Removal Of Cephalexin Research Articles

Investigation of Cephalexin Removal Using Biochar Derived from Nephelium lappaceum Seeds

<p class="MsoNormal" style="line-height:200%;margin-bottom:0cm;mso-layout-grid-align:none;text-align:justify;text-autospace:none;"><span style="font-family:"Times New Roman",serif;font-size:12.0pt;line-height:200%;" lang="EN-US">The improper disposal of drugs into bodies of water has become a severe environmental and health issue. Biochar synthesized from different agro residues could be a potential material for the adsorption of pollutants in aqueous environments. </span><em><i style="mso-bidi-font-style:normal;"><span style="font-family:"Times New Roman",serif;font-size:12.0pt;line-height:200%;" lang="EN-US">Nephelium lappaceum</span></i></em><span style="font-family:"Times New Roman",serif;font-size:12.0pt;line-height:200%;" lang="EN-US"> seeds were pyrolyzed at 600 °C in a pyrolysis reactor incorporating a slow pyrolysis process for carbonization. Fourier-Transform Infrared (FTIR), Scanning Electron Microscope (SEM), and X-ray diffraction (XRD) were used to characterize the biochar before and after adsorption of the pharmaceutical pollutant cephalexin. The effects of several factors, including initial cephalexin concentration, time of contact, dosage of adsorbent, and pH, were considered for the sorption. The findings showed that the Freundlich model offered the greatest fit for adsorption. The better-fitted kinetic model was the pseudo-second-order kinetic. Based on Langmuir isotherm model, the maximum adsorption capacity of cephalexin was obtained as 63.69 mg/g. The adsorption process involves hydrogen bonding, surface complexation, electrostatic and π−π EDA interactions. The current study offers a feasible and optimistic method for using agricultural waste and an alternative adsorbent substance for recovering highly concentrated cephalexin from water-based solutions.<o:p></o:p></span></p>

ZnO/nZVI nanoparticle-enhanced double-slope U-shaped solar distillation: A thermodynamic investigation of cephalexin adsorption

The increasing need for sustainable methods to remove pharmaceutical contaminants like cephalexin and improve water desalination is critical. This study explores ZnO/nZVI nanoparticles synthesized with Jackfruit peel extracts as eco-friendly, cost-effective adsorbents, enhancing water purification in solar desalination systems. This work used a matte black paint coating within a double slope U-shaped solar distiller (DSUD) in a discontinuous experimental setting to examine potential improvements in solar distillation performance. Activated carbon (AC) and bioactive powdered nanoparticles of ZnO/nZVI (nano zerovalent iron), produced from jackfruit peel extracts (JP) were combined in a synergistic way. The effectiveness of cephalexin removal was assessed taking into account the JPAC solution parameters, reaction duration, ZnO/nZVI concentrations in the nanocomposite dosage, and initial nanocomposite concentration. The best conditions for cephalexin adsorption were found to be pH 5 and reaction time of 50 min, which resulted in high absorption efficiencies of 94.74% (nZVI) and 97.53% (ZnO) at room temperature with a JPAC dose of 2.50 g L⁻1. The efficiency of the eco-friendly adsorbent in getting rid of cephalexin was calculated using “pseudo-second-order kinetics” for nanocomposites, which is consistent with the “Langmuir” isothermal absorption process. The nanocomposites as absorbent materials in solar thermal desalination processes, efficient heat transmission and energy storage have been established. JPAC and the addition of steel balls (S) with a silver hue to the DSUD improved the internal heat transfer mechanisms. Thermodynamic of Gibbs free energy and the Laplacian method (TGL), two thermodynamic concepts, were used to extensively study the temperature dynamics of the DSUD with SJPAC components. For ZnO/JPAC, an exceptional distillate production rate was noted from 8:00 to 18:00, with a noteworthy 4.932 L/m2 output in winter and 5.833 L/m2 per day in summer. Using silver balls, ZnO/JPAC generated significant yields over a 24-h period: 8.957 L/m2 in summer and 7.253 L/m2 in winter, with an ideal energy efficiency of 51.05%. The unique advancements in TGL procedures and their environmental consequences are presented in this paper. The field of thermal energy transduction will advance if silver balls are used in DSUD for the synthesis of JPAC, ZnO/JPAC, and nZVI/JPAC, as supported by the theoretical insights presented here.

