scholarly journals Adsorption of Chromium(VI) on Radiation Grafted N,N-dimethylaminoethylmethacrylate onto Polypropylene, from Aqueous Solutions

2017 ◽  
Vol 57 (2) ◽  
Author(s):  
Guillermina Burillo ◽  
Juan Serrano-Gómez ◽  
Juan Bonifacio-Martínez
Keyword(s):  
Contact Time ◽  
Metal Ion ◽  
Adsorption Process ◽  
Maximum Adsorption Capacity ◽  
Ion Adsorption ◽  
Initial Concentration ◽  
Chromium Vi ◽  
Adsorption Data ◽  
Initial Ph ◽  
Chromium Adsorption

Polypropylene (PP) grafted with dimethylaminoethylmethacrylate (DMAEMA), was prepared by irradiation with a <sup>60</sup>Co γ source. The obtained PP-<em>g</em>-DMAEMA was used to study the Cr(VI) ion adsorption as a function of contact time, initial pH, initial concentration of metal ion and temperature. Chromium adsorption data on PP-<em>g</em>-DMAEMA at various initial concentration fit well the Freundlich and Langmuir isotherms. The maximum adsorption capacity (a<sub>max</sub>) was found to be 0.3103 × 0<sup>-4</sup> mol g<sup>-1</sup>. The thermodynamic parameters ΔH<sup>0</sup>, ΔG<sup>0</sup> and ΔS<sup>0</sup> were estimated showing the adsorption process to be exothermic and spontaneous.

scholarly journals Uptake of CrO42- Ions by Fe-Treated Tri-Calcium Phosphate

2019 ◽  
Vol 54 (1) ◽  
Author(s):  
Juan Serrano-Gómez ◽  
Jorge Luis Ramírez-Sandoval ◽  
Juan Bonifacio- Martínez ◽  
Francisco Granados-Correa ◽  
Verónica Elizabeth Badillo-Almaraz
Keyword(s):  
Calcium Phosphate ◽  
Contact Time ◽  
Metal Ion ◽  
Freundlich Isotherm ◽  
Chromium Concentration ◽  
Ion Adsorption ◽  
Batch Experiments ◽  
Initial Concentration ◽  
Adsorption Data ◽  
Chromium Adsorption

CrO42- ion adsorption on Fe-treated tri-calcium phosphate was studied by batch experiments as a function of contact time, initial concentration of metal ion and temperature. Adsorption results showed that at pH 5.5 and 1.0x10-4 M chromium concentration the adsorption capacity of Fe-treated tri-calcium phosphate for CrO42- ions was 7.10x10-3 mmol/g. Chromium adsorption data on Fe-treated tri-calcium phosphate at various initial concentration fitted the Freundlich isotherm. By temperature studies the thermodynamic parameters ∆H0, ∆G0 and ∆S0 were estimated and the obtained results showed that the adsorption reaction was endothermic and spontaneous.    

scholarly journals Ricinus CommunisPericarp Activated Carbon Used as an Adsorbent for the Removal of Ni(II) From Aqueous Solution

2008 ◽  
Vol 5 (4) ◽  
pp. 761-769 ◽  
Author(s):  
S. Madhavakrishnan ◽  
K. Manickavasagam ◽  
K. Rasappan ◽  
P. S. Syed Shabudeen ◽  
R. Venkatesh ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Activated Carbon ◽  
Contact Time ◽  
Metal Ion ◽  
Ricinus Communis ◽  
Ion Concentration ◽  
Batch Mode ◽  
Adsorption Data ◽  
Initial Ph

Activated carbon prepared from Ricinus communis Pericarp was used to remove Ni(II) from aqueous solution by adsorption. Batch mode adsorption experiments are carried out by varying contact time, metal-ion concentration, carbon concentration and pH to assess kinetic and equilibrium parameters. The adsorption data were modeled by using both Langmuir and Freundlich classical adsorption isotherms. The adsorption capacity (Qo) calculated from the Langmuir isotherm was 31.15 mg/g of activated carbon at initial pH of 5.0±0.2 for the particle size 125-250 µm.

