scholarly journals Evaluation of Cd(II) Ion Removal from Aqueous Solution by a Low-Cost Adsorbent Prepared from White Yam (Dioscorea rotundata) Waste Using Batch Sorption

2018 ◽  
Vol 2 (3) ◽  
pp. 35 ◽  
Author(s):  
Edidiong Asuquo ◽  
Alastair Martin ◽  
Petrus Nzerem
Keyword(s):  
Aqueous Solution ◽  
Langmuir Isotherm ◽  
Metal Ion ◽  
Aqueous System ◽  
Ion Concentration ◽  
Dioscorea Rotundata ◽  
First Order ◽  
White Yam ◽  
Pseudo First Order ◽  
Adsorbent Dose

An agricultural residue, white yam (Dioscorea rotundata) tuber peel (YTBS), was used for the removal of Cd(II) ion from an aqueous solution using a batch method. The adsorbent was characterized using FTIR, TGA, SEM, EDX, N2 BET, XRD, and XRF. The optimization of sorption variables such as pH, contact time, adsorbent dose, and initial metal ion concentration at 25 °C were also carried out. The results indicated the dependence of sorption on the adsorbate pH and adsorbent dose, while the adsorption system reached equilibrium in 180 min. The sorption kinetics was fitted to three models (pseudo first order, pseudo second order, and Elovich) to validate the kinetics, and the pseudo first order was the best model for the description of Cd(II) uptake. Equilibrium isotherm modelling was also carried out using the Langmuir, Freundlich, and Temkin models, with the Langmuir isotherm giving the best fitting to the experimental results. The maximum loading capacity (qmax) of the adsorbent for Cd(II) obtained from the Langmuir isotherm model was 22.4 mg∙g−1 with an isotherm constant (KL) of 3.46 × 10−3 L·mg−1 and r2 value of 0.99. This result indicates that the YTBS residue was a good adsorbent for the removal of Cd(II) ion from aqueous system.

scholarly journals Synthesis of citric acid-modified resins and their adsorption properties towards metal ions

2018 ◽  
Vol 5 (8) ◽  
pp. 171667 ◽  
Author(s):  
Xiong Liu ◽  
Longqi Xu ◽  
Yaqing Liu ◽  
Wenqi Zhou
Keyword(s):  
Citric Acid ◽  
Metal Ion ◽  
Adsorption Properties ◽  
Langmuir Model ◽  
Ion Concentration ◽  
First Order ◽  
Adsorption Capacities ◽  
Equilibrium Data ◽  
Pseudo First Order ◽  
Order Rate Equation

Types of resins anchored on citric acid were synthesized and identified. The citric acid-modified resins PS-CA, PS-O-CA and PS-N-CA were synthesized by anchoring citric acid on PS-Cl, PS-OH and PS-NH 2 , respectively. The PS-CA, PS-O-CA and PS-N-CA were used to adsorb Fe 3+ , Al 3+ , Cu 2+ , Pb 2+ , Cd 2+ and Hg 2+ . The influences of pH, adsorption time and metal ion concentration on the adsorption capacities of the resins were investigated. After optimization, PS-CA was a good adsorbent to Fe 3+ , Cu 2+ , Pb 2+ and Cd 2+ with q m values of 143.9 mg g −1 , 77.4 mg g −1 , 18.9 mg g −1 and 119.9 mg g −1 , respectively. PS-N-CA was a good adsorbent to Al 3+ and Hg 2+ with q m values of 176.6 mg g −1 and 114.9 mg g −1 , respectively. The adsorption kinetics and adsorption isotherm experiments indicated that the pseudo-first-order rate equation was more appropriate for characterizing the kinetic data and the Langmuir model was more suitable for fitting the equilibrium data. The reusability of the citric acid-modified resins was also evaluated and these resins exhibited considerable reusability.

scholarly journals Removal Of Copper From Aqueous Solutions By Using Natural And Fe-Modified Clinoptilolite