Theoretical and experimental studies of cephalexin adsorption on aluminium as a new alternative of removal from wastewater

ABSTRACT Cephalexin (CPX) is an antibiotic widely used to treat many infections. CPX has become an emerging pollutant present in wastewater. On the other hand, it is well known that organic compounds can be adsorbed over metal surfaces when the metal is in active state such as when it is rusting. This work proposes an alternative for the elimination of CPX from wastewater, applying electrochemical principles using a conventional and cheap substrate, aluminium. The first part consisted of obtaining the active states of aluminium electrodes carrying out voltametric curves at different pH (4, 7 and 9) to find the particular condition of interaction between CPX and metal surface. The potential was used in the potentiostatic tests to set the activation potential of metal at different times. After the treatment, electrolyte solutions were analysed using UV-vis spectra, and the aluminium surfaces were studied by optical micrographs and X-ray diffraction. In addition, aluminium-CPX interactions were corroborated by quantum-chemical calculations and adsorption isotherms. All results indicate that it was possible for the CPX removal at basic pH conditions, where the molecule adsorption on the aluminium substrate occurs due to a strong electrostatic interaction.

A hydrodynamic cavitation prototype reactor evaluation for decreasing cephalexin concentration in aqueous solution

A prototype of a hydrodynamic cavitation reactor was evaluated to determine the effectiveness of this system on the percentage decrease of cephalexin concentration present in an aqueous solution prepared with ultrapure water. The process variables or factors were pH [5 and 9], number of holes in the cavitation plate [5 and 7] and reaction time (30 min and 60 min). The results indicate that the percentage removal of Cephalexin (CFX) and total organic carbon (TOC) depends on the variables studied and the interaction between them. The highest yields were achieved at pH 5, 5 holes in the cavitation plate and 60 min of reaction reaching values of 24.16 % for CFX and 16.8 % for TOC. It was determined that, for the lowest number of holes in the cavitation plate and acid pH, the phenomenon that guides the process is the hydrodynamic cavitation, when increasing the number of holes and therefore decreasing the intensity of cavitation, the pH becomes more relevant and has incidence on the performance of the analyzed process. On the other hand, it was determined that, also in reaction times of 30 min, removal values very close to the maximum values obtained are achieved. The process can be intensified by the simultaneous application of other advanced oxidation processes to increase the effectiveness.

Exploration of cephalexin adsorption mechanisms onto bauxite and palygorskite and regeneration of spent adsorbents with cold plasma bubbling

The aim of the present study was the direct comparison of two popular minerals, bauxite and palygorskite, as adsorbents for the removal of cephalexin (CPX) from aqueous solutions and the regeneration of the spent adsorbents through cold atmospheric plasma. Batch kinetics and isotherm studies were carried out to evaluate the effect of contact time, initial CPX concentration, adsorbent dosage, pH and temperature. The adsorbents were characterized by ATR-FTIR, N2 sorption, SEM and XRD, while several isotherm, kinetic and thermodynamic models were evaluated attempting to shed light on the adsorption mechanisms. CPX adsorption on both adsorbents was better described by Langmuir model, with an adsorption capacity of 112.36 mg/g for palygorskite and 11.79 mg/g for bauxite. Thermodynamics revealed the endothermic and the spontaneous character of the process, indicating chemisorption as the main adsorption mechanism for both adsorbents. The pseudo-second-order and the Elovich models fitted satisfactorily the adsorption onto bauxite, while adsorption onto palygorskite was well presented by Weber–Morris model, indicating that pore diffusion is also involved in the process. The adsorption capacity of both minerals decreased significantly after being used for several adsorption cycles and then almost completely recovered (regeneration efficiency was 99.6% and 98% for palygorskite and bauxite, respectively) inside a novel cold plasma microbubble reactor energized by high-voltage nanopulses, revealing the potential of these adsorbents to be reused. In addition to the regeneration of the adsorbents, the cold plasma completely eliminated the CPX transferred from the solid to the aqueous phase during the regeneration process.