Extraction of Heavy Metals from Aqueous Medium by Husk Biomass: Adsorption Isotherm, Kinetic and Thermodynamic study

2019 ◽  
Vol 233 (2) ◽  
pp. 201-223 ◽  
Author(s):  
Khalida Naseem ◽  
Rahila Huma ◽  
Aiman Shahbaz ◽  
Jawaria Jamal ◽  
Muhammad Zia Ur Rehman ◽  
...  
Keyword(s):  
Metal Ions ◽  
Aqueous Medium ◽  
Contact Time ◽  
Metal Ion ◽  
Adsorption Process ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adsorbent Dosage ◽  
Adsorption Sites ◽  
Order Kinetic Model

Abstract This study describes the adsorption of Cu (II), Co (II) and Ni (II) ions from wastewater on Vigna radiata husk biomass. The ability of adsorbent to capture the metal ions has been found to be in the order of Ni (II)>Co (II) and Cu (II) depending upon the size and nature of metal ions to be adsorbed. It has been observed that percentage removal of Cu (II), Co (II) and Ni (II) ions increases with increase of adsorbent dosage, contact time and pH of the medium but up to a certain extent. Maximum adsorption capacity (qmax) for Cu (II), Co (II) and Ni (II) ions has been found to be 11.05, 15.04 and 19.88 mg/g, respectively, under optimum conditions of adsorbent dosage, contact time and pH of the medium. Langmuir model best fits the adsorption process with R2 value approaches to unity for all metal ions as compared to other models because adsorption sites are seemed to be equivalent and only monolayer adsorption may occur as a result of binding of metal ion with a functional moiety of adsorbent. Pseudo second order kinetic model best interprets the adsorption process of Cu (II), Co (II) and Ni (II) ions. Thermodynamic parameters such as negative value of Gibbs energy (∆G°) gives information about feasibility and spontaneity of the process. Adsorption process was found to be endothermic for Cu (II) ions while exothermic for Co (II) and Ni (II) ions as signified by the value of enthalpy change (∆H°). Husk biomass was recycled three times for removal of Ni (II) from aqueous medium to investigate its recoverability and reusability. Moreover V. radiata husk biomass has a potential to extract Cu (II) and Ni (II) from electroplating wastewater to overcome the industrial waste water pollution.

scholarly journals Equilibrium and kinetic studies of Cr (VI) removal from synthetic wastewater by Acroptilon repense flower powder

2013 ◽  
Vol 15 (2) ◽  
pp. 40-47 ◽  
Author(s):  
Mohammad Taghi Ghaneian ◽  
Mohammad Hasan Ehrampoush ◽  
Asghar Mosleh Arany ◽  
Behzad Jamshidi ◽  
Mahboobeh Dehvari
Keyword(s):  
Contact Time ◽  
Kinetic Studies ◽  
Synthetic Wastewater ◽  
Initial Concentration ◽  
Russian Knapweed ◽  
Adsorbate Concentration ◽  
Adsorption Data ◽  
Pseudo Second Order ◽  
Chromium Adsorption ◽  
Acroptilon Repens

In this study the removal of Cr (VI) from synthetic wastewater was investigated using Acroptilon repens (Russian Knapweed) flower powder under various conditions (pH, contact time and initial concentration of Cr). The capacity of chromium adsorption at equilibrium conditions by this biosorbent was increased by adsorbate concentration. The results also showed that the removal efficiency of Cr (VI) was increased by increasing the contact time. By increasing the initial concentration of Cr (VI) solution, chromium removal was reduced. The suitability of adsorbents and their constants was tested or evaluated with the Langmuir, Freundlich and Temkin isotherms models. The results indicated that the Freundlich and Langmuir models (R2 > 0.99) gave a better concordance to the adsorption data in comparison with the Temkin equation (R2 = 0.97). The adsorption of Cr (VI) followed the pseudo-second-order kinetics (R2 = 0.991). The study showed that Acroptilon repens flower powder can be used as an effective lignocellulosic biomaterial and biosorbent for the removal of Cr (VI) from wastewater.

scholarly journals Al (III) removal from wastewaters by natural clay and coconut shell

2019 ◽  
Keyword(s):  
Aqueous Solutions ◽  
Contact Time ◽  
Acid Treatment ◽  
Adsorption Process ◽  
Coconut Shell ◽  
Maximum Adsorption Capacity ◽  
Agitation Rate ◽  
Batch Experiments ◽  
Natural Clay ◽  
Initial Ph