2015 ◽  
Vol 23 (36) ◽  
pp. 33-40
Author(s):  
Marek Lipovský ◽  
Maroš Sirotiak ◽  
Maroš Soldán
Keyword(s):  
Metal Ion ◽  
Ion Concentration ◽  
Order Kinetic ◽  
Langmuir Adsorption ◽  
First Order ◽  
Adsorption Processes ◽  
Pseudo Second Order ◽  
Pseudo First Order ◽  
Static Conditions ◽  
Modified Clinoptilolite

Abstract Removal of copper from aqueous solution on the natural and modified clinoptilolite was studied under static conditions. Batch adsorptions of copper were performed to investigate the effects of contact time and initial metal ion concentration. The Freundlich and Langmuir adsorption isotherms were used to analyse the experimental data. The kinetic analyses of the adsorption processes were performed using the pseudo-first-order and pseudo-second-order kinetic models.

scholarly journals The Kinetics of the Adsorption Process of Cr (VI) in Aqueous Solution Using Neem Seed Husk (Azadirachta indica) Activated Carbon

2020 ◽  
pp. 1-13
Author(s):  
A. A. Danmallam ◽  
W. L. Dabature ◽  
N. Y. Pindiga ◽  
B. Magaji ◽  
M. A. Aboki ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Adsorption Process ◽  
Neem Seed ◽  
First Order ◽  
Pseudo Second Order ◽  
Seed Husk ◽  
Pseudo First Order ◽  
Kinetics Of ◽  
Adsorbent Dose

The aim of this research is the study of physico-chemical properties activated carbon prepared from agricultural by product such as Neem Seed Husk (NSH) which is abundantly available in our environment The Activated Carbon (AC) was prepared using H3PO4 as activating agent and carbonized at 300°C for two hours. The results shows that the activated process was successful and can compete favorably with commercial activated carbon. The prepared activated carbon was characterized using Fourier Transform Infrared Spectrophotometer (FT-IR), Scanning Electron Microscopy (SEM), Energy Dispersion X-ray (EDX) and Thermogravimetric Analysis (TGA). The percentage removal of Cr(VI) increased with increase in process parameters such as adsorbent dose, time and temperature while there was a decrease with increase in pH and Initial concentration. It was established from the results that activated carbon produced from Neem seed husk has adsorption capacity which could remove 99.75% Cr (VI) at optimum process conditions (pH-2.0, Cr(VI) concentration-10 mg/L, adsorbent dose 0.5 g/L, Temperature 70 c and contact time 30 mins.). Thus, the adsorption method using activated carbon produced from biomass was used effectively for removing Cr(VI) in a stock solution, seems to be an economical and worthwhile alternative over other conventional methods, because of it availability, low price and multi-purposes. The adsorption data fitted well into Freundlich and Langmuir with correlation coefficient (R2) 0.9522 and 0.9403 respectively. The kinetics of the adsorption process was tested through pseudo-first-order and pseudo-second-order models. The pseudo-second-order kinetic model provided the best correlation for with (R2) 0.993, while the pseudo-first-order was found to be 0.928. The study provided an effective use of low-cost activated carbon as a valuable source of adsorbents for the removal of Cr(VI) ions from aqueous solution.

Kinetics and mechanisms of the reaction of chromium(III) and 2,4-hexanedione in aqueous solution

1989 ◽  
Vol 67 (8) ◽  
pp. 1305-1307 ◽  
Author(s):  
Carlos Blanco ◽  
José M. Hernando ◽  
Manuel Mateo
Keyword(s):  
Aqueous Solution ◽  
Concentration Dependence ◽  
Rate Constants ◽  
Metal Ion ◽  
Reversible Reaction ◽  
First Order ◽  
Pseudo First Order ◽  
Enol Tautomer ◽  
Metallic Species ◽  
Mechanism Of The Reaction

