scholarly journals Arsenic Adsorption Characteristics of Adsorbent Prepared From Spinacia oleracea (Spinach) Leaves

2021 ◽  
Vol 14 (14) ◽  
pp. 51-61
Author(s):  
Prakash Kumar Jha ◽  
Vinay Kumar Jha
Keyword(s):  
Optical Microscopy ◽  
Adsorption Process ◽  
Spinacia Oleracea ◽  
Fine Powder ◽  
Xrd Analysis ◽  
Ion Concentration ◽  
Maximum Adsorption Capacity ◽  
Arsenic Adsorption ◽  
Adsorption Method ◽  
Spinach Leaves

The dry spinach leaves fine powder was modified by activation with conc. H2SO4 and the adsorbent material was then characterized by using FTIR, EDX, optical microscopy, XRD analysis and methylene blue adsorption method. The EDX result showed about 95 % carbon in the adsorbent material. The maximum specific surface area measured was 499 m2/g. The weak and broad XRD diffraction peaks at 2θ angles 20.5 and 42° were characterized as of activated carbon with the appearance of sharp peak of SiO2 at 2θ angle 26.37°. Optical microscopy Image analysis showed the Porous nature of adsorbents. The adsorption of arsenite on the modified spinach leaves powder adsorbent was investigated by varying different experimental parameters such as pH, adsorbent dose, contact time and As (Ⅲ) ion concentration. The adsorption process was found to be best fitted to Langmuir adsorption isotherm model controlled by pseudo-second–order kinetics with the rate constant value 0.01830 g/(mg·min). The maximum adsorption was observed at pH 6 at room temperature. The maximum adsorption capacity for As (Ⅲ) on modified spinach leaves powder was found to be 58.480 mg/g. The value of ∆G was -22 kJ/mole which confirmed the adsorption process was favored by physisorption. The slope of the linear plot of Qt vs t0.5 was linear but not passed through the origin, which indicates that, the intraparticle diffusion was not only rate controlling step.

scholarly journals Iodine adsorption characteristics of activated carbon obtained from Spinacia Oleracea (spinach) leaves

2020 ◽  
Vol 21 (47) ◽  
pp. 1-11
Author(s):  
Prakash Kumar Jha ◽  
Vinay Kumar Jha
Keyword(s):  
Methylene Blue ◽  
Adsorption Process ◽  
Spinacia Oleracea ◽  
Xrd Analysis ◽  
Maximum Adsorption Capacity ◽  
Adsorption Method ◽  
Methylene Blue Adsorption ◽  
Pseudo Second Order ◽  
G Value ◽  
Spinach Leaves

Spinach leaves powder was modified by activation with conc. H2SO4 and was characterized by using FTIR, optical microscopy, XRD analysis and methylene blue adsorption method. The maximum specific surface area measured by the Methylene blue adsorption method was 499 m2/g. The adsorption of iodine was investigated by varying parameters as pH, adsorbent dose, contact time and I2 concentration. The adsorption process was fitted to the Langmuir model controlled by pseudo - second –  order kinetics with a constant rate value of 0.00305 g/(mg·min). The maximum adsorption was at pH 10. The maximum adsorption capacity was 909.091 mg/g. The ∆G value was -25 kJ/mole, which confirmed the physico - chemcal adsorption process.

scholarly journals Studies on the Removal of Cadmium Toxic Metal Ions by Natural Clays from Aqueous Solution by Adsorption Process

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Rajaa Bassam ◽  
Achraf El hallaoui ◽  
Marouane El Alouani ◽  
Maissara Jabrane ◽  
El Hassan El Khattabi ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Process ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Toxic Metal ◽  
Ion Concentration ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Solution Ph ◽  
Natural Clays

The aim of this study is the valorization of the Moroccan clays (QC-MC and QC-MT) from the Middle Atlas region as adsorbents for the treatment of water contaminated by cadmium Cd (II) ions. The physicochemical properties of natural clays are characterized by ICP-MS, XRD, FTIR, and SEM techniques. The adsorption process is investigated as a function of adsorbent mass, solution pH, contact time, temperature, and initial Cd (II) ion concentration. The kinetic investigation shows that the adsorption equilibrium of Cd (II) ions by both natural clays is reached after 30 min for QC-MT and 45 min for QC-MC and fits well to a pseudo-second-order kinetic model. The isotherm study is best fitted by a Freundlich model, with the maximum adsorption capacity determined by the linear form of the Freundlich isotherm being 4.23 mg/g for QC-MC and 5.85 mg/g for QC-MT at 25°C. The cadmium adsorption process was thermodynamically spontaneous and exothermic. The regeneration process showed that these natural clays had excellent recycling capacity. Characterization of the Moroccan natural clays before and after the adsorption process through FTIR, SEM, XRD, and EDX techniques confirmed the Cd (II) ion adsorption on the surfaces of both natural clay adsorbents. Overall, the high adsorption capacity of both natural clays for Cd (II) ions removal compared to other adsorbents motioned in the literature indicated that these two natural adsorbents are excellent candidates for heavy metal removal from aqueous environments.

