Structural and thermodynamic factors in the adsorption process of anthocyanins from eggplant peel onto a carbon adsorbent

2021 ◽  
Author(s):  
Qiongjie Yang ◽  
Conghui Wang ◽  
Zhuo Zhao ◽  
Wei Wei ◽  
Jing Ma ◽  
...  
2017 ◽  
Vol 35 (7-8) ◽  
pp. 721-727 ◽  
Author(s):  
Andrzej Gierak ◽  
Iwona Łazarska

This work presents the results of the investigations of the adsorption process of nitrate, nitrite, and ammonium ions on carbon adsorbent with the application of the solid phase extraction method to isolate and enrich the investigated ions from aqueous solutions of the concentration below 1 mg/L. For the determination of the concentration of the analyzed ions, we applied the ion chromatography method. The sorption capacity for the tested adsorbents as well as the efficiency of the enrichment of the investigated ions were determined.


Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1802
Author(s):  
Taghrid S. Alomar ◽  
Mohamed A. Habila ◽  
Zeid A. Alothman ◽  
Najla AlMasoud ◽  
Saad Saeed Alqahtany

The contamination of water sources with heavy metals is a serious challenge that humanity is facing worldwide. The aim of this work was to evaluate and remediate the metal pollution in groundwater and greywater resources from Riyadh, Saudi Arabia. In addition, we investigated the application of ultrasonic power before adsorption to assess the dispersion of renewable carbon from mixed-waste sources (RC-MWS) as an adsorbent and enhance the water purification process. The renewable carbon adsorbent showed high ability to adsorb Pb(II), Zn(II), Cu(II), and Fe(II) from samples of the actual water under study. The conditions for the remediation of water polluted with heavy metals by adsorptive-separation were investigated, including the pH of the adsorption solution, the concentration of the heavy metal(s) under study, and the competition at the adsorption sites. The enhanced adsorption process exhibited the best performance at a pH of 6 and room temperature, and with a contact time of 60 min. Kinetic studies showed that the pseudo-second-order kinetic model was fitted with the adsorption of Pb(II), Zn(II), Cu(II), and Fe(II) onto the RC-MWS. The adsorption data were well fitted by Langmuir isotherms. The Freundlich isotherm was slightly fitted in the cases of Cu(II), Zn(II), and Fe(II), but not in the cases of Pb(II). The developed adsorption process was successfully applied to actual water samples, including water samples from Deria and Mozahemia and samples from clothes and car washing centers in Riyadh city.


Konversi ◽  
2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Isna Syauqiah ◽  
Desi Nurandini ◽  
Nopi Stiyati Prihatini ◽  
Jamiyaturrasidah Jamiyaturrasidah

The industry of sasirangan – traditional fabric of Banjar Tribe – has been one of prime commodities of South Kalimantan. The coloring process  in sasirangan production used a lot of chemical elements containing heavy metals  and its waste potentially pollute the environment. One of the heavy metal waste contained is copper (Cu) which is toxic to aquatic organisms and humans. The treatment for sasirangan liquid waste can be done by adsorption process using activated carbon as adsorbent. This study aims to determine the appropriate kinetic model for adsorption of Cu metal from sasirangan liquid waste using activated carbon adsorbent made from rice husks.The process was conducted by batch system with chemical and physical activation. Chemical activation was done by soaking the activated carbon of rice husk with HCl solution for 24 hours. While physical activation was carried out by burning in a furnace at 500̊C for 2 hours. The adsorption treatment was given on sasirangan waste samples with variations on contact time (30, 60 and 120 minutes). The results of kinetics study showed that the adsorption process of Cu from sasirangan liquid waste onto rice husk activated carbon adsorbent followed first-order reaction kinetics with a correlation coefficient value (R2) of 0.96 and adsorption rate constant (k1) of 0.0044 min-1.


2019 ◽  
Vol 9 (8) ◽  
Author(s):  
Dominic Justine G. Rondina ◽  
Deanne V. Ymbong ◽  
Macvon Jovy M. Cadutdut ◽  
Jhon Ray S. Nalasa ◽  
Jonas B. Paradero ◽  
...  

