scholarly journals Comparative Study on the Adsorption of [AuCl4]– onto Salicylic Acid and Gallic Acid Modified Magnetite Particles

2018 ◽  
Vol 16 (3) ◽  
pp. 329 ◽  
Author(s):  
Maya Rahmayanti ◽  
Sri Juari Santosa ◽  
Sutarno Sutarno

Salicylic acid-modified magnetite (Mag-SA) and gallic acid-modified magnetite (Mag-GA) particles were prepared by co-precipitation procedure. Characterization results showed the interaction that occurs between the surface of magnetite with salicylic acid (Mag-SA) and gallic acid (Mag-GA) was through hydrogen bonding. Adsorption of [AuCl4]– onto Mag-SA and Mag-GA surfaces as a function of initial pH, contact time, and initial concentration of the [AuCl4]– solution were comparatively investigated. Result showed that the optimum adsorption of [AuCl4]– onto Mag-SA or Mag-GA was found at pH 3. The adsorption process were found to allow the pseudo-second order equation, both for Mag-SA and Mag-GA. The parameters in isotherm adsorption equations conformed to the Langmuir and Freundlich isotherms very well for Mag-GA, but for Mag-SA, only conformed to the Langmuir isotherm very well. The result of this study demonstrate that the ability Mag-GA to adsorb [AuCl4]– higher than Mag-SA.

2016 ◽  
Vol 74 (1) ◽  
pp. 276-286 ◽  
Author(s):  
Bin Huang ◽  
Dan Xiong ◽  
Tingting Zhao ◽  
Huan He ◽  
Xuejun Pan

Biomorphic nano-hydroxyapatite (HAP) was fabricated by a co-precipitation method using cotton as bio-templates and employed in adsorptive removal of ofloxacin (OFL) and triclosan (TCS) that are two representative pharmaceuticals and personal care products (PPCPs). The surface area and porosity, crystal phase, functional group, morphology and micro-structure of the synthesized HAP were characterized by Brunauer–Emmett–Teller isotherm, X-ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron macroscopic and transmission electron microscopy. The effects of initial pH, ionic strength, initial concentration, contact time and temperature on the removal of PPCPs were studied in a batch experiment. The adsorption of OFL and TCS was rapid and almost accomplished within 50 min. Kinetic studies indicated that the adsorption process of OFL and TCS followed the pseudo-first-order and pseudo-second-order models, respectively. The Freundlich isotherm described the OFL adsorption process well but the adsorption of TCS fitted the Langmuir isotherm better. Thermodynamics and isotherm parameters suggested that both OFL and TCS adsorption were feasible and spontaneous. Hydrogen bond and Lewis acid–base reaction may be the dominating adsorption mechanism of OFL and TCS, respectively. Compared to other adsorbents, biomorphic HAP is environmentally friendly and has the advantages of high adsorption capacity, exhibiting potential application for PPCPs removal.


2020 ◽  
Vol 8 (2) ◽  
pp. 77-83
Author(s):  
Maya Rahmayanti ◽  
Guliston Abdillah ◽  
Sri Juari Santosa ◽  
Sutarno Sutarno

Humic acid modifying magnetite particles (Mag-HA) were developed for recovery of gold from chloride solution (HAuCl4). The Mag-HA particles were prepared by co-precipitation procedure with Fe(III) and Fe(II) chloride salts, sodium hydroxide, and humic acid. FTIR characterization for Mag-HA after modification indicated the presence of the specific absorption for functional groups of humic acid and Fe-O bonds, though with lower intensity. The Mag-HA particles exhibited a typical superparamagnetic characteristic with a saturation magnetization of 66.99 emu/g. The Mag-HA particles were applied for AuCl4- adsorption and results showed that the optimum adsorption of [AuCl4]- onto Mag-HA was found at pH 3. The adsorption kinetics can be described by a pseudo-second order equation and the adsorption isotherm of the Mag-HA particles agreed well with Langmuir adsorption equation. The maximum adsorbed amount of [AuCl4]- was 0.62 mmol/g and the XRD analysis confirms that the adsorption of Au(III) by Mag-HA was accompanied by the formation of elemental gold.


