Carbamazepine In Water Research Articles

Piezo-modulated interface field facilitating hydroxyl radical formation of SrTiO3/ZnO heterojunction for water purification

Piezo-modulated interface engineering is an effective method for tuning the charge transfer process to enhance piezocatalytic dynamics. In this study, SrTiO3/ZnO heterojunctions were successfully synthesized via hydrothermal methods to degrade carbamazepine in water. The optimal SrTiO3/ZnO-5 % sample exhibited a remarkable 99.9 % degradation efficiency of carbamazepine within 60 min under ultrasonic vibration. The piezocatalytic reaction rate (k value = 0.0746 min−1) was 4.63 times and 10.97 times higher than that of pure SrTiO3 and pure ZnO, respectively. Reactive species scavenger tests, electron paramagnetic resonance techniques, and bands gap analysis revealed that the enhanced activity can be attributed to the construction of an interfacial electric field in SrTiO3/ZnO heterojunctions and the modification of an internal piezoelectric polarized field. This allowed charge redistribution and transport across the SrTiO3/ZnO heterojunction interface, and facilitated the generation of hydroxyl radicals (HO•) through simultaneous hole oxidation and electron reduction. This study provides a comprehensive mechanistic understanding about piezoelectric heterojunctions in the catalytic redox reactions, and offers valuable insights for designing more effective piezoelectric heterojunctions for the degradation of pharmaceutical organic pollutants.

Electrochemical degradation of carbamazepine in water by a flow-through and pilot-scale reactor with carbon felt electrodes: Parametric study under realistic operational conditions

Carbamazepine (CBZ) is one of the most stable pharmaceutical compounds that is commonly found in the effluents of wastewater treatment plants (WWTP). In this context, this contribution presents a comprehensive analysis of the different operating parameters of a flow-through and pilot-scale cylindrical reactor for hydrogen peroxide (H2O2) generation, in which the degradation of CBZ takes place. The electrochemical system was evaluated using 8 L of electrolytes prepared with tap water in the presence of methanol as dissolved organic matter or spiked tertiary WWTP effluent, at a volumetric flow of 7 L min−1. This reactor (i) improves the mass transport due to its flow-through configuration using fibrous quasi-three-dimensional carbon felt electrodes, (ii) operates without an external oxygen supply to promote the H2O2 electrosynthesis because it is incorporated by a jet aerator (iii) achieves the Fenton reaction at circumneutral pH due to Fe(II) disposition from a cation exchange resin. At first, the carbonaceous materials were electrochemically characterized by cyclic voltammetry measurements. Different operating parameters were evaluated by factorial design methodologies for H2O2 generation, energetic consumption and CBZ removal. The application of a current density of 1.4 mA cm−2, in a cathode-anode-cathode arrangement immersed in a 120 mM ionic strength solution, allowed to obtain up to 6.4 mg H2O2 L−1 after 40 min, consuming 0.44 kWh m−3. Later, the Fenton reaction was validated by a florescence study, and by the incorporation of 0.75 g of granular activated carbon and 5 g of Fe(II) loaded resin, CBZ abatement yields of 68 % and 32 % were obtained using a synthetic solution and a spiked tertiary WWTP effluent, respectively, and up to 28 % of the dissolved total organic carbon was removed. Finally, an analysis of the stability of the carbon felt electrodes was tackled using scanning electron microscopy and energy-dispersive X-ray spectroscopy.