Utilizing Eco-Zno from green synthesis of Musa Acuminata peels and graphene oxide for removal of Cephalexin (CFX) antibiotic in water

Cephalexin (CFX) antibiotic concentration has been used as a marker for identifying emerging pollutants (EPs) in the non-medical setting due to its significant ability to cause antimicrobial resistance with the highest risk quotient. This study aimed to determine the characteristics of Eco-Zinc Oxide-Graphene Oxide (Eco-ZnO/GO) nanocomposite (NC) from green synthesis of Musa Acuminata by using Field Emission Scanning Electron Microscope (FESEM) coupled with Energy Dispersive X-ray Spectroscopy (EDX). The focus of the study is to optimize the efficiency of Eco-ZnO/GO NC from green synthesis of M. Acuminata for removal of CFX by using adsorption. The Response Surface Methodology (RSM) will be used as well to analyzed the adsorbent dosage, irradiation time, and pH value to obtain the optimum condition of the efficiency of Eco-ZnO/GO for the removal of CFX. The average particle sizes for Eco-ZnO and GO were determined to be 10 nm and 300 nm, respectively, by using FESEM. It is deduced that the optimization factors of adsorbent dosage to 100 mg/L, irradiation time to 120 min, and intial concentration of CFX to 100 mg/L could achieve the mean removal of CFX by 22.17 %. The study contributed to the new knowledge of using nanocomposite materials to remove CFX in the water. However, more thorough studies are needed to obtain higher removal capacity.

Preparation of polyhydroquinone graphene oxide nanocomposite for cephalexin removal from water by adsorption: Simulation, kinetics, and thermodynamic studies

Polyhydroquinone graphene oxide nanocomposite was produced and characterized by spectroscopic procedures. This substance was used to eliminate the antibiotic cephalexin from the water. With an initial amount of 700.0 g/L, a dose of 1.0 g/L, 60 min of contact time, and a temperature of 25 °C, the removal percentage was 90.0. Following the Langmuir, Temkin, and D-Rs models were the experimental data. A kinetic model with a pseudo-first order was used to govern the kinetic. At 20, 25, and 30 °C, free energy magnitudes were −47.28, −48.10, and −48.90 kJ/mol. Entropy and enthalpy had values of −0.063 and −0.21 kJ/mol. Thermodynamic parameter values that are negative are a sign of a spontaneous sorption process. Cephalexin's physical sorption on the polymeric polyhydroquinone graphene oxide nanocomposite sorbent was confirmed by the simulation investigation. Cephalexin bound to polymeric polyhydroquinone graphene oxide nanocomposite with a −3.5 kcal/mole binding energy. This technique can be used to remove cephalexin on a wide scale since it is reasonable and eliminates 90 % of cephalexin.

Mn-modified biochars for efficient adsorption and degradation of cephalexin: Insight into the enhanced redox reactivity.

Mn-modified biochars (BCs) were developed by pre-treatment of feedstock (MBCs) or post-modification of biochar (BCM), for simultaneous adsorption and degradation of a model pollutant, cephalexin. The apparent removal rates of cephalexin in the presence of MBCs (2.49 - 6.39×10-2 h-1) and BCM (13.3×10-3 h-1) were significantly higher than that in the presence of biochar prepared under similar conditions (4.2×10-3 h-1). While the •OH generated from the activation of dissolved O2 by the persistent free radicals (PFRs) and phenolic -OH on BC could cause degradation of cephalexin, its removal was drastically enhanced through direct oxidation by the MnOx and related Mn species on Mn-modified BCs. The removal of cephalexin by MBCs decreased as the solution pH was raised from 5.0 to 9.0, which supports the critical role played by Mn3O4 in its oxidation. Removal of cephalexin in the presence of MBCs and Mn3O4 was enhanced with the introduction of Mn(II) ions, suggesting that the Mn3O4 present on MBCs facilitates the re-oxidation of Mn(II) to highly reactive Mn(III). While MnO2 anchored on BCM also enhanced the cephalexin oxidation, the active sites of BC and MnO2 were partially destroyed during post-modification of BC, compromising the redox cycling of Mn(II)/Mn(III) and the generation of •OH. As a result, the performance of BCM in oxidizing cephalexin was inferior to that of MBCs. These findings shed new light on the development of environmentally benign sorbents capable of simultaneously adsorbing and oxidizing organic pollutants.

