scholarly journals Preparation of Ca/Al-Layered Double Hydroxides/Biochar Composite with High Adsorption Capacity and Selectivity toward Cationic Dyes in Aqueous

2021 ◽  
Vol 16 (2) ◽  
pp. 244-252
Author(s):  
Risfidian Mohadi ◽  
Neza Rahayu Palapa ◽  
Aldes Lesbani

Widely reports have evaluated the use of biochar (BC) composites to layered double hydroxide (LDH) to adsorb dyes from wastewater. However, its applicability for adsorbing a mixture of cationic dyes such as Malachite green (MG), Rodhamine-B (Rh-B), and Methylene blue (MB), which causes carcinogenic and mutagenic effects on aquatic life, has not been studied. In this work, we compared the performance of CaAl-LDH/BC adsorbent with or without the addition of BC in the adsorption of cationic dyes. The adsorption study was prepared in a batch system using various temperatures, concentrations, and also contact time. The results of the characterization of Ca/Al-Biochar composite showed the unique diffraction of XRD pattern, and also showed two characteristics of starting materials. Surface area analysis by BET method showed Ca/Al-Biochar composite has a higher surface area than starting material. The results of the adsorption study of MG showed that Ca/Al-Biochar follows the pseudo-second-order kinetic model. The adsorption capacity of MG on Ca/Al-Biochar was up to 71.429 mg/g and shows selectivity toward MG in an aqueous solution. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

2020 ◽  
Vol 15 (3) ◽  
pp. 653-661
Author(s):  
Neza Rahayu Palapa ◽  
Novie Juleanti ◽  
Normah Normah ◽  
Tarmizi Taher ◽  
Aldes Lesbani

Cu-Al layered double hydroxide (LDH) was intercalated with Keggin ion of polyoxometalate           K4[a-SiW12O40] to form Cu-Al-SiW12O40 LDH. The obtained materials were analyzed by X-ray Diffraction (XRD), Fourier Transform Infra Red (FTIR) spectroscopy, and Brunaur-Emmett-Teller (BET) surface area analysis. Furthermore, the materials were used as adsorbents of malachite green from aqueous solution. Some variables for adsorption, such as: effect of adsorption times, malachite green concentration, and also adsorption temperature, were explored. The results showed that diffraction at 11.72° on Cu-Al LDH has interlayer distance of 7.56 Å. The intercalation of that LDH with [a-SiW12O40]4− ion resulted increasing interlayer distance to 12.10 Å. The surface area of material was also increased after intercalation from 46.2 m2/g to 89.02 m2/g. The adsorption of malachite green on Cu-Al and          Cu-Al-SiW12O40 LDHs followed pseudo second order kinetic and isotherm Langmuir model with adsorption capacity of Cu-Al and Cu-Al-SiW12O40 LDHs was 55.866 mg/g and 149.253 mg/g, respectively. That adsorption capacity is equal with increasing interlayer space and surface area properties of material after intercalation. Thus, the adsorption of malachite green on Cu-Al and Cu-Al-SiW12O40 LDHs is unique and dominantly occurred on interlayer space of LDH as active site adsorption. Copyright © 2020 BCREC Group. All rights reserved


2015 ◽  
Vol 737 ◽  
pp. 537-540
Author(s):  
Yan Wei Guo ◽  
Hua Zhang ◽  
Zhi Liang Zhu

A novel Mg/Fe/Ce layered double hydroxide (LDHs) and its calcined product (CLDH) were synthesized and CLDH was used as adsorbents for the removal of chlorate ions. Results showed that the initial solution pH was an important factor influencing the chlorate adsorption. The adsorption behavior of chlorate followed the Langmuir adsorption isotherm with a maximum adsorption capacity of 18.2 mg/g. The adsorption kinetics of chlorate on CLDH can be described by the pseudo-second-order kinetic model. It was concluded that the CLDH material is a potential adsorbent for the purification of polluted water with chlorate.


