Adsorption Of Paracetamol Research Articles

Efficient removal of paracetamol, diclofenac sodium, and tetracycline using green synthesized Fe-zn co-doped sunflower seed shells

ABSTRACT In this study, carbon material obtained from sunflower seed shells and doped with Fe and Zn using mint extract (Fe-Zn-SSSC) was prepared, and the usability of this adsorbent in the removal of paracetamol, diclofenac sodium, and tetracycline was investigated. Fe-Zn-SSSC was characterized by SEM-EDX and FTIR. Additionally, the effects of pH and adsorbent dosage on the removal of paracetamol, diclofenac sodium, and tetracycline were investigated. The removal rates of paracetamol, diclofenac sodium, and tetracycline were obtained as 88.7%, 65.4%, and 76.0% at a pH of 4, after 1 hour of adsorption with 5 g/L Fe-Zn-SSSC, respectively. The best removal of paracetamol, diclofenac sodium, and tetracycline was obtained at pH 4, with qmax values calculated as 14.51 mg/g, 6.33 mg/g, and 8.99 mg/g, respectively. It was determined that the adsorption of paracetamol, diclofenac sodium, and tetracycline with Fe-Zn-SSSC was more compatible with the Langmuir isotherm model and pseudo-second-order kinetic model. As a result, this study demonstrates that carbon materials synthesized from sunflower seed shells can serve as an effective and low-cost adsorbent for drug from water.

Electrochemical sensor based on a glassy carbon electrode modified with a 3D carbon nanoporous composite for the detection of paracetamol in pharmaceutical samples

With the continued appearance of new drugs, there is a growing interest in the development of new analytical tools to detect and quantify drugs using a simple and reliable way. In this work, we describe the development of an electrochemical sensor based on glassy carbon electrodes modified with a carbon tubular nanocomposite for the detection of paracetamol in pharmaceutical samples. Paracetamol shows a strong adsorption on the electrode surface, which makes possible its determination by adsorptive differential pulse voltammetry in 0.1 mol/L citrate–phosphate pH 5 buffer solution. Optimal conditions for dispersion of carbonaceous material and best conditions for surface adsorption of paracetamol were obtained from experimental designs based on response surface methodology. The high adsorption capacity of paracetamol on the 3D carbon nanoporous composite and the sensitivity of the electrochemical technique employed showed a synergistic effect that allowed reaching a detection limit of 30 nmol L− 1 (4.5 ppb). In addition, the reproducibility and the repeatability were 7 and 5 %, respectively. The paracetamol determination from pharmaceutical samples was performed without pre-treatment of samples. The values of paracetamol founded for different pharmaceutical samples were in a very good agreement with those values obtained from the same samples using HPLC. Therefore, the developed electrochemical sensor is a promising, inexpensive, and easy-to-use tool for the detection and quantification of paracetamol in pharmaceutical samples.

Synthesis and characterization of coconut coir biochar as potential adsorbent for removal of pharmaceutical and personal care products in wastewater

Abstract Biochar, a solid by-product of pyrolysis has attracted the attention of researchers because of it properties which is suitable for use as an adsorbent as well as energy source. As an adsorbent, biochar has similar properties to activated carbon which has high surface area, large pore volume, environmental stability, generous functional group, and high resource recovery. On the other hand, pharmaceuticals, and personal care products (PPCPs) – a class of growing environmental contaminants, are increasing public concerns for their possible effects on the ecosystem and human health. Some PPCPs are pervasive, persistent, and bioaccumulative which thus makes them easily found and currently increase in the environment, including groundwater and surface water. The main source of surface water contamination with PPCPs is due to municipal wastewater discharge that has not been adequately treated. Furthermore, due to coconut coir having a significant amount of lignin, it may be thermochemically converted into biochar with a high yield, meeting the requirements for biochar and its use in the adsorption process. This study aims to synthesize biochar from coconut coir, characterize it and determine its potential as an adsorbent for PPCPs. The biochar used for this study were characterized based on their chemical, structural and textural characteristics. The study that demonstrated good results on the adsorption of paracetamol from the aqueous phase of biochar has the potential to eliminate this pollutant by around 92%.

