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.

Nanoparticle Fe3O4 magnetized activated carbon from Armeniaca sibirica shell for the adsorption of Hg(II) ions

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6100-6120
Author(s):  
Yinan Hao ◽  
Yanfei Pan ◽  
Qingwei Du ◽  
Xudong Li ◽  
Ximing Wang
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Entropy Change ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Adsorption Parameters ◽  
Initial Concentration

Armeniaca sibirica shell activated carbon (ASSAC) magnetized by nanoparticle Fe3O4 prepared from Armeniaca sibirica shell was investigated to determine its adsorption for Hg2+ from wastewater. Fe3O4/ASSAC was characterized using XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy), and BET (Brunauer–Emmett–Teller). Optimum adsorption parameters were determined based on the initial concentration of Hg2+, reaction time, reaction temperature, and pH value in adsorption studies. The experiment results demonstrated that the specific surface area of ASSAC decreased after magnetization; however the adsorption capacity and removal rate of Hg2+ increased 0.656 mg/g and 0.630%, respectively. When the initial concentration of Hg2+ solution was 250 mg/L and the pH value was 2, the adsorption time was 180 min and the temperature was 30 °C, and with the Fe3O4/ASSAC at 0.05 g, the adsorption reaching 97.1 mg/g, and the removal efficiency was 99.6%. The adsorption capacity of Fe3O4/ASSAC to Hg2+ was in accord with Freundlich isotherm models, and a pseudo-second-order kinetic equation was used to fit the adsorption best. The Gibbs free energy ΔGo < 0，enthalpy change ΔHo < 0, and entropy change ΔSo < 0 which manifested the adsorption was a spontaneous and exothermic process.

scholarly journals Arsenic removal using Prosopis spicigera L. wood (PsLw) carbon–iron oxide composite

2020 ◽  
Vol 10 (9) ◽  
Author(s):  
Ramasubbu DhanaRamalakshmi ◽  
Mahalingam Murugan ◽  
Vincent Jeyabal
Keyword(s):  
Iron Oxide ◽  
Large Scale ◽  
Adsorption Process ◽  
Arsenic Removal ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Batch Adsorption ◽  
Experimental Conditions ◽  
Initial Concentration ◽  
Oxide Composite

Abstract The present manuscript reports the removal of arsenic from aqueous solution using iron oxide composite of carbon derived from the plant material Prosopis spicigera L. wood which depletes the ground water of ponds, lakes and other water bodies. The adsorbent was characterised by Fourier Transform Infra Red spectroscopy and Scanning Electron Microscope for surface analysis; Brunauer–Emmett–Teller and methylene blue method for surface area determination and pHzpc for surface charge determination. Experimental conditions such as pH, contact time, adsorbate initial concentration and in the presence other ions are varied to study the batch adsorption equilibrium experiment. The adsorption process was tested with Langmuir and Freundlich isotherm model and Langmuir isotherm was best suited. Sorption kinetics was analysed with pseudo-first- and second-order kinetics but adsorption follows second order kinetics. For an initial concentration of 60 mg/L of As(III) ions, adsorption capacity was found to be 83.84 mg/g at pH = 6.0. Thermodynamically the adsorption process is spontaneous, feasible and endothermic in nature. Adsorption involves pore diffusion, external mass transfer and complex formation. Column study was performed to apply this process for large scale treatment.

scholarly journals Synchronized Infection of Cell Cultures by Magnetically Controlled Virus

2005 ◽  
Vol 79 (1) ◽  
pp. 622-625 ◽  
Author(s):  
Hillel Haim ◽  
Israel Steiner ◽  
Amos Panet
Keyword(s):  
Adsorption Process ◽  
Diffusion Rate ◽  
Cell Attachment ◽  
Diffusion Limited ◽  
Rate Limiting Step ◽  
Immunodeficiency Virus ◽  
Rate Limiting ◽  
And Diffusion ◽  
Entry Mechanism

ABSTRACT To override the diffusion-limited adsorption step of viral infection, we magnetically synchronized cell attachment. Human immunodeficiency virus type 1-based lentivirus preparations were rendered magnetically reactive by association with magnetite nanoparticles, 50 nm in diameter. Application of a magnetic field resulted in immediate redistribution of the viral inoculum to the cell-associated state and completion of the productive adsorption process within 1 min. Independent of adsorption time, viral concentration, and diffusion rate, infection subsequently progressed by the receptor-mediated entry mechanism. Synchronization of this rate-limiting step of infection may now be applied to analyze isolated events in the viral replication sequence.