The kinetics and mechanism of the reaction between Cr(III) and 2,4-hexanedione in aqueous solution have been studied. Complexation occurs by coordination of both oxygen atoms of the ligand to the chromium(III) center, with concomitant loss of a proton yielding 1:1 complex of the type [Cr(CH3COCHCOC2H5)(H2O)4]2+. When the metal ion is in pseudo first-order excess the concentration dependence of the observed rate constants agrees with a mechanism involving reversible reaction between the enol tautomer of 2,4-hexanedione and the metallic species Cr(H2O)63+ and Cr(H2O)5OH2+, with rate constants of 8.0 × 10−4 and 3.5 × 10−2 dm3 mol−1 s−1, respectively. Keywords: chromium(III), β-diketones, β-diketonates, kinetics, complexation.

Use of agro-waste (Musa paradisiaca peels) as a sustainable biosorbent for toxic metal ions removal from contaminated water

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Contact Time ◽  
Metal Ion ◽  
Equilibrium Concentration ◽  
Ion Concentration ◽  
Contaminated Water ◽  
Musa Paradisiaca ◽  
Percentage Removal ◽  
Adsorbent Dose

A study of removal of heavy metal ions from heavy metal contaminated water using agro-waste was carried out with Musa paradisiaca peels as test adsorbent. The study was carried by adding known quantities of lead (II) ions and cadmium (II) ions each and respectively into specific volume of water and adding specific dose of the test adsorbent into the heavy metal ion solution, and the mixture was agitated for a specific period of time and then the concentration of the metal ion remaining in the solution was determined with Perkin Elmer Atomic absorption spectrophotometer model 2380. The effect of contact time, initial adsorbate concentration, adsorbent dose, pH and temperature were considered. From the effect of contact time results equilibrium concentration was established at 60minutes. The percentage removal of these metal ions studied, were all above 90%. Adsorption and percentage removal of Pb2+ and Cd2+ from their aqueous solutions were affected by change in initial metal ion concentration, adsorbent dose pH and temperature. Adsorption isotherm studies confirmed the adsorption of the metal ions on the test adsorbent with good mathematical fits into Langmuir and Freundlich adsorption isotherms. Regression correlation (R2) values of the isotherm plots are all positive (>0.9), which suggests too, that the adsorption fitted into the isotherms considered.

scholarly journals Comparative studies on the removal of copper (II) by Ulva fasciata activated carbon and commercially activated carbon

2012 ◽  
Vol 14 (4) ◽  
pp. 88-94 ◽  
Author(s):  
R.P. Suresh Jeyakumar ◽  
V. Chandrasekaran
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
Synthetic Wastewater ◽  
Batch Adsorption ◽  
First Order ◽  
Ulva Fasciata ◽  
Adsorption Data ◽  
Pseudo Second Order ◽  
Pseudo First Order ◽  
Adsorbent Dose

Abstract In this work, the efficiency of Ulva fasciata sp. activated carbons (CCUC, SCUC and SSUC) and commercially activated carbon (CAC) were studied for the removal of Cu (II) ions from synthetic wastewater. Batch adsorption experiments were carried out as a function of pH, contact time, initial copper concentration and adsorbent dose. The percentage adsorption of copper by CCUC, SSUC, SCUC and CAC are 88.47%, 97.53%, 95.78% and 77.42% respectively. Adsorption data were fitted with the Langmuir, Freundlich and Temkin models. Two kinetic models pseudo first order and the pseudo second order were selected to interpret the adsorption data.

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.

scholarly journals Kinetics and mechanism of sol-gel transformation between some trivalent- and tetravalent-metal ions and Sodium alginate Anionic polyelectrolyte with formation of coordination Biopolymeric structure polymembranes Hydrogels of Capillary Structures Ex

2007 ◽  
Vol 3 (1) ◽  
pp. 133-142 ◽  
Author(s):  
Ishaq Abdullah Zaafarany
Keyword(s):  
Sodium Alginate ◽  
Metal Ion ◽  
Sol Gel ◽  
Coordination Geometry ◽  
Large Excess ◽  
First Order ◽  
Pseudo First Order ◽  
The Stability ◽  
Kinetics Of ◽  
Overall Kinetics