Enhanced degradation of carbamazepine in water over Fe3O4@ZIF-8 nanocomposites with persulfate or peroxymonosulfate as activator

In this work, the Fe3O4@ZIF-8 catalyst was prepared by combining Fe3O4 with ZIF-8 for degrading carbamazepine (CBZ) in water, using activated persulfate (PS) and peroxymonosulfate (PMS). We investigated the optimal catalysts and reaction conditions for using PS or PMS as activators by varying the pH, temperature, catalyst dosage, as well as the dosage of PS and PMS, respectively. The results demonstrated that the CBZ removal rate using Fe3O4@ZIF-8 reached 98.1% after 30 min with a mass ratio of Fe3O4 to ZIF-8 = 3:1, temperature = 40°C, catalyst dosage = 0.50 g·L−1, and PS dosage = 0.25 g·L−1, using pH = 3.0. Characterization results show due to the fact that the presence of ZIF-8 facilitates the dispersion of the catalytic active species Fe3O4, prevents the agglomeration of the active species, increases the number of active species, and improves the catalytic performance. Furthermore, radical quenching assay and electron paramagnetic resonance spectra successfully identified the main oxidizing components generated in the system, namely SO4•− and •OH.

Degradation of Carbamazepine in Water by UV-activated Sulfite Process

In this study, the degradation efficiency and mechanism of carbamazepine (CBZ), a typical emerging contaminant in water, in the UV/sulfite process were investigated. The effects of different concentrations of dissolved oxygen [ρ(DO)] on the degradation of CBZ by UV-activated sulfite were investigated. Additionally, under a simulated natural water environment-controlled initial ρ(DO) of (8.0 ±0.2) mg·L-1, the effects of different process parameters (sulfite dosages and reaction pH) and water environmental factors (the presence of HCO3-, Cl-, and humic acids) on the degradation of CBZ were comprehensively analyzed. The results showed that the UV/sulfite process efficiently degraded CBZ with a degradation rate of 85.3% during the 30 min reaction time and followed the pseudo-first order kinetic model with the constant of 0.055 7 min-1. Using the electron spin resonance detection, reactive species quenching tests, and the competition kinetics, the sulfate radicals (SO4-·) and hydroxyl radicals (·OH) in the UV/sulfite process were determined to be the main reactive species and were responsible for the degradation of CBZ with contribution rates of 43.9% and 56.1%, respectively. In addition, the degradation efficiency of CBZ decreased with the increasing concentration of HCO3-, and the presence of Cl- had little effect on the degradation of CBZ, whereas the presence of humic acids significantly inhibited the degradation of CBZ. Moreover, the accumulation of sulfate during the reaction was significantly lower than the limit of the Standard for Drinking Water (GB5749-2022). Additionally, the sulfite consumption rate constant was 0.004 4 min-1, which was significantly lower than the degradation rate constant of CBZ, indicating that sulfite could be activated efficiently by UV light to degrade CBZ in water.

Green synthesized zinc oxide nanoparticles for removal of carbamazepine in water and soil systems

During the COVID-19 pandemic, there was a significant increase in pharmaceutical releases (4 %), which created a pressing global need for solutions. In this study, we explored the use of zinc oxide nanoparticles (GS-ZnONPs) derived from neem (Azadirachta indica) leaves for separating antiepileptic drug carbamazepine (CBZ) from wastewater. CBZ is a major emerging pollutant in wastewater that can be reused for various purposes, including food production and drinking water. The study found that the GS-ZnONPs were effective in removing CBZ from water, with an adsorption capacity of 27.55 mg g−1 at room temperature. The GS-ZnONPs, under optimal conditions of pH 5.0, 100 mg of adsorbent, and 12 mg L−1 of CBZ at 25 °C ± 2 °C, demonstrated a remarkable removal efficiency, successfully eliminating 92.89 % of CBZ from water. Additionally, the study found that CBZ binds strongly to GS-ZnONPs, making them effective for removing CBZ from soil as well. The results suggest that GS-ZnONPs synthesized from neem leaves could be a low-cost and sustainable solution for removing emerging pollutants from wastewater and soil. Future studies could investigate the adsorption mechanisms, functional groups, respective pH ranges, and reuse of these low-cost adsorbents to further optimize their efficiency in tackling emerging pollutants.

