scholarly journals Coating of 2-Aminobenzimidiazole and 1-(o-Tolyl)biguanide Functionalized Silicas on Iron Sand Magnetic Material for Sorption of [AuCl4]–

2019 ◽  
Vol 19 (2) ◽  
pp. 395
Author(s):  
Nuryono Nuryono ◽  
Nur Mutia Rosiati ◽  
Abraham L Rettob ◽  
Suyanta Suyanta ◽  
Yateman Arryanto

Two novel materials of 2-aminobenzimidiazole (AB) and 1-(o-tolyl)biguanide (TB) modified silicas coated on the iron sand magnetic material (MM@SiO2/AB and MM@SiO2/TB) have been synthesized and were used to adsorb Au(III) from Au/Cu/Ni solution. Silica layering MM was modified with polyamino compounds via a sol-gel process using a sodium silicate solution, 3-chloropropyltrimethoxysilane (CPTS) and modifier compounds. Adsorption of Au(III) on MM@SiO2/AB and MM@SiO2/TB was investigated in a batch system by varying pH, initial concentration, contact time and the presence of other metal ions (Cu(II) and Ni(II)). The results showed that MM@SiO2/AB and MM@SiO2/TB were successfully synthesized through the sol-gel process using cross-linking agent CPTS. Adsorption of Au(III) on MM@SiO2/AB and MM@SiO2/TB decreased with the increase of pH and followed the Langmuir isotherm models with adsorption capacity of 17.15 and 9.44 mg/g, respectively. The adsorption kinetics fit to pseudo-second-order model with the rate constants of 1.16 × 10-2 and 1.46 × 10-2 g mg-1 min-1, respectively. MM@SiO2/AB and MM@SiO2/TB gave a high selectivity towards Au(III) in a mixture of Cu(II) and Ni(II). The desorption using thiourea 1 M solution in 1 M HCl of metal ions showed that percentage of Au(III) desorbed was higher than that of Cu(II) and Ni(II).

2017 ◽  
Vol 17 (2) ◽  
pp. 264 ◽  
Author(s):  
Muflikhah Muflikhah ◽  
Bambang Rusdiarso ◽  
Edy Giri Rachman Putra ◽  
Nuryono Nuryono

Modification of silica coated on magnetic material iron sand with chitosan for adsorption of Au(III) has been carried out. Magnetic material (MM) from iron sand was separated using an external magnet, washed with water and HF solution 10%. MM–silica–chitosan material (MMSC) was synthesized via sol gel process and the product was characterized with Fourier Transform Infrared (FT-IR) spectrophotometer, X–ray diffractometer, scanning electron microscopy and energy dispersive X–ray, thermogravimetric analysis, and vibration sample magnetometer. Additionally, the effect of pH on the stability of MMSC has also been tested. The adsorption of Au(III) on MMSC was proceeded in a batch system with variation of pH, contact time, and concentration of absorbate. Adsorbent was separated using external magnet and concentration of Au(III) not adsorbed was analyzed using Atomic Absorption Spectrometer. Characterization result indicated that MMSC was successfully synthesized. Adsorption of Au(III) on MMSC followed pseudo second-order kinetic model with the value of adsorption rate constant (k) of 4.10 x 10-3 g mg-1 min-1 and adsorption isotherm fixed with Langmuir model with the adsorption capacity (qmax) of 149.25 mg g-1.


2015 ◽  
Vol 15 (2) ◽  
pp. 108-115 ◽  
Author(s):  
Sri Hastuti ◽  
Nuryono Nuryono ◽  
Agus Kuncaka

In this research, L-arginine-modified silica (SiO2-Arg) with 3-glycidoxypropyl-trimethoxysilane (GPTMS) as the linking agent has been synthesized through sol gel process for adsorption of Au(III) in aqueous solution. Tetraethyl orthosilicate (TEOS) as the silica source precursor, L-arginine solution 0.9 M with various volume ratios and the linking agent were mixed together to form a gel. SiO2-Arg was characterized using Fourier transform infrared (FTIR) spectrophotometer, thermogravimetric analysis (TGA), and an elemental analysis. Adsorption was carried out in a batch system under various experimental conditions including contact time and initial concentration of metal Au(III). The selectivity of adsorbent toward Au(III) was examined in the presence of Cu(II), Fe(III), and Zn(II) ion at various pHs. Results of characterization showed that silica has been successfully modified with L-arginine. The optimum adsorption of Au(III) on SiO2-Arg was obtained at pH of 3.0 and the adsorption isotherm of Au(III) on SiO2-Arg gives the adsorption capacity of 52.79 mg/g. The kinetic study demonstrates that the adsorption of Au(III) ion follows pseudo-second order with the rate constant of 53197 g mol–1 min–1. The selectivity order of Au-Zn = Au-Cu > Au-Fe. This sol-gel preparation is simple and provides prospective application of SiO2-Arg material as an effective adsorbent for metal ions particularly gold(III).


