Adsorption of arsenic in aqueous solution by RH-Fe-MCM-41

2009 ◽  
Vol 9 (2) ◽  
pp. 121-126 ◽  
Author(s):  
W. Tong-on ◽  
S. Sthiannopkao ◽  
K. W. Kim ◽  
S. Chiarakorn
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Molar Ratio ◽  
Adsorption Efficiency ◽  
Equilibrium Time ◽  
Freundlich Isotherms ◽  
Ph Values ◽  
Co Precipitation ◽  
Langmuir Constants ◽  
Mcm 41

RH-Fe-MCM-41 adsorption efficiency and capacity were examined with arsenic in lower concentrations in aqueous solution under varying pH values. The adsorption of arsenite (As3 + ) and arsenate (As5 + ) by RH-Fe-MCM-41 at the molar ratio of Si/Fe 10 gave removal efficiencies of 47% and 99% for As3 +  and As5 + , respectively, in the 100–1,000 μg l−1 concentration range. For the adsorption test of arsenic the best conditions were found to be an equilibrium time of 12 h at pH 7 for As3 +  and 2 h at pH 4 for As5 + . The adsorption capacity by the Langmuir constants (Qm) for As3 +  and As5 +  were 416.67 μg g−1 and 277.78 μg g−1, respectively, while the Freundlich constants (KF) were 0.583 μg g−1 for As3 +  and 112.87 μg g−1 for As5 + . The fit for As5 +  was good with both the Langmuir and Freundlich isotherms by considering the R2 values, which were quite similar (0.916 and 0.912); As3 +  fit well only with the Langmuir isotherm. The impregnation of iron (Fe3 + ) into the RH-Fe-MCM-41 structure increases the adsorption capacity of As3 +  and As5 +  both by oxidizing As3 +  to As5 +  and by co-precipitation with As5 + .

Adsorptive Removal of Ni(II) Ions from Aqueous Solution by Polyacrylic Acid/Attapulgite Composite Hydrogels

2017 ◽  
Vol 727 ◽  
pp. 859-865 ◽  
Author(s):  
Yi Wei Zheng ◽  
Wen Wen Tao ◽  
Gui Fang Zhang ◽  
Chao Lv ◽  
Yi Ping Zhao ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Polyacrylic Acid ◽  
Swelling Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorptive Removal ◽  
Composite Hydrogels ◽  
Ph Values ◽  
Ft Ir

Polyacrylic acid/attapulgite (PAA/ATP) composite hydrogels used for removal of heavy metal ions from aqueous solution was synthesized via radical polymerization with acrylic acid (AA) and attapulgite (ATP) modified by hydrochloric acid as adsorbent. Chemical composition of the modified ATP was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) and the morphology of the PAA/ATP hydrogels was characterized by scanning electron microscope (SEM), respectively. The swelling ratio, pH-sensitivity and adsorption performance of Ni (II) ions of the composite hydrogels were studied. The results showed the swelling ratio of the PAA/ATP composite hydrogels was higher than that of PAA hydrogels and the composite hydrogels displayed sensitivity to pH values with a sharp increase of swelling ratio when the pH values increased from 4 to 6. Comparing with PAA hydrogels, the composite hydrogels obtained a larger adsorption capacity of Ni (II) ions, the average adsorption capacity could reach 72.8 mg/g and adsorption ratio could reach 84%.

Metal Adsorbent Prepared from Coir Pith as Agricultural Waste: Adsorption of Zn(II) and Pb(II) from Aqueous Solution

2013 ◽  
Vol 545 ◽  
pp. 101-108 ◽  
Author(s):  
Kitirote Wantala ◽  
Nusavadee Pojananukij ◽  
Pongsert Sriprom ◽  
Tinnakorn Kumsaen ◽  
Arthit Neramittagapong ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Calcination Temperature ◽  
Ph Value ◽  
Agricultural Waste ◽  
Initial Solution ◽  
Order Kinetic ◽  
Solution Ph ◽  
Freundlich Isotherms ◽  
Coir Pith