2020 ◽  
Vol 10 (1) ◽  
pp. 33-45 ◽  
Author(s):  
Neza Rahayu Palapa ◽  
Risfidian Mohadi ◽  
Addy Rachmat ◽  
Aldes Lesbani

Layered double hydroxide (LDH) Cu/Al and Cu/Cr had been used as adsorbent of malachite green (MG) in aqueous solution. The properties of Cu/Al and Cu/Cr LDHs were analyzed by X-ray diffraction, surface area analysis (BET) and FTIR spectroscopy. Adsorption study of MG was achieved at pH 9. Adsorption of MG follows the pseudo-second-order kinetic model. Langmuir isotherm was suitable for adsorption of MG on both LDH with a maximum adsorption capacity of 59.52 mg/g. The thermodynamic study indicated that the adsorption process is physisorption, spontaneous, and endothermic process.  Adsorption of MG onto LDHs involve the acid-base interaction between adsorbent and adsorbate.


2021 ◽  
Vol 6 (3) ◽  
pp. 209-217
Author(s):  
Neza Rahayu Palapa ◽  
Tarmizi Taher ◽  
Alfan Wijaya ◽  
Aldes Lesbani

Modification of Cu/Cr layered double hydroxides (LDHs) has been conducted by intercalation using Keggin type polyoxometalate [a-SiW12O40]4- to form CuCr-[a-SiW12O40]. The materials were analyzed by XRD, FTIR, and surface area analyses. Furthermore, materials were used as selectivity adsorbents of cationic dyes such as malachite green, rhodamine-B and methylene blue. The malachite green is more selective than others from an aqueous solution. The adsorption of malachite green showed that the adsorption capacity of CuCr-[a-SiW12O40] was higher than pristine LDHs. The adsorption process was followed pseudo second order kinetic model and Langmuir isotherm adsorption. The Qmax value of CuCr-[a-SiW12O40] reached 55.322 mg/g at 323 K after 100 minutes adsorption time. Thermodynamic parameters such as ΔG, ΔH and ΔS confirm that the adsorption process was endothermic, spontaneous, and more favorable at high temperatures. The intercalated material was higher structural stability toward reusability adsorbent than pristine LDHs.


2021 ◽  
pp. 79-91
Author(s):  
Neza R. Palapa ◽  
Tarmizi Taher ◽  
Novie Juleanti ◽  
Normah Normah ◽  
Aldes Lesbani

Numerous reports have elucidated the use of biochar (BC) to adsorb dyes from wastewater. However, its applicability for adsorbing Procion Red, which causes carcinogenic and mutagenic effects on aquatic life, has not been studied. In this work, biochar produced from rice husk in Sumatera, Indonesia was used as a biosorbent for Procion Red removal from aqueous systems. Rice husk-BC was characterised using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, surface area specific analysis, and scanning electron microscopy (SEM) for mor-phological analysis. The characterisation showed a (002) reflection peak at 2θ = 23° with broad and quite intense diffraction, which indicates reflection of electromagnetic waves by silicates, oxides and carbon present in the rice husk-BC. The surface area and SEM morphologies confirm that after pyrolysis, the surface of the rice husk changed. The FTIR spectra confirm the presence of functional groups such as the carboxylic acids and aromatic compounds. The surface area of rice husk-BC was up to ten times that of its raw material. The results of adsorption studies indicate that adsorption of Procion Red on rice husk-BC follows a pseudo-second-order (PSO) reaction with a rate constant of 0.044 min-1 and Langmuir isotherm models with a coefficient of correlation close to unity. The maximum adsorption capacity increased from 36.900 mg g-1 for the rice husk to 84.034 for the rice husk-BC. Thermodynamic analysis showed positive enthalpy and entropy, indicating that Procion Red adsorption is endothermic; thus, the Gibbs energy values decreased with increase in temperature, indicating that high temperatures are favourable for the adsorption process. Furthermore, the study of adsorption of Procion Red on rice husk-BC and regeneration of the adsorption capacity of rice husk-BC showed the largest drop in the fourth and last cycle.


