scholarly journals Absorption of Cu(II) and Zn(II) from Aqueous Solutions onto Biochars Derived from Apple Tree Branches

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3498
Author(s):  
Shixiang Zhao ◽  
Na Ta ◽  
Xudong Wang
Keyword(s):  
Adsorption Process ◽  
Apple Tree ◽  
Ph Value ◽  
Optimal Dosage ◽  
Initial Concentration ◽  
Surface Precipitation ◽  
Rate Limiting Step ◽  
Endothermic Process ◽  
Pseudo Second Order ◽  
Adsorption Kinetics And Isotherm

The aim of this study was to investigate the adsorption of Cu(II) and Zn(II) onto apple tree branches biochar (BC) produced at 300, 400, 500 and 600 °C (BC300, BC400, BC500, and BC600), respectively. The effect of adsorbent dosage, pH value, contact time, initial concentration of Cu(II) or Zn(II), and temperature on the adsorption process were investigated. The result showed that 5 g BC·L−1 was the optimal dosage to remove Cu(II) and Zn(II) from wastewater and the maximum adsorption efficiency was achieved at a pH of 5.0 for all the BCs when the initial concentration of Cu(II) and Zn(II) were 64 and 65 mg L−1, respectively. Adsorption kinetics and isotherm experiments showed that the pseudo-second order equation and the Langmuir isotherm could best describe the adsorption process, indicating that the adsorption of Cu(II) and Zn(II) onto BCs were monolayer processes and chemisorption was the rate limiting step. The values of ΔG0 for the absorption of Cu(II) and Zn(II) on all BCs were negative, while the values of ΔH0 were positive, suggesting that the absorption was a spontaneous endothermic process. The mechanisms of BC adsorption of metal ions adsorption include surface precipitation, ion exchange, and minor contribution by cation-π interaction. BC500 had highest Cu(II) and Zn(II) adsorption capacity under various conditions (except at pH 2.0). The maximum adsorption capacities of Cu(II) and Zn(II) on BC500 were 11.41 and 10.22 mg·g−1, respectively. Therefore, BC derived from apple tree branches produced at 500 °C can be used as an adsorbent to remove Cu(II) and Zn(II) from wastewater.

scholarly journals Preparation of modified pomelo peel's pulp adsorbent and its adsorption to uranyl ions

2019 ◽  
Vol 6 (3) ◽  
pp. 181986 ◽  
Author(s):  
Pengfei Yang ◽  
Yuanhe Xu ◽  
Jie Tuo ◽  
Ang Li ◽  
LixiAng Liu ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Ph Value ◽  
Raw Material ◽  
Uranyl Ions ◽  
Adsorption Time ◽  
Initial Concentration ◽  
Adsorption Condition ◽  
Adsorption Temperature ◽  
Freundlich Adsorption Isotherm ◽  
Pseudo Second Order

Using pomelo peel's pulp (PPP) as raw material, a new chemically modified PPP was prepared by the process of fermentation, cooking, freeze-drying, and so on. The adsorbent has been characterized by EDS, IR, BET and SEM. The factors of different adsorption conditions such as pH value, adsorption temperature, mass of adsorbent, adsorption time and initial concentration of UO 2 2+ were investigated. The adsorption mechanism was explored by adsorption thermodynamics and kinetics experiments. The results indicate that the pH value is 6.0, the dosage of adsorbent is 500 mg l –1 , the temperature is 50°C and the adsorption time is 90 min, which is the best adsorption condition. When the initial concentration of UO 2 2+ is 35 mg l –1 , the adsorbed amount of uranyl ions by the modified PPP adsorbent can reach 42.733 mg g −1 , 26.8% higher than the adsorption amount of unmodified adsorbent (31.276 mg g −1 ), which is obviously enhanced. The kinetic and thermodynamic experiments show that the adsorption process is in good agreement with the pseudo second-order kinetics model, that it is an endothermic reaction, and the reaction is spontaneous. The adsorption process is entropy-dominated. The Freundlich adsorption isotherm can describe the adsorption process more accurately.

Pseudo-Second-Order Kinetics for the Adsorption of Uranyl Ion onto Peat at Different pH Value

2010 ◽  
Vol 113-116 ◽  
pp. 33-36
Author(s):  
Zhi Rong Liu ◽  
Qin Qin Tao ◽  
Chuan Xi Wen
Keyword(s):  
Contact Time ◽  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Ph Value ◽  
Second Order ◽  
Uranyl Ions ◽  
Batch Tests ◽  
Effects Of Ph ◽  
Pseudo Second Order

Batch tests were used to investigate the effects of pH and contact time on the adsorption capability of peat. The results indicate that adsorption of uranyl ions on peat increase with increasing pH from 1 to 5. However it takes longer contact time to reach the adsorption equilibrium with increase of pH from 1 to 5. The adsorption process can be described by type 1 of the pseudo-second-order kinetics excellently.

