scholarly journals Nanosized centers for mercury(II) ions adsorption on a surface of modified silica

2008 ◽  
Vol 6 (4) ◽  
pp. 581-591 ◽  
Author(s):  
Lyudmila Belyakova ◽  
Oleksandra Shvets ◽  
Diana Lyashenko
Keyword(s):  
Aqueous Medium ◽  
Batch Adsorption ◽  
Modified Silica ◽  
First Order ◽  
Chemically Modified ◽  
First Order Kinetics ◽  
Adsorption Data ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Second Order Equations

AbstractThe present work investigates the adsorptive interactions of Hg(II) ions in aqueous medium with hydroxylated silica, aminopropylsilica and silica chemically modified by β-cyclodextrin. Batch adsorption studies were carried out with various agitation times and mercury(II) concentrations. The maximum adsorption was observed within 15–30 min of agitation. The kinetics of the interactions, tested with the model of Lagergren for pseudo-first and pseudo-second order equations, showed better agreement with first order kinetics (k1 = 3.4 ± 0.2 to 5.9 ± 0.3 min−1). The adsorption data gave good fits with Langmuir isotherms. The results have shown that β-cyclodextrin-containing adsorbent has the largest adsorption specificity to Hg(II): K L = 4125 ± 205 mmol−1. “β-cyclodextrin-NO3-” inclusion complexes with ratio 1: 1 and super molecules with composition C42H70O35 ⊎ 3 Hg(NO3)2 are formed on the surface of β-cyclodextrin-containing silica.

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 Enhancing acidic dye adsorption by modified UiO-66

2020 ◽  
Vol 1 (2) ◽  
pp. 54-62
Author(s):  
Naser Al Amery ◽  
Hussein Rasool Abid ◽  
Shaobin Wang ◽  
Shaomin Liu
Keyword(s):  
Adsorption Process ◽  
Dye Adsorption ◽  
Batch Adsorption ◽  
First Order ◽  
Freundlich Isotherms ◽  
Adsorption Capacities ◽  
Pseudo Second Order ◽  
The Stability ◽  
Second Order Equations ◽  
Better Than

In this study, two improved versions of UiO-66 were successfully synthesised. Modified UiO-66 and UiO-66-Ce were characterised to confirm the integrity of the structure, the stability of functional groups on the surface and the thermal stability. Activated samples were used for removal harmful anionic dye (methyl orange) (MO) from wastewater. Batch adsorption process was relied to investigate the competition between those MOFs for removing MO from aqueous solution. Based on the results, at a higher initial concentration, the maximum MO uptake was achieved by UiO-66-Ce which was better than modified-UiO-66. They adsorbed 71.5 and 62.5 mg g-1 respectively. Langmuir and Freundlich isotherms were employed to simulate the experimental data. In addition, Pseudo first order and Pseudo second order equations were used to describe the dynamic behaviour of MO through the adsorption process. The high adsorption capacities on these adsorbents can make them promised adsorbents in industrial areas.

scholarly journals Removal of Lead from Aqueous Medium Using Xanthate Modified Apple Juice Residue

1970 ◽  
Vol 26 ◽  
pp. 53-60 ◽  
Author(s):  
Deepak Bashyal ◽  
Puspa Lal Homagai ◽  
Kedar Nath Ghimire
Keyword(s):  
Aqueous Medium ◽  
Metal Binding ◽  
Apple Juice ◽  
Lead Removal ◽  
Chemically Modified ◽  
Metal Biosorption ◽  
Ftir Studies ◽  
Monolayer Adsorption ◽  
Adsorption Data ◽  
Pseudo Second Order

This study investigated the feasibility of chemically modified apple juice residue as anovel type of adsorbent for lead removal from aqueous medium. FTIR studies were carriedout to understand the type of functional groups in unmodified and modified apple juiceresidue responsible for metal binding process. Equilibrium adsorption data were fitted interms of monolayer adsorption at pH 4 by batch method. The kinetics was studied forbiosorption processes and data were described by pseudo second order model. Theequilibrium constant and Gibbs free energy of the adsorption at 25°C were determined. Themechanism of sorption was found to obey the ion exchange and complexation method.Keywords: Heavy metal; Biosorption; Xanthate; Iion exchange; ComplexationDOI: 10.3126/jncs.v26i0.3632Journal of Nepal Chemical SocietyVol. 26, 2010Page: 53-60

Research on Adsorption of Pb2+ on to Microspheres Prepared by Rectorite and Humic Acid

2011 ◽  
Vol 233-235 ◽  
pp. 1972-1980 ◽  
Author(s):  
Yu Bin Tang ◽  
Fang Yu ◽  
Fang Yan Chen ◽  
Cheng Chen
Keyword(s):  
Humic Acid ◽  
Adsorption Process ◽  
Batch Adsorption ◽  
Order Model ◽  
Experimental Conditions ◽  
First Order ◽  
Adsorption Data ◽  
Exchange Adsorption ◽  
Elovich Equation ◽  
Pseudo Second Order

