Phosphate recovery from an aqueous solution through adsorption-desorption cycle over thermally treated activated carbon

Abstract The objective of this work was to evaluate the degradation of rhodamine B dye from aqueous solution by photo-Fenton reaction under visible irradiation using a Fe-rich bentonite as a catalyst. The material was thermally treated at a low temperature (200 °C) and characterized by XRD, N2 adsorption-desorption isotherms, FTIR, SEM-EDS and XRF. Iron leaching in aqueous solution after the photo-Fenton reaction was evaluated by atomic absorption spectroscopy. The material exhibited a mesoporous structure, containing a specific surface area of 99 m2.g-1. The catalytic results showed significant dye degradation, reaching 95% of decolorization and 72% of mineralization at 300 min of reaction. The catalyst showed high chemical stability in four reaction cycles. Therefore, this thermally treated Fe-rich bentonite can be considered as a promising catalyst in the heterogeneous photo-Fenton reaction for the degradation of rhodamine B from aqueous solution.

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Studies of adsorption kinetics and regeneration of aniline, phenol, 4-chlorophenol and 4-nitrophenol by activated carbon

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq111225054s ◽

2013 ◽

Vol 19 (2) ◽

pp. 195-212 ◽

Cited By ~ 13

Author(s):

S. Suresh ◽

V.C. Srivastava ◽

I.M. Mishra

Keyword(s):

Activated Carbon ◽

Thermal Desorption ◽

Kinetic Studies ◽

Order Model ◽

Heating Value ◽

High Heating Value ◽

Ftir Spectral Analysis ◽

Pseudo Second Order ◽

Adsorption Desorption ◽

Desorption Cycle

The present paper reports kinetic studies of the adsorption of aniline (AN), phenol (P), 4-chlorophenol (CP) and 4-nitrophenol (NP) from aqueous solution onto granular activated carbon (GAC). In FTIR spectral analysis, the transmittance of the peaks gets increased after the loading of AN, P, CP and NP signifying the participation of these functional groups in the adsorption and it seems that the adsorption of AN, P, CP and NP is chemisorptive in nature. The rates of adsorption were found to obey a pseudo-second order model and that the dynamics of AN, P, CP and NP adsorption are controlled by a combination of surface and pore diffusion. The diffusion coefficient were of the order of 10-10 m2 s-1. Thermal desorption at 623 K was found to be more effective than solvent desorption. GAC performed well for at least five adsorption-desorption cycle, with continuous decrease in adsorption efficiency after each thermal desorption. Owing to its relative high heating value, the spent GAC can be used as co-fuel for the production of heat in a boiler or a furnace.

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Effect of Sodium Benzenesulfonate on SO42− Removal from Water by Polypyrrole-Modified Activated Carbon

Advances in Materials Science and Engineering ◽

10.1155/2021/1442506 ◽

2021 ◽

Vol 2021 ◽

pp. 1-13

Author(s):

Feng Zhang ◽

Dong-Sheng Wang ◽

Fan Yang ◽

Tian-Yu Li ◽

Hong-Yan Li ◽

...

Keyword(s):

Activated Carbon ◽

Adsorption Capacity ◽

Granular Activated Carbon ◽

Langmuir Model ◽

Sulfate Adsorption ◽

Modified Activated Carbon ◽

Pseudo Second Order ◽

Acidic Conditions ◽

Adsorption Desorption ◽

Desorption Cycle

Sodium benzenesulfonate was doped into polypyrrole-modified granular activated carbon (pyrrole-FeCl3·(6H2O)-sodium benzenesulfonate-granular activated carbon; PFB-GAC) with the goal of improving the modified GAC’s ability to adsorb sulfate from aqueous solutions. At a GAC dosage of 2.5 g and a pyrrole concentration of 1 mol L−1, the adsorption capacity of PFB-GAC prepared using a pyrrole:FeCl3·(6H2O):sodium benzenesulfonate ratio of 1000 : 1500 : 1 reached 23.05 mg g−1, which was eight times higher than that for GAC and two times higher than that for polypyrrole-modified GAC without sodium benzenesulfonate. Adsorption was favored under acidic conditions and high initial sulfate concentrations. Doping with sodium benzenesulfonate facilitated polymerization to give polypyrrole. Sodium benzenesulfonate introduced more imino groups to the polypyrrole coating, and the N+ sites improved ion exchange of Cl− and SO42− and increased the adsorption capacity of sulfate. Adsorption to the PFB-GAC followed pseudo-second-order kinetics. The adsorption isotherm conformed to the Langmuir model, and adsorption was exothermic. Regeneration using a weak alkali (NH3·H2O), which released OH− slowly, caused less damage to the polypyrrole than using a strong alkali (NaOH) as the regeneration reagent. NH3·H2O at a concentration of 12 mol L−1 (with the same OH− concentration as 2 mol L−1 NaOH) released 85% of the sorbed sulfate in the first adsorption-desorption cycle, and the adsorption capacity remained >6 mg g−1after five adsorption-desorption cycles.

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Adsorption of gold from thiosulfate solutions with chemically modified activated carbon

Adsorption Science & Technology ◽

10.1177/0263617417698864 ◽

2017 ◽

Vol 36 (1-2) ◽

pp. 408-428 ◽

Cited By ~ 15

Author(s):

Hong Yu ◽

Futing Zi ◽

Xianzhi Hu ◽

Yanhe Nie ◽

Yunlong Chen ◽

...

Keyword(s):

Aqueous Solution ◽

Activated Carbon ◽

Photoelectron Spectroscopy ◽

Freundlich Isotherm ◽

Modified Activated Carbon ◽

New Approach ◽

Complex Adsorption ◽

Adsorption Kinetics And Isotherm ◽

Thiosulfate Leaching ◽

Adsorption Desorption

Adsorption of the gold–thiosulfate complex ion ([Formula: see text]) on silver ferrocyanide (AgFC)-impregnated activated carbon in aqueous solution has been studied in order to find an effectual adsorbent for the thiosulfate extracting gold from ores. This study was performed using AgFC-impregnated activated carbon (AC-Ag-R-FC: AC: activated carbon, Ag: silver nitrate, R: heating, FC: potassium ferrocyanide) and an artificial aqueous solution of [Formula: see text]. Gold–thiosulfate complex adsorption kinetics and isotherm studies were carried out at pH = 9.0 on modified materials. It has been also found that the adsorption fits the intraparticle diffusion and Freundlich isotherm well. In order to understand the adsorption mechanism, raw and modified materials were characterized by N2 adsorption–desorption measurements at 77 K, scanning electron microscopy and X-ray photoelectron spectroscopy. The maximum adsorption capability of [Formula: see text]on AC-Ag-R-FC is 3.55 kgt−1. Clearly, the extraordinary adsorption capacity of AC for [Formula: see text] offers a new approach to address challenging gold–thiosulfate complex separation and could promote the future development of thiosulfate leaching gold process.

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