Carbamazepine Removal Efficiency Research Articles

Insight into interactive synergy of MoS2@CoNC for peroxymonosulfate activation: From bath experiments to continuous flow experiments

As catalysts for peroxymomosulfate (PMS) activation, several carbon materials derived from MOFs have gained considerable attention. Despite this, Fenton-like reactions have always been limited by cycle efficiency of metal’s valence state. In this study, a novel catalyst (MoS2@CoNC), Molybdenum disulfide (MoS2) modified CoNC (derived from ZIF-67), was successfully synthesized. Catalytic experiments indicated that the carbamazepine (CBZ) degradation efficiency could be enhanced in the MoS2@CoNC-PMS process. Moreover, PMS decomposition also exhibited outstanding performance compared with other processes. Various quenching experiments and ESR analyses indicated that CBZ degradation is mainly caused by nonradical oxidation (86.10 %). In addition, Density Functional Theory (DFT), in-situ Raman, and in-situ FTIR were employed to elucidate PMS activation mechanism. The generation pathways of singlet oxygen (1O2), cobalt-oxo species (CoVI = O), and electron transfer were systematically elaborated. X-ray Photoelectron Spectroscopy (XPS) analysis identified unsaturated S as a significant factor contributing to MoS2@CoNC stability. Further investigation into CBZ degradation was conducted using DFT and LC-MS. The toxicity of intermediates was also assessed through TEST and bean sprout cultivation. Additionally, a continuous flow experiment is performed to evaluate the practical application of MoS2@CoNC-PMS. After 10 h, CBZ removal efficiency is approximately maintained at 90 %. Water matrix effects and multi-pollutant degradation also determined that the MoS2@CoNC-PMS process is a promising method for pollutants degradation.

Simultaneous removal of nitrate, copper, carbamazepine, and calcium from micropolluted water by fulvic acid through promotion of denitrification and microbial-induced calcium precipitation: Performance and mechanism

In this paper, a study of the denitrification strain Cupriavidus sp. W12 was conducted to remove copper (Cu2+), carbamazepine (CBZ), and calcium (Ca2+) by microbial-induced calcium precipitation (MICP) after adding fulvic acid (FA). After the addition of 20 mg/L FA, the removal efficiencies of nitrate (NO3–-N), Cu2+, CBZ, and Ca2+ reached 100.0 %, 98.7 %, 96.6 %, and 73.6 %, correspondingly and there was no accumulation of nitrite (NO2–-N). FA stimulated the growth of strain W12, improved electron transfer activity, and facilitated the conversion of gaseous nitrogen. The research revealed that FA might enhance microbial activity and result in a more dense and porous structure of the biological precipitate. Cu2+ and CBZ were removed by co-precipitation and adsorption. As the initial report of FA promoting MICP to remove complex pollutants, this paper offers a theoretical foundation for NO3–-N, Cu2+, CBZ, and Ca2+ remediation in micropolluted water.

CoFe2O4-catalytic ceramic membrane for efficient carbamazepine removal via peroxymonosulfate activation

Poor water removal of low-molecular-weight anthropogenic contaminants is always a key problem in low-pressure membrane filtration process. In this work, we successfully designed and fabricated a novel cobalt-based bimetallic catalytic ceramic membrane (CoFe2O4@CM-2) with peroxymonosulfate (PMS) activation and membrane filtration dual functionality, employing a facile impregnation-filtration-calcination method. The resulting CoFe2O4@CM-2/PMS filtration system was specifically tailored for the removal of carbamazepine (CBZ). Our results demonstrate that the CoFe2O4@CM-2/PMS system achieved efficient removal of CBZ from contaminated waters. Under optimal conditions (PMS dosage of 0.5 mM and an operating flux of 40 L·m−2·h−1), the CoFe2O4@CM-2/PMS system exhibited remarkable CBZ removal efficiency, reaching up to 96.5 %. This efficiency was 32.2 and 19.3 times higher than that achieved by ceramic membrane filtration alone and PMS treatment alone, respectively. Additionally, the CoFe2O4@CM-2/PMS system facilitated 37.0 % mineralization of CBZ and up to 87 % utilization of PMS in the permeate. Furthermore, the CoFe2O4@CM-2/PMS system demonstrated robust performance, removing over 91 % of CBZ across a pH range of 3–9 and maintaining stability stability in the presence of humic acid (HA) interference. Its exceptional anti-fouling ability effectively mitigates membrane flux loss compared to single membrane filtration process. Quenching test, electron paramagnetic resonance (EPR), and X-ray photoelectron spectroscopy (XPS) analyses revealed that 1O2, SO4-∙ and ·OH were the primary active substances in the system, while the redox cycle of Co2+/Co3+ played a crucial role in PMS activation. Moreover, the presence of iron (Fe) in the CoFe₂O₄@CM-2 expedited the Co2+/Co3+ cycle and enhanced PMS activation. This study introduces an innovative approach for fabricating ceramic membranes with catalytic degradation capabilities for organic pollutants and suggests promising avenues for integrating separation and advanced oxidation processes (AOPs) in future applications.