Adsorption of Zn(II) and Pb(II) from aqueous solution were studied by using modified coir pith as an adsorbent. The extended adsorption conditions were investigated as a function of calcination temperature, contact time, adsorbent size, initial pH of solution and initial Zn(II) and Pb(II) concentrations. The adsorption capacity increased rapidly in first 5 minute and reached equilibrium in 120 minutes for Zn(II) and 10 minutes for Pb(II). In case of Zn(II); the results showed that the calcination temperature of modified coir pith above 600oC gave the higher adsorption capacity. The sizes of modified coir pith have no effect on the adsorption capacity. The adsorption capacity increased with increasing initial solution pH value. In case of Pb(II); the calcination temperature of modified coir pith showed no effect on the adsorption capacity. The sizes of modified coir pith showed a little effect on the adsorption capacity. The adsorption capacity increased with increasing of initial solution pH value up to pH of 3 and then stable. The results also corresponded with the Langmuir and Freundlich isotherms and pseudo second order kinetic adsorption models. The modified coir pith gave a higher Zn(II) and Pb(II) adsorption capacity of 29.33 mg Zn(II)/g adsorbent and 36.50 mg Pb(II)/g adsorbent, respectively.

scholarly journals Structural Stability of Ni/Al Layered Double Hydroxide Supported on Graphite and Biochar Toward Adorption of Congo Red

2021 ◽  
Vol 6 (2) ◽  
pp. 85-95
Author(s):  
Patimah Mega Syah Bahar Nur Siregar ◽  
Neza Rahayu Palapa ◽  
Alfan Wijaya ◽  
Erni Salasia Fitri ◽  
Aldes Lesbani
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Layered Double Hydroxide ◽  
Congo Red ◽  
High Performance ◽  
Precipitation Method ◽  
First Order ◽  
Xrd Diffraction ◽  
Co Precipitation ◽  
Double Hydroxide

In this research, Ni/Al layered double hydroxide (LDH) was modified by using co-precipitation method to generate Ni/Al-graphite (Ni/Al-GF) and Ni/Al-biochar (Ni/Al-BC). The adsorbents were applied to remove Congo Red from aqueous solution. The obtained samples were characterized by using XRD, FTIR, BET and TG-DTA. The XRD diffraction pattern of Ni/Al LDH, Ni/Al-GF, and Ni/Al-BC presented the formation of composite with decreasing crystallinity. The surface area modified LDHs was higher than the pristine materials, which was obtained 15.106 m2/g, 21.595 m2/g and 438.942 m2/g for Ni/Al-LDH, Ni/Al-GF, Ni/Al-BC respectively. The adsorption of Congo Red on the materials was tested at diferent parameters and the results exhibited that Congo Red adsorption on LDHs were pseudo-first-order (PFO) kinetic, spontaneous, endothermic and followed Langmuir model. The adsorbents removed Congo Red by high performance stability with adsorption capacity was 116.297 mg/g for Ni/Al-GF and 312.500 mg/g for Ni/Al-BC. These adsorption capacity was higher than the pristine LDH (61.728 mg/g). The regeneration process which carried out for five cycles showed that Ni/Al-GF and Ni/Al-BC have stable structures as reuse adsorbents for Congo Red from aqueous solution.

scholarly journals Adsorption Of Cd(II) Ions From Aqueous Solution By A Low-Cost Biosorbent Prepared From Ipomea Pes-Caprae Stem

2020 ◽  
Vol 9 (3) ◽  
pp. 197-206
Author(s):  
Thaharah Ramadhani ◽  
Faisal Abdullah ◽  
Indra Indra ◽  
Abrar Muslim ◽  
Suhendrayatna Suhendrayatna ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Optimal Condition ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Low Cost ◽  
Ph Values ◽  
Monolayer Adsorption ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ft Ir

The use of a low-cost biosorbent prepared from Ipomoea pes-caprae stem for the adsorption of Cd(II) ions from aqueous solution at different contact times, biosorbent sizes, pH values, and initial Cd(II) ions concentration solution was investigated. The biosorbent was analyzed using Fourier-transform infrared spectroscopy (FT-IR) to find important IR-active functional groups. A scanning electron microscope (SEM) was used to examine the biosorbent morphology. The experimental results showed the highest Cd(II) ions adsorption was 29.513 mg/g  under an optimal condition as initial Cd(II) ions concentration of 662.77 mg/L, 1 g dose, 80-min contact time, pH 5, 75 rpm of stirring speed, 1 atm, and 30 oC. Cd(II) ions' adsorption kinetics obeys the linearized pseudo-second-order kinetics (R2 = 0.996), and the adsorption capacity is based on the optimal condition, and the rate attained was 44.444 mg/g and 0.097 g/mg. Min, respectively. Besides, the adsorption isotherms were very well fitted by the linearized Langmuir isotherm model, and the monolayer adsorption capacity and pore volume determined was 30.121 mg/g and 0.129 L/mg, respectively. These results indicated the chemisorption nature