Preparation of Persimmon Tannins Immobilized on Collagen Adsorbent and Research on its Adsorption to Cr(VI)

2013 ◽  
Vol 743-744 ◽  
pp. 523-530 ◽  
Author(s):  
Jian Cui ◽  
Zhong Min Wang ◽  
Feng Lei Liu ◽  
Pei Bang Dai ◽  
Ran Chen ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Ph Value ◽  
Effect Of Temperature ◽  
Major Influence ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Adsorption Data ◽  
Initial Ph ◽  
Pseudo Second Order ◽  
Ph Range

Persimmon tannins (PT) were immobilized on a matrix of collagen fiber by cross-linking of glutaraldehyde. The adsorption behaviours to Cr (VI) on PT were investigated including the effects of initial pH, initial concentration of Cr (VI), temperature, adsorbent dosage, adsorption kinetics and the recycling performance of PT adsorbents. The results showed that pH value had a major influence in adsorption. PT showed a strong adsorbability to Cr (VI) in the pH range of 1.0 to 3.0, whereas the effect of temperature on the adsorption was comparatively weaker. The adsorption equilibrium could be well described by Freundlich equation. PT adsorption efficiency of Cr (VI) reached 98.04% and the maximum equilibrium adsorption capacity of Cr (VI) was up to 49.01 mg/g at 303 K with a pH value of 2.0, 100 mg/L of initial concentration of Cr (VI) and 0.1g of adsorbent dosage. The adsorption data could be well fitted by pseudo-second-order rate model. PT adsorbents were characterized by FTIR and EDS. The analysis indicated that the adsorption mechanism was mainly contributed by redox adsorption.

Preparation, characterization, and application of synthesized thiourea formaldehyde-calcium alginate in removal of Reactive Black 5

2018 ◽  
Vol 96 (12) ◽  
pp. 1101-1114 ◽  
Author(s):  
A.A. El-Bindary ◽  
A.F. Shoair ◽  
H.A. Kiwaan ◽  
A.R. Hawas
Keyword(s):  
Calcium Alginate ◽  
Adsorption Process ◽  
Ph Value ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Reactive Black 5 ◽  
X Ray ◽  
Ionic Strength Effect ◽  
Infrared Spectrometer ◽  
Pseudo Second Order

Thiourea formaldehyde calcium alginate (TFCA) composite was successfully synthesized and used for removal of Reactive Black 5 (RB5) dye. The synthesized composite was applied and characterized by Fourier transform infrared spectrometer (FTIR) spectra, scanning electron microscope (SEM)/EDS, energy dispersive X-ray analysis (EDX), and X-ray diffraction (XRD). SEM and EDX analyses confirm the homogeneity of the sorbent in term of composition. Batch adsorption experiments were performed to evaluate the adsorption conditions such as pH value, dye concentration, contact time, temperature, and sorbent dose, as well as the ionic strength effect. Experimental data have been modeled by using Langmuir, Freundlich, Dubinin Radushkevich (D–R), and Temkin isotherms. Kinetic adsorption data modeled using PFORE, PSORE, Morris Weber, and Elovich in order to determine thermodynamic parameters (ΔG, ΔH, and ΔS) for the dye adsorbent systems. These data indicated an exothermic spontaneous adsorption process that kinetically followed the pseudo second-order adsorption process and removal of RB5 dye from aqueous solution. The results showed that the maximum adsorption capacity was 0.2 mmol g−1, observed at pH 1 and temperature 25 °C. Equilibrium adsorption was achieved within 60 min.

scholarly journals Coupling of kenaf Biochar and Magnetic BiFeO3 onto Cross-Linked Chitosan for Enhancing Separation Performance and Cr(VI) Ions Removal Efficiency

2020 ◽  
Vol 17 (3) ◽  
pp. 788 ◽  
Author(s):  
Daixi Zhou ◽  
Guangyu Xie ◽  
Xinjiang Hu ◽  
Xiaoxi Cai ◽  
Yunlin Zhao ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Process ◽  
Reaction System ◽  
Freundlich Isotherm ◽  
Fractional Factorial ◽  
Separation Performance ◽  
Initial Concentration ◽  
Rate Limiting Step ◽  
Rate Limiting ◽  
Competing Ions