Study on Adsorption of U(VI) From Aqueous Solution by Activated MgO

2017 ◽  
Author(s):  
Qingqing Liu ◽  
Xiaoyan Li
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Adsorption Process ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Batch System ◽  
15Mg Dose ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Kinetics Of

The activated MgO was synthesized by microwave homo-precipitator method and characterized by SEM, EDS and FT-IR methods. It was used to adsorption of U(VI) from aqueous solution with batch system. The paper discussed the effect of pH, temperature, contact time, adsorbent dose and initial U(VI) concentration on the adsorption. The results showed that activated MgO has good adsorption capacity for U(VI), the removal rate and equilibrium adsorption capacity reached 83.5% and 84.04mg·g−1 at pH 5.0, 15mg dose and 313K,respectively. The adsorption kinetics of U(VI) onto activated MgO were better fitted with pseudo-second-order kinetic.The adsorption isotherm data were fitted well to Freundlich isotherm model.The thermodynamic parameters showed that the adsorption process is endothermic and spontaneous.

Synthesis of the Water-Compatible P-Aminophenol Resin and its Adsorption for Salicylic Acid

2011 ◽  
Vol 311-313 ◽  
pp. 1852-1856 ◽  
Author(s):  
Gu Qing Xiao ◽  
Xue Jun Zhang
Keyword(s):  
Salicylic Acid ◽  
Adsorption Capacity ◽  
Equilibrium Concentration ◽  
Maximum Adsorption Capacity ◽  
Adsorption Dynamics ◽  
First Order ◽  
Rate Limiting Step ◽  
Intra Particle Diffusion ◽  
Rate Limiting ◽  
Order Rate Equation

A novel water-compatible hypercrosslinked resin modified by p-aminophenol was synthesized with chloromethylated polystyrene and p-aminophenol by Friedel-Crafts reaction. The objective of this work was to study the adsorption performances for salicylic acid onto p-aminophenol resin. The results showed that the adsorption capacity of salicylic acid onto p-aminophenol resin was superior to XAD-4 resin. It is seen that the maximum adsorption capacity is observed at pH of 3.0. It was found the adsorption dynamics obeyed the pseudo-first-order rate equation and the intra-particle diffusion was the rate-limiting step. The maximum adsorption capacity of salicylic acid for p-aminophenol resin was measured to be 283.7 mg/g with the equilibrium concentration at 404.6mg/L. The micropore structure, the pore diameter of p-aminophenol resin, the hydrogen bond between p-aminophenol resin and salicylic acid bring the larger adsorption capacity.

scholarly journals Study on the Adsorption Kinetics of Acid Red 3B on Expanded Graphite

2008 ◽  
Vol 5 (4) ◽  
pp. 802-809 ◽  
Author(s):  
Xiu-yan Pang ◽  
Fei Gong
Keyword(s):  
Activation Energy ◽  
Adsorption Kinetics ◽  
Adsorption Process ◽  
Expanded Graphite ◽  
Chemical Oxidation ◽  
Adsorption Rate ◽  
Order Kinetic ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Rate Limiting

Expanded graphite (EG) is a kind of important adsorbent for organic compound such as oil and dyes. We have investigated the adsorption kinetics characteristics of this adsorbent for dye. EG was prepared with 50 mesh crude graphite through chemical oxidation intercalation of potassium permanganate and vitriol, and dye of acid red 3B was used as model sorbate. We have studied the adsorption kinetic models and rate-limiting step of the process. Adsorption rate and activation energy of the adsorption process were calculated. Kinetic studies show that the kinetic data are well described by the pseudo second-order kinetic model. The equilibrium adsorbance increases with the increase of the initial acid red 3B concentration. Initial adsorption rate increases with the increase of the initial dye concentration and temperature. Adsorption process of acid red 3B on EG has small activation energy. Internal diffusion appears to be the rate-limiting step for the adsorption process.

scholarly journals THE STUDY OF ADSORPTION CAPACITY ON BONE CHAR IN WASTEWATER TREATMENT CONTAINED ARSENIC ION

2020 ◽  
Vol 39 (03) ◽  
Author(s):  
VO THANH CONG ◽  
DO QUY DIEM ◽  
NGUYEN VAN SON
Keyword(s):  
Wastewater Treatment ◽  
Optimal Condition ◽  
Adsorption Capacity ◽  
Adsorption Process ◽  
Bone Char ◽  
Positive Research ◽  
Arsenic Adsorption ◽  
Experimental Performance ◽  
Adsorption Time ◽  
Initial Concentration