Utilization of Fe-Oxide Composites for as Removal from Aqueous Solutions

2017 ◽  
Vol 262 ◽  
pp. 630-633
Author(s):  
Alexandra Bekényiová ◽  
Zuzana Danková ◽  
Iveta Štyriaková ◽  
Darina Štyriaková
Keyword(s):  
Metal Ion ◽  
Ion Concentration ◽  
Maximum Adsorption Capacity ◽  
Arsenic Adsorption ◽  
Fe Oxide ◽  
Two Samples ◽  
Oxide Ratio ◽  
Decreasing Ph ◽  
Oxide Composites ◽  
Oxide Sample

This work was done to assess the arsenate (AsV ) removal from the model solution by sorbents based on Fe-oxide. Two samples were compared in sorption properties, synthetically prepared Fe-oxide and bentonite/iron oxide (ratio 2:1). The effect of pH and initial metal ion concentration was investigated. The optimum pH for arsenic adsorption by both samples was found to be about 3.0. The adsorption increased very significantly with decreasing pH for both samples. The Fe-oxide sample achieved the maximum adsorption capacity 24,1 mg.g-1 AsV at pH 3, composite sample 14,1 mg.g -1 AsV at pH 3. The adsorption of AsV on Fe-oxide sample increased with the increasing initial metal ion concentration up to 40 mg/l and then equilibrium was established, by contrast of bentonite/Fe-oxide sample shown no significant change at this concentration range.

scholarly journals Poly (furfural-acetone) as New Adsorbent for Removal of Cu(II) from Aqueous Solution: Equilibrium Study

2010 ◽  
Vol 7 (1) ◽  
pp. 157-165 ◽  
Author(s):  
Tariq S. Najim
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Sorption Process ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Initial Concentration ◽  
Equilibrium Study ◽  
Optimum Ph ◽  
Percent Removal

The batch removal of Cu(II) from aqueous solution using poly (furfural-acetone), (PFA) as adsorbent was investigated in this study. The influences of initial Cu(II) ion concentration (10 to 120 ppm), pH (4-8) and contact time have been reported. Adsorption of Cu(II) is highly pH-dependent and the result indicate that the optimum pH for the removal was found to be 6. At this pH a small amount of PFA, 2 g/L, could remove as much as 97% of Cu(II) from a solution of initial concentration 10 ppm. It was observed that an increase in initial concentration of Cu(II) leads to decrease in percent removal of Cu(II) and increase in amount of Cu(II) adsorbed per unit mass of PFA. The adsorption process of Cu(II) is tested with four isotherm models, Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (D-R). It was found that all models were applicable and the maximum adsorption capacity was found to be 13.66 mg/g. From the isotherm constants it was confirmed that, the sorption process was physisorption.

scholarly journals Adsorptive Removal of Fe (II) By NaOH Treated Rice Husk: Adsorption Equilibrium And Kinetics

2021 ◽  
Vol 14 (14) ◽  
pp. 75-82
Author(s):  
Sunita Shrestha ◽  
Anita Kumari Dhami ◽  
Armila Rajbhandari Nyachhyon
Keyword(s):  
Surface Area ◽  
Rice Husk ◽  
Adsorption Process ◽  
Low Cost ◽  
Second Order ◽  
Maximum Efficiency ◽  
Maximum Adsorption Capacity ◽  
Adsorption Method ◽  
Equilibrium And Kinetics ◽  
Pseudo Second Order