Cr(VI) contamination has posed great threat to both the ecosystem and human health for its carcinogenic and mutagenic nature. A highly effective adsorbent for the removal of Cr(VI) was prepared and its adsorption mechanism was thoroughly discussed in this study. In detail, magnetic BiFeO3 and kenaf biochar were loaded on cross-linked chitosan to obtain chitosan-kenaf biochar@BiFeO3 (CKB) for improving adsorption capacity towards Cr(VI). The adsorption process of Cr(VI) onto CKB was evaluated as a function of the pH, the existence of competing ions, the initial concentration of Cr(VI) and contact time. The results show that CKB exhibits the highest adsorption capacity under the optimal pH 2.0. The presence of competing ions such as Ca2+, NO3−, SO42−, and Cl− decreases the adsorption capacity; among them, Ca2+ and NO3− show the greatest hindrance. By studying the effect of initial Cr(VI) concentration on the adsorption capacity, it was found that CKB in the solution was enough to remove Cr(VI) for all treatments (10–200 mg/L). The adsorption experimental data were well fitted with pseudo-first-order model, suggesting that chemisorption is not the dominant rate-limiting step. Freundlich isotherm model can better explain the adsorption process, indicating a non-ideal adsorption towards Cr(VI) on a heterogeneous surface of CKB. A 25-1 Fractional Factorial Design (FFD) showed that pH and initial concentration of Cr(VI) have significant influence on Cr(VI) adsorption in our reaction system. In general, excellent adsorption efficiency of CKB indicates that it may be a good candidate for the remediation of Cr(VI)-contaminating wastewater.

Thermodynamic and kinetic properties of the adsorption of 4-nitrophenol on graphene from aqueous solution

2015 ◽  
Vol 93 (10) ◽  
pp. 1083-1087 ◽  
Author(s):  
Ali Issa Ismail
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Freundlich Isotherm ◽  
Kinetic Properties ◽  
Initial Concentration ◽  
First Order ◽  
Toxic Materials ◽  
Exothermic Process ◽  
Pseudo Second Order ◽  
Pseudo First Order

Graphene is a newly discovered material and is considered to be the new wonder material for many applications. The recent possibility of obtaining pure and fully characterized graphene opens the door to the study of the adsorption of toxic materials on graphene. The adsorption behavior of p-nitrophenol on graphene was studied in aqueous medium. The effect of each of pH, temperature, and dosage was emphasized. The highest calculated adsorption capacity of 4-nitrophenol was found to be 15.5 mg/g, assuming Langmuir fitting starting from 11.1 mg/g initial concentration at 298 K and pH = 6. Fitting the data using the Freundlich isotherm model predicted a favorable adsorption process (n > 1). The rise and saturation areas of the isotherms were fitted as pseudo first-order and pseudo second-order processes, respectively, with relatively good fit (k1 = 0.0023/s, k2 = 0.68 g mg−1 s−1). The thermodynamic properties indicated a spontaneous and exothermic process.

Adsorption Characters of Mn2+ onto Palygorskites Modified by 1, 10-Phenanthroline and Triethylamine

2010 ◽  
Vol 178 ◽  
pp. 8-16
Author(s):  
Liang Dong Feng ◽  
Bo Qing Chen ◽  
Ying Ying Shi ◽  
Ying Wei Guo ◽  
Jing Huang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Ph Value ◽  
Order Model ◽  
Kinetics Of Adsorption ◽  
Initial Concentration ◽  
Adsorption Capacities ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Kinetics Of

1, 10-phenanthroline and triethylamine modified palygorskites were prepared by microwave irradiation, and characterized with FT-IR technique. The effects of contact time, adsorbent dosage, and pH value of the initial solution on the adsorption characters of Mn2+ were investigated. The adsorption of Mn2+ from aqueous solutions using 1, 10-phenanthroline or triethylamine modified palygorskites were investigated. Experiment results indicated that 1,10-phenanthroline and triethylamine molecules have been successfully grafted to palygorskite. The adsorption was rapid during the first 5 minuts and equilibrium were attained within 60 minutes in the initial concentration of Mn2+ of 50 and 100 mg•L-1, and fast adsorption in the first 10 minutes and slowly increased with the contact time due to the adsorption of palygorskite. The 1, 10-phenanthroline modified palygorskites had higher adsorption capacity than triethylamine modified palygorskites. Compared with natural palggorskites, the Mn2+ ions adsorption capacities of palggorskite modified by 1, 10-phenanthroline or triethylamine were significantly improved. There were less difference in the adsorption capacity between different dasages of 1, 10-phenanthroline modified palygorskites, but the adsorption capacity of Mn2+ adsorbed onto triethylamine modified palygorskites decreased with increasing the dosages. A Lagergren pseudo-second order model best described the kinetics of adsorption of Mn2+ onto the modified palygorskites.