Molecularly imprinted polymer based on deep eutectic solvent as functional monomer for paracetamol adsorption

Paracetamol, a popular analgesic, has been linked to harmful health effects, such as kidney and liver damage. The detection of paracetamol in the environment and its overdose use in humans and animals has raised global concerns, highlighting the need for its efficient removal or detection in real samples. In this study, a deep eutectic solvent-molecularly imprinted polymer (DES-MIP) was synthesized and applied as an adsorbent to recognize the removal of paracetamol selectively. DES-MIP was synthesized using a deep eutectic solvent (DES) as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, and paracetamol as a template. DES was initially prepared by combining choline chloride (ChCl) with methacrylic acid at a molar ratio of 1:2. A deep eutectic solvent-non-imprinted polymer (DES-NIP) was synthesized as a control. The characterization analysis, including Fourier transform infrared spectroscopy (FTIR), Scanning emission microscopy (SEM), and Brunauer-Emmett-Teller (BET) was conducted for both polymers to confirm the synthesis occurred. The selectivity study inferred that DES-MIP (15.95 mg/g) was more selective towards paracetamol than DES-NIP (7.00 mg/g). Response surface methodology (RSM) coupled with central composite design (CCD) was employed to examine the effect of pH, contact time, and dosage on paracetamol adsorption. The analysis of variance (ANOVA) demonstrated the relative significance of process parameters in the adsorption process. The contact time and dosage were found to be more significant than the pH. The result indicated that the optimal conditions for paracetamol adsorption were pH 7, 35 min, and 5.5 mg. The behavior of paracetamol adsorption on DES-MIP was well-fitted using the second-order kinetic and Langmuir isothermal models, respectively. Then, the DES-MIP with optimized parameter studies was applied to herbs, medicine, and dietary supplements, achieving good recoveries of 94.46 %, 86.79 %, and 85.13 % and relative standard deviations (RSD) of 1.15 %, 2.39 %, and 2.52 %, respectively.

Paracetamol and Atenolol mitigation by Fenton and adsorption in-simultaneous process – Adsorbent regeneration and QSAR eco-toxicity prediction

This study aims to study the adsorption and oxidation of Paracetamol (PAR) and Atenolol (ATL) for application in water treatment. The pharmaceutical concentrations were monitored over time to assess the efficiency of the simultaneous process. The pH, contact time, and activated carbon (GAC) concentration were the variables evaluated in the adsorption process. While to the Fenton reaction, the proportion of Fe2+/H2O2 was the variable studied. Outcomes show that the most suitable conditions in the adsorption process to treat 40 mg/L of each pharmaceutical were achieved at 3 g of activated carbon (GAC) and 60 min.Tothe Fenton reaction, a ratio of 0.5 Fe2+/H2O2 was the most suitable condition. The results obtained in the simultaneous process were 17 % of mineralization, and 100 and 73.3 % of degradation of ATL and PAR. respectively. The formation of degradation products also decreased after treatment, suggesting the potential environmental safety of the combined treatment. A regeneration study was conducted to recuperate the GAC. The results showed that a GAC regeneration of 98 % was achieved after 4 cycles by the Fenton process, maintaining the degradation of pollutants evaluated at ∼ 99–98 %. Finally, a toxicity Quantitative Structure-Activity Relationship (QSAR) study was carried out to predict its potential toxicity, showing that it is feasible to conclude that the method has positive implications for environmental safety.

Single and binary adsorption of paracetamol and diclofenac onto biochar produced from pepper stem: Which adsorption properties change in the binary system?

