Sorption Characteristics of Mixed Molecules of Glutaraldehyde from Water on Mesoporous Acid-Amine Modified Low-Cost Activated Carbon: Mechanism, Isotherm, and Kinetics (original) (raw)
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plosone, 2024
To effectively remove Diazinon (DZ), Amoxicillin (AMX), and Crystal Violet (CV) from aquatic environments, a novel granular activated carbon (GAC) modified with Polyethylene glycol 600 (PEG) was created and manufactured. The chemical properties were investigated using a variety of characteristic analyses, including FT-IR, XRD, FESEM, and N 2 adsorption/desorption. The effectiveness of GAC-PEG's adsorption for the removal of DZ, AMX, and CV was assessed under a variety of conditions, including a pH of 4-9 for the solution, 0.003-0.05 g doses of adsorbent, 50-400 ppm starting concentration, and a reaction time of 5-25 min. For DZ, AMX, and CV adsorption, the maximum adsorption capacity (Q max) was 1163.933, 1163.100, and 1150.300 mg g-1 , respectively. The Langmuir isotherm described all of the data from these adsorption experiments, and the pseudo-second-order well explains all-adsorption kinetics. Most contacts between molecules, electrostatic interactions, π-π interactions, hydrogen bonding, and entrapment in the modified CAG network were used to carry out the DZ, AMX, and CV adsorption on the GAC-PEG. The retrievability of the prepared adsorbent was successfully investigated in studies up to two cycles without loss of adsorption efficiency, and it was shown that it can be efficiently separated.
Environmental Technology, 2018
Batch sorption experiments were performed to study the adsorption of six emerging pollutants from aqueous solutions using a commercial granular activated carbon as adsorbent. Caffeine, clofibric acid, diclofenac, gallic acid, ibuprofen and salicylic acid were selected as representative contaminants. The activated carbon was characterized by nitrogen adsorption at 77 K, and through the determination of point of zero charge. The effects of several operational parameters, such as pH, initial concentration of organic molecules, mass of adsorbent and contact time, on the sorption behavior were evaluated. The contact time to attain equilibrium for maximum adsorption was found to be 40 min. The kinetic data were correlated to several adsorption models and the adsorption mechanism found to follow pseudo-second-order and intraparticle-diffusion models, with external mass transfer predominating in the first 15 min of the experiment. The equilibrium adsorption data were
Environmental Technology, 2020
Low molecular weight algal organic matter (AOM), as a frequent water contaminant with poor coagulation efficiency, adversely affects the quality of produced water and serves as a source of potentially carcinogenic disinfection by-products. AOM removal from water is inevitable to eliminate the negative health and environmental impacts. This research evaluates the removal of arginine, phenylalanine and aspartic acid, which are amino acids abundant in AOM. Adsorption experiments were performed at 10, 18 and 25°C and pH 5, 7 and 9 using two different activated carbons (FTL, PIC). Amino acids showed endothermic adsorption behaviour, with a higher removal at higher temperature. Higher temperature increased the diffusion of amino acid molecules, reduced the solution viscosity, or enhanced the hydrophobic interactions contributing to adsorption. The effect of temperature manifested differently during experiments depending on the chemical nature of the amino acids, the pH value and the surface properties of the carbon. Phenylalanine isotherms showed specific waves (Langmuir type 4). pH had a greater effect on arginine adsorption than did temperature. Aspartic acid isotherms exhibited a decrease in adsorption at higher pH values and higher temperatures. The principal mechanisms involved in amino acid adsorption were hydrophobic interactions, electrostatic interactions or hydrogen bonds.
Preparation of environmentally friendly activated carbon for removal of pesticide from aqueous media
International Journal of Industrial Chemistry, 2017
The preparation of eco-friendly low-cost silkworm feces activated carbon (SFAC) for the removal of oxamyl pesticide from aqueous solution has been investigated in batch experiments. Structure and morphology of SFAC were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (SEM). The specific surface area and mean pore diameter were obtained as 75.219 and 0.2035 cm 3 g-1 , respectively. The effect of different physicochemical parameters such as initial oxamyl concentrations, activated carbon dose and contact time has been studied. The results showed that the oxamyl removal on SFAC was unaffected in the pH range of 2-10. The percent removal of oxamyl onto SFAC was 99.48% from aqueous solutions. The adsorption process attained equilibrium within 120 min of contact time. Equilibrium data were analyzed by the Freundlich, Langmuir and Dubinin-Radushkevich (D-R) isotherm models. Freundlich isotherm provided the best fit to the equilibrium data. Adsorption kinetic was fitted well by the pseudo-secondorder kinetic model. The results revealed that SFAC could be used a low-cost and eco-friendly alternative to other adsorbents for the oxamyl removal from aqueous solution.