CuFeS2/GAC particle combined with electrochemical activation of persulfates for efficient degradation of carbamazepine

Electrochemically activated persulfate is a potential advanced oxidation process due to its advantages of environmental friendliness, high efficiency, and convenient operation. An Fe–Cu–S granular activated carbon (CuFeS2/GAC, abbreviated as FCSG) particles electrode was developed and applied to degrade carbamazepine (CBZ) combined with electrochemical activation of persulfate (E-PDS-FCSG) in this work. Compared to two-dimensional electrochemical process (E-PDS), the three-dimensional (3D) E-PDS-FCSG process exhibited higher removal efficiency of CBZ and lower energy consumption. The removal efficiency of CBZ and power consumption increased by 96% and reduced by 67%, respectively. Over 98% of CBZ removal rate was reached within 25 min. Apart from the same free radicals in two-dimensional electrochemical process, both Fe2+ and Cu+ on the surface of three-dimensional particle electrodes can directly activate PDS to produce SO4•–, and the existence of S2− strengthens the circulation of Fe3+/Fe2+ and Cu2+/Cu+. Furthermore, FCSG particle electrode can not only directly enhance the activation of PDS, but also accelerate the electron transfer, and then effectively promoting reactive species generation. LC-MS analysis showed that the main degradation pathways of CBZ involved decarbonylation, deamination, dealkylation, ring opening and mineralization. Moreover, after five cycle experiments, over 80% of CBZ removal rate could be achieved, demonstrating that the E-PDS-FCSG system had excellent electrocatalytic performance and good stability. These findings indicate that FCSG is a promising material and could be used as a particle electrode for removing organic pollutants from water.

Effective peroxymonosulfate activation by lithium cobaltite recovered from spent lithium-ion batteries for enhanced carbamazepine degradation in a wide pH range.

Considering the high cost and complicated recycling process of spent lithium-ion batteries (SLIBs), transforming SLIBs into environment functional materials may be a wise approach. Herein, lithium cobaltite (LCO) cathode powders recovered from SLIBs were used to activate peroxymonosulfate (PMS) for removing carbamazepine (CBZ). The recovered LCO enables a 98.2% removal efficiency of CBZ (2.5mg/L) within 10min, which was effective at a broader pH range (pH = 5.0-11.0). The influence of key factors (initial pH, PMS, and catalyst dosage) and coexisting substances (SO42-, H2PO4-, NO3-, Cl-, HCO3-, and HA) on CBZ degradation were examined in detail. The primary radical species during the degradation of CBZ were proved to be 1O2, SO4-, and.OH that generated from PMS activation initiated by the valence change of Co in recovered LCO. The recovered LCO displayed excellent reusability with about 80.0% removal of CBZ after six cycles. Homogeneous activation of PMS mainly contributed to CBZ degradation in the first run, but the recovered LCO catalyst dominated the heterogeneous activation of PMS for the degradation of CBZ in the second to sixth run. Finally, the CBZ degradation pathways were presented based on the identified intermediates. This research has offered a new strategy of "treating wastes with wastes" to maximize the recycling of electronic wastes to remove emerging pollutants.