Fast degradation of carbamazepine in water by electric discharge plasma

The proliferation of pharmaceuticals in the aqueous environment has adversely impact on human health and ecosystem balance. Pharmaceutical contaminations are difficult to remove effectively by conventional treatment technologies. In order to degrade carbamazepine (CBZ) efficiently, a common antiepileptic drug, three plasma discharge modes were studied, including liquid-phase discharge, air gas-liquid jet and dielectric barrier discharge. It is noteworthy that the degradation efficiency and energy yield reached to highest levels (0.11 g/kWh) when operating at 225 W input power under liquid phase discharge, compared with the other discharge modes. The parameters of concentration, electrode distance, volume, input power and frequency of the discharge were also evaluated and optimized. Plasma emission spectroscopy revealed the degradation process is mainly attributed to reactive oxygen species (ROS), while the role of reactive nitrogen species was not significant. The contributions of diverse ROS were assessed by radical quenching experiments, including p-benzoquinone, p-phthalic acid and tert-butanol. The possible degradation intermediates and pathways of CBZ were tested and analyzed by liquid chromatography-mass spectrometry (LC-MS). Comprehensively consideration of cleanliness, degradation efficiency and application difficulty, liquid-phase discharge treatment is a promising technology for water treatment.

The ability of recycled magnetite nanoparticles to degrade carbamazepine in water through photo-Fenton oxidation at neutral pH

Herein, the recycled magnetite obtained from industrial ferrous scrap was used as an eco-friendly, sustainable iron source in the photo-Fenton degradation of carbamazepine (CBZ), an emerging contaminant in the aqueous environment. Citrate was used as a robust chelating agent to trap and stabilize the iron required for the Fenton reaction. The results proved the formation of the Fe(III)-citrate complex, followed by the reduction of iron to Fe(II) and the formation of harmless molecules such as malonate under UV radiation. The adopted photo-Fenton process in the presence of magnetite (0.3 g/L), H2O2 (0.5 mM), and citrate (0.1 mM) led to about 77 % degradation of CBZ. Then, degradation efficiency was improved to 99 % by increasing the prior contact time between citrate and magnetite. In addition, 1 mM of citrate and 2 mM of H2O2 were found to be the optimal values for the degradation of CBZ under the adopted photo-Fenton process. Eventually, the experiments illustrated that the recycled magnetite could be used in the photo-Fenton process in five successive cycles without losing its efficiency.

Oxidation of Pharmaceuticals by Ferrate(VI)-Amino Acid Systems: Enhancement by Proline.

The occurrence of micropollutants in water threatens public health and ecology. Removal of micropollutants such as pharmaceuticals by a green oxidant, ferrate(VI) (FeVIO42-, Fe(VI)) can be accomplished. However, electron-deficient pharmaceuticals, such as carbamazepine (CBZ) showed a low removal rate by Fe(VI). This work investigates the activation of Fe(VI) by adding nine amino acids (AA) of different functionalities to accelerate the removal of CBZ in water under mild alkaline conditions. Among the studied amino acids, proline, a cyclic AA, had the highest removal of CBZ. The accelerated effect of proline was ascribed by demonstrating the involvement of highly reactive intermediate Fe(V) species, generated by one-electron transfer by the reaction of Fe(VI) with proline (i.e., Fe(VI) + proline → Fe(V) + proline•). The degradation kinetics of CBZ by a Fe(VI)-proline system was interpreted by kinetic modeling of the reactions involved that estimated the rate of the reaction of Fe(V) with CBZ as (1.03 ± 0.21) × 106 M-1 s-1, which was several orders of magnitude greater than that of Fe(VI) of 2.25 M-1 s-1. Overall, natural compounds such as amino acids may be applied to increase the removal efficiency of recalcitrant micropollutants by Fe(VI).

