equilibrium data for MO were best described by the Toth isotherm model (R2 = 0.9644), suggesting multilayer adsorption on heterogeneous adsorption sites with a maximum adsorption capacity of 421.51 mg/g. Finally, FTIR and SEM analyses after adsorption confirmed the presence of MO on the surface of the beads and revealed an intact and stable structure. Overall, the excellent adsorption capability and multi-functionality demonstrated in this study show great potential of the synthesized material for wastewater treatment applications.


2021 ◽  
Vol 5 (1) ◽  
pp. 9
Author(s):  
Muhammad Yusuf Prajitno ◽  
Mohamad Taufiqurrakhman ◽  
David Harbottle ◽  
Timothy N. Hunter

Natural clinoptilolite was studied to assess its performance in removing caesium and strontium ions, using both static columns and an agitated tube reactor (ATR) for process intensification. Kinetic breakthrough curves were fitted using the Thomas and Modified Dose Response (MDR) models. In the static columns, the clinoptilolite adsorption capacity (qe) for 200 ppm ion concentrations was found to be ~171 and 16 mg/g for caesium and strontium, respectively, highlighting the poor material ability to exchange strontium. Reducing the concentration of strontium to 100 ppm, however, led to a higher strontium qe of ~48 mg/g (close to the maximum adsorption capacity). Conversely, halving the column residence time to 15 min decreased the qe for 100 ppm strontium solutions to 13–14 mg/g. All the kinetic breakthrough data correlated well with the maximum adsorption capacities found in previous batch studies, where, in particular, the influence of concentration on the slow uptake kinetics of strontium was evidenced. For the ATR studies, two column lengths were investigated (of 25 and 34 cm) with the clinoptilolite embedded directly into the agitator bar. The 34 cm-length system significantly outperformed the static vertical columns, where the adsorption capacity and breakthrough time were enhanced by ~30%, which was assumed to be due to the heightened kinetics from shear mixing. Critically, the increase in performance was achieved with a relative process flow rate over twice that of the static columns.


2010 ◽  
Vol 171-172 ◽  
pp. 15-18
Author(s):  
Zeng Quan Ji ◽  
Tian Hai Wang ◽  
Kai Hong Luo ◽  
Yao Qing Wang

An extracellular biopolymer (PFC02) produced by Pseudomonas alcaligenes was used as an alternative biosorbent to remove toxic Cd(II) metallic ions from aqueous solutions. The effect of experimental parameters such as pH, Cd(II) initial concentration and contact time on the adsorption was studied. It was found that pH played a major role in the adsorption process, the optimum pH for the removal of Cd(II) was 6.0. The FTIR spectra showed carboxyl, hydroxyl and amino groups of the PFC02 were involved in chemical interaction with the Cd(II) ions. Equilibrium studies showed that Cd(II) adsorption data followed Langmuir model. The maximum adsorption capacity (qmax) for Cd(II) ions was estimated to be 93.55 mg/g. The kinetic studies showed that the kinetic rates were best fitted to the pseudo-second-order model. The study suggestted that the novel extracellular biopolymer biosorbent have potential applications for removing Cd(II) from wastewater.


2016 ◽  
Vol 75 (1) ◽  
pp. 106-114 ◽  
Author(s):  
Lucas Meili ◽  
Társila Santos da Silva ◽  
Daniely Carlos Henrique ◽  
João Inácio Soletti ◽  
Sandra Helena Vieira de Carvalho ◽  
...  

In this work, the potential of ouricuri (Syagrus coronata) fiber as a novel biosorbent to remove methylene blue (MB) from aqueous solutions was investigated. The fiber was prepared and characterized according to the fundamental features for adsorption. A 23 experimental design was used to evaluate the effects of adsorbent dosage (M), fiber diameter (D) and agitation (A) on the adsorption capacity. In the more adequate conditions, kinetic and equilibrium studies were performed. The experimental design results showed that M = 10 g L−1), D = 0.595 mm and A = 200 rpm were the more adequate conditions for MB adsorption. Based on the kinetic study, it was found that the adsorption process was fast, being the equilibrium was attained at about 5 min, with 90% of color removal. The isotherm was properly represented by the Sips model, and the maximum adsorption capacity was 31.7 mg g−1. In brief, it was demonstrated that ouricuri fiber is an alternative biosorbent to remove MB from aqueous media, taking into account the process efficiency and economic viewpoint.