A sustainable system for decontamination of cephalexin antibiotic using electrocoagulation technology and response surface methodology

AbstractThe emergence of synthetic micropollutants in wastewater due to domestic and industrial use has presented new challenges for treatment processes. Among these pollutants, pharmaceutical and personal care products (PPCPs) are considered emerging contaminants due to their potential to enter drinking water sources. Antibiotics, in particular, are of significant concern due to their high consumption in veterinary and human applications. In this study, the electrocoagulation (EC) process is used as an efficient technique for the removal of cephalexin (CFX) from pharmaceutical wastewater. The study aims to explore the ability of the EC process to remove CFX and optimize its performance using the response surface method based on Central Composite Design (RSM‐CCD). The effects of initial CFX concentration, electrolysis time, initial pH, and electrode type (non‐insulated and insulated) were considered in the optimization process. This research is distinct as it examines the influence of key factors on the elimination of CFX. The results showed that electrolysis time had the most significant effect on CFX removal using the EC process. The analysis of variance (ANOVA) test was used to evaluate the importance of independent variables and their interaction. The optimal operating conditions for maximum removal efficiency (86.53%) were an initial CFX concentration, reaction time, and initial pH of 34 mg/L, 34.35 min, and 6.5, respectively, using an insulated electrode. Under these optimal conditions, predicted CFX removal was 93.54%. These findings demonstrate that RSM‐CCD is a useful tool for optimizing electrochemical removal processes for micropollutants such as CFX from wastewater streams. The study highlights the importance of considering electrode type in optimizing EC processes for micropollutant removal from wastewater.

Novel three-dimensional graphene oxide modified with hyper-branched dendrimer for removal of cephalexin from aqueous solutions by applying Taguchi statistical method

Novel three-dimensional graphene oxide modified with hyper-branched dendrimer for removal of cephalexin from aqueous solutions by applying Taguchi statistical method

Developing a g-C3N4/NiFe2O4 S-scheme hetero-assembly for efficient photocatalytic degradation of cephalexin

The step-scheme (S-scheme) heterojunctions with superior redox capability have recently emerged as one of the most promising materials for cleaning up of contaminated environments. Herein, we synthesized g-C3N4/NiFe2O4 (NFC) heterojunction photocatalyst via a hydrothermal route for the degradation of Cephalexin (CPX). The integration of g-C3N4 and NiFe2O4 into heterojunction with an effective S-scheme transfer which prevents the recombination of essential photoexcited electron-hole pairs leads to excellent 99.3% of photocatalytic degradation of CPX within 60 min under visible light. The scavenging experiments suggested •OH and •O2- radicals generated on high potential bands of S-Scheme g-C3N4/NiFe2O4 as active species responsible for high performance CPX removal. The degradation intermediates were examined by Liquid Chromatography mass spectroscopy (LC-MS) and a probable pathway of CPX degradation was proposed accordingly. The inherent work function between g-C3N4 and NiFe2O4 leads to bending of conduction and valence bands which subsequently forms an built-in electric field across the interface facilitating the superior separation of photogenerated electrons and holes. The five subsequent recycling tests demonstrated the catalyst’s strong photocatalytic stability and the easy recovery process because of its magnetic characteristic. This research may bring fresh insights for constructing magnetic photocatalysts based on g-C3N4, which are both highly effective and stable. Additionally, it also paves a path for the designing of S-scheme heterojunctions with great performance for environmental remediation applications.