<p>This paper describes the adsorption of Al3+ ions from aqueous solutions, by natural clay (from Sakarya's Yenigün district) and coconut shell modified by means of acid treatment. Batch experiments were carried out to determine the effect of various factors such as initial pH (4-9), temperature (20, 40, 70 oC), initial concentration (10 to 200 mg L-1) and contact time (1-120 minute) on the adsorption process. The adsorption experiments were performed at a temperature of 20 ±2 oC), at 200 rpm agitation rate, with an adsorbent level of 1 g L-1, produced 98.95% (at pH 6) and 92.83% (at pH 7) maximum Al3+ removal efficiency for clay and coconut shell based adsorbents respectively. Furthermore, the process was found to be exothermic for clay and endothermic for coconut. XRF and XRD analyses of the clay variety used in adsorption analyses revealed it to be saponite clay, within the larger group of smectite clay minerals. The application of Langmuir revealed maximum adsorption capacity of 149.25 mg g-1 for natural clay adsorbent (NCA), and 120.482 mg g-1 for coconut shell adsorbent (CSA). Moreover, adsorption kinetics were found to be consistent with the second order kinetics (R2 &gt; 0.95). The result shows that, natural clay and coconut shell adsorbents are effective adsorbents to remove Al3+ from aqueous solutions with good adsorption rate (&gt;92.8%).</p>

scholarly journals Kinetics and Thermodynamics Studies of Copper(II) Adsorption onto Activated Carbon Prepared from Salacca zalacca Peel

Molekul ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 63
Author(s):  
Dewi Yuanita Lestari ◽  
Endang Widjajanti Laksono
Keyword(s):  
Activated Carbon ◽  
Contact Time ◽  
Metal Ion ◽  
Adsorption Process ◽  
Biogenic Carbon ◽  
Adsorption Data ◽  
Batch Technique ◽  
Langmuir Isotherm Model ◽  
G Value ◽  
Highly Porous

Highly porous and stable materials, such as alumina, silica, carbon, zeolite, and bentonite,  are well known and have been used as metal ion adsorbents. However, the use of biogenic carbon as adsorbent is relatively rare. The adsorption of copper(II) onto activated carbon extracted from Salcaca zalacca peel was studied. The effect of initial copper concentration, contact time, and a series temperature was studied. Adsorption was carried out in a batch technique. The adsorption equilibrium was reached after 60 minutes of contact time. The adsorption data had a better fitting line for the Langmuir isotherm model. The Langergren and also Ho and Mc Kay equations were used to predict the adsorption kinetics. The adsorption process obeyed a second-order kinetics model. The Thermodynamic parameters were ∆H°= -42.4180 kJ/mol; ∆S°= -0.0843 kJ/mol; ∆G°<0. These values indicated that the adsorption was exothermic and spontaneous. The low ∆G° value revealed that the main mechanism controlling the adsorption process was physisorption.

Use of Fly Ash in the Removal of Copper, Nickel and Zinc from Wastewater

1993 ◽  
Vol 28 (2) ◽  
pp. 369-384 ◽  
Author(s):  
T. Viraraghavan ◽  
Murali M. Dronamraju
Keyword(s):  
Fly Ash ◽  
Thermodynamic Parameters ◽  
Contact Time ◽  
Adsorption Process ◽  
Initial Concentration ◽  
Copper Nickel ◽  
Adsorption Data ◽  
Ph Range ◽  
Langmuir And Freundlich Models

Abstract The effectiveness of fly ash in adsorbing copper, nickel and zinc was studied by conducting batch kinetic and isotherm studies. The effect of contact time, pH, initial concentration of the adsorbate, and temperature on the adsorption process was studied. Fly ash was found to be an effective adsorbent. The contact time necessary to attain equilibrium was found to be two hours. Maximum adsorption occurred in the pH range of 3.0 to 3.5. The Langmuir and Freundlich models were found to be applicable to the adsorption data of copper, nickel and zinc. Thermodynamic parameters suggested the exothermic nature of the adsorption process.

scholarly journals Modeling and Optimizing of NH4+ Removal from Stormwater by Coal-Based Granular Activated Carbon Using RSM and ANN Coupled with GA

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 608
Author(s):  
Aixin Yu ◽  
Yuankun Liu ◽  
Xing Li ◽  
Yanling Yang ◽  
Zhiwei Zhou ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Contact Time ◽  
Adsorption Process ◽  
Removal Rate ◽  
Granular Activated Carbon ◽  
Operating Conditions ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Initial Concentration ◽  
Rsm Optimization

