scholarly journals Recovery of Pd(II) from Aqueous Solution by Polyethylenimine-Crosslinked Chitin Biosorbent

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 593
Author(s):  
Zhuo Wang ◽  
Su Bin Kang ◽  
Sung Wook Won
Keyword(s):  
Adsorption Equilibrium ◽  
Average Pore Size ◽  
Fixed Bed ◽  
Sem Analysis ◽  
Order Model ◽  
Average Pore ◽  
Fixed Bed Column ◽  
Practical Applications ◽  
Pseudo Second Order ◽  
Adsorption Desorption

This study reports the recovery of Pd(II) from acid solution by a polyethylenimine (PEI)-crosslinked chitin (PEI-chitin) biosorbent. FE-SEM analysis demonstrated that there are many slot-like pores on PEI-chitin. The N2 adsorption–desorption experiment revealed that the average pore size was 47.12 nm. Elemental analysis verified the successful crosslinking of PEI with raw chitin. The Langmuir model better explained the isotherm experimental data and the theoretical maximum Pd(II) uptake was 57.1 mg/g. The adsorption kinetic data were better described by the pseudo-second-order model and the adsorption equilibrium was achieved within 30 min for all initial Pd(II) concentrations of 50–200 mg/L. In the fixed-bed column, the adsorption of Pd(II) on PEI-chitin showed a slow breakthrough and a fast saturation performance. The desorption experiments achieved a concentration factor of 8.4 ± 0.4; in addition, the adsorption–desorption cycles in the fixed-bed column were performed up to three times, consequently confirming the good reusability of PEI-chitin for Pd(II) recovery. Therefore, the PEI-chitin can be used as a promising biosorbent for the recovery of Pd(II) in practical applications.

scholarly journals Synthesis of PANI@ZnO Hybrid Material and Evaluations in Adsorption of Congo Red and Methylene Blue Dyes: Structural Characterization and Adsorption Performance

2021 ◽  
Author(s):  
Imane Toumi ◽  
Halima Djelad ◽  
Faiza Chouli ◽  
Benyoucef Abdelghani
Keyword(s):  
Methylene Blue ◽  
Congo Red ◽  
Average Pore Size ◽  
Isotherm Models ◽  
Order Model ◽  
Average Pore ◽  
Freundlich Model ◽  
Pseudo Second Order ◽  
Adsorption Desorption ◽  
Best Fit

Abstract In this research, a simple oxidation chemical process was applied for the synthesis of novel PANI@ZnO nanocomposite. The prepared nanocomposites were characterized by XPS, XRD, FTIR, SEM, TGA and N2 adsorption-desorption isotherms. Thereby, PANI@ZnO highest SBET values (about 40.84 m2.g− 1), total mesoporous volume (about 3.214 cm3.g− 1) and average pore size (about 46.12 nm). Afterwards, the prepared nanomaterial was applied as novel nanoadsorbent for the adsorption of Congo Red (CR) and Methylene Blue (MB) dyes from aqueous solutions at 298 K and pH 5.0. Besides, the pseudo-second-order model was obtained the best for the adsorption of both dyes. In the case of isotherm models, the Freundlich model showed the best fit. After removal, the spent adsorbent was regenerated. With the regeneration repeated five cycles, the PANI@ZnO regeneration efficiency remained at a very adequate level.

Adsorption of crystal violet with diatomite earth&carbon by a modification of hydrothermal carbonization process

2015 ◽  
Vol 73 (6) ◽  
pp. 1463-1471 ◽  
Author(s):  
Zhang Yanzhuo ◽  
Li Jun ◽  
Chen Guanghui ◽  
Bian Wei ◽  
Lu Yun ◽  
...  
Keyword(s):  
Crystal Violet ◽  
Adsorption Process ◽  
Hydrothermal Carbonization ◽  
Dyeing Wastewater ◽  
Order Model ◽  
Average Pore ◽  
Printing And Dyeing Wastewater ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Adsorption Desorption