Study on the Effect of Amphoteric Bagasse Hemicellulose on Heavy Metal Adsorption

2011 ◽  
Vol 399-401 ◽  
pp. 1282-1288 ◽  
Author(s):  
Li Jun Wang ◽  
Xin Liang Liu ◽  
Meng Ling Weng ◽  
Shuang Xi Li ◽  
Fu Sheng Wu ◽  
...  
Keyword(s):  
Linear Model ◽  
Metal Ion ◽  
Ph Value ◽  
Absorption Capacity ◽  
Heavy Metal Adsorption ◽  
Adsorption Dynamics ◽  
Adsorption Time ◽  
Initial Concentration ◽  
Ph Values ◽  
Pseudo Second Order

In this paper, ions i.e. Cu2+, Pb2+and Cd2+ were absorbed by the amphoteric bagasse hemicelluloses, and the influences of pH value, adsorption time and the initial concentration of metal ion have been studied. The results show that the optimal adsorption pH values for Cu2+, Pb2+ and Cd2+ are 6.5, 6.0 and 7.5, respectively. The adsorption capacity to ions Cu2+, Pb2+ and Cd2+ reaches the maximum values when the adsorption time is 180 min. Net adsorption to ions Cu2+, Pb2+ and Cd2+ increases with increasing the initial concentration of the metal ions. Analysis results of adsorption dynamics show that the adsorption of Cu2+, Pb2+ and Cd2+ follows Ho 's Pseudo second-order kinetics linear model. It can be seen from the adsorption isothermal research that absorption of the amphoteric bagasse hemicelluloses to ions Cu2+, Pb2+and Cd2+ can be well described by the Langmuir isotherm linear model. Moreover, the theoretical values of the maximum absorption capacity qmax for ions Cu2+, Pb2+ and Cd2+ were determined to be 21.98 mg/g, 81.97 mg/g and 31.85 mg/g, respectively.

scholarly journals Novel Ag/Kaolin Nanocomposite as Adsorbent for Removal of Acid Cyanine 5R from Aqueous Solution

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Saeedeh Hashemian ◽  
Mohammad Reza Shahedi
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Adsorption Process ◽  
Alkaline Condition ◽  
Order Kinetic ◽  
Nano Composite ◽  
Order Kinetic Model ◽  
Endothermic Process ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

Ag/kaolin nanocomposite was prepared by reduction of Ag+ion with ethanol at alkaline condition on kaolin surface. Nanocomposite was characterized by FTIR, XRD, TEM, and BET methods. Results showed the Ag/kaolin composite has particle size 50 nm. The surface area was increased from kaolin to Ag/kaolin from 1.0215 to 7.409 m2 g−1, respectively. Ag/kaolin nanocomposite was used for adsorption of acid cyanine 5R (AC5R) from aqueous solution. The effect of parameters such as contact time, pH, and mass of nano composite has been investigated. The maximum percentage of adsorption of AC5R was found at pH 3 and contact time of 60 min. The higher percentage removal of AC5R by Ag/kaolin than kaolin can be attributed to catalytic activity of Ag on the surface of kaolin. The experimental data was fitted by pseudo-second-order kinetic model. The adsorption isotherm data could be well interpreted by Langmuir isotherm model. From the results of thermodynamic study, the adsorption process of AC5R onto Ag/kaolin nanocomposite was spontaneous and endothermic process. The process is clean and safe for purifying of water pollution.

Sorption properties of Amberlite XAD 7 functionalized with sodium β-glycerophosphate

2016 ◽  
Vol 88 (12) ◽  
pp. 1143-1154
Author(s):  
Andreea Gabor ◽  
Corneliu Mircea Davidescu ◽  
Adina Negrea ◽  
Mihaela Ciopec ◽  
Cornelia Muntean ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Ph Value ◽  
Sorption Properties ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
X Ray ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Best Fit ◽  
Efficient Adsorbent

Abstract This paper presents the sorption properties of a new adsorbent material prepared by impregnating Amberlite XAD 7 polymer with sodium β-glycerophosphate. For impregnation, the pellicular vacuum solvent vaporization method was employed. The functionalization was evidenced by energy dispersive X-ray analysis. The usefulness of this material and its performances were studied for the adsorption of the rare earth element La(III) in batch experiments. The influence of various parameters affecting the adsorption of lanthanum like contact time, initial concentration, pH value, and temperature was studied. The kinetic of the adsorption process was best described by the pseudo-second-order model. Sips isotherm was found to be the best fit of the equilibrium data. The maximum adsorption capacity of the functionalized material was of 33.8 mg La(III)/g. The values of thermodynamic parameters (ΔGo, ΔHo, ΔSo) showed that the adsorption process was endothermic and spontaneous. The results proved that Amberlite XAD 7 functionalized with sodium β-glycerophosphate is an efficient adsorbent for the removal of La(III) ions from aqueous solutions. Quantum chemistry was performed using Spartan software.

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