The low cost adsorbents were prepared from raw rice husk (RRH) and NaOH treated rice husk (NRH). Then prepared materials were characterized by XRD, FTIR and surface area of rice husk adsorbent were determined by methylene blue adsorption method. XRD showed amorphous nature with low crystallinity of the material. The FTIR spectra showed the presence of oxygenated functional groups such as ester, phenol, carbonyl and silica on the material. The surface area of RRH and NRH were found to be 387 and 417 m2/g respectively. Thus, prepared adsorbents were used for the removal of Fe(II) ion from aqueous solution. The influence of various parameters like pH, adsorbent doge, and contact time were studied for the better adsorption of Fe(II) on rice husk adsorbents. Results revealed that the maximum efficiency was achieved at pH 3 for Fe(II). The adsorption process was found to be best fitted to Langmuir adsorption isotherm model controlled by pseudo-second–order kinetics with the rate constant value i.e. 0.0218 and 0.0235 g/(mg·min) for RRH and NRH respectively.  The χ2 values of pseudo second order was found to be lower which confirmed chemisorption, involving ion exchange and valence forces through sharing or exchange of electrons between adsorbent and adsorbate. The maximum adsorption capacity for Fe(II) on RRH and NRH was found to be 2.9 mg/g and 5.6 mg/g respectively. The positive ∆G value represents the randomness of the system during adsorption process. The slope of the linear plot of Qt vs t0.5 was linear but not passed through the origin, which indicates that, the intraparticle diffusion was not only rate controlling step. Temkin value showed the maximum binding energy (KT) for NRH was 16.4 L/g and for RRH it was 12.2 L/g. 

scholarly journals Study of an adsorption method for trace mercury based on Bacillus subtilis

2021 ◽  
Vol 19 (1) ◽  
pp. 1164-1170
Author(s):  
Yijin Li ◽  
Shanhong Xia
Keyword(s):  
Bacillus Subtilis ◽  
Optical Microscopy ◽  
Functional Groups ◽  
Adsorption Mechanism ◽  
Adsorption Process ◽  
Mercury Determination ◽  
Adsorption Efficiency ◽  
Adsorption Method ◽  
Adsorption Performance ◽  
Highly Efficient

Abstract In order to decrease the difficulty in trace mercury determination, an adsorption method for trace mercury based on Bacillus subtilis cells was proposed in this article. The adsorption process was characterized by optical microscopy and SEM. The adsorption mechanism was analyzed by IR. The adsorption performance was studied by measuring the concentration of supernate and calculating the adsorption efficiency. When adsorbing Hg2+, Bacillus subtilis cells gathered and their structure turned coarse. The IR results illustrated that functional groups bound with Hg for complexation during adsorption. Bacillus subtilis completed adsorption for trace Hg2+ in 15 min. The adsorption efficiency was maintained above 80% under low Hg2+ concentrations (<200 µg/L). The proposed study illustrates that Bacillus subtilis cells are highly efficient and easily obtained material for the adsorption of trace mercury, which shows potential to be further used in the pretreatment of trace Hg2+ detection.

scholarly journals Kinetic, Isotherm, and Thermodynamic Studies for Ag(I) Adsorption Using Carboxymethyl Functionalized Poly(glycidyl methacrylate)

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1090 ◽  
Author(s):  
Jiling Zhao ◽  
Shixing Wang ◽  
Libo Zhang ◽  
Chen Wang ◽  
Bing Zhang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Glycidyl Methacrylate ◽  
Adsorption Process ◽  
Removal Rate ◽  
Single Layer ◽  
Silver Ions ◽  
Ion Concentration ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Kinetics And Isotherms

Industrial wastewater contains large amounts of silver ions. Here, a new adsorbent was synthesized by functionalizing poly(glycidyl methacrylate) with carboxymethyl groups. The adsorbent was used to recover Ag(I) in wastewater. Fourier transform infrared spectroscopy, zeta potential, scanning electron microscopy, and X-ray photoelectron spectroscopy were used to characterize the adsorbent. The experimental parameters affecting the adsorption are solution pH, contact time, and initial silver ion concentration. The optimum pH for adsorption of Ag(I) is pH 4. The maximum adsorption capacity at pH 4 is 157.05 mg/g, and the adsorption reaches equilibrium at 300 min. The kinetics and isotherms of the adsorption process were described by pseudo second-order, Langmuir and D-R models, respectively. The adsorption process was a single layer chemical adsorption, exothermic, feasible, and spontaneous. The adsorption mechanism is electrostatic or chelation. The adsorbent selectively absorbed Ag(I) from coexisting ions (Cu2+, Ni2+, Co2+, Zn2+). Finally, the removal rate of silver ions decreased from 79.29% to 65.01% after four repetitive experiments, which proved that the adsorbent had good reusability. The adsorbent has great potential benefit in removing Ag(I).

