scholarly journals Use of agro-industrial residues of plantain (Musa paradisiaca) in the adsorption of Ni (II)

Author(s):  
Candelaria Tejada-Tovar ◽  
Ángel Villabona-Ortíz ◽  
Walter Cortina-Góngora ◽  
Betty Díaz-Navarro ◽  
Rodrigo Ortega Toro

The presence of heavy metals in aqueous media represents a severe threat to ecosystems because they are non-biodegradable, toxic, and carcinogenic. In the present work, the utilization of agro-industrial residues from obtaining plantain starch for removing Ni (II) was studied, establishing the effect of temperature, adsorption dose, and initial concentration. The kinetics, equilibrium, and thermodynamic parameters that determine the process were studied. For this purpose, tests were carried out in a batch system maintaining constant stirring (200 rpm), pH (2), and solution volume (100 mL). The remaining metal concentration was determined by atomic adsorption at 237 nm. It was found that the best adsorption conditions were given at 55 ºC, 0.6775 g, and 368 mg/L obtaining a maximum adsorption capacity of 47.57 mg/g corresponding to a removal of 87%. The kinetic model that best fits the experimental data was a pseudo-second-order model, and the isotherm that describes the process is Langmuir and Freundlich, so the adsorption is given by chemisorption and multilayers. The thermodynamic parameters determined suggest that the process is favourable, not spontaneous, endothermic, and irreversible under the studied conditions. The results show that the residual biomass from the obtaining of plantain starch is a good precursor for absorbing Ni (II) in an aqueous solution.

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1437
Author(s):  
Chih Ming Ma ◽  
Bo-Yuan Yang ◽  
Gui-Bing Hong

Hydrogel beads based on the husk of agarwood fruit (HAF)/sodium alginate (SA), and based on the HAF/chitosan (CS) were developed for the removal of the dyes, crystal violet (CV) and reactive blue 4 (RB4), in aqueous solutions, respectively. The effects of the initial pH (2–10) of the dye solution, the adsorbent dosage (0.5–3.5 g/L), and contact time (0–540 min) were investigated in a batch system. The dynamic adsorption behavior of CV and RB4 can be represented well by the pseudo-second-order model and pseudo-first-order model, respectively. In addition, the adsorption isotherm data can be explained by the Langmuir isotherm model. Both hydrogel beads have acceptable adsorption selectivity and reusability for the study of selective adsorption and regeneration. Based on the effectiveness, selectivity, and reusability of these hydrogel beads, they can be treated as potential adsorbents for the removal of dyes in aqueous solutions.


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.


2018 ◽  
Vol 77 (5) ◽  
pp. 1313-1323 ◽  
Author(s):  
Jianjun Zhou ◽  
Xionghui Ji ◽  
Xiaohui Zhou ◽  
Jialin Ren ◽  
Yaochi Liu

Abstract A novel magnetic bio-adsorbent (MCIA) was developed, characterized and tested for its Cd(II) removal from aqueous solution. MCIA could be easily separated from the solution after equilibrium adsorption due to its super-paramagnetic property. The functional and magnetic bio-material was an attractive adsorbent for the removal of Cd(II) from aqueous solution owing to the abundant adsorption sites, amino-group and oxygen-containing groups on the surface of Cyclosorus interruptus. The experimental results indicated that the MCIA exhibited excellent adsorption ability and the adsorption process was spontaneous and endothermic. The adsorption isotherm was consistent with the Langmuir model. The adsorption kinetic fitted the pseudo-second-order model very well. The maximum adsorption capacity of Cd(II) onto MCIA was 40.8, 49.4, 54.6 and 56.6 mg/g at 293, 303, 313 and 323 K, respectively. And the MCIA exhibited an excellent reusability and impressive regeneration. Therefore, MCIA could serve as a sustainable, efficient and low-cost magnetic adsorbent for Cd(II) removal from aqueous solution.


2020 ◽  
Vol 81 (4) ◽  
pp. 773-780
Author(s):  
Paola Santander ◽  
Estefanía Oyarce ◽  
Julio Sánchez

Abstract The adsorption of methyl orange (MO) in aqueous solution was evaluated using a cationic polymer (Amberlite IRA 402) in batch experiments under different experimental variables such as amount of resin, concentration of MO, optimum interaction time and pH. The maximum adsorption capacity of the resin was 161.3 mg g−1 at pH 7.64 at 55 °C and using a contact time of 300 min, following the kinetics of the pseudo-first-order model in the adsorption process. The infinite solution volume model shows that the adsorption rate is controlled by the film diffusion process. In contrast, the chemical reaction is the decisive step of the adsorption rate when the unreacted core model is applied. A better fit to the Langmuir model was shown for equilibrium adsorption studies. From the thermodynamic study it was observed that the sorption capacity is facilitated when the temperature increases.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mashael Alshabanat ◽  
Ghadah Alsenani ◽  
Rasmiah Almufarij

The adsorption of crystal violet (CV) onto date palm fibers (DPFs) was examined in aqueous solution at 25°C. The experimental maximum adsorption capacity value was0.66×10−6. Langmuir, Freundlich, Elovich and Temkin models were applied to describe the equilibrium isotherms. The influence of pH and temperature on dye removal was evaluated. The percentage removal of CV dye by adsorption onto DPF at different pH and temperatures showed that these factors play a role in the adsorption process. Thermodynamic analysis was performed, and the Gibbs free energyΔGο, enthalpy changeΔHο, and entropyΔSοwere calculated. The negative values ofΔGοindicate spontaneous adsorption. The negative value ofΔHοindicates that the interaction between CV and DPF is exothermic, and the positive value ofΔSοindicates good affinity between DPF and CV. The kinetic data were fitted to a pseudo-second-order model.


