scholarly journals Highly effective removal of antibiotics from aqueous solution by magnetic ZnFe2O4/activated carbon composite

2020 ◽  
Vol 82 (5) ◽  
pp. 877-886
Author(s):  
Yun-Xia Li ◽  
Lei Wang ◽  
Fang-Fang Chai ◽  
Hong-Fei Jing ◽  
Zhu-Qing Gao ◽  
...  

Abstract Water pollution from antibiotics has attracted a lot of attention for its serious threat to human health. In this study, a magnetic adsorbent (zinc ferrite/activated carbon (ZnFe2O4/AC) was synthesized via microwave method to effectively remove gemifioxacin mesylate (GEM) and moxifloxacin hydrochloride (MOX). Based on the porosity of AC and the magnetism of ZnFe2O4, the resulting ZnFe2O4/AC has high adsorption capacities and can be easily separated from the solid–liquid system via a magnetic field. The largest adsorption capacities for GEM and MOX can reach up to 433.4 mg g−1 and 388.8 mg g−1, respectively, higher than those of reported adsorbents such as MIL-101 and MOF-808. Fastest adsorptions of GEM and MOX were found at 5 min, and solution pH and coexisting salts do not have a significant influence on the adsorption process. The adsorption mechanism analysis indicates that electrostatic interaction and H-bond interaction contribute to the effective adsorption.

2010 ◽  
Vol 62 (8) ◽  
pp. 1888-1897 ◽  
Author(s):  
Nan Chen ◽  
Zhenya Zhang ◽  
Chuanping Feng ◽  
Miao Li ◽  
Rongzhi Chen ◽  
...  

Kanuma mud, a geomaterial, is used as an adsorbent for the removal of fluoride from water. The influences of contact time, solution pH, adsorbent dosage, initial fluoride concentration and co-existing ions were investigated by batch equilibration studies. The rate of adsorption was rapid with equilibrium being attained after about 2 h, and the maximum removal of fluoride was obtained at pH 5.0–8.0. The Freundlich isotherm model was found to represent the measured adsorption data well. The negative value of the thermodynamic parameter ΔG suggests the adsorption of fluoride by Kanuma mud was spontaneous, the endothermic nature of adsorption was confirmed by the positive ΔH value. The negative ΔS value for adsorbent denoted decreased randomness at the solid/liquid interface. The adsorption process using Kanuma mud followed the pseudo-second-order kinetic model. Fluoride uptake by the Kanuma mud was a complex process and intra-particle diffusion played a major role in the adsorption process. It was found that adsorbed fluoride could be easily desorbed by washing the adsorbent with a solution of pH 12. This indicates the material could be easily recycled.


2021 ◽  
Author(s):  
Yousef Rashtbari ◽  
Shirin Afshin ◽  
Asghar Hamzezadeh ◽  
Soumya Ghosh ◽  
Ayoob Rastegar ◽  
...  

Abstract Furfural is an organic aromatic compound that has attracted considerable interest as a potential chemical for the production of biochemical and biofuels. However, furfural has proved to possess ecotoxic effect on the environment and to humans, therefore measures are required to prevent these effects. One of the most widely used methods for eliminating furfural is the surface adsorption process.The present study focused on the structure and morphology of the composite nanoparticles, investigated using FTIR, XRD, BET and FE-SEM techniques.Furthermore, the variables of time, solution pH, dosage composite and initial furfural were evaluated. Furfural adsorption was performed by spectrophotometer at a wavelength of 227 nm. The removal efficiency under optimal conditions for furfural (Furfural concentration of 250 mg/L, the composite dose of 4 g/L, the reaction time of 60 min and pH = 7) was 81.46%. In addition, the study of isotherm and adsorption kinetics for furfural showed that the adsorption process follows the Langmuir isotherm and quasi-quadratic kinetics. The qmax of the composite was determined by the Langmuir model of222.22 mg/g. Therefore, the present study exclusively showedthat the activated carbon coated with nZVI nanoparticles used as an effective and environmentally friendly adsorbent for furfural removal from aqueous solutions. Furthermore, this study could possibly have applied for the adsorbtion of other chemical cmpounds such as dyes,metronidazole,aniline.


Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 180
Author(s):  
Diana Hernández-Monje ◽  
Liliana Giraldo ◽  
Juan Moreno-Piraján

The enthalpy of immersion for five activated carbons (with different surface chemistry) in cyclohexane and hexane was determined in order to observe the intensity of the solid–liquid interaction. The enthalpy of immersion was related to the properties of activated carbons, such as micropore volume, total basic groups content, and the EoWo product, that characterized each solid-liquid system. The values for the immersion enthalpy were between −21.2 and −91.7 J g−1 for cyclohexane and between −16.4 and −66.1 J g−1 for hexane. It showed greater interaction between the cyclohexane and the activated carbons and it was related to the properties of this adsorbate, such as molecular size and molecular arrangement. The difference in the enthalpy of immersion between the solvents per unit of micropore volume for the set of activated carbons was calculated obtaining a value of −487 J cm−3.


2019 ◽  
Vol 79 (7) ◽  
pp. 1357-1366 ◽  
Author(s):  
Rabia Boudia ◽  
Goussem Mimanne ◽  
Karim Benhabib ◽  
Laurence Pirault-Roy

Abstract This work concerns the elimination of the organic pollutant; Bemacid Red (BR), a rather persistent dye present in wastewater from the textile industry in western Algeria, by adsorption on carbon from an agricultural waste in the optimal conditions of the adsorption process. An active carbon was synthesized by treating an agro-alimentary waste, the date stones that are very abundant in Algeria, physically and chemically. Sample after activation (SAA) with phosphoric acid was highly efficient for the removal of BR. The characterization of this porous material has shown a specific surface area that exceeds 900 m2/g with the presence of mesopores. The iodine value also indicates that the activated carbon obtained has a large micro porosity. The reduction of the infrared spectroscopy (FTIR) bands reveals that the waste has been synthesized and activated in good conditions. Parameters influencing the adsorption process have been studied and optimized, such as contact time, adsorbent mass, solution pH, initial dye concentration and temperature. The results show that for a contact time of 60 min, a mass of 0.5 g and at room temperature, the adsorption rate of the BR by the SAA is at its maximum. Pseudo-first-order, pseudo-second-order and intraparticle diffusion models were studied to analyse adsorption kinetics. The result shows the adsorption kinetic is best with the pseudo-second-order model. In this study, Langmuir, Freundlich and Temkin isotherms were investigated for adsorption of BR onto SAA. The Freundlich and Temkin isotherms have the highest correlations coefficients. The suggested adsorption process involves multilayer adsorption with the creation of chemical bonds. The mechanism of adsorption of BR by SAA is spontaneous and exothermic, and the Gibbs free energy values confirm that the elimination of the textile dye follows a physisorption.


2005 ◽  
Vol 23 (5) ◽  
pp. 407-416 ◽  
Author(s):  
Xianjia Peng ◽  
Zhaokun Luan ◽  
Hongmei Zhang ◽  
Binghui Tian ◽  
Bin Fan

A novel organobentonite was prepared by modifying bentonite with poly(dimethyldiallylammonium chloride) (PDMDAAC), a harmless and cost-effective type of polycation. Zeta potential and X-ray diffraction measurements suggest that PDMDAAC was intercalated into the bentonite interlayer space. PDMDAAC—bentonite has been found to be effective for the removal of p-nitrophenol with a removal rate of 81.4% being achieved. The adsorption process was pH-dependent and was slightly decreased by the Ca2+ and Mg2+ ions co-existing in the solution. A dual-phase adsorption mechanism was suggested for the process. The adsorbents obtained from the regeneration of PDMDAAC—bentonite still exhibit good adsorption capacities.


2016 ◽  
Vol 103 ◽  
pp. 87-96 ◽  
Author(s):  
Janardhan Reddy Koduru ◽  
Lakshmi Prasanna Lingamdinne ◽  
Jiwan Singh ◽  
Kwang-Ho Choo

2021 ◽  
Vol 60 (1) ◽  
pp. 365-376
Author(s):  
Xiaoxing Zhang ◽  
Hui Liu ◽  
Jin Yang ◽  
Li Zhang ◽  
Binxia Cao ◽  
...  