The high colority and difficulty of decolorization are the most important tasks on printing and dyeing wastewater. This study investigates the ability of diatomite earth&carbon (DE&C) as an adsorbent to removal crystal violet (CV) from aqueous solutions. Fourier transform infrared spectroscopy results indicate the importance of functional groups during the adsorption of CV. The obtained N2 adsorption–desorption isotherm values accord with well IUPAC type II. Our calculations determined a surface area of 73.15 m2 g−1 for DE&C and an average pore diameter of 10.56 nm. Equilibrium data of the adsorption process fitted very well to the Langmuir model (R2 > 0.99). The results of kinetics study showed that the pseudo-second-order model fitted to the experimental data well. The thermodynamic parameters were also evaluated. ΔH° <0, ΔS° > 0 and ΔG° < 0 demonstrated that the adsorption process was spontaneous and exothermic for dye. Furthermore the positive value of ΔS° reflected good affinity of the CV dye.

scholarly journals Highly Effective Adsorption of Caffeine by a Novel Activated Carbon Prepared From Coconut Leaf

2021 ◽  
Author(s):  
Elvio N. Oliveira ◽  
Alex T. Meneses ◽  
Samara F. de Melo ◽  
Franciele M. R. Dias ◽  
Maisa T. B. Perazzini ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
Physical Adsorption ◽  
Average Pore Size ◽  
Kinetic Studies ◽  
Amorphous Structure ◽  
Operating Conditions ◽  
Average Pore ◽  
Pseudo Second Order ◽  
Adsorption Desorption

Abstract The disposal of coconut wastes is costly and damaging to the environment, but its uses are advantageous activated carbons production. Coconut leaves waste were used for activated carbon production by pyrolysis at 500º C and activation with potassium carbonate. The activated carbon was used for caffeine removal from aqueous solution. The coconut leaves activated carbon showed a predominantly amorphous structure from X-ray diffraction analysis and a pH at the zero charge point of 7.9. From the N2 adsorption/desorption method, the adsorbent showed a predominance of mesopores, with average pore size of 45.48 ηm and a surface area of 678.03 m2/g. From kinetic studies the data followed the pseudo-second order, where the intraparticle diffusion can be neglected. The adsorption isotherms were satisfactorily adjusted for the Redlich-Peterson model and a type curve L was identified. The thermodynamic parameters showed that adsorption occurred spontaneously, was exothermic and governed by physical adsorption. The artificial neural networks developed were capable of predicting both kinetics and equilibrium adsorption data under different operating conditions and was comparable to the traditional models available in literature in the training experiments, encouraging its use for data generalization when an efficient dataset is used. In conclusion, coconut leaves waste showed to be a promising feedstock to produce activated carbon aiming caffeine removal from water and wastewater.

Biochar caged zirconium ferrite nanocomposites for the adsorptive removal of Reactive Blue 19 dye in a batch and column reactors and conditions optimizaton

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shazia Perveen ◽  
Raziya Nadeem ◽  
Shaukat Ali ◽  
Yasir Jamil
Keyword(s):  
Experimental Data ◽  
Low Dose ◽  
Fixed Bed ◽  
Breakthrough Curves ◽  
Adsorption Efficiency ◽  
Fixed Bed Column ◽  
Flow Rates ◽  
Adsorptive Removal ◽  
Reactive Blue 19 ◽  
Pseudo Second Order

Abstract Biochar caged zirconium ferrite (BC-ZrFe2O5) nanocomposites were fabricated and their adsorption capacity for Reactive Blue 19 (RB19) dye was evaluated in a fixed-bed column and batch sorption mode. The adsorption of dye onto BC-ZrFe2O5 NCs followed pseudo-second-order kinetics (R 2 = 0.998) and among isotherms, the experimental data was best fitted to Sips model as compared to Freundlich and Langmuir isotherms models. The influence of flow-rate (3–5 mL min−1), inlet RB19 dye concentration (20–100 mg L−1) and quantity of BC-ZrFe2O5 NCs (0.5–1.5 g) on fixed-bed sorption was elucidated by Box-Behnken experimental design. The saturation times (C t /C o  = 0.95) and breakthrough (C t /C o  = 0.05) were higher at lower flow-rates and higher dose of BC-ZrFe2O5 NCs. The saturation times decreased, but breakthrough was increased with the initial RB19 dye concentration. The treated volume was higher at low sorbent dose and influent concentration. Fractional bed utilization (FBU) increased with RB19 dye concentration and flow rates at low dose of BC-ZrFe2O5 NCs. Yan model was fitted best to breakthrough curves data as compared to Bohart-Adams and Thomas models. Results revealed that BC-ZrFe2O5 nanocomposite has promising adsorption efficiency and could be used for the adsorption of dyes from textile effluents.