The importance of combating the contamination of water resources with emerging pollutants must be kept all the more in view by scientists, since such pollutants are harmful and pose challenges for traditional water treatment methods. The current study was designed to scrutinize the adsorption properties of a low-cost biochar for two pharmaceuticals in both single and binary systems. The work was focused on understanding how paracetamol (PARA) and diclofenac (DIC) co-adsorb, and it can serve as a beacon for similar studies, especially in modeling the adsorption processes of such systems. Using a low-cost biochar from pepper stem (PS) with a high surface area = 727.5 m2/g as adsorbent, experiments were carried out in both the single and binary systems to investigate the adsorption behavior of the mentioned pharmaceuticals. Results showed that, in the single system, the PS biochar demonstrates a slightly greater adsorption capability for both PARA and DIC, with a capacity of 354.66 and 256.10 mg/g, respectively, compared to its capacity for each pharmaceutical in the presence of the other in the solution. Interestingly, the effect of the presence of one of the pharmaceuticals on the thermodynamic parameters (ΔGº, ΔSº, and ΔHº) of the other was ignorable, and interactions such as hydrogen bonding, π-π, n-π, and anion-π interactions were at work for the adsorption processes, with different extends in each pharmaceutical-biochar case. On the other hand, the presence of one of the pharmaceuticals was effective on the kinetics of the adsorption process of the other and caused a decrease in its adsorption rate, especially in the initial stage of the process. Overall, in addition to the suitability of pepper stem biochar for PARA and DIC, results showed that the presence of one pharmaceutical is not influential on all the adsorption properties of the other, and the results can be exploited for studding similar systems.

Adsorption equilibrium, kinetic, and thermodynamic studies on the removal of paracetamol from wastewater using natural and HDTMA-modified clay

In this study, the adsorption efficiency of low-cost raw and modified clay was investigated. The modified clay was characterized through various technics including X-ray diffraction, XRF spectroscopy, FT-IR spectroscopy, and Electron microscopy SEM to analyze the evolution of raw clay structure and morphology. Paracetamol was chosen as an adsorbate to evaluate the removal performance from the aqueous medium. Factors influencing the uptake of paracetamol, such as pH, equilibrium time, adsorbent dosage, and initial concentration of paracetamol, were examined. The results obtained showed that the raw clay was successfully modified by HDTMA, which increased adsorption capacity thanks to new hydrophobic interaction. The adsorption of paracetamol on the modified clay reached equilibrium at a contact time of 120 min. Isothermal and kinetic models used in this study showed that the adsorption followed the Langmuir-isotherm and pseudo-second-order kinetic models. The maximum experimental adsorption capacity predicted by Langmuir model is about 112.63 mg/g, which is much higher than that obtained for the unmodified sample (62.11 mg/g). These results show that modified natural Moroccan clay can be used as low-cost and eco-friendly adsorbent nanomaterials to remove emerging pharmaceutical contaminants from water.

Sequestration of hexavalent chromium and paracetamol from water using deoiled hemp stem-twigs and roots and activated carbon

In the present study, deoiled hemp stem-twigs and roots and activated carbon were used to remove chromium and paracetamol. The hemp-based materials were characterized, and the surface area of the activated carbon samples increased more than 55-fold compared to the untreated materials. The pore volume of the carbon samples also increased, which can be attributed to the degradation of volatiles during carbonization and acid treatment. Contact time experiments showed that the uptake rate for hexavalent chromium was fast in the initial phase and equilibrium was reached in about 30 min for activated carbon from stem-twigs and activated carbon from hemp roots, while it took about 40 min for untreated hemp stem-twigs and untreated hemp roots. The trends for paracetamol show that the rate was slow compared to hexavalent chromium. Equilibrium was reached in about 120 min for all materials. pH solution 2 was optimal for the uptake of hexavalent chromium, while pH solution 6 was optimal for the adsorption of paracetamol. The data for enthalpy show that the sorption processes were endothermic and predominantly physisorptive. The values for Gibbs free energy were negative, indicating that the sorption was spontaneous and feasible.

Toward Cleaner Ecosystems; Elimination of Paracetamol Drug via Mesoporous Activated Carbon Date Pits