Adsorption of selected pharmaceuticals on activated carbons from water
E3S Web of Conferences, 2018
The possibility of using activated carbon for the removal of salicylic acid andiibuprofen sodium has been explored. These compounds are observed in crude and treated sewage and in surface water. The effect of pH on the adsorption efficiency was assessed. Tests were carried out from solutions with pH ranging from 2 to 10 (salicylic acid) and from 6 to 10 (iibuprofen sodium). It was found that the higher pH, the lower the adsorption of the compounds tested. Salicylic acid was most efficiently adsorbed from a solution with pH = 2, in which it occurred mainly in an undissociated form. The achieved efficiency of salicylic acid adsorption from solutions with pH=2 was 91%, while from those with pH=10, it was 55% (Co=4 mmol/L). The efficiency of removing ibuprofen sodium from the pH=6 solution was 64%, while from the pH = 10 solution, 60%.The adsorption of both salicylic acid and ibuprofen sodium follows the kinetics equation of the pseudo-2nd order. For the description of the adsorption is...
Journal of Contaminant Hydrology, 2018
In this study, commercial activated carbons (GAB and CBP) were successfully used for the removal of two phenoxy acetic class-herbicides, 4-chloro-2-methyl phenoxy acetic acid and 2.4-dichlorophenoxy acetic acid (MCPA and 2.4-D) from aqueous solution. The adsorbent materials were characterized, and their equilibrium adsorption capacity was evaluated. The results suggest that the microporous properties of GAB activated carbon enhanced the adsorption capacity, in comparison to CBP carbon. Thus, the increasing in the ionic strength favored the adsorption removal of both pesticides, indicating that electrostatic interactions between the pollutant and the adsorbate surface are governing the adsorption mechanism, but increasing pH values decreased adsorption capacity. Experimental data for equilibrium was analyzed by two models: Langmuir and Freundlich. Finally, computational simulation studies were used to explore both the geometry and energy of the pesticides adsorption.
Water Science & Technology: Water Supply, 2009
Bisphenol A (BPA) and ethynylestradiol (EE2), two representative endocrine disrupting compounds (EDCs), were tested for their adsorbabilities onto two powdered activated carbons (PACs). The main aim of the study was to create a prediction tool for the determination of the EDCs adsorbabilities at low ng.L 21 level. Single solute solution adsorption isotherms at high concentrations, for prediction purposes, and low concentrations, for verification of the prediction, were performed for one EDC/PAC couple. Over the whole range of concentration, results showed that the Langmuir-Freundlich model better suits the adsorption phenomenon than the Freundlich or Langmuir model. Kinetics experiments were carried out on the same EDC/PAC couple. HSDM modelling of single solute adsorption kinetics at high concentration allowed determining the kinetic coefficients k f and D s ; both were shown to dominate the mass transfer mechanism. Competitive adsorption isotherms at high and low concentrations showed that downward extrapolation of low concentration adsorption capacities from solely high concentration information results in acceptable error compared to the total range isotherm. The IAST-EBC approach combined with the Langmuir-Freundlich single solute model, for the target compound, and the Langmuir model, for the EBC, appears as an acceptable global model.
Activated Carbon for Pharmaceutical Removal at Point-of-Entry
Processes, 2021
Pharmaceuticals are an increasing problem in waterways due to improper disposal and lack of removal at wastewater treatment plants. Long-term exposure impacts to humans are unknown but have been observed in model organisms (i.e., fish), impacting reproduction, changing temperament, and causing organ damage. The application of activated carbon (AC) for organic contaminant removal is widespread and applied successfully for water treatment. The objective of this study is to rapidly adsorb ibuprofen using AC to determine the feasibility as a point-of-entry treatment option for removal of pharmaceuticals in the toilet. AC factors analyzed include type of AC raw material, adsorbent particle size, contact time, and competitive adsorption of ibuprofen and common toilet bowl cleaner components such as chlorine and methylene blue dye. A coconut-based AC with a high surface area adsorbed the highest quantity of ibuprofen. There was no significant impact to ibuprofen adsorption upon the introdu...
Environmental Science and Pollution Research, 2017
Adsorption of three pharmaceuticals and personal care products (PPCPs), namely caffeine, ibuprofen and triclosan on commercial powdered activated carbon was examined in aqueous medium. The contaminants were chosen based on their diverse log K ow (octanol-water partition coefficient) viz. − 0.07 for caffeine, 3.97 for ibuprofen and 4.76 for triclosan to examine the role of hydrophobicity on adsorption process. The adsorbent characterisation was achieved using BET surface area, SEM, pore size distribution studies and FTIR. Influence of mass of PAC, contact time, solution pH and initial concentration on adsorption capacity of PAC was studied. Adsorption isotherms and kinetics were applied to establish the mechanism of adsorption. The kinetics followed pseudosecond order with physisorption occurring through particle diffusion. The Freundlich model fitted best among the isotherm models. The adsorption capacity increased in the order CFN < IBU < TCS which correlates with increasing hydrophobicity (log K ow), molecular weight and decreasing water solubility, respectively. We conclude that micro-pollutant hydrophobicity contributes towards adsorption on activated carbon.