scholarly journals Photodecolourization of congo red dye in presence of Ni3+ layered double hydroxide

2021 ◽  
Vol 30 ◽  
pp. 02010
Author(s):  
Irina Ryltsova ◽  
Evgenia Tarasenko ◽  
Olga Lebedeva

Layered double hydroxide containing Ni3+ (Mg/AlNi-LDH) was successfully synthesized by co-precipitation in an oxidizing media. The resulted product was characterized using X-ray diffraction, wavelength dispersive X-ray fluorescence spectrometry. The activity of Mg/AlNi-LDH in the process of photodegradation of Congo red dye using UV light irradiation was evaluated. The initial rate of photodegradation of the dye in the presence of LDH is 1.6 times higher than that of UV irradiated solution. The kinetic data obtained for photodegradation process can be adequately described by pseudo-first-order kinetic model. The presence of Mg/AlNi – LDH leads to increased photodegradation yield compared to destruction only by UV irradiation.

2019 ◽  
Vol 814 ◽  
pp. 463-468 ◽  
Author(s):  
Hong Tham Nguyen Thi ◽  
Duy Chinh Nguyen ◽  
Thi Thuong Nguyen ◽  
Van Thuan Tran ◽  
Huu Vinh Nguyen ◽  
...  

This In this study, the Ca-Al layered double hydroxide was used as a potential adsorbent for the removal of Congo red from aqueous solutions. The effects of Initial concentration and contact time on the adsorption properties of Congo red by Ca-Al LDHs were studied. The removal rate of Conge red reached to 59.416 mg/g under room temperature with 0.2g of adsorbent, initial concentration of 50 ppm, adsorption time of 210 min, shaking speed of 90r/min. The experimental equilibrium data for the removal of Congo red were evaluated by various isotherm models. The pseudo-second-order kinetic models were found to fit the adsorption kinetics, and the equilibrium data were appropriately fitted to Langmuir and Freundlich model adsorption isotherm.


2010 ◽  
Vol 5 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Karna Wijaya ◽  
Iqmal Tahir ◽  
Nanik Haryanti

The preparation of Fe2O3-montmorillonite and it's application as a catalyst for congo red dye photodegradation has been carried out. Fe2O3-montmorillonite was prepared by mixing the iron complexes pillaring agent and montmorillonite. The product was calcined at 250 oC for 5 hours. Montmorillonite and calcined product was analyzed by X-ray diffractometry (X-RD), infrared spectrophotometry (FTIR), gas  sorption analyser, X-ray fluorescense (X-RF) and UV/Vis diffuse reflectance spektrophotometry (UV-DRS). Fe2O3-montmorilonite then was used as a catalyst on congo red dye photodegrdation by UV-illuminating a mixture of 50 mg Fe2O3-montmorillonite and 25 mL congo red 10­-4M at 365 nm at various illuminating times. Adsorption of congo red on Fe2O3-montmorillonite and montmorillonite was also performed as a comparison. Result of X-RD analysis showed that the 001 reflection of  Fe2O3-montmorillonite was not  detected that probably indicating the formation of house of card stucture and this result was supported also by the analysis result of distribution of pores and SEM photography result. Results of the XRF analysis showed that iron content increased  from 5.21 % (w/w) in montmorillonite to 25.12 % (w/w) in Fe2O3-montmorillonite. UV- DRS analysis showed the increament of band gap energy from 3.69 eV in the iron oxide bulk to 3.8 eV in Fe2O3-montmorillonite. Specific surface area of the montmorillonite also increased significantly from 69,71 m2/g to 126,49 m2/g and total pores volume increased from 50.70x10-3 mL/Å/g  to 107.89x10-3 mL/Å/g, respectively. Photodegradation of congo red using Fe2O3-montmorillonite caused the decreament of congo red concentration up to 90.22 %  on UV illumination for 60 minutes. Adsorption of congo red on Fe2O3-montmorillonite reached 84.4% and on  montmorillonite was 75.15 %.   Keywords: photodegradation, congo red, Fe2O3-montmorillonite, UV light


2016 ◽  
Vol 27 (1) ◽  
pp. 232-237 ◽  
Author(s):  
Ridha Lafi ◽  
Khaled Charradi ◽  
Mohamed Amine Djebbi ◽  
Abdessalem Ben Haj Amara ◽  
Amor Hafiane

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

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.