2015 ◽  
Vol 5 (1) ◽  
pp. 45
Author(s):  
Tchuifon Tchuifon Donald Raoul ◽  
Nche George Ndifor-Angwafor ◽  
Ngakou Sadeu Christian ◽  
Kamgaing Théophile ◽  
Ngomo Horace Manga ◽  
...  

<p>The present study is based on the adsorption of cadmium (II) ions on rice husk and egussi peeling, unmodified and modified with nitric acid in aqueous solution, using batch technique. It was carried out as a function of contact time, dosage, pH and initial concentration. The equilibrium time was achieved within 25 minutes for unmodified rice husk (Glu NT) and 20 minutes for unmodified egussi peeling (Cuc NT) with an adsorbed quantity of 13.18 mg/g. In the case of modified materials, we obtained 15 minutes for modified rice husk (Glu HNO3) and 10 minutes for modified egussi peeling (Cuc HNO3) with an adsorbed quantity of 18.77 mg/g. The maximum biosorption occurred at pH 5.5 for all biosorbents. The adsorbent mass for maximum adsorption was 0.4 g giving an adsorption capacity of 62.02 % for unmodified adsorbents. In the case of modified adsorbents, the minimal mass at which maximum adsorption occurred was 0.4 g giving an adsorption capacity of 98.33 % and 0.6 g giving an adsorption capacity of 98.33 % for modified rice husk and egussi peeling respectively. The adsorbent/adsorbate equilibrium was well described by the pseudo-second order kinetic model and by Langmuir’s and Freundlich adsorption model. This models showed that the adsorption of cadmium (II) is a chemisorption process.</p>


2021 ◽  
Vol 10 (1) ◽  
pp. 59-66
Author(s):  
Son Le Lam ◽  
Phu Nguyen Vinh ◽  
Hieu Le Trung ◽  
Tan Le Thua ◽  
Nhan Dang Thi Thanh ◽  
...  

Glucomannan/graphene oxide (GM/GO) hydrogel was synthesized by using calcium hydroxide as the crosslinker. The synthesized material was characterized by using IR, XRD, SEM, EDX and RAMAN technology. The composite hydrogel was used for removal of organic dyes from aqueous solution. The results showed that the GM/GO hydrogel had a porous structure and a high adsorption capacity toward methylene blue (MB). The pseudo-second-order kinetic model could fit the rate equation of MB adsorption onto the GM/GO hydrogel. The adsorption of MB onto GM/GO hydrogel was a spontaneous process. In addition, the equilibrium adsorption isotherm data indicated that equilibrium data were fitted to the Langmuir isotherm and the maximum dye adsorption capacity was 198,69 mg.g-1. Moreover, the hydrogel was stable and easily recovered and adsorption capacity was around 97% of the initial saturation adsorption capacity after being used five times.


SAINTIFIK ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 104-115
Author(s):  
Agusriyadin Agusriyadin