The purpose of this study is to remove pharmaceuticals drugs from water due to high potential impact on human health. Specifically, non-prescriptive drugs like paracetamol drug, which cause infections to various human organs like liver, kidneys and immunity system. Activated carbon (AC) was synthesized from date pits via thermal and chemical carbon activation using air at high temperature and phosphoric acid respectively, three ratios of (AC:Acid) were prepared to adsorb the most commonly used antipyretic and analgesic drug "Paracetamol" from aqueous solutions. The experiments were done in the department of Chemical Engineering and department of Chemistry, between September 2018 and August 2019. Characterization of the activated carbon (AC) was carried out through surface area analysis (BET), X-ray diffraction (XRD), spectroscopic Fourier Transform Infrared (FTIR), thermal (Thermogravimetric analysis TGA) and derivative thermogravimetry (DTG), and microscopic (scanning electron microscopy SEM) techniques. Several parameters for Paracetamol adsorption from aqueous solutions were tested, and the optimum parameters were as follow: contact time= 150 min, pH= 7.0, temperature= 25ºC, (AC:Acid) ratio = 1:1. The equilibrium data were fitted to different adsorption isotherms, the two-step Langmuir isotherm gave the best fit to the data, and the pseudo-second-order model represented the adsorption process as dynamic studies illustrated. Thermodynamic parameters showed the process was exothermic (-15.7 kJ/mol) and physisorption. The results of the experiments showed the removal efficiency using AC (1:1) ratio was 92.9%, and the entire removal was attained using 16 g/L. The maximum paracetamol uptake at equilibrium was 165 mg/g. The used carbon in the adsorption process can be cleaned and reused again (regeneration), the regeneration efficiencies were 60% for hot water method and 68% for methanol method. This clearly helps toward cleaner ecosystems.

Unlocking the paracetamol adsorption mechanism in graphene tridimensional-based materials: an experimental-theoretical approach

The omnipresence of emerging contaminants in the aquatic environment is indisputable. These contaminants include chemical substances not removed in traditional water and sewage treatment processes. To ensure the quality of water and healthy aquatic ecosystems, new treatment technologies and materials are essential to effectively control the presence of these contaminants in the aquatic environment. More than that, it is important to know how molecules interact with these new materials. A low-cost alternative currently available is adsorption. Despite this method being widely studied, describing the interaction mechanisms between the materials and the analytes is not usual, limiting the obtainment of more efficient materials. Thus, the objective of this work was to understand, in a theoretical-experimental way, the forms of interaction in the adsorption of the drug paracetamol, widely used worldwide, in materials based on graphene with different chemical and structural properties. For this, kinetic and isothermal experimental studies were carried out using four materials that contemplated different dimensions, pore sizes, and oxidation degrees. In theoretical studies, density functional theory (DFT) simulations were performed to cover quantum details, revealing how paracetamol interacts with different graphene structures. According to theoretical studies, binding energies, binding distances, and charge transfer between oxidized graphene and paracetamol drug are compatible with physical adsorption, strongly dependent on the type and number of functional groups on the graphene surface. These results agree with the experimental data where the highest adsorptions were observed precisely for materials containing a higher proportion of functional groups and where these groups are more available (more porous), with adsorptive capacities reaching 235.7 mg/g. Our findings contribute to scientific knowledge about using graphene structures as an adsorbent material, providing a solid basis for future studies and developing more efficient and advanced water treatment technologies.

Glutaraldehyde Crosslinked Alginate-Chitosan Nanoparticles as Paracetamol Adsorbent

Paracetamol contained in wastewater can cause adverse effects on animal ecosystems, such as fish living in waters and cause harmful effects on humans. Adsorption techniques are used to remove these pharmaceutical compounds. Alginate-chitosan nanoparticles are non-toxic and effectively used as adsorbents to remove pharmaceutical compounds in wastewater. Research on glutaraldehyde crosslinked alginate-chitosan nanoparticles as paracetamol adsorbent has been carried out. This research used the ionic gelation method. Nanoparticles were characterized using transmission electron microscopy (TEM), scanning electron microscope (SEM-EDX) and Fourier transform infra-red spectrophotometer (FTIR). Furthermore, the nanoparticles were used for paracetamol adsorption. The results showed that the form nanoparticles are coarse solid powder and brownish yellow. The TEM image shows an average nanoparticle size of 8.22 nm. Glutaraldehyde crosslinked alginate-chitosan nanoparticles adsorbed paracetamol with adsorption kinetics followed a pseudo-second-order or Ho-McKay model, the adsorption rate constant of 0.0324 g mg−1 min−1. The isotherm study of paracetamol adsorption by glutaraldehyde cross-linked alginate-chitosan nanoparticles followed the isotherm Dubinin-Radushkevich isotherm model with a free energy value of 707.1068 kJ mol−1, and this value indicates the adsorption process by chemically or chemisorption.