As a key parameter in the adsorption process, removal rate is not available under most operating conditions due to the time and cost of experimental testing. To address this issue, evaluation of the efficiency of NH4+ removal from stormwater by coal-based granular activated carbon (CB-GAC), a novel approach, the response surface methodology (RSM), back-propagation artificial neural network (BP-ANN) coupled with genetic algorithm (GA), has been applied in this research. The sorption process was modeled based on Box-Behnben design (BBD) RSM method for independent variables: Contact time, initial concentration, temperature, and pH; suggesting a quadratic polynomial model with p-value < 0.001, R2 = 0.9762. The BP-ANN with a structure of 4-8-1 gave the best performance. Compared with the BBD-RSM model, the BP-ANN model indicated better prediction of the response with R2 = 0.9959. The weights derived from BP-ANN was further analyzed by Garson equation, and the results showed that the order of the variables’ effectiveness is as follow: Contact time (31.23%) > pH (24.68%) > temperature (22.93%) > initial concentration (21.16%). The process parameters were optimized via RSM optimization tools and GA. The results of validation experiments showed that the optimization results of GA-ANN are more accurate than BBD-RSM, with contact time = 899.41 min, initial concentration = 17.35 mg/L, temperature = 15 °C, pH = 6.98, NH4+ removal rate = 63.74%, and relative error = 0.87%. Furthermore, the CB-GAC has been characterized by Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET). The isotherm and kinetic studies of the adsorption process illustrated that adsorption of NH4+ onto CB-GAC corresponded Langmuir isotherm and pseudo-second-order kinetic models. The calculated maximum adsorption capacity was 0.2821 mg/g.

scholarly journals Comparative Biosorption Studies of Hexavalent Chromium Ion onto Raw and Modified Palm Branches

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Mona A. Shouman ◽  
Nady A. Fathy ◽  
Soheir A. Khedr ◽  
Amina A. Attia
Keyword(s):  
Adsorption Process ◽  
Isotherm Models ◽  
Ammonium Bromide ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Chemically Modified ◽  
Chromium Vi ◽  
Adsorption Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The waste of palm branches (PB) was tested for its ability to remove chromium (VI) from aqueous solution by batch and column experiments. Palm branches chemically modified with an oxidizing agent (sulphuric acid) then coated with chitosan and surfactant (hexadecyl trimethyl ammonium bromide surfactant, HDTMA), respectively, were carried out to improve the removal performance of PB. The results of their Cr (VI) removal performances are pH dependent. The adsorption data could be well interpreted by the Langmuir, Freundlich, and Flory-Huggins isotherm models. The maximum adsorption capacity obtained from the Langmuir model for the chitosan coated oxidized palm branches is 55 mg/mg. The adsorption process could be described by pseudo-second-order kinetic model. The intraparticle diffusion study revealed that film diffusion might be involved. The biosorbents were successfully regenerated using 1 M HCL solution.

Chromium Removal from Aqueous Solution by Microwave-Modified Phosphogypusum

2014 ◽  
Vol 955-959 ◽  
pp. 16-20 ◽  
Author(s):  
Ping Ning ◽  
Lei Shi ◽  
Yue Hong Yang ◽  
Yang Cheng
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Adsorption Process ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Freundlich Model ◽  
Chromium Vi ◽  
Removal Capacity ◽  
Ph Range ◽  
Best Fit

The removal of chromium (VI) ions from aqueous solution by microwave-modified phosphogypsum was studied. The removal capacity of microwave-modified phosphogypsum for chromium (VI) ions was examined as a function of solution pH, contact time, adsorbent dosage. Before a series of the adsorption studies, phosphogypsum was pre-conditioned with microwave. It was observed that the adsorption of the chromium (VI) ions onto the phosphogypsum in the pH range of 2 and 11. The chromium (VI) adsorption process was described with the Langmuir and Freundlich theories, and the Freundlich model indicated the best fit to the adsorption process. Maximum adsorption capacity of microwave-modified phosphogypsum was found to be 3.126 mg g−1. The results proved that the microwave-modified phoshogypsum is a suitable adsorbent for the removal of chromium (VI) ions from aqueous solution.

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