2021 ◽  
Author(s):  
Mohammad Dinari ◽  
Shirin Shabani

Abstract Herein, we report the synthesis of Cu-Ca-Al/NO3-based layered double hydroxide through co-precipitation methodology. The prepared layered double hydroxide was then modified with itaconic acid. The physicochemical properties of the prepared materials were studied using Fourier transform-infrared spectroscopy, scanning electron microscopy, X-ray diffraction analysis, thermogravimetric analysis, and nitrogen adsorption/desorption technique. The prepared materials were then applied as novel adsorbents for the removal of Congo red as a model of an anionic dye from aqueous media. To reach maximum adsorption, the effect of parameters including sample solution pH, adsorbent amount, contact time, and initial concentration of Congo red on the adsorption process was investigated. Kinetic studies were also conducted to study the mechanism of adsorption. In this regard, the kinetic models of pseudo-first-order, pseudo-second-order, Elovich, and intra-particle diffusion were studied. The results showed that the adsorption of Congo red onto Cu-Ca-Al-LDH and LDH-ITA adsorbents followed the pseudo-second-order kinetic model. To evaluate the equilibrium adsorption data, different isotherms including Langmuir, Freundlich, and Dubinin-Radushkevich were also applied. The data revealed that the Freundlich isotherm provided the best fit with the equilibrium data of both adsorbents. Maximum adsorption capacities of 81 and 84 mg g− 1 were obtained using Cu-Ca-Al-LDH and LDH-ITA adsorbents, respectively.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1202
Author(s):  
Zita Timár ◽  
Truong Ngoc Hung ◽  
Cora Pravda ◽  
Zoltán Kónya ◽  
Ákos Kukovecz ◽  
...  

L-Cysteinate-intercalated CaAl-layered double hydroxide (LDH) was prepared by the co-precipitation method producing highly crystalline hydrocalumite phase with a well-pillared interlayer gallery. The obtained materials were characterized by X-ray diffractometry, IR as well as Raman spectroscopies. By performing interlamellar oxidation reactions with peracetic acid as oxidant, oxidation of cysteinate to cystinate in aqueous and cysteinate sulfenic acid in acetonic suspensions occurred. The oxidations could be performed under mild conditions, at room temperature, under neutral pH and in air. It has been shown that the transformation pathways are due to the presence of the layered structure, that is, the confined space of the LDH behaved as molecular reactor.


Fibers ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Saadia Lahreche ◽  
Imane Moulefera ◽  
Abdelkader El El Kebir ◽  
Lilia Sabantina ◽  
M’hamed Kaid ◽  
...  

The present work was aimed to evaluate the adsorption properties of activated carbons based on prickly pear seeds (PPS) and conductive polymer matrix based on polyaniline (PANI) for the removal of anionic Congo red (CR) dye from aqueous solutions. The adsorbent was prepared by polymerization of aniline in the presence of activated PPS by phosphoric acid and sodium hydroxide. The samples were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and the Brunauer–Emmett–Teller (BET) methods. The adsorption kinetics were studied using UV-visible (UV/Vis) spectroscopy. The characterization data suggest that the adsorption of the Congo red dye is enhanced because PANI chain molecules, which are especially accountable for removal through π—π interaction and H-bonding with the CR, are adsorbed/tethered onto the acid-activated PPS (PPSH), and thus surmount the mass transfer limitation by being best exposed to the CR-adsorbed molecule. The adsorption kinetics follows the pseudo-second order process. The correlation coefficients (R2) for Langmuir, Freundlich and Tempkin showed that the adsorption values obey Freundlich and Tempkin isotherm models. Moreover, the isotherm was most accurately described by the Freundlich model, and the maximum removal percentage was calculated to be 91.14% under optimized conditions of pH 6.6, 1 g/L of adsorbent dosage, and an initial CR dye concentration of 20 mg·L−1. Importantly, the hybrid adsorbent exhibited the highest adsorption capacity (80.15%) after five cycles of the adsorption–desorption process. Thermodynamic parameters, such as entropy changes, enthalpy changes and Gibbs free energy, were also evaluated. These results indicated that the PANI matrix can generally be better utilized for the removal of Congo red dye when appropriately dispersed on the surface of suitable support materials. These results provide a new direction to promote the separable adsorbents with increasing performance for adsorption of dye impurities from wastewater.


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