Exploring the simultaneous mass transport of nimesulide and paracetamol adsorption on activated carbon: A PVSDM approach

Pore Volume and Surface Diffusion Model (PVSDM) was advanced to Extended PVSDM for modeling multicomponent adsorption systems. The dynamic adsorption of nimesulide and paracetamol on activated carbon was investigated through single and binary adsorption experiments. Langmuir and Extended Langmuir isotherms were used as local equilibrium functions, respectively. The results reveal that single and binary adsorption were affected by both external mass transport and intraparticle diffusion. The coexistence of nimesulide and paracetamol led to a competitive adsorption phenomenon, wherein nimesulide exhibited a higher affinity for the activated carbon surface, primarily occupying its surface active sites, while paracetamol diffuse into the pore volume to be adsorbed, especially at higher initial pharmaceutical concentrations. These findings emphasize the necessity of employing the robust Extended PVSDM for predicting the complex dynamics of binary adsorption. The findings also provide valuable insights that can significantly contribute to the development of efficient adsorption processes, addressing urgent environmental challenges.

Removal of Paracetamol and Cu2+ from Water by Using Porous Carbons Derived from Agrowastes

Dende and babassu coconuts are largely used in tropical countries, namely in Brazil, for the extraction of oils from kernels. The remaining biowastes are industrially processed to produce porous carbons (PCs). PCs derived from dende and babassu biowastes and produced at an industrial scale have been characterized by textural, chemical, and ecotoxicological parameters. A commercial activated carbon (CC) of mineral origin has been used as a benchmarking material. Although the CC sample presented a higher surface area (SBET = 1083 m2/g), the PCs derived from the biowastes were richer in micropores (Vmicro = 0.25–0.26 cm3/g), while the CC carbon presented wider pore size distribution with a higher mesopore volume (Vmeso = 0.41 cm3/g). All the adsorbents used in this work have shown a non-acute ecotoxic behavior for the bacterium Vibrio fischeri (EC50-30 min > 99% v/v). The adsorbents have been tested for paracetamol and Cu2+ adsorption in mono- and bicomponent solutions. The uptake capacities of paracetamol (qe, 98–123 mg g−1) and Cu2+ (qe, 15–18 mg g−1) from monocomponent solutions were similar to the ones obtained in the bicomponent solutions, indicating no competition or cooperative effects but a site-specific adsorption. This finding represents an advantage for the removal of these adsorbates when present in the same solution as they can be adsorbed under similar rates as in the single systems. Paracetamol adsorption was related to micropore filling, π-π interactions, and H-bonding, whereas Cu2+ removal was attributed to the cation exchange mechanism and complexation to the hydroxyl groups at the carbons’ surface.

Promising Porous Carbon Material Derived from Argan Paste Cake by KOH Activation, for Paracetamol Removal

This study focuses on the preparation and characterization of activated carbon derived from Argan paste cake through carbonization at 300 °C followed by activation at 800 °C, utilizing KOH as the activation agent with a ratio of 1:1. The objective of this research is to compare the adsorption capacity of the obtained sample, referred to as APC-300-800, with a commercially available granular activated carbon (GAC) purchased from Aquasorb. The preparation involved various characterization techniques such as BET (Brunauer–Emmett–Teller) analysis, XRD (X-ray diffraction), and SEM (scanning electron microscopy). BET analysis revealed that APC-300-800 exhibited a high surface area of 1937 m2/g. Subsequently, adsorption tests were conducted, leading to the observation that APC-300-800 conforms to the second pseudo-order kinetic model, and the adsorption of paracetamol can be accurately described by the Dubinin–Radushkevich isotherm model, exhibiting an R2 value of 0.89665. The maximum adsorption capacity of paracetamol on APC-300-800, as determined by the Langmuir model, was found to be 344.82 mg/g. Additionally, thermodynamic studies revealed that the adsorption process on APC-300-800 was primarily governed by physisorption, while for GAC, it was attributed to chemisorption. These findings highlight the potential of APC-300-800 as an efficient adsorbent for water treatment applications, showcasing its favorable adsorption characteristics compared to commercially available alternatives.