Preparation and Characterization of Fe2O3/ SBA-15 for Fischer-Tropsch Process

2020 ◽  
Vol 850 ◽  
pp. 144-150
Author(s):  
Agija Stanke ◽  
Valdis Kampars ◽  
Oana A. Lazar ◽  
Marius Enachescu
Keyword(s):  
Average Pore Size ◽  
Direct Synthesis ◽  
Synthesis Method ◽  
Xrd Analysis ◽  
Hexagonal Structure ◽  
Catalyst Characterization ◽  
Average Pore ◽  
Pluronic P123 ◽  
Silica Source ◽  
Adsorption Desorption

In this study Fe2O3/SBA-15 catalyst was synthesized via direct synthesis method under acidic conditions using triblock copolymer Pluronic P123 as template, tetraethyl orthosilicate as a silica source and Fe (NO3)3∙9H2O as iron source. Template was removed using extraction and calcination. The obtained catalyst was characterized using XRD analysis, WDXRF spectroscopy, N2 adsorption-desorption analysis and STEM–EDX measurements. Results of catalyst characterization showed that the synthesized Fe2O3/SBA-15 is mesoporous silica with 2D p6mm hexagonal mesostructure loaded with 15.6 wt.% Fe2O3. Average pore size was 6.95 nm, homogeneous immobilized Fe2O3 nanoparticles do not disrupt the porous hexagonal structure of the support.

scholarly journals Removal of nitrate from synthetic aqueous solution and groundwater in a continuous pilot system using chemical activated carbon derived from walnut shell

2016 ◽  
Vol 11 (4) ◽  
pp. 784-795 ◽  
Author(s):  
Abolghasem Alighardashi ◽  
Shooza Shahali
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Average Pore Size ◽  
Fixed Bed ◽  
Walnut Shell ◽  
Maximum Adsorption Capacity ◽  
Average Pore ◽  
Langmuir Adsorption ◽  
Bet Specific Surface Area ◽  
Nitrate Adsorption

Excessive nitrate in the water impose a danger to human health and contribute to eutrophication. The present continuous fixed bed pilot study was carried out using granular activated carbon made from walnut shell for removal of nitrate from aqueous solution and natural groundwater. The carbon was characterized using SEM, FTIR and BET. The BET specific surface area and average pore size before nitrate adsorption were 1434.6 m2g−1 and 2.08 nm, respectively, and after were 633.28 m2g−1 and 2.04 nm, respectively. Optimum removal of nitrate was achieved at a contact time of 2 min, pH of 6.5 and a nitrate concentration of 200 mg/l. The hydraulic loading rate was calculated to be 10 m3/h.m2 and the maximum adsorption capacity using the Langmuir adsorption isotherm model (R2 = 0.99) was 10 mg NO3/g. These experiments were also carried out using groundwater and the removal of nitrate decreased from 68% to 60% because of competition with other cations and anions.

scholarly journals Recovery of phosphate from aqueous solution by magnetically recycled modified polishing powder composites

2019 ◽  
Vol 80 (7) ◽  
pp. 1357-1366
Author(s):  
Jianming Liu ◽  
Runying Bai ◽  
Junfeng Hao ◽  
Bowen Song ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Ligand Exchange ◽  
Adsorption Process ◽  
High Adsorption ◽  
Order Model ◽  
Powder Composites ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ph Level ◽  
Adsorption Desorption