Fe-metal organic framework converts mechanical energy with piezoelectric polarization to remove carbamazepine in water: Efficiency, pathway and mechanism

Piezocatalysis is a new technique that directly transforms mechanical energy into chemical energy. Although this approach can potentially be used to replace traditional water treatment methods, the structural tailorability and limited surface area of conventional inorganic piezoelectric materials restrict their catalytic efficiency. Herein, we employed a piezoelectric material made of an organic Fe-metal organic framework (MOFs) to purify water via piezocatalysis. We analyzed the physicochemical properties of MIL-100(Fe), including its piezoelectricity, bandgap structure, and charge separation efficiency. Carbamazepine (CBZ) was used as a representative aqueous drug pollutant, and MIL-100(Fe) removed 92 % of CBZ in 30 min via applying ultrasonication (US), which was 5.1 and 11.5 times higher than either the individual MIL-100(Fe) or US. The mechanical US stresses generated a built-in electric field in MIL-100(Fe) to promoted free charge migration, and also modulated the band structure of the sample. This promoted the production of reactive oxygen species. In this work, shows that porous piezoelectric nanostructures based on MOFs can convert mechanical energy into chemical energy to drive chemical oxidation processes.

Enhanced degradation of carbamazepine in water over SC-modified NiFe2S4 nanocomposites by peroxymonosulfate activation

In this study, novel Semi-coke-modified NiFe2S4 nanocomposites with different mass ratios are successfully prepared by hydrothermal method to activate peroxymonosulfate (PMS) for the degradation of carbamazepine (CBZ) in water. The factors affecting the degradation of CBZ, such as initial solution pH, PMS and catalyst dosage, inorganic anions, and humic acid (HA) are investigated. The possible PMS activation mechanism and CBZ possible degradation pathways are also explored. The results show that the performance of SCNF-0.5/PMS (mass ratio of SC:NiFe2S4 = 1:2) is better than that of monomeric NiFe2S4 and semi-coke (SC). X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) spectrometer, and free radical quenching experiments show that both non-radical (1O2 and Ov) and free radical pathways (SO4− and OH) may be responsible for the degradation of CBZ, but 1O2 is dominant active species. S2− promotes the Ni2+/Ni3+, Fe2+/Fe3+ cycle to ensure the stable performance of the catalyst, and the oxygen vacancies (Ov) in the SC act synergistically with the catalyst to promote the degradation of CBZ. This study may provide new insights into the degradation of antibiotics in water by modifying stable bimetallic sulfide to activate PMS.

TiO2 (Core)/Crumpled Graphene Oxide (Shell) Nanocomposites Show Enhanced Photodegradation of Carbamazepine.

The presence of pharmaceuticals and personal care products (PPCPs) in aquatic systems is a serious threat to human and ecological health. The photocatalytic degradation of PPCPs via titanium oxide (TiO2) is a well-researched potential solution, but its efficacy is limited by a variety of environmental conditions, such as the presence of natural organic macromolecules (NOM). In this study, we investigate the synthesis and performance of a novel photoreactive composite: a three-dimensional (3D) core (TiO2)-shell (crumpled graphene oxide) composite (TiGC) used as a powerful tool for PPCP removal and degradation in complex aqueous environments. TiGC exhibited a high adsorption capacity (maximum capacity 11.2 mg/g, 100 times larger than bare TiO2) and a 30% enhancement of photodegradation (compared to bare TiO2) in experiments with a persistent PPCP model, carbamazepine (CBZ). Furthermore, the TiGC performance was tested under various conditions of NOM concentration, light intensity, CBZ initial concentration, and multiple cycles of CBZ addition, in order to illustrate that TiGC performance is stable over a range of field conditions (including NOM). The enhanced and stable performance of TiCG to adsorb and degrade CBZ in water extends from its core-shell composite nanostructure: the crumpled graphene oxide shell provides an adsorptive surface that favors CBZ sorption over NOM, and optical and electronic interactions between TiO2 and graphene oxide result in higher hydroxyl radical (•OH) yields than bare TiO2.

