scholarly journals Adsorption Characteristics of Phosphate Ions by Pristine, CaCl2 and FeCl3-Activated Biochars Originated from Tangerine Peels

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.

2008 ◽  
Vol 5 (4) ◽  
pp. 742-753 ◽  
Author(s):  
M. Sujatha ◽  
A. Geetha ◽  
P. Sivakumar ◽  
P. N. Palanisamy

An Experimental and theoretical study has been conducted on the adsorption of methylene blue dye using activated carbon prepared from babul seed by chemical activation with orthophosphoric acid. BET surface area of the activated carbon was determined as 1060 m2/g. Adsorption kinetics, equilibrium and thermodynamics were investigated as a function of initial dye concentration, temperature and pH. First order Lagergren, pseudo-second order and Elovich kinetic models were used to test the adsorption kinetics. Results were analyzed by the Langmuir, Freundlich and Temkin isotherm models. Based on regression coefficient, the equilibrium data found fitted well to the Langmuir equilibrium model than other models. The characteristics of the prepared activated carbon were found comparable to the commercial activated carbon. It is found that the babul seed activated carbon is very effective for the removal of colouring matter.


2014 ◽  
Vol 70 (1) ◽  
pp. 102-107 ◽  
Author(s):  
Caroline Trevisan Weber ◽  
Gabriela Carvalho Collazzo ◽  
Marcio Antonio Mazutti ◽  
Edson Luiz Foletto ◽  
Guilherme Luiz Dotto

Papaya (Carica papaya L.) seeds were used as adsorbent to remove toxic pharmaceutical dyes (tartrazine and amaranth) from aqueous solutions, in order to extend application range. The effects of pH, initial dye concentration, contact time and temperature were investigated. The kinetic data were evaluated by the pseudo first-order, pseudo second-order and Elovich models. The equilibrium was evaluated by the Langmuir, Freundlich and Temkin isotherm models. It was found that adsorption favored a pH of 2.5, temperature of 298 K and equilibrium was attained at 180–200 min. The adsorption kinetics followed the pseudo second-order model, and the equilibrium was well represented by the Langmuir model. The maximum adsorption capacities were 51.0 and 37.4 mg g−1 for tartrazine and amaranth, respectively. These results revealed that papaya seeds can be used as an alternative adsorbent to remove pharmaceutical dyes from aqueous solutions.


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.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Jin Wang ◽  
Qiufang Yao ◽  
Chengmin Sheng ◽  
Chunde Jin ◽  
Qingfeng Sun

Via a one-step ultrasonication method, cellulose nanofibril/graphene oxide hybrid (GO-CNF) aerogel was successfully prepared. The as-prepared GO-CNF possessed interconnected 3D network microstructure based on GO nanosheets grown along CNF through hydrogen bonds. The aerogel exhibited superior adsorption capacity toward four kinds of antibiotics. The removal percentages (R%) of these antibiotics were 81.5%, 79.5%, 79.1%, and 73.9% for Doxycycline (DXC), Chlortetracycline (CTC), Oxytetracycline (OTC), and tetracycline (TC), respectively. Simultaneously, the adsorption isotherms were well fitted to Langmuir model and kinetics study implied that the adsorption process was attributed to pseudo-second-order model. The maximum theoretical adsorption capacities of GO-CNF were 469.7, 396.5, 386.5, and 343.8 mg·g−1 for DXC, CTC, OTC, and TC, respectively, calculated by the Langmuir isotherm models. After five cycles, importantly, the regenerated aerogels still could be used with little degradation of adsorption property. Consequently, the as-synthesized GO-CNF was a successful application of effective removal of antibiotics.


2012 ◽  
Vol 30 (1) ◽  
pp. 81-95 ◽  
Author(s):  
Fadela Nemchi ◽  
Benaouda Bestani ◽  
Nouredine Benderdouche ◽  
Mostefa Belhakem ◽  
Louis Charles de Minorval

Adsorbents prepared from seawater algae, viz. green Ulva lactuca (PGA) and brown Systoceira stricta (PBA), by chemical activation were successfully tested for the removal of Supranol Yellow 4GL dye from aqueous solutions. Impregnation in 20% phosphoric acid for 2 h at 170 °C and subsequent air activation at 600 °C for 3 h significantly enhanced the adsorption capacities of both algae relative to their inactivated states. Parameters influencing the adsorption capacity such as contact time, adsorbent dosage, pH and temperature were studied. Similar experiments were carried out with commercially available Merck activated carbon (MAC) for comparative purposes. Adsorption efficiencies were measured at a pH 2 and dosages of 8 g/ℓ and 12 g/ℓ for PGA and PBA, respectively. Batch adsorption experiments resulted in maximum adsorption capacities determined from Langmuir models of up to 263, 93 and 84 mg/g for PGA, PBA and MAC, respectively. BET, FT-IR analyses, iodine number and Methylene Blue index determination were also performed to characterize the prepared adsorbents. The adsorption kinetics were found to comply with the pseudo-second-order model with intra-particle diffusion being the rate-determining step. Thermodynamic analysis confirmed that the adsorption reaction was spontaneous and endothermic. These studies indicate that these seawater algae could be used as low-cost alternatives for the removal of dyes.