Removal of Cd2+ from Aqueous Solution Using MgAlCO3 -Layered Double Hydroxide

2011 ◽  
Vol 8 (2) ◽  
pp. 13 ◽  
Author(s):  
Nurul Izza Taib ◽  
Norzuyanti Mohd Aris
Keyword(s):  
Contact Time ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Freundlich Isotherms ◽  
Exothermic Process ◽  
Temperature And Pressure ◽  
Co Precipitation ◽  
Double Hydroxide

Anion clay hydrotalcite MgAlCO3 with a Mg/Al molar ratio of 3:1 was synthesized by co-precipitation at room temperature and pressure. The physicochemical properties were evaluated using Powder X-Ray Diffraction (PXRD), Fourier Transform Infrared (FTIR) spectroscopy and Thermogravimetric Analysis (TGA). The efficacy of anion clay hydrotalcite in the removal of Cd2+ from aqueous solutions was investigated with respect to contact time, initial concentration, pH, adsorbent dosage and temperature. The Cd2+ removal increased with the increased in contact time, adsorbent dosage, pH and initial concentration. Adsorption decreases with increasing initial concentration and temperature, for which the latter is indicative of an exothermic process. The equilibrium adsorption capacity of MgAlCO3 was evaluated using linear Langmuir and Freundlich isotherms with respect to the separation factor, RL .

Adsorption of Chloride Anion from Aqueous Solution by Calcined (Mg-Al) Hydrotalcites of Different Mg/Al Ratio

2011 ◽  
Vol 233-235 ◽  
pp. 420-426 ◽  
Author(s):  
Dong Jin Wan ◽  
Dan Qu ◽  
Hua Xiao ◽  
Yong De Liu ◽  
Ting Lu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Chloride Ion ◽  
Interlayer Spacing ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Maximum Adsorption Capacity ◽  
Batch Mode ◽  
X Ray ◽  
Electric Charge Density

Hydrotalcites (HT-X) of different Mg/Al ratio (X is Mg/Al molar ratio, 3 and 4) was synthesized by co-precipitation method. Calcined HTLCs (CHT-X) at 500°C have been shown to recover their original layered structure by taking up chloride ion from aqueous solution. Adsorption of chloride by CHT-X was investigated in batch mode. The kinetics study showed that the pseudo-second-order kinetics model could be used to describe the adsorption process satisfactorily. The equilibrium isotherm showed that the Langmuir model gave a better fit to the experimental data than the Freundlich model. The maximum adsorption capacity of CHT-3 was 83.33 mg/g; CHT-4 was 90.09 mg/g .The samples of different Mg/Al ratio have different crystallite size, thus showing different adsorption capacity. As the Mg/Al ratio increases from 3 to 4; the electric charge density between the layers becomes weaker; the interlayer spacing increases; the sample shows greater adsorption capacity. The HT-X where characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron dispersive X-ray analysis (EDX).

scholarly journals Removal of Lead from Aqueous Solution by Adsorption using Magnesium Aluminium Hydrogenphosphate Layered Double Hydroxides

2014 ◽  
Vol 8 (1) ◽  
Author(s):  
Zaini Hamzah ◽  
Mohd Najif Ab Rahman ◽  
Yamin Yasin ◽  
Siti Mariam Sumari ◽  
Ahmad Saat
Keyword(s):  
Aqueous Solution ◽  
Layered Double Hydroxide ◽  
Molar Ratio ◽  
Maximum Adsorption Capacity ◽  
Lead Removal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
Double Hydroxide ◽  
Double Hydroxides

Layered double hydroxide with molar ratio of 4 (MAN 4) was synthesized by co-precipitation and followed by hydrothermal method. The compound was then later going through ion exchange with K2HPO4 for 48 hours to produce MgAlHPO4 (MAHP 4). The solid produced were characterized using X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR). Adsorption of lead solution by MAHP 4 was carried out using batch experiment by mixing the lead solution and the solid of layered double hydroxide. The effects of various parameters such as contact time, pH, adsorbent dosage and initial concentration were investigated. The optimum pH for lead removal was found to be at pH of 5 and the optimum time of lead removal was found at 2 hours. The isotherm data was analysed using Langmuir and the correlation coefficient of 0.998 was obtained. The maximum adsorption capacity, Qo (mg/g) of 500 mg/g was also recorded from the Langmuir isotherm. The remaining lead solution was determined by using EDXRF (Energy Dispersive X-Ray Fluorescence spectrometry) model MiniPal 4 (PAN analytical). The results in this study indicate that MAHP 4 was an interesting adsorbent for removing lead from aqueous solution.

