Elution profile of cationic and anionic adsorbate from exhausted adsorbent using solvent desorption

Author(s):  
Himanshu Patel

Abstract Present invention involves to study the elution profile of anionic and cationic compounds from exhausted adsorbents using various eluents. Batch elution studies of anionic components like Congo Red dye and Carbonate ion; and cationic compounds such as Methylene blue dye and Cadmium metal from previously used naturally prepared adsorbents i.e. Gulmohar (Delonix regia) leaf powder - GLP; and Neem (Azadirachta indica) leaf powder – NLP and their derivatives were conducted. Different eluents used for batch study were various acids and alkaline solution having various concentration and solvents having different functional groups in seven sorption-desorption cycles. The batch data were accessed by kinetic models (Pseudo First-, Pseudo Second-order, Intra-partice and Elovic equation). Column elution experiments of Congo red and Cadmium from NLP and activated charcoal from NLP (AC-NLP) respectively was performed using selected eluent. Sorption and elution process plots and parameters for seven sorption–desorption cycles were evaluated and discussed. Plots of life cycle indicating activity-indicator equations were drawn, and their parameters were calculated and mentioned. From desorption efficiencies, it revealed that desorption exploration is predominately depends upon pH factor.

2018 ◽  
Vol 11 ◽  
pp. 117862211881168 ◽  
Author(s):  
Christine Jeyaseelan ◽  
Nisha Chaudhary ◽  
Ravin Jugade

Dyes are a major cause of concern nowadays as large quantities are being released into water bodies causing pollution. In this article, modified chitosan (sulphate crosslinked) has been studied for the removal of Congo red (a benzidine-based anionic diazo dye) which is a toxic dye introduced into water bodies from textile industries. Sulphate-crosslinked chitosan (SCC) was prepared in the laboratory and the characterization of SCC was done by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). Various parameters such as pH, contact time, adsorbent dosage, and concentration of adsorbent were optimized. The adsorption capacity was determined at pH 3.0, at which the percentage recovery was about 90% and followed Freundlich adsorption isotherm with an adsorption capacity of 91.8 mg/g. The adsorption followed pseudo-second-order kinetics. Various thermodynamic parameters were also determined for the change in adsorption with temperature. The SCC was regenerated with NaOH and showed good recycling capacity. The modified chitosan was applied for the removal of Congo red from industrial wastewater samples (spiked).


2018 ◽  
Vol 23 (6) ◽  
pp. 1053-1060 ◽  
Author(s):  
Raquel Studart de Farias ◽  
Hugo Leonardo de Brito Buarque ◽  
Mabel Ribeiro da Cruz ◽  
Luana Meg Freitas Cardoso ◽  
Tamyris de Aquino Gondim ◽  
...  

ABSTRACT This study investigates the potential use of amino-functionalized silica gel as an adsorbent for the recovering of congo red dye from aqueous solution. The effects of pH, contact time, and temperature were determined and evaluated. Equilibrium isotherms were also studied. The adsorption kinetics was modeled by pseudo-first order and pseudo-second order. Furthermore, desorption of congo red was preliminarily studied. The pH range from 4.5 to 7.0 was favorable for the adsorption of congo red onto amine modified silica at 25ºC. Higher adsorption capacity was obtained at 50ºC. Langmuir and Freundlich models were fitted to the adsorption equilibrium data. The best fittings were obtained with the pseudo-second order and Langmuir model for kinetics and equilibrium, respectively. Desorption studies suggest that ion exchange might be the major mode of adsorption. KOH solution was the best desorbing agent for recovering the adsorbed dye.


2019 ◽  
Vol 814 ◽  
pp. 463-468 ◽  
Author(s):  
Hong Tham Nguyen Thi ◽  
Duy Chinh Nguyen ◽  
Thi Thuong Nguyen ◽  
Van Thuan Tran ◽  
Huu Vinh Nguyen ◽  
...  

This In this study, the Ca-Al layered double hydroxide was used as a potential adsorbent for the removal of Congo red from aqueous solutions. The effects of Initial concentration and contact time on the adsorption properties of Congo red by Ca-Al LDHs were studied. The removal rate of Conge red reached to 59.416 mg/g under room temperature with 0.2g of adsorbent, initial concentration of 50 ppm, adsorption time of 210 min, shaking speed of 90r/min. The experimental equilibrium data for the removal of Congo red were evaluated by various isotherm models. The pseudo-second-order kinetic models were found to fit the adsorption kinetics, and the equilibrium data were appropriately fitted to Langmuir and Freundlich model adsorption isotherm.


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.


2021 ◽  
Vol 6 (2) ◽  
pp. 74-79
Author(s):  
Patimah Mega Syah Bahar Nur Siregar ◽  
Normah ◽  
Novie Juleanti ◽  
Alfan Wijaya ◽  
Neza Rahayu Palapa ◽  
...  