Abstract Iron phosphate-modified pollen microspheres (pollen@FePO4) were prepared and applied as sorbents for the removal of heavy metals (Cd2+ and Pb2+) from the aqueous solution. Batch sorption studies were conducted to investigate the effects of solution pH, contact time, sorbent dosage, and metal concentration on the adsorption process. The sorption of Cd2+ and Pb2+ ions on pollen@FePO4 corresponds to the pseudo-second-order model and Langmuir isotherm, which is similar to the unmodified pollen. At pH 5.92, pollen@FePO4 offers maximum adsorption capacities of 4.623 and 61.35 mg·g−1 for Cd2+ and Pb2+, respectively. The faster sorption kinetics and higher adsorption capacities of Cd2+ and Pb2+ ions onto pollen@FePO4 than pollen indicates that it might be a promising material for the removal of heavy metal ions in aqueous solutions. The possible adsorption mechanism involves electrostatic and chemisorption for Cd2+ and mainly complexion for Pb2+.


2016 ◽  
Vol 54 ◽  
pp. 42-57 ◽  
Author(s):  
Kassahun Dejene ◽  
Khalid Siraj ◽  
Shimeles Addisu Kitte

This study was aimed for removal of phenol from water using activated carbon synthesize from avocado kernel seeds by adsorption onto it. For adsorption process cleaned and washed avocado kernel seeds (Persea americana) were dried at 100°C in an oven overnight and carbonization was carried out by increasing the furnace temperature at a rate of 5 °C/min to a final temperature of 800 °C for 160 minutes. Then, the activated carbon was powdered and sieved, washed with distilled water until the solution pH reached 7.0. Optimization of activated carbon was performed through effects of solution pH, contact time; initial phenol concentration and temperature of the adsorption. The kinetic studies of the adsorption process were achieved by verifying various models and the data obtained was best fitted to pseudo-second-order kinetic model. The isotherms models were analyzed with Langmuir, Freundlich and Temkin to validate the adsorption process. It was found that Langmuir model was best fitted to the obtained result for both adsorbents.


2018 ◽  
Vol 18 (2) ◽  
pp. 222 ◽  
Author(s):  
Fatma Fatma ◽  
Poedji Loekitowati Hariani ◽  
Fahma Riyanti ◽  
Wiwin Sepriani

The alumina-activated carbon has the ability to adsorb and desorb the procion red MX-5B. The research evaluated the influence of desorption agent, contact time, and temperature on desorption process of procion red MX-5B dye with alumina-activated carbon composite and the adsorption capacity of the composite after desorption process. The desorption agents used in desorption process were solution with pH 2−10, H2O2 30 % (v/v), methanol 70% (v/v) and ethanol 70% (v/v). The variation of contact time was in the range from 30 to 270 min and the temperature was set between 30−75 °C. The result concluded that the highest desorption efficiency up to 98.56% was achieved using ethanol 70% (v/v) for 240 min at 45 °C. The desorption kinetic followed the pseudo-first-order with the release constant (kdes) of 6.56 × 10-2 min-1. The SEM micrograph showed there is a more porous surface on the composite after the desorption compared to before the desorption. The EDX analysis indicated that alumina content in the composite was reduced after desorption process. FTIR spectra of the composite before and after desorption process showed a peak of Al−O at 592 and 590 cm-1 which was proved that alumina still exists in the composite after the desorption process. The alumina-activated carbon composite was re-used to adsorb procion red MX-5B dye. After three times of desorption and re-adsorption process, the capacity adsorption was decreased from 12.38 to 7.38 mg/g.


Author(s):  
Andressa Jenifer Rubio ◽  
Rosângela Bergamasco ◽  
Natália Ueda Yamaguchi

With the increasing use of several pesticides in agriculture, including the Glyphosate which is the herbicide most widely consumed worldwide, there is a need for the development of diversified and effective water treatment, since glyphosate consumption can cause serious health problems on animals, humans and plants. As an alternative treatment, the removal of glyphosate from the water can be obtained with the use of activated carbon, and further to leverage its results, may be used the impregnation of silver and copper on the activated carbon, since the activated carbon in the purest form it is marketed often not sufficiently effective for removing some pollutants. Therefore, this study aimed at the removal of glyphosate by an adsorption process using activated carbon impregnated with 0.5% silver and 0.5% copper with the aim of increasing the adsorption efficiency when compared to activated carbon. It was observed that the removal of glyphosate is improved when using the impregnated metal compounds, being 66.1% with the adsorbent GAC / AgCu and only 21.1% with GAC. It is still needed profound research related to characterization and adsorption experiments to better explain the adsorption mechanism that occurs in this process. However, it can be concluded that the granular activated carbon soaked with 0.5% silver and copper developed in the present work may be named as a possible technology for improving the quality of water intended for human consumption for removal of the glyphosate herbicide.


Sign in / Sign up

Export Citation Format

Share Document