Occurrence of the antiepileptic carbamazepine in water and bivalves from marine environments: A review

A vast literature has already demonstrated that pharmaceutical drugs exert negative impacts on aquatic organisms but data is sparse on the occurrence of these contaminants in marine aquatic environments and their biota, particularly in comparison with freshwater systems. In marine environments, bivalves are known as good bioindicator species for environmental pollution monitoring. This review summarizes the current knowledge on carbamazepine (CBZ) concentrations in the marine environment (seawater and bivalves) and the analytical methods involved in the drug determination. Carbamazepine was chosen based on its ubiquitous occurrence and proven negative impacts on the aquatic organisms. Overall, CBZ is distributed in the marine environment with concentrations up to ∼ 1 μg/L, revealing its stability and high persistence. Also, CBZ was found in some species of marine bivalves, with concentrations up to 13 ng/g dry weight (DW), however, a bioaccumulation factor could not be calculated due to the absence of CBZ determination in seawater samples for most of the studies. CapsuleCarbamazepine is found in seawater up to the low μg/L level, and in bivalve tissue up to a few ng/g DW, with SPE and LC as the techniques of choice for drug extraction and identification.

Luminescence-colour-changing sensing toward neurological drug carbamazepine in water and biofluids based on white light-emitting CD/Ln-MOF/PVA test papers

Nanomolar-level carbamazepine in water and biofluids has been determined using a white-light-emitting test paper via luminescence-colour-changing sensing.

Methyl Paraben and Carbamazepine in Water and Striped Catfish (Pseudoplatystoma magdaleniatum) in the Cauca and Magdalena Rivers.

Between 2017 and 2019, samplings were carried out in the San Jorge, Cauca and Magdalena River basins in Colombia, to determine the presence of methyl paraben and carbamazepine in water and Pseudoplatystoma magdaleniatum. For the analysis of the samples, a validation of the analytical method was performed, following the EPA method 1694 (Pharmaceutical and personal care products in water), with slight modifications. This was done by liquid-chromatography tandem mass spectrometry, for quantification of methyl paraben and carbamazepine, including parameters of linearity, accuracy precision and veracity. Carbamazepine was found in the Magdalena River at 8.03 ± 0.01µg/L in transition season. In fish samples, methyl paraben and carbamazepine were detected in a range between 32and 90.80µg/kg in transition and dry seasons.

Developing an ultrasonic-assisted d-µ-SPE method using amine-modified hierarchical lotus leaf-like mesoporous silica sorbent for the extraction and trace detection of lamotrigine and carbamazepine in biological samples

Herein, an ultrasonic-assisted dispersive micro solid-phase extraction method was developed. In this study, we used an amine-modified hierarchical lotus leaf-like mesoporous silica sorbent along with HPLC-UV analysis to simultaneously extract and subsequently measure lamotrigine and carbamazepine in water and biological media. Initially, the synthesis of amine-modified hierarchical lotus leaf-like mesoporous silica sorbent was accomplished and later it was characterized by various techniques such as Scanning Electron Microscopy (SEM), High-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), elemental analysis (CHN), Fourier Transform Infrared spectroscopy (FT-IR), N2 adsorption–desorption (BET) and thermogravimetric analysis (TGA). Following on, the sorbent was utilized for the extraction of the analytes, and the variables affecting the extraction efficiency were optimized. The optimal conditions for the presented ultrasonic-assisted d-µ-SPE method were: pH 8.5, sorbent amount 24 mg, sonication time in the sorption step 3.5 min, elution by 1.0 mL MeOH: acetic acid (96: 4 (v/v %)) and sonication time for desorption 3 min. Under the optimal condition, the calibration curve was linear over the concentration range of 5–500 µg L−1, for urine and plasma samples (5.0 mL), and 1–100 µg L−1 for water samples (10 mL). The practical and feasible limit of quantification (L.O. Q) for the detection of LTG and CBZ by the proposed method was 5.0 µg L−1 in urine and plasma samples and 1.0 µg L−1 in water samples. In order to assess the extraction efficiency, the method was applied to various spiked real water samples. The average relative recoveries obtained from the fortified samples varied between 96 and 106% with the relative standard deviations of 4.4–7.9%.