2020 ◽  
Vol 1 (2) ◽  
pp. 54-62
Author(s):  
Naser Al Amery ◽  
Hussein Rasool Abid ◽  
Shaobin Wang ◽  
Shaomin Liu

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.


2020 ◽  
Vol 168 ◽  
pp. 00026
Author(s):  
Liliia Frolova ◽  
Mykola Kharytonov ◽  
Iryna Klimkina ◽  
Oleksandr Kovrov ◽  
Andrii Koveria

Plasma method is used to synthesize manganese ferrite. The basic properties of ferrite are determined by IR spectroscopy, UV spectroscopy, X-ray phase analysis, vibration magnetometry. The paper shows that the use of magnetically controlled sorbent allows to purify waste waters from chromium (III). The process of adsorption of chromium cations (III) is investigated. The kinetics of the process is studied. To describe the equilibrium isotherms, the experimental data are analysed by the models of Langmuir, Freundlich isotherms. Pseudo-first order, pseudo-second-order, and Weber-Morris are used to elucidate the kinetic parameters and mechanism of the adsorption process. It has been established that the removal of Cr (III) cations is described by the pseudo-second order of the Langmuir reaction and mechanism.


2020 ◽  
Vol 5 (2) ◽  
pp. 59
Author(s):  
Nurlisa Hidayati ◽  
Risfidian Mohadi ◽  
Elfita Elfita ◽  
Aldes Lesbani

Zn/Al-citrate LDHs was synthesized using co precipitation method at basic condition and the material were applied as adsorbent of malachite green (MG) dye in aqueous medium using batch system. Adsorption of MG onto Zn/Al-citrate was investigated through kinetic, isotherm adsorption and thermodynamic studies. Kinetic model was fitted PSO than PFO for MG adsorption. The rate of adsorption 𝑘2 for Zn/Al LDHs was 0.000692 g.mg−1 min−1 and 0.000371 g for Zn/Al-citrate LDHs.mg−1 min−1. Adsorption of malachite green onto Zn/Al LDHs and Zn/Al citrate LDHs was investigated and following Langmuir adsorption isotherm model shows chemical adsorption process. The adsorption capacity maximum of Zn/Al-citrate is 333 mg/g from Zn/Al LDHs is only 111 mg/g. Thermodynamic parameters of Zn/Al-citrate confirmed adsorption process was endothermic and spontaneous.


2022 ◽  
Author(s):  
Chuqing Yao ◽  
Yaodong Dai ◽  
Shuquan Chang ◽  
Haiqian Zhang

Abstract In this work, novel Prussian blue tetragonal nanorods were prepared by template-free solvothermal methods for removal of radionuclide Cs and Sr. It was worth that Prussian blue nanorods exhibited the better adsorption performance than co-precipitation PB or Prussian blue analogue composites. Thermodynamic analysis implied that adsorption process was spontaneous and endothermic which was described well with Langmuir isotherm and pseudo-second-order equation, the maximum adsorption capacity of PB nanorod was estimated to be 194.26 mg g-1 and 256.62 mg g-1 for Cs+ and Sr2+. The adsorption mechanism of Cs+ and Sr2+ was studied by X-ray photoelectron spectroscopy, X-ray diffraction and 57Fe Mössbaure spectroscopy, the results revealed that Cs+ entered in PB crystal to generate a new phase, the most of Sr2+ was trapped in internal crystal and the other exchanged Fe2+. Furthermore, the effect of co-existing ions and pH for PB adsorption process were also investigated. The results suggest that PB nanorods were outstanding candidate for removal of Cs+ and Sr2+ from radioactive wastewater.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2496
Author(s):  
Keyan Yang ◽  
Jingchen Xing ◽  
Jianmin Chang ◽  
Fei Gu ◽  
Zheng Li ◽  
...  