Abstract This study investigated a magnetically recycled modified polishing powder (CMIO@PP) as an adsorbent of phosphate; the CMIO@PP was synthesized by combining the modified La/Ce-containing waste polishing powder with CaO2-modified Fe3O4 (CMIO). Results indicate that the CMIO@PP nanocomposite presents a crystal structure comprising La (OH)3, Ce (OH)3, and Fe3O4, and that CMIO is uniformly dispersed in the modified polishing powder. The CMIO@PP (1:3) is a suitable choice considering its magnetism and adsorption capacity. The magnetic adsorbent exhibits a high adsorption capacity of 53.72 mg/g, a short equilibrium time of 60 min, and superior selectivity for phosphate. Moreover, the adsorbent strongly depends on the pH during the adsorption process and maintains a large adsorption capacity when the pH level is between 2 and 6. The adsorption of phosphate by the CMIO@PP (1:3) accords with the Langmuir isotherm model, and the adsorption process follows the pseudo-second order model. Meanwhile, adsorption–desorption experiments show that the adsorbent could be recycled a few times and that a high removal efficiency of phosphate from civil wastewater was achieved. Finally, mechanisms show that the adsorption of phosphate by the CMIO@PP (1:3) is mainly caused by electrostatic attraction and ligand exchange.

scholarly journals Iron Oxide-Coated Gravel Fixed Bed Column Study Performance to Remove Mixed Metals from Landfill Leachate

2019 ◽  
Vol 122 ◽  
pp. 01002 ◽  
Author(s):  
Ibrahim Yildiz ◽  
Banu Sizirici
Keyword(s):  
Iron Oxide ◽  
Fixed Bed ◽  
Breakthrough Curves ◽  
Fixed Bed Column ◽  
Desorption Process ◽  
Column Study ◽  
Regeneration Capability ◽  
Synthetic Leachate ◽  
Adsorption Desorption ◽  
Study Performance

Iron oxide-coated gravel as an adsorbent was employed in continuous fixed bed column study to remove Fe(II), Ni(II), and Zn(II) simultaneously in synthetic leachate samples. Experimental and modeled adsorption capacities derived from the breakthrough curves showed the adsorption capacity order of Zn(II)>Fe(II)> Ni(II). Iron oxide-coated gravel column removed 58.24% of Zn(II), 47.71% of Fe(II), and 39.45% of Ni(II). Desorption process was studied in order to test the regeneration capability of iron oxidecoated gravel. It was seen that 99.64 % of Ni(II), 99.54% of Fe(II) and 6.75% of Zn (II) were recovered through the first cycle of adsorption/desorption. In the second cycle, the recovery rates dropped to 81.4% for Ni(II), 80% for Fe(II) and 4% for Zn(II). Based on these results, iron oxide coated gravel has potential to remove mixed metal ions simultaneously in aqueous solutions.

Mathematical Modeling of the Anthocyanins Adsorption/Desorption from Blueberries on Amberlite FPX-66 Resin in A Fixed Bed Column

2015 ◽  
Vol 40 (1) ◽  
pp. e12323 ◽  
Author(s):  
Amandeep K. Sandhu ◽  
Yun Cai ◽  
Bhaskar Janve ◽  
Wade Yang ◽  
Yavuz Yagiz ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Fixed Bed ◽  
Fixed Bed Column ◽  
Adsorption Desorption

Adsorption of Cobalt Ions on Molded Magnesium Silicate

2013 ◽  
Vol 807-809 ◽  
pp. 704-707
Author(s):  
Li Li Mao ◽  
Hai Zeng Wang ◽  
Qing Wang
Keyword(s):  
Adsorption Process ◽  
Average Pore Size ◽  
Chemical Properties ◽  
Magnesium Silicate ◽  
Average Pore ◽  
Cobalt Ions ◽  
Adsorption Time ◽  
Physico Chemical ◽  
Adsorption Desorption ◽  
Adsorbent Dose

The groundwater contaminated with cobalt is attracted more and more concern. In this study, molded magnesium silicate (MMS) was successfully prepared and the physico-chemical properties were determined by N2 adsorption/desorption isotherm and Scanning Electron Microscopy (SEM). Surface area and the average pore size were 333.19 m2·g-1 and 4.442 nm. Adsorption experiments of removal of cobalt ions was investigated as the function of initial concentration, adsorbent dose and adsorption time. Adsorption process was rapid and adsorption equilibriums were achieved soon.

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