scholarly journals Selective recovery of platinum from spent autocatalyst solution by thiourea modified magnetic biocarbons

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shao-Yi Lo ◽  
Wahid Dianbudiyanto ◽  
Shou-Heng Liu
Keyword(s):  
Adsorption Capacity ◽  
Noble Metals ◽  
Freundlich Isotherm ◽  
Platinum Group Metals ◽  
Rapid Decline ◽  
Maximum Adsorption Capacity ◽  
Mixed Solution ◽  
Batch Tests ◽  
Pseudo Second Order ◽  
Adsorption Kinetics And Isotherm

AbstractThe precious platinum group metals distributed in urban industrial products should be recycled because of their rapid decline in the contents through excessive mining. In this work, thiourea modified magnetic biocarbons are prepared via an energy-efficient microwave-assisted activation and assessed as potential adsorbents to recover platinum ions (i.e., Pt(IV)) from dilute waste solution. The physicochemical properties of prepared biocarbons are characterized by a series of spectroscopic and analytic instruments. The adsorption performance of biocarbons is carried out by using batch tests. Consequently, the maximum adsorption capacity of Pt(IV) observed for adsorbents is ca. 42.8 mg g−1 at pH = 2 and 328 K. Both adsorption kinetics and isotherm data of Pt(IV) on the adsorbents are fitted better with non-linear pseudo second-order model and Freundlich isotherm, respectively. Moreover, the thermodynamic parameters suggest that the Pt(IV) adsorption is endothermic and spontaneous. Most importantly, the adsorbents exhibit high selectivity toward Pt(IV) adsorption and preserve ca. 96.9% of adsorption capacity after six cyclic runs. After adsorption, the regeneration of the prepared adsorbents can be effectively attained by using 1 M thiourea/2% HCl mixed solution as an eluent. Combined the data from Fourier transform infrared and X-ray photoelectron spectroscopies, the mechanisms for Pt(IV) adsorption are governed by Pt–S bond between Pt(IV) and thiourea as well as the electrostatic attraction between anionic PtCl62− and cationic functional groups of adsorbents. The superior Pt(IV) recovery and sustainable features allow the thiourea modified magnetic biocarbon as a potential adsorbent to recycle noble metals from spent autocatalyst solution.

Kinetics of lead ion biosorption from aqueous solution onto lyophilized Aspergillus niveus

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Hülya Karaca ◽  
Turgay Tay ◽  
Merih Kıvanç
Keyword(s):  
Adsorption Capacity ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Lead Ions ◽  
Lead Ion ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Aspergillus Niveus ◽  
Pseudo Second Order

The biosorption of lead ions (Pb2+) onto lyophilized fungus Aspergillus niveus was investigated in aqueous solutions in a batch system with respect to pH, contact time and initial concentration of the ions at 30 °C. The maximum adsorption capacity of lyophilized A. niveus was found to be 92.6 mg g−1 at pH 5.1 and the biosorption equilibrium was established about in 30 min. The adsorption capacity obtained is one of the highest value among those reported in the literature. The kinetic data were analyzed using the pseudo-first-order kinetic, pseudo-second-order kinetic, and intraparticle diffusion equations. Kinetic parameters, such as rate constants, equilibrium adsorption capacities, and related correlation coefficients for the kinetic models were calculated and discussed. It was found that the adsorption of lead ions onto lyophilized A. niveus biomass fit the pseudo-second-order kinetic model well. The Langmuir and Freundlich isotherm parameters for the lead ion adsorption were applied and the Langmuir model agreed better with the adsorption of lead ions onto lyophilized A. niveus.

scholarly journals Self-Regeneration Hybrid Hydrogel for Bisphenol A Adsorption in Water

2021 ◽  
Author(s):  
Mingyue Piao ◽  
Hongxue Du ◽  
Yuwei Sun ◽  
Honghui Teng
Keyword(s):  
Bisphenol A ◽  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Significant Loss ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Hybrid Hydrogel ◽  
Polyethylene Glycol Diacrylate ◽  
Glycol Diacrylate ◽  
Pseudo Second Order