An eco-friendly and novel water treatment material was synthesized using sodium lignosulfonate modified polystyrene (SLPS), which can be used to eliminate phenols in aqueous solution. SLPS was characterized by BET, FTIR, SEM, and EDS. The effect of the initial pH value, phenol content, adsorption time, and temperature on the absorbability of phenol in SLPS was investigated through adsorption experiments. It was found that SLPS could efficiently adsorb phenol in aqueous solution at a pH value of about 7. The test results revealed that the kinetic adsorption and isotherm adsorption could be successfully described using the pseudo second-order and Langmuir models, respectively. It was illustrated that the phenol adsorption on SLPS was dominated by chemisorption and belonged to monolayer adsorption. The max. phenol adsorption value of SLPS was 31.08 mg/g at 30 °C. Therefore, SLPS displayed a great potential for eliminating phenol from polluted water as a kind of novel and effective adsorbent.


Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 861
Author(s):  
Ling Zhou ◽  
Michal Slaný ◽  
Bingbing Bai ◽  
Weichao Du ◽  
Chengtun Qu ◽  
...  

In this study, hierarchical MgAl-LDH (layered double hydroxide) nanoparticles with a flower-like morphology were prepared under a hydrothermal condition by employing worm-like micelles formed by cetyltrimethylammonium bromide (CTAB) and salicylic acid (SA) as templates. The morphology and structure of the materials were characterized by Brunauer–Emmett–Teller (BET), SEM, and XRD analyses. The performance for the adsorption of sulfonated lignite (SL) was also investigated in detail. FTIR was used to detect the presence of active functional groups and determine whether they play important roles in adsorption. The results showed that the hierarchical MgAl-LDH nanoparticles with a specific surface area of 126.31 m2/g possessed a flower-like morphology and meso–macroporous structures. The adsorption capacity was high—its value was 1014.20 mg/g at a temperature of 298 K and an initial pH = 7, which was higher than traditional MgAl-LDH (86 mg/g). The adsorption process of sulfonated lignite followed the pseudo-second-order kinetics model and conformed to Freundlich isotherm model with a spontaneous exothermic nature. In addition, the hierarchical MgAl-LDH could be regenerated and used, and the adsorption was high after three adsorption cycles. The main adsorption mechanisms were electrostatic attraction and ion exchange between the hierarchical MgAl-LDH and sulfonated lignite.


2017 ◽  
Vol 17 (3) ◽  
pp. 343 ◽  
Author(s):  
Ozi Adi Saputra ◽  
Alifia Harista Rachma ◽  
Desi Suci Handayani

Synthesis of amino functionalized organosilane (AFOS) via UV-irradiation method has been conducted. In this research, the precursors for synthesizing AFOS are 3-glycydiloxypropyl trimethoxysilane (GPTMS) and ethylene diamine. Synthesis of amino functionalized organosilane was performed for 16 h monitored by Infra-red spectroscopy technique. The morphological structure of AFOS was observed by scanning electron microscopy. The adsorption process was conducted in the batch method using Remazol Brilliant Blue R (RBBR) as anionic dye model. In this study, the pH, contact time and dyes concentration were varied to determine the optimum pH, kinetic and isotherm adsorption. Based on the calculation, the kinetic rate of the RBBR adsorbed onto AFOS was determined by k2 (pseudo second-order). Moreover, the isotherm study showed that the Langmuir model fitted for the adsorption of RBBR onto AFOS with Qm by 21.3 mg g-1.


Author(s):  
Rada Petrović

Because of its abundance and toxicity, heavy metals have become a seriousenvironmental problem. The presence of heavy metals, such as Cr(VI), in thewatercourses leads to numerous health problems in humans and animals. Cr(VI) ishighly toxic, even in low concentrations. Because of its carcinogenic, mutagenic andteratogenic effects on human beings, Cr(VI) is considered one of the most criticalpollutants. Due to this, it is necessary to remove Cr(VI) from wastewater prior to itsdischarge into the recipient.This paper studied the possibility for application of bentonite as an adsorbent forCr(VI) from aqueous medium. The characterization of bentonite was determined withchemical composition, specific surface, XRD method and FTIR. Optimal parameterssuch as pH of solution, adsorbent weight, time of adsorption and temperaturewere examined. Values of those parameters were: initial pH value of solution pH=2,adsorbent weight 2 g, time of adsorption 60 min, temperature 308 K. Experimentaldata were obtained by Freundlich and Langmuir isotherm adsorption models as wellas pseudo-first and pseudo-second order kinetics. Results were best described withFreundlich isotherm adsorption model and pseudo-second order kinetics.


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