Rectorite (REC), humic acid (HA) and polyvinyl alcohol (PVA) were used to prepare microspheres. Batch adsorption experiments of Pb2+ion on to the microspheres were performed. The results obtained indicate that adsorption time, the microspheres dosage and temperature were the main factors influencing the adsorptive capacities. The adsorption data for Pb2+ion were well described by the Freundlich, Langmuir and Temkin models. The kinetic experimental data properly correlated with the pseudo-first-order model, pseudo-second-order model and Elovich equation. The adsorption process is spontaneous, endothermic and out-of-order. The whole adsorption process is mainly controlled by entropies. The adsorption can be classified as chemical adsorption. The mechanisms for the adsorption of Pb2+ion on to the microspheres involved ion-exchange adsorption of Pb2+or the formation of complex compound. Under the experimental conditions employed, the removal of Pb2+ion attained value of 96.05%.

scholarly journals Kinetics of Oxidation of Hexakis (P-chloroaniline) Cobalt (II) Chloride by Potassium Iodate

2003 ◽  
Vol 2 (1) ◽  
pp. 34-38
Author(s):  
B. Edison ◽  
S. Peter
Keyword(s):  
Kinetic Parameters ◽  
Aqueous Medium ◽  
Neutral Salt ◽  
Complex Solution ◽  
Potassium Iodate ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
First Order Kinetics ◽  
Kinetics Of

Vit B12 is an important complex of cobalt3 . The rate of oxidation of the Synthesized complex Hexakis(p-chloral aniline) cobalt((II) chloride follows first order kinetics with respect to the complex and oxidant potassium iodate1,2,4-8 in aqueous medium. Increasing in the concentration of complex solution increases the rate of the oxidation. The rate of the reaction is studied by changing the acid concentrations of the medium , by changing the temperature and by introducing the neutral salt (NaCl) in the Medium. From this study the kinetic parameters Ea, A,∆S#,∆G#,∆H# are found out. From the observed fats it is inferred that the reaction follows three steps.

Kinetics of Phenol Adsorption onto Activated Carbon Fiber

2011 ◽  
Vol 356-360 ◽  
pp. 1524-1527
Author(s):  
Mei Li ◽  
Yi Luo ◽  
Ru Chun Wu ◽  
Hong Yu Liang ◽  
Shuang Fei Wang
Keyword(s):  
Activated Carbon ◽  
Carbon Fiber ◽  
Activated Carbon Fiber ◽  
Order Kinetic ◽  
Phenol Adsorption ◽  
First Order ◽  
Adsorption Data ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Rate Controlling Step

The adsorption of phenol onto activated carbon fiber (ACF) from aqueous solutions were studied.The adsorption kinetics of phenol by ACF can be described by the Lagergren first-order and pseudo second-order kinetic models, respectively.The Lagergren first-order was verified to be the best to describe the adsorption data. The intraparticle diffusion is not the only rate-controlling step .

scholarly journals Removal of methylene blue (MB) by bimetallic- metal organic framework

2020 ◽  
Vol 2 (1) ◽  
pp. 36-49
Author(s):  
Naser Al Amery ◽  
Hussein Rasool Abid ◽  
Shaobin Wang ◽  
Shaomin Liu
Keyword(s):  
Adsorption Capacity ◽  
Metal Organic Framework ◽  
Future Research ◽  
Batch Adsorption ◽  
Intraparticle Diffusion Model ◽  
First Order ◽  
Metal Organic ◽  
Pseudo Second Order ◽  
Langmuir And Freundlich Models ◽  
Second Order Equations

In this study, three improved versions of UiO-66 metal organic frameworks (MOFs) were synthesised successfully: Different ratios of Ca+2/Zr+4 were used to synthesise UiO-66, UiO-66-10%Ca and UiO-66-30%Ca. Batch adsorption experiments were achieved to remove MB from wastewater by UiO-66-Ca. UiO-66-10%Ca exhibited the highest adsorption capacity with maximum  MB adsorption capacity of 15 mg. g–1 in UiO-66-30%Ca while UiO-66 demonstrated lower MB loading. Langmuir and Freundlich models have been employed to describe isotherms. A kinetics study indicated pseudo first-order and pseudo second-order equations. In addition, an intraparticle diffusion model was utilised. The results presented here may facilitate the further enhancement of UiO-66 MOFs and advance the synthesis of multimetal MOFs in future research.

