scholarly journals KINETIKA ADSORPSI ION EMAS(III) OLEH HIBRIDA MERKAPTO SILIKA

2015 ◽  
Vol 10 (1) ◽  
Author(s):  
Saprini Hamdiani ◽  
Nuryono Nuryono ◽  
Bambang Rusdiarso
Keyword(s):  
Rice Husk ◽  
Adsorption Kinetics ◽  
Rice Husk Ash ◽  
Sol Gel ◽  
Second Order ◽  
Static System ◽  
Sol Gel Process ◽  
Before And After ◽  
Pseudo Second Order ◽  
The Difference

Abstrak: Telah dilakukan kajian kinetika adsorpsi ion emas(III) oleh adsorben hibrida merkapto silika (HMS). HMS disintesis melalui proses sol-gel dengan prekursor natrium silikat (Na2SiO3) dari abu sekam padi. HMS dibuat dengan menambahkan asam klorida pada campuran senyawa 3-(trimetoksilil)-1-propantiol (TMSP) dan larutan Na2SiO3. Kinetika adsorpsi ditentukan dengan melakukan adsorpsi sistem statik (batch) dengan variasi waktu. Jumlah ion emas yang teradsorpsi dihitung secara kuantitatif berdasarkan selisih konsentrasi logam sebelum dan setelah adsorpsi yang dianalisis dengan spektroskopi serapan atom (SSA). Data menunjukkan interaksi HMS dengan ion emas cenderung mengikuti pola kinetika reaksi pseudo orde-2 dengan nilai konstanta laju reaksi (k) = 1x10-2 g mg-1min-1. Berdasarkan nilai perubahan energi bebas Gibbs adsorpsi standar (-ΔG°= 34,63-37,99 kJ/mol) menunjukkan bahwa adsorpsi berlangsung secara kimia (kemisorpsi).Kata kunci: kinetika, emas, merkapto, silika, abu sekam padi, pseudo orde-2.Abstract: Adsorption kinetics study has been done of gold(III) ions by mercapto silica hybrid (MSH) adsorben. MSH was synthesized by sol-gel process with sodium silicate (Na2SiO3) from rice husk ash as a precursor. MSH made by adding hydrochloric acid to 3-(trimetoksilil)-1-propantiol (TMSP) compounds and Na2SiO3 solution. Adsorption kinetics are determined by adsorption static system (batch) with variation of time. The amount of the adsorbed gold ions is quantified by the difference in metal concentration before and after adsorption analyzed by atomic absorption spectroscopy (AAS). The data showed, MSH interaction with gold ion tends to follow the pattern of reaction kinetics pseudo-second-order with rate constant (k) =1x10-2 g mg-1min-1. Based on the value of the standard Gibbs free energy for adsorption (-ΔG°= 34,63-37,99 kJ/mol) showed that the adsorption takes place chemically (chemisorption).Keywords: kinetics, gold, mercapto, silica, rice husk ash, pseudo-second-order.

scholarly journals Synthesis of Silica-Salen Derivative from Rice Husk Ash and its Use for Extraction of Divalent Metal Ions Co(II), Ni(II) and Cu(II)

2019 ◽  
Vol 20 (1) ◽  
pp. 16 ◽  
Author(s):  
Duha Hussien Attol ◽  
Hayder Hamied Mihsen
Keyword(s):  
Metal Ions ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Divalent Metal Ions ◽  
Prepared Compound ◽  
Absorption Bands ◽  
Pseudo Second Order ◽  
Ft Ir

Rice husk ash (RHA) was used to prepare sodium silicate, which in turn was functionalized with 3-(chloropropyl)triethoxysilane employing the sol-gel technique to form RHACCl. Chloro group in RHACCl was replaced with iodo group forming RHACI. Ethylenediamine was immobilized on RHACI in order to prepare it for the reaction with salicylaldehyde to form a silica derivative-salen. FT-IR analysis indicated the presence of secondary amine and –NH and C=N absorption bands. XRD analysis revealed the occurrence of the broad diffused peak with maximum intensity at 22–23° (2θ). BET measurements showed also that the surface area of the prepared compound is 274.55 m2/g. Elemental analysis proved the existence of nitrogen in the structure of the prepared compound. The silica derivative-salen showed high potential for extraction and removal of heavy contaminating metal ions Ni(II), Cu(II), and Co(II) from aqueous solutions. The kinetic study demonstrates that the adsorption of the metal ions follows the pseudo-second order.