Efficient carbamazepine removal from wastewater using a continuous three-dimensional electro-Fenton system at natural pH

This research presents an innovative approach for removing carbamazepine (CBZ), a persistent pharmaceutical contaminant, using a three-dimensional electro-Fenton (TDEF) system. The preliminary phase involved validating the configuration of the TDEF reactor. First, commercial electrodes, metal-mixed oxide as the anode, and stainless steel as the cathode were selected. After that, a third particulate electrode was introduced, working with two options: vineyard biochar and a lab-made conglomerate of perovskite and carbon black. Additionally, two collector systems were evaluated for easy recovery and reuse of this three-dimensional particulate electrode: a thermoplastic tube and a silicone bag. Among the tested configurations, the perovskite conglomerate retained within a silicone bag proved the most effective, achieving a 91 % CBZ removal efficiency at a natural pH (6.5) during a 5-hour batch operation. Considering excellent results, the system's efficacy was confirmed working on fortified tertiary wastewater (FTW) in continuous mode, emphasizing the adaptability to real-world conditions. Moreover, the reusability of microparticles was confirmed for three consecutive cycles, as well as through the characterization study using FTIR, without important modifications in the material after use. Results confirmed the technology's potential for removing CBZ operating with real conditions. Thus, the proposed process represents an alternative treatment to remove CBZ efficiently in a wide range of concentrations from real wastewater in a continuous treatment with a reasonable energy cost (ca. 27 kW/h·gCZP). This novel system represents a cost-effective, straightforward experimental setup suitable for future scaling and industrial applications.

Piezoelectric PMS activation by ZnO embedded polytetrafluoroethylene membrane for efficient degradation of carbamazepine

The wide-spread micropollutants in water have posed severe risks to human health and eco-environment. However, the current treatment techniques generally suffer from low efficiency, high cost and unpractical application feasibility. In this study, a piezoelectric membrane was fabricated by embedding zinc oxide (ZnO) nanorods with several micrometer length into polytetrafluoroethylene nanofiber membrane and applied for the removal of carbamazepine (CBZ) from water. After the sintering, the prepared membrane showed a narrower pore size distribution with the average pore size of ∼1.7 µm. The addition of ZnO nanorods could significantly improve the piezoelectric property of the membrane. During the membrane filtration, the peroxymonosulfate could be effectively activated by the prepared piezoelectric membrane with 2 % ZnO dosage to generate free radicals, achieving about 83.1 % of CBZ from water. According to the radical quenching tests and electron spin-resonance analysis, the hydroxyl radical, sulfate radical, singlet oxygen and superoxide radical greatly participated in the CBZ removal. The CBZ removal efficiency in the US/PMS/PTFE@ZnO-2 system was decreased by 18.2 % after continuous 5-cycle operation, but the performance could be easily renewed by methanol rinsing, demonstrating its attractive reusability and application potential on the efficient removal of micropollutants from water.

Exploring the roles of ascorbic acid/L-cysteine in boosted carbamazepine degradation by biochar-CuFe2O4/Fe2O3/CuO/peroxymonosulfate: Taguchi optimization and mechanistic studies

The present research aimed to improve the efficiency of a novel walnut shell biochar-CuFe2O4/Fe2O3/CuO (BC-CuFeO) nanocomposite for the activation of peroxymonosulfate (PMS) for the degradation of carbamazepine (CBZ), as a recalcitrant organic pollutant. Ascorbic acid (H2A) and L-cysteine (LC) were utilized to significantly increase CBZ removal efficiency in the BC-CuFeO/PMS system. An L-16 Taguchi design was applied to identify the relative significance of the operating parameters for the degradation of CBZ. In addition, both the BC-CuFeO/PMS/H2A and BC-CuFeO/PMS/LC systems demonstrated outstanding CBZ degradation performance in the presence of humic acid, sodium chloride, and sodium nitrate, respectively. The scavenging experiments indicated that 1O2, ·OH, O2•−, and SO4•− were responsible for CBZ degradation in the BC-CuFeO/PMS/H2A system, while O2•−, 1O2, and ·OH contributed to CBZ degradation in the BC-CuFeO/PMS/LC system. Furthermore, the intermediates and pathways of CBZ degradation were determined via Q-TOF-MS analysis, and the potential toxicity of the products was assessed via Toxicity Estimation Software Tool analysis. The practicality of the nanocomposites was also evaluated through the fabrication of catalytic balls and catalytic membranes, followed by the study of their stability for wastewater treatment. In conclusion, this study provides novel and promising PMS activation methods for the efficient removal of recalcitrant pollutants from wastewater.