Abstract          The kinetics of sol-gel transformation between A13+, La 3+ and Th4+ metal ion electrolytes and sodium alginate sol have been studied complexometrically at various  temperatures. In the presence of a large excess of sodium alginate sol concentration over that of metal ion electrolyte, the pseudo first–order plots of exchange showed sigmoidal curves with two distinct stages. The initial part was relatively fast and curved significantly at early times, followed by a slow decrease in the rates of exchange over longer time periods. The rate constants of gelation showed second-order overall kinetics which was first order in the concentration of both reactants. The thermodynamic parameters have been evaluated and tentative gelation mechanisms consistent with the kinetic results of gelation are suggested. The stability of these ionotropic metal-alginate complexes has been discussed in terms of the coordination geometry and strength of chelated bonds.

scholarly journals Photocatalytic degradation of sulfamethazine in aqueous solution using ZnO with different morphologies

2018 ◽  
Vol 5 (4) ◽  
pp. 171457 ◽  
Author(s):  
Zhigang Yi ◽  
Juan Wang ◽  
Tao Jiang ◽  
Qiong Tang ◽  
Ying Cheng
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Degradation ◽  
Reaction System ◽  
Degradation Pathway ◽  
Order Reaction ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Different Shapes ◽  
Pseudo First Order ◽  
Release Ratio

In this study, photocatalytic experiments of 20 mg l −1 sulfamethazine (SMN) in aqueous solution containing ZnO with different morphologies, tetra-needle-like ZnO (T-ZnO), flower-like ZnO (F-ZnO) and nanoparticles ZnO (P-ZnO), were performed. The results indicated that photocatalytic degradation of SMN was effective and followed the pseudo-first-order reaction, but the degree of SMN mineralization showed obvious differences using ZnO with different shapes. After 12 h irradiation, 86%, 71% and 50% of the initial total organic carbon was eliminated in SMN suspension containing T-ZnO, F-ZnO and P-ZnO, respectively. The release ratio of sulfur was close to 100% in the presence of T-ZnO, but reached to 86% and 67% in the presence of F-ZnO and P-ZnO, respectively. The release ratio of nitrogen was about 76%, 63% and 40% using T-ZnO, F-ZnO and P-ZnO as photocatalyst, respectively. The morphology of ZnO played an important role in determining its catalytic activity. Seven intermediates were observed and identified in the UV/T-ZnO reaction system by LC-MS/MS analysis, and a possible degradation pathway was proposed.

scholarly journals Adsorption of Cr6+ Onto Unmodified and Hydrochloric Acid Modified African Nutmeg Pod (Monodora myristica) from Aqueous Solution

2019 ◽  
pp. 1-8
Author(s):  
F. U. Okwunodulu ◽  
H. O. Chukwuemeka-Okorie ◽  
N. M. Mgbemena ◽  
J. B. I. Kalu
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Low Ph ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Particle Sizes ◽  
Monodora Myristica ◽  
Best Fit

The removal of Cr6+ from aqueous solution using unmodified and hydrochloric modified African nutmeg pod was studied. The effects of particle size, pH and initial metal ions concentration adsorbed were investigated. The amount of metal ion adsorbed increased as the initial metal ion concentration increased and also decreased at low pH of 2 for both modified and unmodified African nutmeg pod.  400 µm and 250 µm were the optimum particle sizes for both modified and unmodified African nutmeg pod respectively, values given as 75.8 mg/g for the modified and 93.39 mg/g for the unmodified. Generally, it was observed that the unmodified African nutmeg pod showed greater adsorption capacity than the modified African nutmeg pod. The equilibrium experimental data were examined via Langmuir and Freundlich isotherm models.  Freundlich isotherm model gave the best fit for the data in both unmodified and modified African nutmeg pod based on the correlation coefficients (R2 values) gotten. The results of the study showed that the African nutmeg pod is efficient for the removal of Cr6+ from aqueous solutions especially when unmodified.

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