Synthesis of bimodal porous silica from rice husk ash via sol–gel process using chitosan as template

2008 ◽  
Vol 62 (10-11) ◽  
pp. 1476-1479 ◽  
Author(s):  
T. Witoon ◽  
M. Chareonpanich ◽  
J. Limtrakul
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Sol Gel ◽  
Porous Silica ◽  
Sol Gel Process

scholarly journals Synthesis and Characteristics of Rice Husk Ash Based Magnetic Hydrogel (RHA-MH) for H2 Generation

2019 ◽  
pp. 01-09
Author(s):  
Irvan Dahlan ◽  
Muhammad Syafieq Abd Halim
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Sol Gel ◽  
Cross Linking ◽  
Sem Images ◽  
Sem Image ◽  
H2 Generation ◽  
Magnetic Hydrogel ◽  
Before And After ◽  
Hydrolysis Of

Abstract: In this study, magnetic hydrogel was synthesized from rice husk ash (RHA-MH) using two methods, i.e. sol-gel and cross-linking methods. The prepared rice husk ash based magnetic hydrogel (RHA-MH) were used as a catalyst for H2 generation through hydrolysis of sodium borohydride (NaBH4). Factors effecting hydrolysis reaction such as effect of RHA calcination temperature and method used to synthesis the catalyst were investigated. The RHA-MH1200 synthesised via cross-linking and sol-gel methods (using RHA calcined at 1200°C) shows the shortest time taken (5.64 min and 11.18 min, respectively) to produce 40 mL of H2 gas as compared to RHA-MH600 (i.e. 10.47 min and 13.18 min respectively, for both methods using RHA calcined at 600°C). The prepared and spent RHA-MH were also characterized using Scanning Electron Microscopy (SEM)/Energy Dispersive X-ray (EDX) analysis. From SEM image, it could be concluded that silica (SiO2) could successfully be utilized as the supporting material for stabilizing magnetic iron oxide (Fe3O4) nanoparticles. The SEM image also showed that the overall structure was relatively porous. Moreover, the SEM images of magnetic hydrogel before and after the hydrolysis of NaBH4 exhibited similar physical structures. Keywords: Hydrogen; NaBH4 hydrolysis; Rice husk ash based magnetic hydrogel (RHA-MH); Sol-gel; Cross-linking

Mechanoactivation Of Rice Husk Ash In Laboratory Conditions

2019 ◽  
pp. 20-26
Keyword(s):  
Mechanical Activation ◽  
Rice Husk ◽  
Amorphous Silica ◽  
Silicon Oxide ◽  
Rice Husk Ash ◽  
Pozzolanic Activity ◽  
Maximum Solubility ◽  
Laboratory Conditions ◽  
Before And After ◽  
Mineral Additive

In many rice producing countries of the world, including in Vietnam, various research aimed at using rice husk ash (RHA) as a finely dispersed active mineral additive in cements, concrete and mortars are being conducted. The effect of the duration of the mechanoactivation of the RHA, produced under laboratory conditions in Vietnam, on its pozzolanic activity were investigated in this study. The composition of ash was investigated by laser granulometry and the values of indicators characterizing the dispersion of its particles before and after mechanical activation were established. The content of soluble amorphous silicon oxide in rice husk ash samples was determined by photocolorimetric analysis. The pizzolanic activity of the RHA, fly ash and the silica fume was also compared according to the method of absorption of the solution of the active mineral additive. It is established that the duration of the mechanical activation of rice husk ash by grinding in a vibratory mill is optimal for increasing its pozzolanic activity, since it simultaneously results in the production of the most dispersed ash particles with the highest specific surface area and maximum solubility of the amorphous silica contained in it. Longer grinding does not lead to further reduction in the size of ash particles, which can be explained by their aggregation, and also reduces the solubility of amorphous silica in an aqueous alkaline medium.

Adsorption Kinetics of Pb2+ Ions Using Chitosan Nanoparticles

2013 ◽  
Vol 367 ◽  
pp. 45-49
Author(s):  
Ying Hong ◽  
Ze Hui Zhong ◽  
You Shi Liu
Keyword(s):  
Adsorption Kinetics ◽  
Chitosan Nanoparticles ◽  
Second Order ◽  
Isotherm Model ◽  
Order Model ◽  
Adsorption Characteristics ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Second Order Model

Chitosan nanoparticles were prepared by crosslinkingusing TPP. SEM showed that chitosan nanoparticles were successfully obtained.The adsorption characteristics of chitosan nanoparticles were evaluated. Theresults demonstrated that chitosan nanoparticles were suitable for adsorbent toremoval Pb2+. The parameters for the adsorption of Pb2+by chitosan nanoparticles were also determined. It was shown that chitosannanoparticles were fit for Langmuir’s isotherm model and that the adsorptionkinetics of Pb2+ described by the pseudo-second-order model could bebest.