2015 ◽  
Vol 6 (2) ◽  
pp. 310-324 ◽  
Author(s):  
Selvaraj Dinesh Kirupha ◽  
Selvaraj Kalaivani ◽  
Thangaraj Vidhyadevi ◽  
Periyaraman Premkumar ◽  
Palanithamy Baskaralingam ◽  
...  

A novel poly [2,5-(1,3,4-thiadiazole)-benzalimine] abbreviated as TDPI adsorbent was synthesized using simple polycondensation technique. The synthetic route involves the preparation of 2,5-diamino-1,3,4-thiadiazole from 2,5-dithiourea and subsequent condensation with terephthalaldehyde. The resin was chemically characterized using Fourier transform infrared (FT-IR), 1H-NMR, and 13C-NMR spectroscopic analysis. Surface morphology and thermal stability were analyzed using scanning electron microscopy (SEM) and thermo-gravimetric analysis (TGA). The effect of the pH value of solution, contact time, adsorbent dose, and initial metal ion concentration were investigated by batch equilibrium adsorption experiments. Kinetic studies show that the adsorption of metal ions onto the resin proceeds according to the pseudo-second-order model and the equilibrium data were best interpreted by the Redlich–Peterson isotherm. The experimental values of the adsorption capacities of Pb2+, Cu2+, Ni2+, and Cd2+ on to TDPI could reach up to 437.2, 491.6, 493.7, and 481.9 mg.g−1 respectively. The exothermic nature of the process, the affinity of the adsorbent towards the metal ions and the feasibility of the process are explained in the thermodynamic parameters. The resin stability and re-usability studies suggest that the resin is chemically stable (0.3 N HCl and H2SO4) and could be regenerated without any serious decline in performance.


Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2218 ◽  
Author(s):  
Carlos Grande-Tovar ◽  
William Vallejo ◽  
Fabio Zuluaga

In this work, we synthesized chitosan grafted-polyacrylic acid (CS-g-PA) through surface-initiated atom transfer radical polymerization (SI-ATRP). We also studied the adsorption process of copper and lead ions onto the CS-g-PA surface. Adsorption equilibrium studies indicated that pH 4.0 was the best pH for the adsorption process and the maximum adsorption capacity over CS-g-PA for Pb2+ ions was 98 mg·g−1 and for Cu2+ it was 164 mg·g−1, while for chitosan alone (CS), the Pb2+ adsorption capacity was only 14.8 mg·g−1 and for Cu2+ it was 140 mg·g−1. Furthermore, the adsorption studies indicated that Langmuir model describes all the experimental data and besides, pseudo-second-order model was suitable to describe kinetic results for the adsorption process, demonstrating a larger kinetic constant of the process was larger for Pb2+ than Cu2+. Compared to other adsorbents reported, CS-g-PA had comparable or even superior adsorbent capacity and besides, all these results suggest that the new CS-g-PA polymers had potential as an adsorbent for hazardous and toxic metal ions produced by different industries.


2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Md. Nabul Sardar ◽  
Nazia Rahman ◽  
Shahnaz Sultana ◽  
Nirmal Chandra Dafader

Abstract This study focuses on the adsorption of hazardous Cr (III) and Cu (II) ions from aqueous solution by applying modified waste polypropylene (PP) fabric as an adsorbent. Pre-irradiation technique was performed for grafting of sodium styrene sulfonate (SSS) and acrylic acid (AAc) onto the PP fabric. The monomer containing 8% SSS and 16% AAc in water was used. Graft yield at 30 kGy radiation dose was 390% when 4% NaCl was added as additive. The prepared adsorbent was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermo-gravimetric analysis (TGA) and dynamic mechanical analyzer (DMA). The influences of different parameters including pH, contact time, temperature and initial metal ion concentration were also investigated. The equilibrium adsorption data were better fitted to the Langmuir isotherm model with maximum monolayer adsorption capacity 384.62 mg/g for Cr (III) and 188.68 mg/g for Cu (II) ions. The kinetic data were better explained by pseudo first-order kinetic model having good matching between the experimental and theoretical adsorption capacity. The adsorption process was spontaneous, endothermic and thermodynamically feasible. Furthermore, investigation of desorption of metal ions and reuse of the adsorbent suggesting that the adsorbent is an efficient and alternative material in the removal of Cr (III) and Cu (II) from aqueous media.


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