Abstract Hybrid hydrogel was synthesized by immobilizing TiO2 in polyethylene glycol diacrylate (TiO2@PEGDA) as an efficient adsorbent with photocatalysis property for bisphenol A (BPA) elimination. TiO2@PEGDA exhibited spherical and rough structure with limited crystallinity and abundant functional groups. The contact angle was 61.96°, indicating that TiO2@PEGDA is hydrophilic. The swelling capacity of TiO2@PEGDA (9.0%) was decreased compared with pristine PEGDA (15.6%). Adsorption results demonstrated that the maximum adsorption capacity of TiO2@PEGDA (101.4 mg/g) for BPA was slightly higher than pristine PEGDA (97.68 mg/g). The adsorption capacity was independent with pH at pH ＜ 8.0, and decreased obviously when the value of pH was higher than 8.0. The adsorption behavior was fitted well with the pseudo-second-order kinetic and the Freundlich isotherm model. Both ΔG0 and ΔH0 were negative, indicating that BPA adsorbed on TiO2@PEGDA was an exothermic and spontaneous process. Regeneration study was performed by photocatalysis, and the adsorption capacity was 85.6% compared with the initial capacity after four cycles of illumination, indicating that TiO2@PEGDA could be recycled without significant loss of adsorption capacity. Consequently, TiO2@PEGDA can serve as an eco-friendly and promising material for efficiently adsorbing BPA with self-clean property.

scholarly journals Development of Natural Cation Exchanger for the Treatment of Lead ions from Aqueous Solution

2013 ◽  
Vol 29 ◽  
pp. 34-43
Author(s):  
Puspa Lal Homagai
Keyword(s):  
Adsorption Capacity ◽  
Sugarcane Bagasse ◽  
Active Sites ◽  
Freundlich Isotherm ◽  
Saccharum Officinarum ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Fast Kinetics ◽  
Pseudo Second Order

Cellulose, hemicelluloses and lignin are the main constituents found in sugarcane (Saccharum officinarum) bagasse having many surface active sites containing hydroxyl and/or phenolic groups which are effective for chemical modification. The biowaste was first charred with concentrated sulphuric acid and then the charred aminated sugarcane bagasse (CASB) was prepared by reduction followed by oxidation. The developed bio-sorbent was characterized by SEM, TGA/DTA, FTIR and elemental analysis. Batch adsorption methods were carried out to determine Pb+2 sorption capacities at different pH ranges and sorbate concentrations. The maximum adsorption capacity for Pb+2 was found to be 323 mg g-1 with an efficiency of 98% at pH 4.The experimental data showed a good fit to Langmuir isotherm as compared to Freundlich isotherm models. The kinetics was best fitted with the pseudo-second order model. The adsorption equilibrium was attained within 20 min. The high adsorption capacity and fast kinetics results of the charred aminated sugarcane bagasse indicated that it might be potential adsorbent for the removal of lead from contaminated water. DOI: http://dx.doi.org/10.3126/jncs.v29i0.9235Journal of Nepal Chemical SocietyVol. 29, 2012Page: 34-43Uploaded date : 12/3/2013

scholarly journals Coke-Based Carbon Sorbent: Results of Gold Extraction in Laboratory and Pilot Tests

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 508 ◽  
Author(s):  
Svetlana Yefremova ◽  
Alma Terlikbayeva ◽  
Abdurassul Zharmenov ◽  
Askhat Kablanbekov ◽  
Lara Bunchuk ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Noble Metals ◽  
Total Pore Volume ◽  
Freundlich Isotherm ◽  
Exchange Capacity ◽  
Carbon Sorbent ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Gold Extraction ◽  
Dynamic Exchange

Coke-based carbon sorbent (CBCS) was produced using special coke fines with the following characteristics: ash, 4.5%; iodine adsorption capacity, 52%; specific surface area, 600 m2 g−1; and total pore volume, 0.4 cm3 g−1. Gold adsorption from real production cyanide solutions in batch and column laboratory experiments was studied. The optimum adsorbent/solution ratio was 0.2 g/20 cm3. Sorption equilibrium occurred after 60 min of phase-time contact. The CBCS maximum adsorption capacity for gold was found to be 1.2 mg g−1. Both the Langmiur and Freundlich isotherm models confirmed that gold adsorption by CBCS proceeds favorably, but the Freundlich isotherm best describes the adsorption equilibrium. The CBCS dynamic exchange capacity (100 g t−1) and full dynamic exchange capacity (4600 g t−1) for gold were determined in column tests. It was revealed using SEM that adsorbate was retained in sorbent pores. The possibility of completely eluting gold from CBCS was demonstrated. A CBCS pilot test to recover gold from 200 dm3 of the cyanide solution containing (mg dm−3) 2.6 Au, 0.42 Ag, and 490 Cu was carried out. The total amount of noble metals (Au + Ag) adsorbed was 99.99% and gold ions was 94%. The CBCS maximum adsorption capacity for gold reached 2900 g t−1.