2018 ◽  
Vol 917 ◽  
pp. 162-166 ◽  
Author(s):  
Agus Ismail ◽  
Insan Akbar Alamsyah ◽  
Muhammad Kholil ◽  
Bambang Heru Susanto ◽  
Mohamad Nasikin

We report a method to adjust the size of silica nanoparticles from silica sand. In this study, synthesized silica nanoparticles by sol gel process from silica sand were conducted, with previously was controlled the size of silica sand by mechanical milling. Silica sand was milled by High Energy Milling in order to reduce the size into powder form. Effect of milling time shown the content of sodium and silicon is increased in sodium silicate solution obtained from various times of silica sand milling (30, 60 and 90 minutes, respectively) which is reacted with sodium hydroxide 8 M. The result of silica nanoparticles from sol gel process of sodium silicate solution were characterized using atomic absorption spectroscopy, scanning electron microscopy and X-ray diffraction techniques. It was found that the size of silica nanoparticles could be tailored with the change of milling time.


Author(s):  
Cristiano da Silva ◽  
Maiyara Prete ◽  
César Tarley ◽  
Júlio Afonso ◽  
Emerson Ribeiro

Ternary oxide silica-alumina-zirconia (SiO2/Al2O3/ZrO2) obtained by the sol-gel process was applied as novel adsorbent of ions in aqueous solution. Batch isotherms were performed using standard CuII, CdII and CaII solutions at variable pH and different concentrations. Adsorption capacity was best at weakly acidic pH. The maximum adsorption capacities were 2.28 mg g−1 for CaII, 9.89 mg g−1 for CdII, and 14.88 mg g−1 for CuII. The adsorption data fitted well to the single and dual-site Langmuir-Freundlich isotherm models. However, since the adsorption is very low in the sites with high energy, the single-site Langmuir-Freundlich provided a good fit as well. Whereas, the site responsible for the most ion adsorption was assigned to the Zr−OH group. A real sample of produced water was also tested. The new adsorbent showed a wide ability to retain many metal ions (alkali-earth, transition, and p-block metals) and even some anions were also caught by the adsorbent. The ternary oxide silica-alumina-zirconia was found to be a promising alternative adsorbent for metal ions in aqueous media.


2019 ◽  
Vol 1 (3) ◽  
pp. 91
Author(s):  
Mas Inda Putrinesia ◽  
Nurlina Nurlina ◽  
Winda Rahmalia

Research on the study of kinetics and isotherm adsorption of Pb(II) by polyaniline/silica gel (PANI/SiO2) composite from glass waste has successfully been done. The polymerization of silica gel was prepared by sol-gel process. Meanwhile, PANI/SiO2 composite was prepared using sulfuric acid (H2SO4) as its dopants and hydrogen peroxide (H2O2) for oxidation process. Composition of oxide compound in PANI/SiO2 composite was analyzed by X-Ray Fluorosence (XRF) and Gas Sorption Analyzer (GSA). Adsorption of Pb(II) was carried out by contacting PANI/SiO2 with Pb(NO3)2 solution for 20, 40, 60 and 80 minutes, with concentrations of 150, 200, 250, 300, 350 and 400 mg/L. The optimum contact time was reached at 40 minutes. This adsorption followed pseudo-second order model with R2= 0.996. The first optimum adsorption capacity was reached in the concentration of 250 mg/L. Isotherm adsorption followed Langmuir models with R2= 0.954 (monolayer capacity= 51.02 mg/g).