Design and modeling adsorption kinetics of methylene blue on zeolite adsorbents and clay

2016 ◽  
Vol 28 (5) ◽  
pp. 582-599 ◽  
Author(s):  
Maaza Lamia ◽  
Djafri Fatiha ◽  
Bouchekara Mohammed ◽  
Djebbar Mustapha ◽  
Djafri Ayada
Keyword(s):  
Methylene Blue ◽  
Design Methodology ◽  
Synthesis Method ◽  
Batch Adsorption ◽  
Adsorption System ◽  
Content Type ◽  
First Order ◽  
Pseudo Second Order ◽  
Kinetics Of

Purpose The purpose of this paper is to examine the batch adsorption system of a cationic dye (methylene blue, widely used in various sectors) on two adsorbents; ZSM-5 zeolite which was prepared with the molar composition: 0.2057 Na2O-0.00266 Al2O3-SiO2-0.68 (pyrrolidine)-40 H2O-0.12 H2SO4. Design/methodology/approach By the hydrothermal synthesis method, and the purified clay and is analyzed by IR and DRX method. Findings For this, the authors conducted a parametric study of adsorption and effect of several important parameters on the adsorption of BM on the material used, in particular, the contact time (equilibrium is established after 120 min), different concentrations of adsorbents, different masses, the pH and temperature. The experiments demonstrated the crucial role of these parameters. A kinetic study was done and kinetic models were applied to the experimental results such as the pseudo-first order, pseudo-second order. Originality/value This work is original.

Adsorption of Lead Ions onto Citric Acid Modified Rubber (Hevea brasiliansis) Leaves

2014 ◽  
Vol 896 ◽  
pp. 288-291 ◽  
Author(s):  
Shariff Ibrahim ◽  
Megat Ahmad Kamal Megat Hanafiah ◽  
Faisal Fadzil
Keyword(s):  
Citric Acid ◽  
Aqueous Solutions ◽  
Functional Groups ◽  
Kinetic Models ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
First Order Kinetics ◽  
Adsorption Data ◽  
Leaf Powder ◽  
Pseudo Second Order

The removal of Pb(II) from aqueous solutions by citric acid modified rubber leaf powder (CARL) was investigated. The higher adsorptive removal of Pb(II) from aqueous solutions by CARL compared to untreated rubber leaf powder was due to the presence of more carboxylic functional groups in the former system. Batch adsorption experiments were conducted to study the effect of pH, contact time for the removal of Pb(II) from Pb(II) aqueous systems and the mechanism of adsorption process was studied by kinetic models, pseudo-first and pseudo-second order kinetic models. The functional groups on CARL played an important role in the adsorption of Pb(II). The kinetic and equilibrium adsorption data were well modeled using pseudo-first-order kinetics. Normal 0 21 false false false MS X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-fareast-font-family:Calibri; mso-bidi-font-family:"Times New Roman";}

scholarly journals Removal of Nitrate Ions Using Thermally and Chemically Modified Bioadsorbents

2021 ◽  
Vol 11 (18) ◽  
pp. 8455
Author(s):  
Candelaria Tejada-Tovar ◽  
Ángel Villabona-Ortíz ◽  
Ángel Darío Gonzalez-Delgado
Keyword(s):  
Adsorption Capacity ◽  
Ammonium Chloride ◽  
Batch Adsorption ◽  
Freundlich Model ◽  
Nitrate Ions ◽  
Chemically Modified ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Nitrate Anions ◽  
Water Eutrophication

Nitrate ions are one of the causes of surface water eutrophication. In the present research, the effective adsorption of nitrate ions (NO3) on bioadsorbents prepared from yam skins (Dioscorea alata) was evaluated. The yam skin was chemically modified with ammonium chloride (NH4Cl), and biochar was prepared from the thermally modified biomass. The results were compared with commercial coal (CC). The bioadsorbents were characterized by SEM-EDS analysis, which showed that the synthesized adsorbents have a heterogeneous surface with pores. The batch adsorption tests showed that the pH has the most significant effect on the NO3 adsorption capacity when using the modified yam skin (MYP), obtaining as best conditions pH 12 and a 0.5 mm particle size with an adsorption capacity of 25.75 mg/g; the best adsorption capacity when using the carbon synthesized from yam skin (CYP) and CC was obtained at pH 2, reaching values of 36 and 33.34 mg/g, respectively. The following performance in terms of adsorption capacity was found: CYP > CC > MYP, according to Langmuir’s model. The equilibrium isotherm of NO3 adsorption on MYP and CYP was adjusted by the Freundlich model, while the Langmuir model described adsorption on CC. The kinetics of all the systems studied showed a good fit to the pseudo-first-order, pseudo-second-order and Elovich models with R2 > 0.95, suggesting a mechanism of chemical adsorption by means of species exchange between the aqueous phase and the surface of the material, with the intervention of an intraparticle diffusion stage; based on these findings, the studied biomasses reached promising adsorption capacities in the removal of nitrate anions, showing that the carbon synthesized from yam skins and modified with ammonium chloride had a remarkable behavior in comparison with commercial carbon and NH4Cl-modified yam skins.

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