scholarly journals Fe(OH)3/kaolinite nanoplatelets: Equilibrium and thermodynamic studies for the adsorption of Pb(II) ions from aqueous solution

2021 ◽  
Author(s):  
CI Chemistry International
Keyword(s):  
Adsorption Capacity ◽  
Langmuir Isotherm ◽  
Metal Ion ◽  
Adsorption Process ◽  
Ion Concentration ◽  
Maximum Adsorption Capacity ◽  
Clay Deposits ◽  
Effects Of Ph ◽  
Langmuir Isotherm Model ◽  
Removal Of Metal Ions

Development of a sustainable route for preparation Fe(OH)3/kaolinite nanoplatelets from Batin El-Ghoul clay deposits, south Jordan with uniform plate-like morphology. Fe(OH)3/kaolinite nanoplatelets is an efficient adsorbent for the removal of Pb(II) ions from aqueous solutions. Effects of pH solution, adsorbent dose, initial metal ion concentration, contact time, and temperature on the adsorption process were examined. The Langmuir isotherm model is the best fit model to predict the experimental data and the adsorption capacity. Maximum adsorption capacity on Langmuir isotherm was 370.37 mg/g. Thermodynamic parameters revealed that the negative values of ΔGo and the positive value of ΔHo, the adsorption process was spontaneous and endothermic. Results revealed that Fe(OH)3/kaolinite is promising for the removal of metal ions from effluents.

Purification of water contaminated with heavy metals by example of lead as promising material based on graphene nanostructures

2020 ◽  
pp. 34-43
Author(s):  
N. R. Memetov ◽  
◽  
A. V. Gerasimova ◽  
A. E. Kucherova ◽  
◽  
...  
Keyword(s):  
Adsorption Process ◽  
Phenol Formaldehyde ◽  
Phenol Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Parameter Estimates ◽  
Maximum Adsorption Capacity ◽  
Ecological Situation ◽  
Characteristic Parameters ◽  
Purification Of Water ◽  
Graphene Nanostructures

The paper evaluates the effectiveness of the use of graphene nanostructures in the purification of lead (II) ions to improve the ecological situation of water bodies. The mechanisms and characteristic parameters of the adsorption process were analyzed using empirical models of isotherms at temperatures of 298, 303, 313 and 323 K, which correspond to the following order (based on the correlation coefficient): Langmuir (0.99) > Temkin (0.97) > Dubinin – Radushkevich (0.90). The maximum adsorption capacity of the material corresponds to the range from 230 to 260 mg/g. We research the equilibrium at the level of thermodynamic parameter estimates, which indicates the spontaneity of the process, the endothermic nature and structure change of graphene modified with phenol-formaldehyde resin during the adsorption of lead (II) ions, leading to an increase in the disorder of the system.

As(III) Removal by Dynamic Adsorption onto Amberlite XAD7 Functionalized with Crown Ether and Doped with Fe(III) Ions

2019 ◽  
Vol 70 (7) ◽  
pp. 2330-2334
Author(s):  
Mihaela Ciopec ◽  
Adina Negrea ◽  
Narcis Duteanu ◽  
Corneliu Mircea Davidescu ◽  
Iosif Hulka ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Arsenic Removal ◽  
Arsenic Concentration ◽  
Fixed Bed ◽  
World Health ◽  
Arsenic Content ◽  
Arsenic Adsorption ◽  
Stage Of Development ◽  
Wide Range ◽  
Health Organization

Arsenic content in groundwater�s present a wide range of concentration, ranging from hundreds of micrograms to thousands of micrograms of arsenic per litter, while the maximum permitted arsenic concentration established by World Health Organization (WHO) is 10 mg L-1. According to the WHO all people, regardless of their stage of development and their social economic condition, have the right to have access to adequate drinking water. The most efficient and economic technique used for arsenic removal is represented by adsorption. In order to make this remediation technique more affordable and environmentally friendly is important to new materials with advance adsorbent properties. Novelty of present paper is represented by the usage of a new adsorbent material obtained by physical - chemical modification of Amberlite XAD polymers using crown ethers followed by iron doping, due to well-known affinity of arsenic for iron ions. Present paper aims to test the obtained modified Amberlite polymer for arsenic removal from real groundwater by using adsorption in a fixed bed column, establishing in this way a mechanism for the adsorption process. During experimental work was studied the influence of competing ions from real water into the arsenic adsorption process.

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