Enhanced removal performance for Congo red by coal-series kaolin with acid treatment

Niu, Sanxin; Xie, Xiaokang; Zheng, Wei; Zheng, Linhui; Gao, Feng; Miao, Yang

doi:10.1080/09593330.2019.1670269

Cited by 8 publications

(4 citation statements)

References 31 publications

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“…These peaks are associated with the presence of kaolinite. Similar diffraction peaks were reported by Meroufel et al 8 and Niu et al 24 The diffraction peak at 20.86° is associated with quartz. 8 In addition to the typical peaks of kaolin, new peaks at 19°, 28.9°, 32.1°, 33.8°, 35°, 48.7°, 54.6°, 59.5° and 62° were observed in XRD spectra of KZF and KZF-200.…”

Section: Adsorbent Characterizationsupporting

confidence: 87%

Removal of Diazo Dye Direct Red 28 and Tetra Azo Dye Direct Black 22 Using Synthesized Magnetic Kaolin Supported Zinc Ferrite

Fındık

2022

ACSi

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The presence of dye molecules in water resources has harmful effects on environment. Therefore, it is important to remove dyes from wastewater using eco-friendly materials. In this study, adsorptive removal of diazo dye Direct Red 28 (DR-28) and tetra azo dye Direct Black 22 (DB-22) was investigated by using a new composite, kaolin supported zinc ferrite (KZF) as adsorbent. Characteristics of the composite, KZF were determined using various techniques such as FTIR, SEM, XRD, VSM, and EDS/Mapping. The adsorption of DR-28 and DB-22 on KZF was studied as a function of contact time, initial dye concentration, adsorbent amount, temperature, initial pH of the solution as well as the heat treatment of the composite. The removal of DR-28 was found to be 92.4% for the KZF concentration of 1g/200mL, initial dye concentration of 20 mg/L, contact time of 120 min at original pH and 21 °C. On the other hand the removal of DB-22 was found to be 91.7% under the same conditions at 40 °C. The results showed that Langmuir isotherm is suitable for the adsorption of DR-28 and DB-22 on KZF under given conditions. It was found that adsorption of DR-28 on KZF was exothermic while that of DB-22 was endothermic. The enthalpy changes (ΔH0) for the adsorption of DR-28 and DB-22 dyes on KZF were found to be –24.59 kJ/mol and 61.95 kJ/mol respectively. ΔS0 for the adsorption of DR-28 dye was found to be negative while ΔS0 for the adsorption of DB-22 was positive. The kinetic data fitted well to the pseudo second order model for the adsorption of DR-28 and DB-22 on KZF composite. These results showed that the prepared adsorbent KZF could be used as an adsorbent for the efficient removal of anionic dyes.

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Section: Adsorbent Characterizationsupporting

confidence: 87%

Removal of Diazo Dye Direct Red 28 and Tetra Azo Dye Direct Black 22 Using Synthesized Magnetic Kaolin Supported Zinc Ferrite

Fındık

2022

ACSi

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“…The negative values for ΔG θ at different temperatures indicated that the adsorption of CR and TC occurred in a spontaneous process. In addition, as the temperature increased, a more significant decrease was observed in the ΔG θ values, suggesting that higher temperature can be conducive to the CR and TC adsorption (Niu et al 2021). The positive value of ΔH θ indicated that the adsorption process was endothermic, and increasing the temperature was beneficial to the adsorption process.…”

Section: Adsorption Isotherms and Thermodynamicsmentioning

confidence: 96%

Adsorption of Congo red and tetracycline onto water treatment sludge biochar: characterisation, kinetic, equilibrium and thermodynamic study