scholarly journals Corn stalk as starting material to prepare a novel adsorbent via SET-LRP and its adsorption performance for Pb(II) and Cu(II)

2020 ◽  
Vol 7 (3) ◽  
pp. 191811
Author(s):  
Yazhen Wang ◽  
Shuang Li ◽  
Liqun Ma ◽  
Shaobo Dong ◽  
Li Liu
Keyword(s):  
Adsorption Capacity ◽  
Potassium Hydroxide ◽  
Adsorption Process ◽  
Hydroxylamine Hydrochloride ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Corn Stalk ◽  
Order Model ◽  
Adsorption Performance ◽  
Pseudo Second Order

Corn stalk was used as the initial material to prepare a corn stalk matrix-g-polyacrylonitrile-based adsorbent. At first, the corn stalk was treated with potassium hydroxide and nitric acid to obtain the corn stalk-based cellulose (CS), and then the CS was modified by 2-bromoisobutyrylbromide (2-BiBBr) to prepare a macroinitiator. After that, polyacrylonitrile (PAN) was grafted onto the macroinitiator by single-electron transfer living radical polymerization (SET-LRP). A novel adsorbent AO CS-g-PAN was, therefore, obtained by introducing amidoxime groups onto the CS-g-PAN with hydroxylamine hydrochloride (NH 2 OH · HCl). FTIR, SEM and XPS were applied to characterize the structure of AO CS-g-PAN. The adsorbent was then employed to remove Pb(II) and Cu(II), and it exhibited a predominant adsorption performance on Pb(II) and Cu(II). The effect of parameters, such as temperature, adsorption time, pH and the initial concentration of metal ions on adsorption capacity, were examined in detail during its application. Results suggest that the maximum adsorption capacity of Pb(II) and Cu(II) was 231.84 mg g –1 and 94.72 mg g −1 , and the corresponding removal efficiency was 72.03% and 63%, respectively. The pseudo-second order model was more suitable to depict the adsorption process. And the adsorption isotherm of Cu(II) accorded with the Langmuir model, while the Pb(II) conformed better to the Freundlich isotherm model.

scholarly journals EQUILIBRIUM, KINETIC AND THERMODYNAMIC STUDIES OF ADSORPTION OF METHYLENE BLUE ON ACTIVATED CARBON FROM COCOA POD SHELLS

2021 ◽  
Vol 9 (11) ◽  
pp. 62-72
Author(s):  
Akissi Lydie Chantal Koffi ◽  
◽  
Djamatche Paul Valery Akesse ◽  
Herman Yapi Yapo ◽  
David Leonce Kouadio ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Freundlich Isotherm ◽  
Entropy Change ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Physiochemical Parameters ◽  
Batch Tests ◽  
Pseudo Second Order

The aim of this research is to investigate the feasibility of using activated carbon from cocoa pod shells, waste from agriculture to adsorb methylene blue from aqueous solutions through batch tests. Various physiochemical parameters such as, contact time, initial dye concentration, adsorbent dosage, pH of dye solution and temperature were investigated in a batch-adsorption technique. The process followed the pseudo-second order kinetics model which showed chemical adsorption. Langmuir and Freundlich isotherm models were used to determine adsorption constants. The maximum adsorption capacity at 30°C is 526.31 mg/g. Thermodynamic parameters such as enthalpy change (∆Hº), free energy change (∆Gº) and entropy change (∆Sº) were studied, and the adsorption process of BM was found to be exothermic and spontaneous.

Adsorptive Removal of Drimarene Brilliant Blue by Thermo Stable, Eco-friendly Graphene Oxide Reinforced Polyvinyl Alcohols Hydrogels With High Reusability Potential

2021 ◽  
Author(s):  
Adeel Mustafa ◽  
Nazia Yaqoob ◽  
Maheen Almas ◽  
Shagufta Kamal ◽  
Khalid Mahmood Zia ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Thermo Gravimetric Analysis ◽  
Freundlich Isotherm ◽  
Brilliant Blue ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Pseudo Second Order

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.

scholarly journals Efficient removal of lead ions from aqueous solutions using ZnSe/ZnO/Bio-CaCO3

2020 ◽  
Vol 81 (1) ◽  
pp. 91-101
Author(s):  
Yi Yan ◽  
Shuai Yang ◽  
Feng Jiang ◽  
Yuwei Luo ◽  
Hejun Gao ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Lead Ions ◽  
X Ray ◽  
Hydrolysis Method ◽  
Transmission Electron ◽  
Initial Ph ◽  
Pseudo Second Order ◽  
Adsorption Kinetics And Isotherm