Study on the adsorption capacity Congo Red of nanocomposite xCoFe2O4 /(1-x)TiO2-5%La

2021 ◽  
Vol 10 (3) ◽  
pp. xx-xx
Author(s):  
Hue Dang Thi Minh ◽  
Chien Hoang Thi ◽  
Mai Nguyen Thi Tuyet ◽  
Hoang Tran Vinh ◽  
Huyen Tran Thi Thu ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Congo Red ◽  
Treatment Process ◽  
Structural Characteristics ◽  
Nanocomposite Materials ◽  
Adsorption Efficiency ◽  
High Adsorption ◽  
Step Procedure ◽  
Co Precipitation ◽  
Hydrothermal Methods

In this paper, nanocomposite materials of xCoFe2O4/(1-x)(TiO2–5%La) (x = 0.2) were synthesized in a two-step procedure, combining a co-precipitation and hydrothermal methods. The morphological and structural characteristics of the material were studied through XRD, SEM, EDS, BET measurements. The materials showed the high adsorption capacity for a organic dye - Congo Red (CGR) . The adsorption efficiency reaches 99.34% after 10 minutes of treatment process, with the amount of adsorbent used is 0.04g /100ml of solution of 32 µmol/l CGR.

Adsorption of Mercury(II) Ion in Aqueous Solution by Using Bentonite-Based Monolith

2021 ◽  
Vol 885 ◽  
pp. 77-84
Author(s):  
Darmadi ◽  
Mahidin ◽  
Siti Syifa Azzahra ◽  
Munadiya Masrura
Keyword(s):  
Aqueous Solution ◽  
Metal Removal ◽  
Batch Reactor ◽  
Heavy Metal Removal ◽  
Solution Concentration ◽  
Environmental Safety ◽  
Adsorption Efficiency ◽  
Ion Removal ◽  
Non Linear ◽  
Langmuir Constants

The removal of mercury from the waterbody remains a severe challenge in ensuring environmental safety due to its highly toxic and non-biodegradable properties. Adsorption is an evidently effective method for heavy metal removal in water. This research aims to study the mercury (II) ion adsorption behavior in aqueous solution onto extruded natural bentonite in monolithic structure, bentonite-based monolith (BBM) adsorbent. BBM was characterized by XRD, BET, and SEM, the results verify BBM could improve adsorption performance assumed on its structure. Adsorption efficiency, isotherm model, and adsorption kinetic were investigated. Experiments were performed in a lab-scale batch reactor with mercury solution concentration varied from 1 to 5 mg/L. The maximum adsorption efficiency discovered to be 63,9%. The experimental data fitted well to Langmuir isotherm (non-linear) and kinetic model pseudo first order (non-linear), revealing the maximum monolayer capacity (Qo) of BBM to be 0,187 mg/g with Langmuir constants KL and aL are 0,215 L/g dan 1,151 L/mg respectively. These value confirms that BBM adsorbent encompasses tremendous potential for mercury (II) ion removal in a solution.

scholarly journals Removal of methylene blue from aqueous solution using Mg-Fe, Zn-Fe, Mn-Fe layered double hydroxide

2020 ◽  
Vol 81 (12) ◽  
pp. 2522-2532
Author(s):  
Zhongliang Shi ◽  
Yanmei Wang ◽  
Shuyu Sun ◽  
Cheng Zhang ◽  
Haibo Wang
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Langmuir Adsorption ◽  
Molar Ratios ◽  
Pseudo Second Order ◽  
Co Precipitation ◽  
Double Hydroxide ◽  
Double Hydroxides

Abstract Layered double hydroxides (LDH) with highly flexible and adjustable chemical composition and physical properties have attracted tremendous attention in recent years. A series of LDH with different M (Mg, Zn, Mn)-Fe molar ratios were synthesized by the double titration co-precipitation method. The effect of the factors, including M (Mg, Zn, Mn) : Fe molar ratio, pH, and M-Fe LDH dosage, on the ability of the prepared M-Fe LDH to remove cationic methylene blue (MB) dye from aqueous solution were investigated. Results indicated that the removal efficiency of MB (10 mg/L) was the best at the M (Mg, Zn, Mn): Fe molar ratio of 3:1 by using 2.0 g/L of M-Fe LDH at pH 6.0 under 298.15 K. Mg-Fe LDH had the highest removal performance (71.94 mg/g at 298.15 K) for MB compared to those of the Zn-Fe and Mn-Fe LDH. Zn-Fe LDH with the smallest activation energy resulted in the fastest adsorption rate of MB. The pseudo-second-order model and Langmuir adsorption isotherm were also successfully applied to fit the theory of M-Fe LDH for removal of MB.

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