Wastewater treatment is one of the urgent and important issues in environmental protection. Nowadays, many methods to treat wastewater in industry were found to which adsorption applied as an effective method. Among possible adsorbents, bone char appeared to be of important application especially for heavy metals. In this study, we are applied char bone char sample as an adsorbent at optimal condition on previous investigation to adsorb arsenic ion (type of As5+ ion) contained in wastewater. The detail in experimental performance, the initial concentration, capacity adsorption, and adsorption time at optimal condition of arsenic ion solution were examined. The results of arsenic adsorption process were found that the optimization of initial concentration to be As5 sample with adsorption capacity of 0.124 mg arsenic ion/g bone char at time of 60 minute. In addition, the optimal adsorption time on As5 sample was also determined as 90 minutes with capacity adsorption of 0.02 mg arsenic ion/ g bone char. The positive research results of the adsorption on bone char have pointed out a possible application of bone char as an adsorbent in future.

scholarly journals Removal of triphenylmethane dye from aqueous solutions through an adsorption process over waste materials

2020 ◽  
Vol 10 (4) ◽  
pp. 5772-5779
Keyword(s):  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Dye Removal ◽  
Functional Group ◽  
Adsorption Process ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Pseudo Second Order ◽  
Best Fit

Water pollution is the most significant issue due to rapid growing industrial development especially textile dye industry. Therefore, the adsorption process experiment was conducted to determine the removal ability of the adsorbent chosen. The removal rate and adsorption capacity of Phenol red and Cresol were analyzed by using eggshell adsorbent in the adsorption process. The experiment was conducted with parameters of initial concentration, dosage, pH and contact time. Results indicated that the removal rate achieved more than 90% and the adsorption capacity exceeded more than 5 mg/g. The functional group before adsorption process eggshell adsorbent and after adsorption process eggshell adsorbent was analyzed by using FTIR (Fourier Transform Infrared Spectroscopy). The study of adsorption isotherm and kinetics model was carried out to identify the efficiency of the eggshell adsorbent reacting with the dye solution. The adsorption isotherm that applied in this research was Langmuir isotherm, Jovanovic isotherm and Freundlich isotherm. Moreover, Pseudo-first-order and Pseudo-second-order chosen were conducted to determine the kinetic studies. In short, eggshell adsorbent is highly effective on dye removal through adsorption capacity. The functional group of the eggshell adsorbent was found such as alcohols, phenol, alkanes, carbonyls, ester, saturated aliphatic, aldehydes, aromatics, 2°amines and phosphorus. For kinetics study, Freundlich isotherm was analyzed as the best fit isotherm model as it achieved the highest R2 value which is closed to 1 and Pseudo-second-order was analyzed as the best fit kinetic model in this experiment. Therefore, eggshell adsorbent is highly effective in dye removal.

scholarly journals Sheet-like Skeleton Carbon Derived from Shaddock Peels with Hierarchically Porous Structures for Ultra-Fast Removal of Methylene Blue

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2554
Author(s):  
Panlong Dong ◽  
Hailin Liu ◽  
Shengrui Xu ◽  
Changpo Chen ◽  
Suling Feng ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Adsorption Process ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Initial Concentration ◽  
Hierarchically Porous ◽  
Column Adsorption

To remove the pollutant methylene blue (MB) from water, a sheet-like skeleton carbon derived from shaddock peels (SPACs) was prepared by NaOH activation followed by a calcination procedure under nitrogen protection in this study. Characterization results demonstrated that the as-prepared SPACs displayed a hierarchically porous structure assembled with a thin sheet-like carbon layer, and the surface area of SPAC-8 (activated by 8 g NaOH) was up to 782.2 m2/g. The as-prepared carbon material presented an ultra-fast and efficient adsorption capacity towards MB due to its macro-mesoporous structure, high surface area, and abundant functional groups. SPAC-8 showed ultrafast and efficient removal capacity for MB dye. Adsorption equilibrium was reached within 1 min with a removal efficiency of 99.6% at an initial concentration of 100 mg/g under batch adsorption model conditions. The maximum adsorption capacity for MB was up to 432.5 mg/g. A pseudo-second-order kinetic model and a Langmuir isotherm model described the adsorption process well, which suggested that adsorption rate depended on chemisorption and the adsorption process was controlled by a monolayer adsorption, respectively. Furthermore, column adsorption experiments showed that 96.58% of MB was removed after passing through a SPAC-8 packed column with a flow rate of 20 mL/min, initial concentration of 50 mg/L, and adsorbent dosage of 5 mg. The as-prepared adsorbent displays potential value in practical applications for dye removal due to its ultrafast and efficient adsorption capacity.

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.

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