Degradation and Mineralization of Carbamazepine Using an Electro-Fenton Reaction Catalyzed by Magnetite Nanoparticles Fixed on an Electrocatalytic Carbon Fiber Textile Cathode.

Pharmaceutical wastes are considered to be important pollutants even at low concentrations. In this regard, carbamazepine has received significant attention due to its negative effect on both ecosystem and human health. However, the need for acidic conditions severely hinders the use of conventional Fenton reagent reactions for the control and elimination of carbamazepine in wastewater effluents and drinking water influents. Herein, we report of the synthesis and use of flexible bifunctional nanoelectrocatalytic textile materials, Fe3O4-NP@CNF, for the effective degradation and complete mineralization of carbamazepine in water. The nonwoven porous structure of the composite binder-free Fe3O4-NP@CNF textile is used to generate H2O2 on the carbon nanofiber (CNF) substrate by O2 reduction. In addition, ·OH radical is generated on the surface of the bonded Fe3O4 nanoparticles (NPs) at low applied potentials (−0.345 V). The Fe3O4-NPs are covalently bonded to the CNF textile support with a high degree of dispersion throughout the fiber matrix. The dispersion of the nanosized catalysts results in a higher catalytic reactivity than existing electro-Fenton systems. For example, the newly synthesized Fe3O4-NPs system uses an Fe loading that is 2 orders of magnitude less than existing electro-Fenton systems, coupled with a current efficiency that is higher than electrolysis using a boron-doped diamond electrode. Our test results show that this process can remove carbamazepine with high pseudo-first-order rate constants (e.g., 6.85 h–1) and minimal energy consumption (0.239 kW·h/g carbamazepine). This combination leads to an efficient and sustainable electro-Fenton process.

Removal of carbamazepine in water by electro-activated carbon fiber-peroxydisulfate: Comparison, optimization, recycle, and mechanism study

Treatment of a persistent organic pollutant, carbamazepine (CBZ), in aqueous solution by a novel and sustainable method, Electro-activated carbon fiber-peroxydisulfate (E-ACF-PDS), was investigated and compared with ACF adsorption, Peroxydisulfate (PDS), ACF-peroxydisulfate (ACF-PDS), E-Pt (Pt-plating titanium as cathode in electrolysis), E-ACF (ACF as cathode in electrolysis), and Electro-Pt-peroxydisulfate (E-Pt-PDS) processes, respectively. The removal rate of CBZ by E-ACF-PDS was 98.78% in 30 min, which was much higher than that of the others. Besides, several tests were performed to investigate the role of operational conditions (pH, peroxydisulfate concentration, electrode potential, temperature, and water matrix) in E-ACF-PDS process. Moreover, it is worth noting that even after recycling ACF for 100 times, the removal rate of CBZ in 30 min decreased only slightly from 98.78% to 97.35% in E-ACF-PDS process. In addition, the surface functional groups, FTIR spectrum, Raman spectrum, BET surface area, micropore volume, and SEM images of ACF before and after long time service were investigated and the results revealed that the ACF could maintain the original features in E-ACF-PDS process even after 100 cycles, while the ACF alone was seriously damaged in ACF-PDS process after 50 cycles. These results suggested that the E-ACF-PDS process could remarkably enhance the removal of CBZ in aqueous solution due to the simultaneous adsorption of contaminants and the increase in the generation of active radicals on ACF. The electrons on cathode could inhibit the destruction of ACF caused by chemical oxidation such as sulfate radicals, hydroxyl radicals, and peroxydisulfate. Therefore, the E-ACF-PDS process may provide an effective and sustainable approach to water treatment for the elimination of contaminants of emerging concern in water.

N-Doped TiO₂-Coated Ceramic Membrane for Carbamazepine Degradation in Different Water Qualities.