Abstract In this study, a novel activated carbon adsorbent from the press mud of a sugarcane industry was used to remove methyl orange dye (MOD) from aqueous solution and was optimized via response surface methodology using the central composite design. The adsorbent was characterized by FTIR and SEM analysis and showed the presence of functional groups such as alcohols, nitriles, amides, alkane, alkyl halides, and alkenes, and it also showed fibrous surface morphological appearance. The factors affecting MOD adsorption, such as initial concentration, adsorbent dose, and contact time were examined, and optimal pH 2.0 to remove MOD in an aqueous solution that is found in various studies is also utilized. The results showed maximum MOD removal rate of 98.68% when the initial concentration, adsorbent dose, and contact time were optimally set as 24.17 mg/L, 0.5 g, and 20 min, respectively. The analysis of the equilibrium data revealed that MOD adsorption using press mud activated carbon best fitted the Langmuir isotherm (R2 = 0.96103) which implies monolayer adsorption process. Also, the kinetics of MOD adsorption using press mud activated carbon followed a pseudo-first-order model (R2 = 0.96096) which means that the active sites are proportional to the non-active sites during the adsorption process.


2017 ◽  
Vol 35 (7-8) ◽  
pp. 744-750 ◽  
Author(s):  
Katarzyna Jedynak ◽  
Dariusz Wideł ◽  
Jerzy Oszczudłowski

In the present work adsorption of selected phthalates from the water samples on mesoporous carbon material was investigated. Carbon material was obtained by soft-templating method in the presence of citric acid. Adsorption process of phthalates was carried out from water solution using static method with sonication for process acceleration. Phthalates extraction from water phase, after adsorption on carbon material, was carried out using solid phase microextraction method. Extracted samples were analyzed using gas chromatography coupled with mass spectrometry method. Considering obtained experimental results it can be indicated that almost 100% of phthalates were adsorbed from water solutions. The efficiency of adsorption decreases with increasing molecular weight of phthalates.


Author(s):  
Андрей Викторович Твардовский ◽  
Дмитрий Сергеевич Зайцев ◽  
Анатолий Алексеевич Фомкин

Впервые проведены комплексные исследования адсорбционной деформации - сорбострикции микропористого углеродного адсорбента ФАС-3 при адсорбции паров бензола из потока газа-носителя - азота в неравновесных условиях. Изучены изотермы адсорбции паров бензола микропористым углеродным адсорбентом ФАС-3 в равновесных условиях. Были представлены формулы и проведены расчеты изменений энтропии и внутренней энергии адсорбента в адсорбционном процессе. For the first time, complex studies were carried out on adsorption deformation - sorbostriction of the microporous carbon adsorbent FAS-3 at adsorption of benzene vapors from the flow of carrier gas - nitrogen in non-equilibrium conditions. Adsorption isotherms of benzene vapors by the microporous carbon adsorbent FAS-3 under equilibrium conditions has been studied. Calculations of changes in the entropy and internal energy of the adsorbent in the adsorption process were performed.


2020 ◽  
pp. 34-43
Author(s):  
N. R. Memetov ◽  
◽  
A. V. Gerasimova ◽  
A. E. Kucherova ◽  
◽  
...  

The paper evaluates the effectiveness of the use of graphene nanostructures in the purification of lead (II) ions to improve the ecological situation of water bodies. The mechanisms and characteristic parameters of the adsorption process were analyzed using empirical models of isotherms at temperatures of 298, 303, 313 and 323 K, which correspond to the following order (based on the correlation coefficient): Langmuir (0.99) > Temkin (0.97) > Dubinin – Radushkevich (0.90). The maximum adsorption capacity of the material corresponds to the range from 230 to 260 mg/g. We research the equilibrium at the level of thermodynamic parameter estimates, which indicates the spontaneity of the process, the endothermic nature and structure change of graphene modified with phenol-formaldehyde resin during the adsorption of lead (II) ions, leading to an increase in the disorder of the system.


2019 ◽  
Author(s):  
Chem Int

The removal of Cd(II) and Pb(II) ions from aqueous medium was studied using potato peels biomass. The adsorption process was evaluated using Atomic Absorption Spectrophotometer (AAS). The Vibrational band of the potato peels was studied using Fourier Transform Infrared Spectroscopy (FTIR). The adsorption process was carried out with respect to concentration, time, pH, particle size and the thermodynamic evaluation of the process was carried at temperatures of 30, 40, 50 and 60(0C), respectively. The FTIR studies revealed that the potato peels was composed of –OH, -NH, –C=N, –C=C and –C-O-C functional groups. The optimum removal was obtained at pH 8 and contact time of 20 min. The adsorption process followed Freundlich adsorption and pseudo second-order kinetic models with correlation coefficients (R2) greater than 0.900. The equilibrium adsorption capacity showed that Pb(II) ion was more adsorbed on the surface of the potato peels biomass versus Cd (II) ion (200.91 mg/g > 125.00 mg/g). The thermodynamic studies indicated endothermic, dissociative mechanism and spontaneous adsorption process. This study shows that sweet potato peels is useful as a low-cost adsorbent for the removal of Cd(II) and Pb(II) ions from aqueous medium.


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