Synthesis of magnetic bio-nanocomposites for drug release and adsorption applications

Aims: Synthesis of nanocarrier Fe3O4/silica-starch/PNVCL for drug delivery and Fe3O4/GO-starch for antibiotic removal applicationsBackground: In the first part, the new magnetic nanocomposite including Fe3O4 nanoparticles coated with silica, anchored starch nanoparticles, and poly(N-vinylcaprolactam) and then, loaded by acetazolamide. In the second part, magnetic starch nanocomposites were synthesized and modified with graphene oxide.Methods: The drug loading, release and intrinsic cytotoxicity were measured. Also, the potential of Fe3O4/GO-starch as an adsorbent to remove cephalexin antibiotics from aqueous solutions was evaluated.Result: In the first part, the maximum drug adsorption was occurred at pH = 7 on the nanocarrier and the Langmuir model looks more suitable for describing the adsorption process at room temperature. The second study showed that the maximum adsorption of cephalexin at pH 4 for magnetic nanocomposites in good agreement with the Freundlich model and the adsorption kinetics followed the quasi-quadratic model.Conclusion: It seems that the prepared nanocarrier Fe3O4/silica-starch/PNVCL can be utilized as a promising candidate for drug delivery. Also, magnetic nanocomposites of Fe3O4/GO-starch can be used as suitable and inexpensive adsorbents in cephalexin removal.

Hematite Fe2O3@nitrogen-doped graphene core-shell photocatalyst for efficient cephalexin degradation under visible light irradiation

Recently, photocatalysis has been a promising technology for removing pharmaceutical antibiotics due to low energy utilization and cost-effectiveness. In this study, hematite Fe2O3 was encapsulated with nitrogen-doped graphene to produce an active and stable Fe2O3@NGr core-shell flatform for photocatalytic degradation of cephalexin. Fe2O3@NGr under visible light irradiation delivered an impressive cephalexin degradation efficiency of 90% within 60 min, superior to free-standing Fe2O3 (40%) and NGr (15%) species, respectively. Also, it could bring a lasting catalyst for light-driven cephalexin removal. The improvements were synergistically attributed to two following effects. First, the facile generation and transfer of electron-hole pairs in the Fe2O3@NGr core-shell design were achieved under visible light. Second, the active surface of NGr shell weakly bound to the CO gas as a central intermediate species in the decomposition by-products, speeding up the cephalexin removal. Thus, these two basic factors provided mechanistic insights into the working of Fe2O3@NGr core-shell system in terms of cephalexin degradation under visible light.

Achieving high separation of cephalexin in a photocatalytic membrane reactor: What is the best method for embedding catalyst within the polysulfone membrane structure?

The aim of this study is to achieve the best performance for the photocatalytic membrane reactor (PMR) in cephalexin removal. To this end, SrTiO3 photocatalyst with the bandgap of 2.85 eV and crystalline size 50 nm is embedded in the membrane structure using four methods, including blending with membrane matrix (BM), photograft polymerization (GP), interfacial polymerization (IP) and spin coating (SC). Investigation the PMR performance shows that, due to high porosity (68 %), the maximum drug flux (371 L/m2h) passes through the BMi membrane. Because of high flux, BMi membrane suffers from high fouling where presence of SrTiO3 can reduce it by at most 6 %. On the other hand, presence of SrTiO3 across the IPi surface, because of high surface area for performing photocatalytic degradation reactions, causes reduction of membrane fouling by 69 % compared to the raw membrane. The largest share of cephalexin membrane separation (80 %), due to the minimum MWCO (660 g/mol), is related to SCi membrane and the greatest share of the cephalexin photocatalytic degradation (59 %) as the shortest bandgap (3.19 eV) is associated with the GPi membrane. Overall, the highest rate of cephalexin removal (membrane separation plus photocatalytic degradation) is reported for SCi membranes, followed by IPi, GPi and BMi membranes, respectively. Hence, in order to achieve high flux, BMi; low fouling, IPi; high photocatalytic degradation, GPi and high separation, SCi membrane are suggested. Given the challenge ahead of any type of catalytic reactor, the proper method should be chosen for embedding the catalyst within the membrane structure.