Evaluación de la eliminación de carbamazepina de aguas residuales de hospital en un biofiltro no convencional y aplicación de electro-oxidación como pretratamiento

Hospital wastewater (HWW) is characterized by a high drug concentration, which can cause endocrine effects and bacterial resistance, among others. For this study, carbamazepine (CBZ) was selected as a contaminant model to evaluate the removal efficiency from HWW of recalcitrant pharmaceuticals in a non conventional biofilter (BF), packed with a mixture of wood chips (Prosopis) and porous rock (pouzzolane). The effect of electro-oxidation (EO) as pre-treatment was assessed as well. A biofilm adapted to the HWW was developed in the BF. The addition of high concentrations of CBZ (1 000 and 10 000 µg/l) to the influent HWW did not affect the removal efficiency of the BF to remove organic matter (73 %) and ammonia nitrogen (99 %), proving that the biomass was not inhibited by the CBZ’s concentration. The BF showed a significant removal of CBZ by adsorption during the start up. The bed filter showed an adsorption capacity of 19.84 µg/g (Co = 10 000 µg/l). After the bed filter saturation operated in steady state, the BF removed by biotransformation 17.2 ± 7.4 % of CBZ which, in terms of concentration (1 551 ± 664 µg/l), is bigger than the concentration in most of the reports for hospital, pharmaceutical and municipal WW effluents, which are between 0.1 and 890 µg/l. By applying electro-oxidation as a pretreatment, the global removal efficiency of CBZ increased to 55 ± 5.96 %. In the hybrid system, the EO biotransformed the CBZ, and in the BF the nitrogen and the COD were removed and showed CBZ desorption.

Piezoelectric-channels in MoS2-embedded polyvinylidene fluoride membrane to activate peroxymonosulfate in membrane filtration for wastewater reuse

The conjugation of membrane filtration (MF) with advanced oxidation process (AOPs) is being considered as an alternative advanced treatment process for the potable reuse of wastewater. Beyond conventional MF/AOPs conjugation, a new downstream MF process with piezoelectric-channels induced piezo-activated peroxymonosulfate (PMS) is herein constructed to deal with antiepileptic carbamazepine (CBZ) pollutants through polyvinylidene fluoride (PVDF) membrane (PVDF-M10). Through a MF process, ca. 93.8% CBZ pollutants can be removed under an ultrasonic-assisted piezo-activation PMS, whereas only 18.3% and 60.2% CBZ can be removed by using pure PVDF membrane under the same condition and PVDF-M10 membrane without ultrasonic-assisted piezo-activation. Even after 9-cycles, CBZ removal efficiency was maintained at 56.4% under this MF process. These superior performances are attributed to the piezoelectric exfoliated-MoS2 nanosheets (E-MoS2) embedded PVDF nanofibers in PVDF-M10 membrane, which lead to rich piezoelectric-channels in the membrane. These piezoelectric-channels not only produced more charges to activate PMS to boost the yield of reactive oxide species (ROS) but also provided an ideal platform for the rapid reaction between CBZ and ROS during MF process. This investigation develops a new MF technique to conjugate piezo-activation of PMS-AOPs for the efficient removal of emerging pollutants for the potable reuse of wastewater.

Fe3O4 decorated with α-cyclodextrin for enhanced peroxymonosulfate(PMS)-activated degradation of PPCPs

In this work, novel Fe3O4@α-CD nanoparticle was synthesized for the catalytic activation of peroxymonosulfate (PMS) towards carbamazepine (CBZ) degradation. The effect of α-CD content, Fe3O4@α-CD dosage and PMS concentration on the catalyst activity were systematically evaluated. The results showed the synergistic effect between α-CD and Fe3O4 can greatly improve the removal efficiency of CBZ in the Fe3O4@α-CD/PMS system. CBZ removal efficiency gained 73.37% in 5 min at pH 7.0 with PMS 1 mM, Fe3O4@α-CD load 0.4 g/L and CBZ 10 μM. The variation in the removal efficiency of different PPCPs under the same conditions mainly ascribed to the adsorption of α-CD and the activation of PMS by Fe3O4 to generate free radicals, in which sulfate radical (SO4·−) and hydroxyl radicals (·OH) was determined as the reactive species in the Fe3O4@α-CD/PMS system. Density functional theory (DFT) calculations was also utilized to optimize the structure of composite and confirmed that the charge distribution mainly concentrate on Fe3O4. As deduced from the LC-MS analysis, the possible CBZ degradation pathways were proposed. CBZ degradation efficiency still reached 54% after three cycle, which indicates that Fe3O4@α-CD catalyst has a good reusability potential and practical applications.