Bamboo sawdust-derived high surface area activated carbon for remarkable removal of paracetamol from aqueous solution: sorption kinetics, isotherm, thermodynamics, and regeneration studies

Abstract Due to its widespread consumption, paracetamol (PCT) has emerged as one of the leading contaminants that pollute water. Herein, a PCT removal of 99.6% was achieved using chemically activated carbon (CAC), derived from bamboo sawdust using KOH/FeCl3 as an activating agent, at optimal conditions of PCT (20 mg/L), CAC (0.5 g/L), contact time (90 min), and pH (8). Kinetic study revealed that the PCT adsorption process followed the pseudo-second-order kinetic model (R2 = 0.99), indicating that chemical adsorption dominated the adsorption mechanism. On the other hand, isotherm experimental data were best described by the Langmuir (R2 = 0.98) and Freundlich (R2 = 0.96) models. CAC had a maximum Langmuir monolayer capacity of 188.67 mg/g at a PCT concentration of 120 mg/L. Moreover, the Redlich–Peterson model gave the best fit (R2 = 0.99) to the experimental data, confirming that PCT adsorption was monolayer adsorption onto the heterogeneous surface. Thermodynamically, the PCT adsorption was exothermic, spontaneous, and favorable. The reusability study depicted that CAC can be successfully reused for five consecutive adsorption–desorption cycles. Furthermore, the application of CAC to environmental samples showed interesting results. The overall adsorption study indicated that CAC could serve as a promising adsorbent for eliminating PCT from water.

Effective removal of selected pharmaceuticals from sewerage treatment plant effluent using natural clay (Na-montmorillonite)

The consumption of pharmaceuticals has rapidly increased on a global scale due to the serious increase in Covid-19, influenza and respiratuar sinsityal virus, which is called “triple epidemic” in the world. The use of non-prescription analgesic and anti-inflammatory drugs (AAIDs), especially paracetamol, is higher compared to pre-pandemic. This increased the AAIDs load discharged to the aqueous media through sewerage treatment plant (STP). Therefore, simple and effective treatment options for removing AAIDs from STP effluents are needed. The aim of the study was to remove AAIDs (paracetamol, acetylsalicylic acid, codeine, diclofenac, ibuprofen, indomethacin, ketoprofen, mefenamic acid, naproxen, and phenylbutazone) from STP effluents by nearly pure natural clay Na-montmorillonite. The Na-montmorillonite taken from the Ordu region in the northern part of Turkey. Surface area of the Na-montmorillonite is 99.58 m2/g and CEC is 92.40 meq/100 g. The removal efficiencies of AAIDs using Na-montmorillonite were between 82 ± 5% (ibuprofen) and 94 ± 4% (naproxen). Paracetamol was used as a model compound in kinetic and isotherm model studies. Freundlich isotherm model and the pseudo second order kinetic model were the best-fit using the obtained experimental data. Film diffusion governed its rate mechanism. The paracetamol adsorption capacity was acquired as 244 mg/g at 120 min contact time at pH 6.5 at 25 °C. With this study, it could be shown that montmorillonite can be used effectively to eliminate paracetamol from STP effluent. Natural clay can be used as a simple, inexpensive and effective adsorbent for removing AAIDs from STP effluents.

Application of a biochar produced from malt bagasse as a residue of brewery industry in fixed-bed column adsorption of paracetamol

We report the removal of paracetamol from aqueous systems using a fixed-bed packed with biochar obtained from pyrolysis of malt bagasse residue (MBR). MBR biochar was characterized by carbonization yield, pH, Fourier-transform infrared spectroscopy (FTIR), and specific surface area (BET method). High surface area biochar (308.6 m² g-1) was fixed in a bed sorption column and sorption capacity was studied by varying the mass of sorbent and sorbate flow rate. Sorption isotherms (breakthrough curves) in the traditional "S" shape were observed in the assays. The nonlinear models of Thomas, Bohart-Adams and Yan-Viraraghavan were applied to the experimental data, with the model of Yan-Viraraghavan best describing the behavior of the isotherms, with a good mean coefficient of determination (R²) of 0.9883. Breakthrough times were greater at lower flow rates and greater sorbent amounts, and the effect of sorbent mass alone upon adsorption capacity (qexp) was not significant for a given flow rate. Thus, beer processing residue can be a source of raw material for the production of value-added MBR biochar, since it showed good sorption results of paracetamol in the biochar fixed-bed column, reaching sorption capacities at equilibrium up to 27.65 mg g-1 depending on the experimental parameters adopted.