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1437
Author(s):  
Chih Ming Ma ◽  
Bo-Yuan Yang ◽  
Gui-Bing Hong

Hydrogel beads based on the husk of agarwood fruit (HAF)/sodium alginate (SA), and based on the HAF/chitosan (CS) were developed for the removal of the dyes, crystal violet (CV) and reactive blue 4 (RB4), in aqueous solutions, respectively. The effects of the initial pH (2–10) of the dye solution, the adsorbent dosage (0.5–3.5 g/L), and contact time (0–540 min) were investigated in a batch system. The dynamic adsorption behavior of CV and RB4 can be represented well by the pseudo-second-order model and pseudo-first-order model, respectively. In addition, the adsorption isotherm data can be explained by the Langmuir isotherm model. Both hydrogel beads have acceptable adsorption selectivity and reusability for the study of selective adsorption and regeneration. Based on the effectiveness, selectivity, and reusability of these hydrogel beads, they can be treated as potential adsorbents for the removal of dyes in aqueous solutions.


Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 32 ◽  
Author(s):  
Changgil Son ◽  
Wonyeol An ◽  
Geonhee Lee ◽  
Inho Jeong ◽  
Yong-Gu Lee ◽  
...  

This study has evaluated the removal efficiencies of phosphate ions (PO43−) using pristine (TB) and chemical-activated tangerine peel biochars. The adsorption kinetics and isotherm presented that the enhanced physicochemical properties of TB surface through the chemical activation with CaCl2 (CTB) and FeCl3 (FTB) were helpful in the adsorption capacities of PO43− (equilibrium adsorption capacity: FTB (1.655 mg g−1) > CTB (0.354 mg g−1) > TB (0.104 mg g−1)). The adsorption kinetics results revealed that PO43− removal by TB, CTB, and FTB was well fitted with the pseudo-second-order model (R2 = 0.999) than the pseudo-first-order model (R2 ≥ 0.929). The adsorption isotherm models showed that the Freundlich equation was suitable for PO43− removal by TB (R2 = 0.975) and CTB (R2 = 0.955). In contrast, the Langmuir equation was proper for PO43− removal by FTB (R2 = 0.987). The PO43− removal efficiency of CTB and FTB decreased with the ionic strength increased due to the compression of the electrical double layer on the CTB and FTB surfaces. Besides, the PO43− adsorptions by TB, CTB, and FTB were spontaneous endothermic reactions. These findings demonstrated FTB was the most promising method for removing PO43− in waters.


2021 ◽  
Vol 19 (9) ◽  
pp. 46-54
Author(s):  
Makarim A. Mahdi ◽  
Aymen A.R. Jawad ◽  
Aseel M. Aljeboree ◽  
Layth S. Jasim ◽  
Ayad F. Alkaim

The AAc/GO nanocomposite hydrogel was successfully employed as a polymeric Nano sorbent of the removal efficiency of M G dye from the model. The complication of the mechanism of the adsorption system was completely exposed by examining how solution pH affects adsorption, Ionic strength isotherm models, kinetic models, and thermodynamics. The adsorption of the MG dye was greatly dependent on the solution pH. The Freundlich model has been demonstrated to be the most accurate in describing the MG dye sorption, whilst the Langmuir model was shown to be the least accurate. Additionally, these integrated mechanisms fit nicely within the framework of a pseudo-second-order model. Additionally, the contact time at equilibrium short (ten minutes) required to MG removes demonstrates the AAc/GO nanocomposite hydrogel can be considered an efficient and potentially useful adsorbent for MG removal from industrial effluents.


2017 ◽  
Vol 2 (1) ◽  
pp. 13-26
Author(s):  
Tengku Khamanur Azma Tg. Mohd Zamri ◽  
Mimi Sakinah Abd Munaim ◽  
Zularisam Ab Wahid

Natural dye extracted from the rhizome of Curcuma longa L. were applied to bamboo yarns using exhaustion dyeing process. This study investigates the dyeing behaviour of Curcumin; the major color component isolated from rhizomes of Curcuma longa L.on bamboo yarn. Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich isotherm models were used to test the adsorption process of curcumin on bamboo yarn. Comparison of regression coefficient value indicated that the Freundlich isotherm most fitted to the adsorption of curcumin onto bamboo yarn. Furthermore, the kinetics study on this research fitted the pseudo-second order model which indicates that the basis of interaction was chemical adsorption.


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