Recent Advancements in the Treatment of Emerging Contaminants Using Activated Persulfate Oxidation Process

Emerging contaminants (ECs) usually refer to pesticides, polycyclic aromatic hydrocarbons (PAHs), dioxins, personal care products, cosmetics, and medications. Due to the strong demand and quick growth of these businesses, the ECs have continuously been found in alarming amounts in groundwater, surface water, and wastewater. These ECs provide a significant non-esthetic threat to the ecosystem as a whole and can cause significant non-esthetic contamination when released into the aquatic environment. The conventional wastewater treatment techniques such as activated sludge, membrane filtration, coagulation, adsorption, and ozonation showed ECs removal performance to a certain extent. In turn, numerous emerging advanced oxidation processes (AOPs), especially activated persulfate oxidation, have garnered a huge amount attention due to their outstanding performance in the remediation of ECs. This article presents a systematic and critical review of electro, sono and thermal activation of persulfate for the treatment of ECs. The effect of key parameters such as electrode materials, solution pH, persulfate concentration, current density, and temperature on electro, sono- and thermal-activated degradation of ECs was discussed. The possible reaction mechanism of ECs degradation was also elucidated in detail. It was closed with a note on the situation now and the future course of electro, sono and thermal activation in ECs degradation applications. Experiments performed in recent studies show that with the aid of persulfate in electro activation, the removal efficiency of chemical oxygen demand can be achieved up to 72.8%. Persulfate activated by sono shows 100% removal efficiency of 1,1,1-trichloroethane and sulfamethoxazole. While for thermal activation of persulfate, 100% removal efficiency of carbamazepine, atrazine and sulfamethazine was achieved. All these vital shreds of evidence are substantial enough to picture the negative impact of ECs on the environment.

Enhancement of carbamazepine removal rate using Tetradesmus obliquus KNUA061 and NaOCl and utilization of the resulting biomass

Pharmaceutical and personal care products (PPCPs) are discharged into receiving water bodies mainly from sewage treatment plants. Due to the inefficient removal in conventional wastewater treatment facilities, PPCPs have become a major concern to aquatic ecosystems, water quality, and public health worldwide since they cause harmful effects on aquatic life and human even at low doses. Among the PPCPs, carbamazepine (CBZ) is one of the most commonly prescribed anticonvulsant drugs and consumed more than 1,000 tons per year. Due to its structural complexity, CBZ is known as recalcitrant compound highly stable during wastewater treatment. Consequently, it has become one of the most frequently detected pharmaceuticals in waste water, surface water, and even drinking water. In this study, Korean indigenous microalgae strains were tested as eco-friendly and cost-effective solutions for CBZ removal. Based on the preliminary biological CBZ degradation tests, Tetradesmus obliquus KNUA061 demonstrating the best CBZ removal rate was selected for further experiments. In order to increase strain KNUA061's CBZ removal efficiency, NaOCl, which is widely accepted in the water purification process, was used as an additional stimulus to induce stress conditions. At around 20 μg L−1 CBZ, addition of 1.0 mg NaOCl resulted in approximately 20% of removal rate increase without suppressing cells growth. Roughly 90% of CBZ remained its original form and the composition of the transformed secondary metabolites was less than 10% during the biodegradation process by the microalga. Based on the results of the antioxidant enzyme activities, degree of lipid oxidation, and amino acid contents, it was concluded that the redox-defence system in microalgal cells may have been activated by the NaOCl treatment. Biomass analysis results showed that higher heating value (HHV) of strain KNUA061 biomass was higher than those of lignocellulosic energy crops suggesting that it could be utilized as a possible renewable energy source. Even though its biodiesel properties were slightly below the international standards due to the high PUFA contents, the biodiesel produced from T. obliquus KNUA061 could be used as a blending resource for transportation fuels. It was also determined that the microalgal biomass has acceptable feasibility as a sustainable dietary supplement feedstock due to its high essential amino acid contents.

Removal of Carbamazepine in Aqueous Solution by CoS2/Fe2+/PMS Process.

