scholarly journals Biosorption potentials of acid modified Saccharum bengalense for removal of methyl violet from aqueous solutions

2017 ◽  
Vol 23 (3) ◽  
pp. 399-409 ◽  
Author(s):  
Muhammad Din ◽  
Kiran Ijaz ◽  
Khalida Naseem

In the present work, Saccharum bengalense (SB) was treated with sulfuric acid to enhance its efficiency. Methyl violet (MV), a cationic dye, was removed from aqueous medium using acid modified S. bengalense (A-SB). Different parameters like adsorbent dosage, stirring speed, temperature, contact time and effect of initial concentration of dye on rate of adsorption of dye from aqueous medium was studied. Experimental data obtained from adsorption of MV was analyzed by applying pseudo first order, pseudo second order and intra-particle diffusion models and it was found that the data best follows the pseudosecond order kinetics. Thermodynamic parameters indicate that adsorption reaction was spontaneous, feasible and endothermic in nature. Different adsorption isotherm models, like Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Temkin, were used to study the mechanism of adsorption process and experimental data was well fitted by the Langmuir adsorption isotherm.

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Ankur Gupta ◽  
Chandrajit Balomajumder

Fe modified rice husk was prepared as a low cost biosorbent for the removal of Cr(VI) and phenol both singly and in combination from single and binary simulated synthetic waste water. Rice husk was modified by treating with FeSO4·7H2O. The results showed that impregnation of iron onto the surface of rice husk improved the adsorption capability of both Cr(VI) and phenol. The effects of process parameters for multicomponent system such as pH, adsorbent dose, and contact time onto the percentage removal of both Cr(VI) and phenol were investigated. The experimental data for the adsorption of both Cr(VI) and phenol onto the surface of Fe modified rice husk applied to various kinetic and adsorption isotherm models. Multicomponent isotherm models such as Nonmodified Langmuir, Modified Langmuir, Extended Langmuir, Extended Freundlich, Competitive Nonmodified Redlich Peterson, Competitive Modified Redlich Peterson were applied. The results show that Extended Freundlich model best described the experimental data for both Cr(VI) and phenol from binary solution. Pseudo second-order model agreed well with Cr(VI) while pseudo first-order model agreed well with phenol. Maximum adsorption capacity in synthetic binary solution of Cr(VI) and phenol was found to be 36.3817 mg g−1for Cr(VI) and 6.569 mg g−1for phenol, respectively.


Minerals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 254 ◽  
Author(s):  
Lvshan Zhou ◽  
Tongjiang Peng ◽  
Hongjuan Sun ◽  
Xiaogang Guo ◽  
Dong Fu

A precipitation reaction method was employed to prepare mesopore calcium carbonate (CaCO3) using rape flower pollen as the template. CaCO3 adsorbent was characterized using X-ray diffraction (XRD), scanning electronic microscopy (SEM), and Brunner−Emmet−Teller measurements (BET). The equilibrium adsorption data on amoxicillin were explained using Langmuir, Freundlich, and Temkin adsorption isotherm models. The pseudo-first order, second order, pseudo-second order, and intra-particle diffusion kinetic models were used to explore adsorption kinetics. Equilibrium adsorption of as-prepared CaCO3 was better depicted using the Langmuir adsorption model with an R2 of 0.9948. The separation factor (RL) was found to be in the range of 0 < RL < 1, indicating the favorable adsorption of amoxicillin. The adsorption capacity of mesopore CaCO3 reached 13.49 mg·g−1 in 0.2 g∙L−1 amoxicillin solution. The values of adsorption thermodynamic parameters (ΔHθ, ΔSθ, ΔGθ) were obtained. In addition, the adsorption process turned out to be endothermic and spontaneous for the CaCO3 product at 298 K, 308 K, and 318 K.


2016 ◽  
Vol 15 ◽  
Author(s):  
Linda Biaw Leng Lim ◽  
Namal Priyantha ◽  
Hui Hsin Cheng ◽  
Nur Afiqah Hazirah

This study focused on the use of Parkia speciosa (Petai) pod as a potential adsorbent for the removal of crystal violet (CV) dye. Batch adsorption isotherm experiments carried out under optimized conditions were fitted to six isotherm models, namely Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Redlich-Peterson and Sips. Of these, the Sips model best described the adsorption isotherm of Petai pod for the removal of CV dye, giving a desirable adsorption capacity (qmax) of 163.2 mg g-1. Adsorption kinetics was found to follow the pseudo-second order, and further, intra-particle diffusion played a significant role. This study also revealed that the adsorption of CV by Petai pod is influenced by the ionic strength of the medium. However, Petai pod showed resilience towards changes in medium pH.  


2013 ◽  
Vol 726-731 ◽  
pp. 2191-2197 ◽  
Author(s):  
Su Yun He ◽  
Cai Yun Han ◽  
Su Fang He ◽  
Hua Wang ◽  
Chun Xia Liu ◽  
...  

This research presented the kinetic performance of arsenic absorption by mesostructure SBA-15 functionalized with Al2O3. The SBA-15 was previously synthesised and subsequently functionalized via impregnation of alumina oxides. The absorption of arsenic(V) was studied as a function of absorbent dosage and contact time. The experimental data were fitted to kinetic pseudo-first order, pseudo-second order and the intra-particle diffusion model. The pseudo-second order model presented the best correlation with the experimental data. Both surface absorption and intra-particle diffusion were acting during arsenic uptake, except for absorbent dosage of 0.1g, which was mainly controlled by the intra-particle diffusion.