2021 ◽  
pp. 1-19
Author(s):  
Bengi Özkahraman ◽  
Eren Yıldırım ◽  
Serkan Emik ◽  
Işıl Acar

This study deals with the potential use of poly(N-isopropylacrylamide-co-itaconic acid) temperature-sensitive hydrogels as an adsorbent for the removal of Cu(II) and Pb(II) ions from aqueous solutions. For this aim, the adsorption properties of hydrogels were examined by adsorption capacities, adsorption isotherm, and adsorption kinetics experiments. To describe the adsorption characteristics of hydrogels, the obtained experimental data were evaluated by Langmuir, Freundlich, Redlich-Peterson, and Dubinin-Radushkevich isotherm models. Adsorption kinetics experiments were carried out not only in single systems but also in binary systems where both ions were at equal initial concentrations for competitive adsorption studies. To predict the behaviors of the competitive and non-competitive adsorption process of ions onto hydrogels, the experimental adsorption data were analyzed by the pseudo-first-order model and the pseudo-second-order model. According to non-competitive ion removal findings, the adsorption capacities followed order Cu(II) >  Pb(II) for all hydrogels, and the pseudo-second-order kinetic model explained the adsorption properties of the hydrogels. Competitive ion removal studies showed that all hydrogels were selective to Cu(II) ion. Furthermore, in the case of comparative investigations both of competitive Cu(II) and competitive Pb(II) removal by hydrogels, the metal ion removal capacity of N10 hydrogel was found as a bit higher than that of N7.5 and N5 in 48 h. That is, as the acidic group content increased in the hydrogel network, the adsorption capacity values also increased. In addition, the reusability of temperature-sensitive hydrogels seems possible without regeneration or after regenerating with acid, in case the temperature is increased above the LCST. Furthermore, even if it cannot be reused, these hydrogels that retain metal ions reach very small volumes by shrinking when the LSCT is exceeded, and thus they can be eliminated more easily than other conventional gels due to their small size. As a result, this temperature-sensitive hydrogel may propose as an alternative environmentally friendly adsorbent candidate for can be used for water purification and wastewater treatment.


2012 ◽  
Vol 441 ◽  
pp. 603-607 ◽  
Author(s):  
Wen Liang Mao ◽  
Hai Xiang Chen ◽  
Lei Wang

The main purpose of this study was to characterize the adsorption behavior of naphthalene, one of polycyclic aromatic hydrocarbons (PAHs), on silk fabric. Typical batch reactors were used to perform adsorption kinetics and isotherm experiments. It was found in this study that the pseudo-second-order model described the sorption kinetics data well. An adsorption isotherm in the form of Linear Equation was observed, and the adsorbed capacity was influenced evidently by the enhanced temperature. In addition, the results demonstrated that silk fabric could adsorb large amounts of naphthalene from water, and the maximum exceeded 700 μg/g.


KIMIKA ◽  
2019 ◽  
Vol 30 (2) ◽  
pp. 17-26
Author(s):  
Kevinilo P. Marquez ◽  
Rufus Mart Caesar R. Ramos

The study aims to quantitatively assess the capability of lignin extracted from Saccharum spontaneum L. (talahib grass) as an adsorbent of chromium (III) and phenolphthalein in aqueous solution through kinetic methods. Results show that using lignin as an adsorbent, the percentage removal for both chromium (III) and phenolphthalein in aqueous solution are 31.70% and 74.98%, respectively, based on the optimum exposure time of the adsorbent, which is 6.5 hours for chromium (III) and 60 minutes for phenolphthalein. Results from the mechanistic analysis show that a pseudo-second order adsorption kinetic model fits better than a pseudo-first order model for both substrates. Also, among the six selected adsorption isotherm models used in this study, the Flory-Huggins isotherm can best predict the properties of the adsorption process of both phenolphthalein and chromium (III) at equilibrium. Further improvement of the extracted lignin through various physical and chemical modifications may improve its ability to remove the contaminants.


2014 ◽  
Vol 809-810 ◽  
pp. 907-911
Author(s):  
Jun Long Wang ◽  
Jie Hou ◽  
Ting Jiang ◽  
Yong Jun He ◽  
Yao Dong Liang

Dry waters with an average diameter of 82 μm were prepared by a high speed mixed route. The formaldehyde absorption kinetics of dry waters was investigated by simulating indoor formaldehyde pollution in glass chamber. The results showed that pseudo-second order model could be used to simulate the adsorption process; the adsorption rate was highest in the initial 60 minutes; when the adsorption lasted for 180 minutes, the adsorption reached equilibrium.


2021 ◽  
Vol 19 (9) ◽  
pp. 46-54
Author(s):  
Makarim A. Mahdi ◽  
Aymen A.R. Jawad ◽  
Aseel M. Aljeboree ◽  
Layth S. Jasim ◽  
Ayad F. Alkaim

The AAc/GO nanocomposite hydrogel was successfully employed as a polymeric Nano sorbent of the removal efficiency of M G dye from the model. The complication of the mechanism of the adsorption system was completely exposed by examining how solution pH affects adsorption, Ionic strength isotherm models, kinetic models, and thermodynamics. The adsorption of the MG dye was greatly dependent on the solution pH. The Freundlich model has been demonstrated to be the most accurate in describing the MG dye sorption, whilst the Langmuir model was shown to be the least accurate. Additionally, these integrated mechanisms fit nicely within the framework of a pseudo-second-order model. Additionally, the contact time at equilibrium short (ten minutes) required to MG removes demonstrates the AAc/GO nanocomposite hydrogel can be considered an efficient and potentially useful adsorbent for MG removal from industrial effluents.


Sign in / Sign up

Export Citation Format

Share Document