In this study, chitosan was extracted from shrimp shells by demineralization and deproteination processes. The extracted chitosan was used to modify the layered double hydroxide and used as an adsorbent for the removal of congo red from aqueous solutions. Composites were successfully synthesized using M2+/Al (M2+ = Zn, Mg, Ni) and chitosan (CH) and the samples obtained were characterized using XRD and FTIR. The X-ray diffraction (XRD) pattern appeared at the layered double hydroxide peak of 2? = 11.63°; 23.00°; 35.16°; and 61.59° and chitosan at 2? = 7.93° and 19.35. The composite appearing in the layered double hydroxide and chitosan indicated that the composite material has been successfully synthesized. The XRD diffraction patterns of Zn/Al-CH, Ni/Al-CH, and Mg/Al-CH showed low crystallinity. The Fourier Transform Infrared (FTIR) spectra verifying absorption spectrum showed the presence of two bands at 3448 cm-1, 1382cm-1 characteristic to both chitosan and LDH. Adsorption of Congo Red (CR) followed the pseudo-second-order and Langmuir isotherm models. The adsorption capacities of Zn/Al-CH, Ni/Al-CH, and Mg/Al-CH were 181.818 mg/g, 227.273 mg/g, and 344.828 mg/g, respectively. The layered double hydroxide-chitosan composite adsorption was endothermically characterized by positive enthalpy and entropy values. On the other hand, the adsorption spontaneously was characterized by a negative Gibbs free energy value. The composites in this study were formed from LDH modified from chitosan extracted from shrimp shells to form Zn/Al-CH, Ni/Al-CH, and Mg/Al-CH. The results of the characterization showed a number of characteristics that resembled the constituent materials in the form of LDH and chitosan. After being applied as an adsorbent to absorb Congo red dye, it then showed the most effective results using Mg/Al-CH adsorbent with an adsorption capacity of 344.828 mg/g.


2019 ◽  
Vol 25 (12) ◽  
pp. 72-84
Author(s):  
Abeer I Alwared ◽  
Israa Sabah

The Wheat husk is one of the common wastes abundantly available in the Middle East countries especially in Iraq. The present study aimed to evaluate the Wheat husk as low cost material, eco-friendly adsorbents for the removal of the carcinogenic dye (Congo red dye) from wastewater by investigate the effect of, at different conditions such as, pH(3-10), amount of adsorbents (1-2.3gm/L),and particle size (125-1000) μm, initial Congo red dye concentration(10, 25 , 50 and 75mg/l)  by batch experiments. The results showed that the removal percentage of dye increased with increasing adsorbent dosage, and decreasing particle size. The maximum removal and uptake reached (91%) , 21.5mg/g, respectively for 25 initial concentration, pH 6.7 and 1.5 g/l Wheat husk dosage. The experimental data fitted well to Langmuir isotherm mode. The kinetic data support the assumptions of chemisorption were indicates a good fitting to the pseudo-second-order model.


2021 ◽  
Vol 926 (1) ◽  
pp. 012051
Author(s):  
Desnelli ◽  
W R Asri ◽  
Hasanudin ◽  
M Said ◽  
P L Hariani

Abstract The process of pillarization of metal oxide Zn/Fe compounds in bentonite has been carried out. The study of adsorbent weight, pH, adsorption time, and initial concentration were investigated to get the optimum reduction of Congo red and Procion red concentration. In addition, the pseudo kinetic also determined to investigate the rate and type of adsorption. From the experiment, the optimum conditions for removal of Congo red for the adsorbent weight, pH, and adsorption time were 0.02 g, 2, 20 minutes, respectively, while for the removal of Procion red was 0.04 g, 2, 20 minutes, respectively and both of adsorbent followed the pseudo-second-order model kinetics with chemisorption mechanism. Although the optimum conditions for removal of the two dyes were similar, in fact the percentage removal of the Congo red dye was greater. In conclusion, the Zn/Fe pillared bentonite was more suitable for the removal of the Congo red than Procion red.


2010 ◽  
Vol 156-157 ◽  
pp. 217-224 ◽  
Author(s):  
Shan Ping Li ◽  
Jiang Jie Cui

We studied the effects of surface modification of bentonite with chitosan on its ability to adsorb Congo Red (CR) dye. The adsorption behavior of CR from aqueous solution onto raw (RB) and chitosan-modified (CMB) bentonite samples was investigated as a function of parameters such as initial CR concentration, contact time, pH and temperature. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to confirm the surface modification. Compared with RB, the adsorption capacity of CMB for CR was greatly enhanced. Kinetic studies indicated that the adsorption of CR on both RB and CMB followed the pseudo-second-order kinetic model. From the thermodynamic parameters, the adsorption of CR on RB and CMB is spontaneous and endothermic. The results indicate that chitosan-modified bentonite provides an important advantage for CR dye adsorption over raw bentonite.


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