Abstract The sheet-like adsorbent of the eggshell wastes was prepared by the thermal hydrolysis method. The structure of the adsorbent was characterized by scanning electron microscope, Brunauer-Emmett-Teller, X-ray diffraction, transmission electron microscope, and X-ray photoelectron spectrometer. The adsorption capacity was investigated in a Pb2+ solution. The effects of initial pH, salt concentration, contact time, and adsorbate concentration on the adsorption of lead ions were investigated in detail. The morphology of the adsorbent was sheet-like microspheres. Zinc selenide/zinc oxide could be uniformly loaded onto the eggshell waste surface, which could effectively enhance the specific surface area of the eggshell wastes. The adsorption kinetics and isotherm followed the pseudo-second-order and Langmuir–Freundlich isotherm model, respectively. The synthesized adsorbent showed a maximum lead adsorption capacity of 1,428.78 mg/g at room temperature. Ion-exchange was the main adsorption mechanism.

scholarly journals Preparation of ureido-functionalized PVA/silica mesoporous fibre membranes via electrospinning for adsorption of Pb2+ and Cu2+ in wastewater

2017 ◽  
Vol 76 (9) ◽  
pp. 2526-2534 ◽  
Author(s):  
Meimei Zhou ◽  
Weizhen Tang ◽  
Pingping Luo ◽  
Jiqiang Lyu ◽  
Aixia Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Isotherm Model ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Adsorption Desorption

Abstract Ureido-functionalized mesoporous polyvinyl alcohol/silica composite nanofibre membranes were prepared by electrospinning technology and their application for removal of Pb2+ and Cu2+ from wastewater was discussed. The characteristics of the membranes were investigated by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and N2 adsorption-desorption analysis. Results show that the membranes have long fibrous shapes and worm-like mesoporous micromorphologies. Fourier transform infrared spectroscopy confirmed the membranes were successfully functionalized with ureido groups. Pb2+ and Cu2+ adsorption behavior on the membranes followed a pseudo-second-order nonlinear kinetic model with approximately 30 minutes to equilibrium. Pb2+ adsorption was modelled using a Langmuir isotherm model with maximum adsorption capacity of 26.96 mg g−1. However, Cu2+ adsorption was well described by a Freundlich isotherm model with poor adsorption potential due to the tendency to form chelating complexes with several ureido groups. Notably, the membranes were easily regenerated through acid treatment, and maintained adsorption capacity of 91.87% after five regeneration cycles, showing potential for applications in controlling heavy metals-related pollution and metals reuse.

scholarly journals Process Optimization and Adsorptive Mechanism for Reactive Blue 19 Dye by Magnetic Crosslinked Chitosan/MgO/Fe3O4 Biocomposite

2021 ◽  
Author(s):  
Ali H. Jawad ◽  
Rangabhashiyam S ◽  
Ahmed Saud Abdulhameed ◽  
Syed Shatir A. Syed-Hassan ◽  
Zeid A. ALOthman ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Textile Dye ◽  
Adsorption Parameters ◽  
Solution Ph ◽  
Equilibrium Study ◽  
Reactive Blue 19 ◽  
Pseudo Second Order ◽  
Adsorptive Mechanism

Abstract A new biocomposite magnetic crosslinked glutaraldehyde-chitosan/MgO/Fe3O4 (CTS-GL/MgO/Fe3O4) adsorbent was prepared and applied for the removal of reactive blue 19 (RB 19) synthetic textile dye. The prepared CTS-GL/MgO/Fe3O4 was subjected to the several instrumental characterizations such as XRD, FTIR, SEM-EDX, pH-potentiometric titration, and pHpzc analyses. The influence of the input adsorption parameters such as A: CTS-GL/MgO/Fe3O4 dosage, B: initial solution pH, C: process temperature, and D: contact time on RB 19 removal efficiency was statistically optimized using Box-Behnken design (BBD). The analysis of variance (ANOVA) indicates the presence of five significant statistical interactions between input adsorption parameters i.e. (AB, AC, AD, BC, and BD). The adsorption kinetic and equilibrium study reveals a good to the pseudo-second-order model, and multilayer adsorption as proven by Freundlich isotherm model, respectively. The maximum adsorption capacity of CTS-GL/MgO/Fe3O4 towards RB19 was found to be 193.2 mg/g at 45 ºC. This work highlights the development of feasible and recoverable magnetic biocompsite adsorbent with desirable adsorption capacity towards textile dyes with good separation ability by using an external magnetic field.

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