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.


2016 ◽  
Vol 17 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Tianli Han ◽  
Xiaoman Zhang ◽  
Xiangqian Fu ◽  
Jinyun Liu

Chitosan nanoparticle (CS NP)-modified MnO2 nanoflakes were presented as a novel adsorbent for fast adsorption of Pb(II) from aqueous solution. Loading dense CS NPs onto mono-dispersive flower-like MnO2 nanostructures reduces the overlap of CS during adsorption, and thus improves the contact of functional adsorption sites on the surface of MnO2 nanoflakes with heavy metal ions. The results show that the removal efficiency of the nanoadsorbents reaches up to 93% in 3 min for Pb(II). In addition, the maximum adsorption capacity, effects of adsorbent dosage and pH value, and the reusability were investigated. The kinetic process and adsorption isotherm fit well with the pseudo-second-order model and Langmuir model, respectively. These findings provide a potential strategy to address the overlap issue of some common nanoadsorbents.


2020 ◽  
Vol 13 (2) ◽  
pp. 080-090
Author(s):  
Daniel Eneji Sani ◽  
John O. Idoko ◽  
Enyojo Samson Okwute ◽  
Matthew Chijioke Apeh

Unactivated adsorbent was prepared from Moringa oleifera seed shells precursor, characterized and evaluated for aqueous phase removal of phenol. The effects of operational parameters such as initial phenolic solution pH and adsorbent dosage on equilibrium sorption were studied. Adsorption isotherms and kinetic experiments performed at (25 oC) furnished some equilibrium and kinetic parameters, respectively. UAMSS shows favorable attributes on (pH, bulk density, attrition, iodine number/surface area, surface charge/functional groups and Fourier transform infrared FTIR). Phenol uptake decreases with increase in solution pH for the adsorbent. Maximum adsorption capacity Qmax (mg/g) was (6.95). The optimal pH for phenol adsorption was attained at pH 3, adsorption kinetics obeyed closely pseudo-second-order model. Adsorption of phenol was well described by Langmuir isotherm. The adsorbent shows a promise of applicability in dephenolation of aqueous effluents/wastewater.


Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 178
Author(s):  
Serap Sezen ◽  
Vijay Kumar Thakur ◽  
Mehmet Murat Ozmen

Currently, macroporous hydrogels have been receiving attention in wastewater treatment due to their unique structures. As a natural polymer, alginate is used to remove cationic dyes due to its sustainable features such as abundance, low cost, processability, and being environmentally friendly. Herein, alginate/montmorillonite composite macroporous hydrogels (cryogels) with high porosity, mechanical elasticity, and high adsorption yield for methylene blue (MB) were generated by the one-step cryogelation technique. These cryogels were synthesized by adding montmorillonite into gel precursor, followed by chemical cross-linking employing carbodiimide chemistry in a frozen state. The as-prepared adsorbents were analyzed by FT-IR, SEM, gel fraction, swelling, uniaxial compression, and MB adsorption tests. The results indicated that alginate/montmorillonite cryogels exhibited high gelation yield (up to 80%), colossal water uptake capacity, elasticity, and effective dye adsorption capacity (93.7%). Maximum adsorption capacity against MB was 559.94 mg g−1 by linear regression of Langmuir model onto experimental data. The Pseudo-Second-Order model was fitted better onto kinetic data compared to the Pseudo-First-Order model. Improved porosity and mechanical elasticity yielding enhanced dye removal capacity make them highly potential alternative adsorbents compared to available alginate/montmorillonite materials for MB removal.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nadavala Siva Kumar ◽  
Hamid M. Shaikh ◽  
Mohammad Asif ◽  
Ebrahim H. Al-Ghurabi

AbstractThis study investigated a novel agricultural low-cost bio-waste biochar derived from wood apple fruit shell waste via the pyrolysis method, which is modified by ball milling and utilized to remove toxic phenol and chlorophenols (4-CPh and 2,4-DCPh) from contaminated aqueous media. The ball-milled wood apple fruit shell waste biochar (WAS-BC) sorbent was systematically analyzed by BET, CHN, and FTIR as well as particle size, SEM–EDS, XPS and TGA studies. The sorption equilibrium and kinetic studies exhibit that the sorption capacity was greater than 75% within the first 45 min of agitation at pH 6.0. The uptake capacity of 2,4-DCPh onto WAS-BC was greater than those of 4-CPh and phenol. Equilibrium results were consistent with the Langmuir isotherm model, while the kinetic data were best represented by the Elovich and pseudo-second-order model. The maximum uptake of phenol, 4-CPh, and 2,4-DCPh was 102.71, 172.24, and 226.55 mg/g, respectively, at 30 ± 1 °C. Thus, this study demonstrates that WAS-BC is an efficient, low-cost sorbent that can be used for the elimination of phenol and chlorophenol compounds from polluted wastewater.


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