Langmuir ◽  
2000 ◽  
Vol 16 (22) ◽  
pp. 8536-8538 ◽  
Author(s):  
Shaheen A. Al-Muhtaseb ◽  
M. Douglas LeVan ◽  
James A. Ritter

2012 ◽  
Vol 229-231 ◽  
pp. 100-104 ◽  
Author(s):  
Yun Fei Shi ◽  
Xiang Jun Liu ◽  
Hui Jiao Nie ◽  
Yin Shu Liu

The adsorption isotherm model of water vapor on activated alumina is an essential equation in designing the performance of adsorption. In this paper, the currently existed 14 isotherm models of water adsorption are summarized. The correlations among these models are analyzed. These isotherm models are evaluated by fitting the water adsorption data on Rhone-Poulenc activated alumina. The results show that AD-Toth, AD-LRC, AD-UNILAN and DMAP can fit the experimental data well.


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.


Author(s):  
Zahra Ashouri Mehranjani ◽  
Majid Hayati-Ashtiani ◽  
Mehran Rezaei

Abstract In this research, natural bentonite and its acid-activated forms were employed as adsorbents for the adsorption of Ni2+ ions from wastewater. Natural bentonite was activated with 2M sulfuric acid, 4.5 h and 95 °C (the beast acid-activated sample with the highest adsorption capacity) and the other 6M sulfuric acid, 7.5 h and 95 °C (the worst acid-activated sample with the lowest adsorption capacity). The adsorption of Ni2+ was studied through experiments including equilibrium contact time and selectivity. The equilibrium time of contact for bentonite was obtained at 180 min. The Ni2+ separation process along with Zn2+ selectivity studies was considered through adsorption experiments. The results showed that there was a maximum amount of Ni2+ adsorption in the absence of Zn2+ for all samples. The results showed the best fit is obtained with the pseudo-second-order kinetic model. Working out different bentonite types to determine the best kinetic models, we explored the Langmuir and Florry–Huggins models provided a good fit with experimental data for acid-activated bentonites and the best results from linear forms of the adsorption isotherm models for fitting the experimental data of natural bentonite are obtained Langmuir, Temkin and Freundlich models.


Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 32 ◽  
Author(s):  
Changgil Son ◽  
Wonyeol An ◽  
Geonhee Lee ◽  
Inho Jeong ◽  
Yong-Gu Lee ◽  
...  

This study has evaluated the removal efficiencies of phosphate ions (PO43−) using pristine (TB) and chemical-activated tangerine peel biochars. The adsorption kinetics and isotherm presented that the enhanced physicochemical properties of TB surface through the chemical activation with CaCl2 (CTB) and FeCl3 (FTB) were helpful in the adsorption capacities of PO43− (equilibrium adsorption capacity: FTB (1.655 mg g−1) > CTB (0.354 mg g−1) > TB (0.104 mg g−1)). The adsorption kinetics results revealed that PO43− removal by TB, CTB, and FTB was well fitted with the pseudo-second-order model (R2 = 0.999) than the pseudo-first-order model (R2 ≥ 0.929). The adsorption isotherm models showed that the Freundlich equation was suitable for PO43− removal by TB (R2 = 0.975) and CTB (R2 = 0.955). In contrast, the Langmuir equation was proper for PO43− removal by FTB (R2 = 0.987). The PO43− removal efficiency of CTB and FTB decreased with the ionic strength increased due to the compression of the electrical double layer on the CTB and FTB surfaces. Besides, the PO43− adsorptions by TB, CTB, and FTB were spontaneous endothermic reactions. These findings demonstrated FTB was the most promising method for removing PO43− in waters.


2021 ◽  
Author(s):  
khaled Mostafa ◽  
H. Ameen ◽  
A. Ebessy ◽  
A. El-Sanabary

Abstract Our recently tailored and fully characterized poly (AN)-starch nanoparticle graft copolymer having 60.1 G.Y. % was used as a starting substrate for copper ions removal from waste water effluent after chemical modification with hydroxyl amine via oximation reaction. This was done to change the abundant nitrile groups in the above copolymer into amidoxime one and the resultant poly (amidoxime) resin was used as adsorbent for copper ions. The resin was characterized qualitatively via rapid vanadium ion test and instrumentally by FT-IR spectra and SEM morphological analysis to confirm the presence of amidoxime groups. The adsorption capacity of the resin was done using the batch technique, whereas the residual copper ions content in the filtrate before and after adsorption was measured using atomic adsorption spectrometry. It was found that the maximum adsorption capacity of poly (amidoxime) resin was 115.2 mg/g at pH 7, 400ppm copper ions concentration and 0.25 g adsorbent at room temperature. The adsorption, kinetics and isothermal study of the process is scrutinized using different variables, such as pH, contact time, copper ion concentration and adsorbent dosage. Different kinetics models comprising the pseudo-first-order and pseudo-second-order have been applied to the experimental data to envisage the adsorption kinetics. It was found from kinetic study that pseudo-second-order rate equation was better than pseudo-first-order supporting the formation of chemisorption process. While, in case of isothermal study, the examination of calculated correlation coefficient (R2) values showed that the Langmuir model provide the best fit to experimental data than Freundlich one.


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