scholarly journals CHARACTERISTIC OF XONOTLITE SYNTHESIZED BY HYDROTHERMAL REACTION USING RICE HUSK ASH AND ITS APPLICATION TO ABSORB CHROME (III) SOLUTION

2021 ◽  
Vol 55 (6) ◽  
Author(s):  
Trung Kien Pham ◽  
Tran Ngo Quan
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Hydrothermal Reaction ◽  
Mekong Delta ◽  
Molar Ratio ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Xrf Scanning ◽  
Before And After ◽  
Chrome Iii

In this paper, we report on synthesizing xonotlite, calcium silicate hydrate (CSH), via a hydrothermal reaction using rice husk from the Mekong Delta, Vietnam. The rice husks were burnt at 1000 °C for 3 h. Grey rice husk ash was collected, then mixed with Ca(OH)2 at a Ca/Si molar ratio of 1 : 1. This was followed by a hydrothermal reaction at 180 °C for 24 h and 48 h to obtain the xonotlite mineral. Before and after adsorption, 3-mm xonotlite pellets were thoroughly characterized using X-ray diffractometry (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and ultraviolet-visible (UV-VIS) spectroscopy. This material has potential application in chromium(III) removal during a chrome-plating process. The adsorption efficiency of the 3-mm pellet samples reached more than 76 % after 12 h.

scholarly journals Harnessing of Newly Tailored Poly (Acrylonitrile)-Starch Nanoparticle Graft Copolymer for Copper Ion Removal via Oximation Reaction

2021 ◽  
Author(s):  
khaled Mostafa ◽  
H. Ameen ◽  
A. Ebessy ◽  
A. El-Sanabary
Keyword(s):  
Experimental Data ◽  
Adsorption Capacity ◽  
Graft Copolymer ◽  
Adsorption Kinetics ◽  
Copper Ions ◽  
Copper Ion ◽  
Second Order ◽  
First Order ◽  
Pseudo Second Order ◽  
Pseudo First Order

Abstract Our recently tailored and fully characterized poly (AN)-starch nanoparticle graft copolymer having 60.1 G.Y. % was used as a starting substrate for copper ions removal from waste water effluent after chemical modification with hydroxyl amine via oximation reaction. This was done to change the abundant nitrile groups in the above copolymer into amidoxime one and the resultant poly (amidoxime) resin was used as adsorbent for copper ions. The resin was characterized qualitatively via rapid vanadium ion test and instrumentally by FT-IR spectra and SEM morphological analysis to confirm the presence of amidoxime groups. The adsorption capacity of the resin was done using the batch technique, whereas the residual copper ions content in the filtrate before and after adsorption was measured using atomic adsorption spectrometry. It was found that the maximum adsorption capacity of poly (amidoxime) resin was 115.2 mg/g at pH 7, 400ppm copper ions concentration and 0.25 g adsorbent at room temperature. The adsorption, kinetics and isothermal study of the process is scrutinized using different variables, such as pH, contact time, copper ion concentration and adsorbent dosage. Different kinetics models comprising the pseudo-first-order and pseudo-second-order have been applied to the experimental data to envisage the adsorption kinetics. It was found from kinetic study that pseudo-second-order rate equation was better than pseudo-first-order supporting the formation of chemisorption process. While, in case of isothermal study, the examination of calculated correlation coefficient (R2) values showed that the Langmuir model provide the best fit to experimental data than Freundlich one.

scholarly journals Guidelines for general adsorption kinetics modeling

2020 ◽  
Vol 74 (1) ◽  
pp. 65-70
Author(s):  
Bojana Obradovic
Keyword(s):  
Adsorption Kinetics ◽  
Scale Up ◽  
Second Order ◽  
Particle Diffusion ◽  
Analysis And Evaluation ◽  
Inappropriate Use ◽  
Adsorption Processes ◽  
Intra Particle Diffusion ◽  
Elovich Equation ◽  
Pseudo Second Order

Adsorption processes are widely used in different technological areas and industry sectors, thus continuously attracting attention in the scientific research and publications. Design and scale-up of these processes are essentially based on the knowledge and understanding of the adsorption kinetics and mechanism. Adsorption kinetics is usually modeled by using several well-known models including the pseudo-first and pseudo-second order models, the Elovich equation, and the intra-particle diffusion based models. However, in the scientific literature there are a significant number of cases with the inappropriate use of these models, utilization of erroneous expressions, and incorrect interpretation of the obtained results. This paper is especially focused on applications of the pseudo-second order, intra-particle diffusion and the Weber-Morris models, which are illustrated with typical examples. Finally, general recommendations for selection of the appropriate kinetic model and model assumptions, data regression analysis, and evaluation and presentation of the obtained results are outlined.

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