Fabrication and characterization of Ti/polyaniline-Co/PbO2–Co for efficient electrochemical degradation of cephalexin in secondary effluents

The traditional interlayer of PbO2 electrode possessed many problems, such as short service lifetime and limited specific surface area. Herein, a novel and efficient Ti/polyaniline-Co/PbO2–Co electrode was conctructed employing cyclic voltammetry to introduce a Co-doped polyaniline interlayer and anodic electrodeposition to synthetize a β-PbO2-Co active layer. Compared with pristine PbO2 electrode, Ti/polyaniline-Co/PbO2–Co exhibited more compact crystalline shape and higher active sites amounts. Pratically, the electrochemical degradation of 5 mg L−1 cephalexin in real secondary effluents was effectively achieved by the novel anode with 87.42% cephalexin removal and 71.8% COD mineralization after 120 min of 15 mA cm−2 electrolysis. The hydroxyl radical production and electrochemical stability were increased by 3.16 and 3.27 times respectively. The cephalexin degradation pathway was investigated by combining a density functional theory-based theoretical approach and LC-QTrap-MS/MS. The most likely cleavage point of the β-lactam ring was the O=C–N bond, whose attack would produce small molecular compounds containing the thiazole and 4, 6-thiazine rings. Further oxidation produced inorganic ions; quantitative investigations indicated the amino groups to undergo decomposition to form aqueous NH4+, which was further oxidized to NO3−. The accumulation of NO3− and SO42−, combined with a decrease in toxicity toward Escherichia coli, demonstrated the efficient mineralization of cephalexin on the Ti/polyaniline-Co/PbO2–Co electrode.

Removal of Cephalexin from Wastewater Using Prepared Activated Carbon

In this study adsorption technique was used for the removal of antibiotic pollutants from wastewater. Cephalexin (CEX) was selected for the current study purpose as it is commonly used drug. Commercial activated carbon (AC) was used as the nano-adsorbent considering its high degree of porosity, availability, economic considerations, and environmental friendliness. Batch adsorption of cephalexin by commercially prepared activated carbon was used for the study. The parameters considered in the experiment include time, pH, concentration of adsorbent, adsorbate, and temperature of 298.15 K was maintained. It was found experimentally that with pH in acidic range (3-7), contact time of 1 hour, and 5mg per 20 ml dosage of adsorbent, the maximum removal efficiency of 87% was achieved. Isotherm and kinetic studies were carried out in this study. Keeping all these parameters constant, the method was tried out on stimulated hospital effluent and removal efficiency of 85% was obtained against cephalexin.

A high-performance microreactor integrated with chitosan/ Bi2WO6/CNT/TiO2 nanofibers for adsorptive/photocatalytic removal of cephalexin from aqueous solution

A Z-scheme Bi2WO6/CNT/TiO2 photocatalyst was synthesized hydrothermally and loaded on chitosan nanofibers with different mass percentages using the electrospinning process. The batch adsorption experiments for chitosan nanofibrous samples containing Bi2WO6/CNT/TiO2 revealed that the adsorption process and its kinetic followed the Langmuir isotherm and pseudo-second-order model, respectively. A planar microreactor with a reusable plate-type configuration was fabricated employing an inexpensive micromachining technique and integrated with chitosan/Bi2WO6/CNT/TiO2 nanofibers. The synergistic effect of the adsorption and photocatalysis was assessed for removing cephalexin under simulated sunlight irradiation in a continuous flow microreactor. The nanofibers containing 15 wt% of Bi2WO6/CNT/TiO2 exhibited the most removal efficiency. The effects of operational variables were investigated in the microreactor and optimized using response surface methodology as light intensity = 17.45 W/m2, retention time = 256 s, pH = 4.8, and initial cephalexin concentration = 29 mg/L. At this condition, cephalexin and TOC removal efficiencies reached 99.2% and 92.4%, respectively. The kinetic of disappearance of cephalexin under optimal conditions followed the Langmuir-Hinshelwood model. The adsorption equilibrium constant deduced from this model was similar to that one calculated from the Langmuir isotherm model. At the optimum condition, cephalexin removal efficiency reduced to 80% after 1500 min of microreactor operation and the nanofibers revealed appropriate stability and reusability.