Chen

et al. 2022

Water Science and Technology

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In this study, readily available inexpensive water treatment sludge (WTS) was used to prepare adsorbent for the removal of Congo red (CR) and tetracycline (TC) from aqueous solutions. The structural characteristics and adsorption properties of WTS biochar were characterised via scanning electron microscope, energy dispersive X − ray spectroscopy, Brunauer − Emmett − Teller and Fourier Transform infrared spectroscopy. In batch experiments, the adsorption factors, kinetics, isothermal curves and thermodynamics of the adsorption properties were investigated. The optimum preparation condition of WTS biochar was 400 °C for 4 h under O2 − limited pyrolysis, which exhibited increased specific surface area and pore structures. The best adsorption was observed when the pH of the CR and TC solutions was 7 and 4, respectively. The adsorption process followed the pseudo − second − order model, indicating that the main control step was the chemical adsorption process. Isotherm data were best described by the Langmuir model, and the maximum adsorption capacities for CR and TC were 116.4 and 58.5 mg·g−1, respectively. Thermodynamic parameters revealed that the adsorption process was spontaneous and endothermic. According to the analysis, the adsorption mechanism of CR could be attributed to electrostatic attraction, π–π conjugation and hydrogen bonding, whereas that of TC was potentially associated with cation exchange, complex precipitation, π–π conjugation and hydrogen bonding.

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“…In particular, azo dyes are one of the most widely used synthetic dyes, accounting for more than half of the total dyes. Under special conditions, azo dyes can decompose to produce a variety of carcinogenic aromatic amines, which may cause human diseases and cancer after activation [2][3][4][5][6][7]. Therefore, azo-dye wastewater must be treated innocuously before discharge.…”

Section: Introductionmentioning

confidence: 99%

Preparation of Novel Magnetic Sodium Alginate-Ferric(III) Gel Beads and Their Super-Efficient Removal of Direct Dyes from Water

2020

J Polym Environ

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Novel magnetic sodium alginate-based biopolymer Fe 3 O 4 @SA-Fe was successfully prepared by the cross-linking reaction of sodium alginate (SA) and Fe(III) ions and adding magnetic ferric oxide (Fe 3 O 4 ), and characterized by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), Fourier Transform-Infrared (FTIR), X-ray Photoelectron Spectroscopy (XPS) and Vibrating Sample Magnetometer (VSM), respectively. The effects of preparation and adsorption conditions on the adsorbent were investigated by adsorbing Congo red (CR) and Direct red 23 (DR 23) dyes. The results showed that the synthesized Fe 3 O 4 @SA-Fe polymer gel beads exhibited super-high adsorption property and good stability when the mass concentrations of SA, Fe(III) ions and Fe 3 O 4 are 16, 12.5 and 7 g/L at room temperature respectively. The adsorption rates of two dyes by Fe 3 O 4 @SA-Fe were very fast at 298 K, and the time required to reach the equilibrium was very short, which was 30 min for CR and 60 min for DR 23. Moreover, the dye removal efficiencies were over 99.4% and 95.2% in a wide pH range of 2.0 ~ 9.0 for CR and 2.0 ~ 10.0 for DR 23, respectively. The adsorption process could be accurately described by the pseudo-second-order rate model, which were mostly controlled by intra-particle diffusion. The fitting results of isothermic data by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models revealed that the equilibrium data completely obeyed the Langmuir model and the obtained maximum adsorption capacities of CR and DR 23 were 3333 and 1429 mg/g at 298 K, respectively. FTIR, UV-Vis and XPS analysis indicated that the electrostatic adsorption, hydrogen bonding and ligand exchange promoted the interaction between dye molecules and Fe 3 O 4 @SA-Fe. A green magnetic biosorbent Fe 3 O 4 @SA-Fe gel beads with simple preparation method and high-cost performance can be used for super-efficient purification of high-concentration dye effluent and quickly separated from the aqueous phase and recovered, which would have a good application prospect.

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Enhanced removal performance for Congo red by coal-series kaolin with acid treatment

Cited by 8 publications

References 31 publications

Removal of Diazo Dye Direct Red 28 and Tetra Azo Dye Direct Black 22 Using Synthesized Magnetic Kaolin Supported Zinc Ferrite

Removal of Diazo Dye Direct Red 28 and Tetra Azo Dye Direct Black 22 Using Synthesized Magnetic Kaolin Supported Zinc Ferrite

Adsorption of Congo red and tetracycline onto water treatment sludge biochar: characterisation, kinetic, equilibrium and thermodynamic study

Preparation of Novel Magnetic Sodium Alginate-Ferric(III) Gel Beads and Their Super-Efficient Removal of Direct Dyes from Water

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