Penelitian ini bertujuan untuk menguji kemampuan AK dan AKPM dalam mengadsorpsi ion Cu (II), pengaruh parameter adsorpsi dan mekanisme adsorpsi. AK dan AKP Madsorben dibuat dari residu ampas kelapa. Adsorben dikarakterisasi dengan FTIR, SEM dan EDS. Pengaruh parameter adsorpsi seperti pH awal, dosis adsorben, waktu kontak dan konsentrasi ion Cu (II) awal diperiksa untuk menentukan kondisi optimum serapan tembaga (II). Ion Cu (II) yang teradsorpsi diukur berdasarkan pada konsentrasi Ion Cu (II) sebelum dan sesudah adsorpsi menggunakan metode AAS. Hasil karakterisasi menunjukkan bahwa struktur pori dan gugus fungsi tersedia pada permukaan adsorben. Menurut percobaan efek pH, kapasitas adsorpsi maksimum dicapai pada pH 7. Waktu kontak optimal dan konsentrasi tembaga awal (II) ditemukan masing-masing pada 120 menit dan 100 mg L-1. Data eksperimental sesuai dengan model kinetik orde dua orde dua, dan Langmuir isoterm adsorpsi yang diperoleh paling sesuai dengan data adsorpsi. Kapasitas adsorpsi maksimum adsorben ditemukan menjadi 4,73 dan 6,46 mg g-1 pada kondisi optimal. The results of characterization showed that the pore structure and the functional groups were available on adsorbent surface. According to the pH effect experiments, the maximum adsorption capacity was achieved at pH 7. Optimum contact time and initial copper(II) concentration were found at 120 min and 100 mg L-1, respectively. The experimental data were comply with the pseudo-second-order kinetic model, and Langmuir adsorption isotherm obtained best fitted the adsorption data. The maximum adsorption capacity of the adsorbents was found to be 4.73 and 6.46 mg g-1 at optimum conditions.


Author(s):  
Xiaochun Yin ◽  
Nadi Zhang ◽  
Meixia Du ◽  
Hai Zhu ◽  
Ting Ke

Abstract In this paper, a series of bio-adsorbents (LR-NaOH, LR-Na2CO3 and LR-CA) were successfully prepared by modifying Licorice Residue with NaOH, Na2CO3 and citric acid, which were used as the adsorbents to remove Cu2+ from wastewater. The morphology and structure of bio-adsorbents were characterized by Fourier Transform Infrared, SEM, TG and XRD. Using static adsorption experiments, the effects of the adsorbent dosage, the solution pH, the adsorption time, and the initial Cu2+ concentration on the adsorption performance of the adsorbents were investigated. The results showed that the adsorption process of Cu2+ by the bio-adsorbents can be described by pseudo-second order kinetic model and the Langmuir model. The surface structure of the LR-NaOH, LR-Na2CO3 and LR-CA changed obviously, and the surface-active groups increased. The adsorption capacity of raw LR was 21.56 mg/g, LR-NaOH, LR- Na2CO3 significantly enhanced this value up to 43.65 mg/g, 43.55 mg/g, respectively. After four adsorption-desorption processes, the adsorption capacity of LR-NaOH also maintained about 73%. Therefore, LR-NaOH would be a promising adsorbent for removing Cu2+ from wastewater, and the simple strategy towards preparation of adsorbent from the waste residue can be as a potential approach using in the water treatment.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Uzma ◽  
Sultan Alam ◽  
Hanif Subhan ◽  
Luqman Ali Shah ◽  
Noor Saeed Khattak

Abstract Removal of noxious dyes from waste water is highly desirable for the safety of humans, aquatic life and natural environment. The issue was addressed in the present work by one pot fabrication of polyacrylamide/Gum Arabic (pAAm/GA) composite hydrogel which was applied as sorbent for basic blue-3 (BB3) eradication. The synthesis of the material was confirmed by scanning electron microscopy (SEM), Fourier Transformed Infrared (FTIR) spectroscopy and thermo gravimetric analysis (TGA). Besides, the same techniques also evidenced BB3 uptake by the hydrogel. In distilled water, the swelling capacities of the hydrogel was investigated at pH 7 and the nature of water diffusion into the hydrogel was probed from the resultant data. The composite hydrogel reached equilibrium point in 24 h after which no appreciable water absorption occurred. The adsorption of BB3 by the hybrid material was comprehensively investigated which involved the effect of contact time, temperature and pH on the sorption capacity of the hybrid sorbent. The obtained data fitted well into pseudo second order kinetic model and the adsorption took place in three consecutive kinetic phases. Moreover, sorption thermodynamics revealed non spontaneous and endothermic nature of BB3 sorption accompanied with increase in degree of order.


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