The photocatalytic degradation of the model pollutant carbamazepine (CBZ) was investigated under simulated solar irradiation with an N-doped TiO2-coated Al2O3 photocatalytic membrane, using different water types. The photocatalytic membrane combines photocatalysis and membrane filtration in a single step. The impact of each individual constituent such as acidity, alkalinity, dissolved organic matter (DOM), divalent cations (Mg2+ and Ca2+), and Cl− on the degradation of CBZ was examined. CBZ in water was efficiently degraded by an N-doped TiO2-coated Al2O3 membrane. However, elements added to the water, which simulate the constituents of natural water, had an impact on the CBZ degradation. Water alkalinity inhibited CBZ degradation mostly due to increase in pH while radical scavenging by carbonate was more dominant at higher values (>200 mg/L as CaCO3). A negative effect of Ca2+ addition on photocatalytic degradation was found only in combination with phosphate buffer, probably caused by deposition of CaHPO4 or CaHPO4·2H2O on the catalyst surface. The presence of Cl− and Mg2+ ions had no effect on CBZ degradation. DOM significantly inhibited CBZ degradation for all tested background organic compounds. The photocatalytic activity of N-doped TiO2-coated Al2O3 membranes gradually decreased after continuous use; however, it was successfully regenerated by 0.1% HCl chemical cleaning. Nevertheless, dissolution of metals like Al and Ti should be monitored following acid cleaning.

Electrochemical removal of carbamazepine in water with Ti/PbO2 cylindrical mesh anode

Carbamazepine (CBZ) is one of the most frequently detected organic compounds in the aquatic environment. Due to its bio-persistence and toxicity for humans and the environment its removal has become an important issue. The performance of the electrochemical oxidation process and in situ production of reactive oxygen species (ROS), such as O3 and H2O2, for CBZ removal have been studied using Ti/PbO2 cylindrical mesh anode in the presence of Na2SO4 as supporting electrolyte in a batch electrochemical reactor. In this integrated process, direct oxidation at anode and indirect oxidation by in situ electrogenerated ROS can occur simultaneously. The effect of several factors such as electrolysis time, current intensity, initial pH and oxygen flux was investigated by means of an experimental design methodology, using a 2(4) factorial matrix. CBZ removal of 83.93% was obtained and the most influential parameters turned out to be electrolysis time, current intensity and oxygen flux. Later, the optimal experimental values for CBZ degradation were obtained by means of a central composite design. The best operating conditions, analyzed by Design Expert(®) software, are the following: 110 min of electrolysis at 3.0 A, pH = 7.05 and 2.8 L O2/min. Under these optimal conditions, the model prediction (82.44%) fits very well with the experimental response (83.90 ± 0.8%). Furthermore, chemical oxygen demand decrease was quantified. Our results illustrated significant removal efficiency for the CBZ in optimized condition with second order kinetic reaction.

Sonoelectrochemical oxidation of carbamazepine in waters: optimization using response surface methodology

AbstractBACKGROUNDThe decomposition of carbamazepine (CBZ) in synthetic solution and in municipal effluent was investigated using a sono‐electrochemical reactor. Sono‐electrolysis was conducted using two concentrical electrodes installed in a cylindrical reactor containing a ceramic transducer.RESULTSCBZ concentration (C0=10 mg L−1) optimally diminished up to 90% by applying a current intensity of 4.86 A for 177 min and by imposing an ultrasound power of 38.29 W. The optimal conditions were subsequently applied for tertiary treatment of municipal wastewater effluent contaminated with 10 µg CBZ L−1. The reported removal efficiencies of CBZ, TOC, COD and colour were 93%, 60%, 93% and 86%, respectively. Likewise, the toxicity was completely removed (bacterium Vibrio fisheri) from the municipal wastewater effluent (>96%).CONCLUSIONSThe advantages of coupling ultrasonication and electrooxidation (US‐EO) treatment for CBZ removal were demonstrated. An experimental design methodology based on response surface methodology was applied to determine the optimal experimental conditions in terms of cost/effectiveness of removal. © 2014 Society of Chemical Industry