Applications of Computational and Statistical Models for Optimizing the Electrochemical Removal of Cephalexin Antibiotic from Water

One of the most serious effects of micropollutants in the environment is biological magnification, which causes adverse effects on humans and the ecosystem. Among all of the micro-pollutants, antibiotics are commonly present in the aquatic environment due to their wide use in treating or preventing various diseases and infections for humans, plants, and animals. Therefore, an aluminum-based electrocoagulation unit has been used in this study to remove cephalexin antibiotics, as a model of the antibiotics, from water. Computational and statistical models were used to optimize the effects of key parameters on the electrochemical removal of cephalexin, including the initial cephalexin concentration (15–55 mg/L), initial pH (3–11), electrolysis time (20–40 min), and electrode type (insulated and non-insulated). The response surface methodology-central composite design (RSM-CCD) was used to investigate the dependency of the studied variables, while the artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS) methods were applied for predicting the experimental training data. The results showed that the best experimental and predicted removals of cephalexin (CEX) were 88.21% and 93.87%, respectively, which were obtained at a pH of 6.14 and electrolysis time of 34.26 min. The results also showed that the ANFIS model predicts and interprets the experimental results better than the ANN and RSM-CCD models. Sensitivity analysis using the Garson method showed the comparative significance of the variables as follows: pH (30%) > electrode type (27%) > initial CEX concentration (24%) > electrolysis time (19%).

Low-Cost and Eco-Friendly Hydroxyapatite Nanoparticles Derived from Eggshell Waste for Cephalexin Removal

This work describes the hydroxyapatite nanoparticle (HAP) preparation from eggshell waste and their application as an adsorbent for Cephalexin (Ceph) antibiotic removal from aqueous solutions. Chemical precipitation with phosphoric acid was used to evaluate the feasibility of calcium oxide for HAP preparation. The structural properties of HAP were characterized by X-ray diffraction, which revealed the formation of the hydroxyapatite crystalline phase formation. In addition, transmitting electron spectroscopy showed an irregular shape with a variation in size. The impact of various experimental conditions on the removal efficiency such as the solution’s pH, contact time, HAP mass, solution temperature, and Ceph concentration were studied. Experimental data showed that HAP could remove most Ceph species from aqueous solutions within 1 h at pH = 7 with 70.70% adsorption efficiency utilizing 50 mg of the HAP. The removal process of Ceph species by HAP was kinetically investigated using various kinetic models, and the results showed the suitability of the pseudo-second-order kinetic model for the adsorption process description. Moreover, the removal process was thermodynamically investigated; the results showed that the removal was spontaneous endothermic and related to the randomness increase. The data confirmed that HAP had high efficiency in removing Ceph antibiotics from an aqueous solution.

Cephalexin removal by persulfate activation using simulated sunlight and ferrous ions.

This study presents the main results related to the use of activated persulfate (PS) in the elimination of the beta-lactam antibiotic cephalexin (CPX). Experiments were done using K2S2O8 and simulated sunlight. A face-centered central composite experimental design was used to analyze the effects of the solution pH and the PS concentration on the reaction, and to determine the optimized conditions that favor the CPX elimination. The results indicated that the removal of CPX is promoted by an acidic pH and under the higher evaluated PS dose (7.5 mg L-1). CPX total removal was achieved in 30 min. The analysis of the effect of the pollutant initial concentration indicated that a pseudo-first-order kinetics model can be used to describe the reaction. Likewise, the use of Fe2+ ions for PS activation (in the dark) was evaluated and established that a higher concentration of ions favors the pollutant removal. Control tests and under the presence of scavenger agents indicated that both HO• and SO4-• radicals would be present in the solution and promote the CPX elimination. The assessment of the solution dissolved organic carbon, nitrates and sulfates was also carried out, and indicated that a portion of the organic matter was mineralized.