Iron-engineered mesoporous biocarbon composite and its adsorption, activation, and regeneration approach for removal of paracetamol in water

Three-dimensional multi-porous Iron Oxide/carbon (Fe2O3/C) composites derived from tamarind shell biomass were synthesized by a single-step co-pyrolysis technique and utilized for Paracetamol (PAC) dismissal in the combined adsorption, and advanced oxidation such as electrochemical regeneration techniques. The Fe2O3/C composites were prepared by different pyrolysis temperatures, and named as TS750 (without Fe2O3at 750 °C), MTS450 BCs (Low-450 °C), MTS600 BCs (Moderate-600 °C) and MTS750 BCs (high-750 °C), respectively. As-prepared Fe2O3/C composite was characterized by FE-SEM, XRD, BET, and XPS analysis. The specific surface area and the spatial interaction between the interlayers of Fe2O3 and C were significantly improved by increasing the pyrolysis temperatures from 450 to 750 °C, which improved the adsorption capacity of Fe2O3/C composites in terms of higher rate constants and chemisorption kinetics. The Pseudo-second-order kinetics model fitted in the adsorption test results of Fe2O3/C composites with the highest correlation co-efficiency. The Langmuir-isotherms model fitted in the adsorption test of the TS750 and MTS450 BCs. The Freundlich isotherms model is more fit with MTS600 and MTS750 BCs. Based on the isotherm results, the MTS750 BCs achieved 46.9 mg/g of maximum PAC adsorption capacity. The optimized MTS750 composites could be completely recovered by using an advanced electrochemical oxidation regeneration approach within 180 min. Also, with the adsorption and recovery process, the TOC removal rate improved to ∼79.4%. After the 6th cycle electrochemical oxidation process, the obtained results of the re-adsorption test showed the stabile adsorption activity of the sorbent material. The data outcomes herein propose that this type of combined adsorption and electrochemical approach will be useful in commercial water treatment plants.

Removal of Paracetamol by Powdered Activated Carbon Synthesized From Orange Peels

This study aims to investigate the removal of Paracetamol active ingredient from aqueous solutions with the use of powdered activated carbon obtained by ZnCl2 activation of orange peels. Equilibrium values of initial paracetamol concentration (100-500 mg L-1), pH (2-10), adsorbent dose (10-500 mg) and contact time (5-120 minutes) parameters in the removal of paracetamol from aqueous solutions are evaluated. The adsorption mechanism of paracetamol is explained with the kinetic models. The highest correlation among Langmuir, Freundlich, Temkin, and Dubinin-Radushkevichi isotherms applied to experimental data was determined as Freundlich isotherm with R2 =0.95. Pseudo-first-order and pseudo-second-order kinetic models were applied, and it was found that the latter, whose correlation coefficient is determined as R2 =0.99, is the best model to explain paracetamol adsorption. As a result of this study, it can be seen that powdered activated carbon synthesized from orange peel is an effective adsorbent in the removal of paracetamol and can be easily applied thanks to its low cost.

A comprehensive study on paracetamol and ibuprofen adsorption onto biomass-derived activated carbon through experimental and theoretical assessments

The paper reports an experimental and theoretical work about the adsorption of paracetamol (PCM) and ibuprofen (IBP) onto a new activated carbon synthesized starting from the tree pods deriving from Erythrina speciosa. The adsorbent shows good porous properties, with a BET surface area of 795.1 m2/g, and an average pore volume of 0.422 cm3 g−1. Adsorption tests are carried out by varying the most important operating parameters. The adsorption capacity of both IBP and PCM results to be maximum at pH = 3, i.e., where the adsorbate molecules are found in neutral form. Adsorption isotherms indicated that IBP adsorption capacity increases with temperature up to 96.28 mg g−1, while an opposite trendwas retrieved for PCM, which decreased until 50.40 mg g−1. For a theoretical analysis, a double layer model (DLM) is adopted in order to provide an interpretation of the occurring adsorption mechanisms. The theoretical approach indicates that both IBP and PCM are adsorbed bya multi-molecular way, i.e. each functional group on the adsorbent surface accommodates more than one molecule at the same time. Finally, the adsorption energy reveals that a physical adsorption is responsible for both IBP and PCM adsorption on the synthesized adsorbent.