Carbamazepine (CBZ), as a typical pharmaceutical and personal care product (PPCP), cannot be efficiently removed by the conventional drinking water and wastewater treatment process. In this work, the CoS2/Fe2+/PMS process was applied for efficient elimination of CBZ. The CBZ removal efficiency of CoS2/Fe2+/PMS was 2.5 times and 23 times higher than that of CoS2/PMS and Fe2+/PMS, respectively. The intensity of DMPO-HO• and DMPO- followed the order of Fe2+/PMS < CoS2/PMS < CoS2/Fe2+/PMS, also suggesting the CoS2/Fe2+/PMS process has the highest oxidation activity. The effects of reaction conditions (e.g., CoS2 dosage, Fe2+ concentration, PMS concentration, initial CBZ concentration, pH, temperature) and water quality parameters (e.g., , , , , , humic acid) on the degradation of CBZ were also studied. Response surface methodology analysis was carried out to obtain the best conditions for the removal of CBZ, which are: Fe2+ = 70 µmol/L, PMS = 240 µmol/L, CoS2 = 0.59 g/L. The sustainability test demonstrated that the repeated use of CoS2 for 8 successive cycles resulted in little function decrease (<10%). These findings suggest that CoS2/Fe2+/PMS may be a promising method for advanced treatment of tailwater from sewage treatment plant.

Determination and degradation of carbamazepine using g-C3N4@CuS nanocomposite as sensitive fluorescence sensor and efficient photocatalyst

• g-C 3 N 4 @CuS nanocomposite was synthesized by thermal polymerization of melamine as a fluorescent sensor. • The nanocomposite was used as a sensor for the sensitive and selective determination of carbamazepine. • Significant factors for maximizing fluorescence response were optimized by Box-Behnken design. • Carbamazepine degradation by g-C 3 N 4 @CuS nanocomposite was investigated. In this study, a new sensor for carbamazepine (CBZ) determination is designed. Graphitic carbon nitride (g-C 3 N 4 ) -coupled with CuS nanoparticles exhibits an intensive fluorescence signal. Upon adding CBZ to the dispersed solution of g-C 3 N 4 @CuS resulted in the fluorescence quenching that can be used as a sensitive and selective chemical sensor for the quantitative determination of the CBZ. The photocatalytic performance of g-C 3 N 4 @CuS via CBZ degradation under visible light was also investigated. The removal efficiency of CBZ due to efficient photocatalytic degradation by g-C 3 N 4 @ CuS was 98.5% under visible light illumination for 5 h. This fluorescence sensor's behavior for quantitative sensing of CBZ was also examined, The effects of significant influencing variables, including pH, buffer types, buffer concentration, and dopant ratio were studied and optimized using response surface methodology (RSM). Under the optimum experimental conditions, the detection limit was 12.61 nM, and the linear range was 0 to 4.23 µM. This sensor showed many advantages, such as sensitivity, good selectivity, nontoxicity, simple operation, and low cost. The results showed the successful application in the determination of CBZ in human serum samples.

Degradation of carbamazepine by high-voltage direct current gas-liquid plasma with the addition of H2O2 and Fe2.

Carbamazepine (CBZ) is a typical psychotropic pharmaceutical which is one of the most commonly detected persistent pharmaceuticals in the environment. The degradation of CBZ in the aqueous solution was studied by a direct current (DC) gas-liquid phase discharge plasma combined with different catalysts (H2O2 or Fe2+) in this study. The concentrations of reactive species (H2O2, O3, and NO3-) and •OH radical yield in the liquid were measured during the discharge process. The various parameters that affect the degradation of CBZ, such as discharge powers, initial concentrations, initial pH values, and addition of catalysts, were investigated. The energy efficiency was 25.2mg·kW-1·h-1 at 35.7W, and the discharge power at 35.7W was selected to achieve the optimal balance on the degradation effect and energy efficiency. Both acidic and alkaline solution conditions were conducive to promoting the degradation of CBZ. Both H2O2 and Fe2+ at low concentration (10-100mg/L of Fe2+, 0.05-2.0mmol/L of H2O2) were observed contributing to the improvement of the CBZ degradation rate, while the promotional effect of CBZ degradation was weakened even inhibition would occur at high concentrations (100-200mg/L of Fe2+, 2.0-5.0mmol/L of H2O2). The degradation rate of CBZ was up to 99.1%, and the total organic carbon (TOC) removal efficiency of CBZ was up to 67.1% in the plasma/Fe2+ (100mg/L) system at 48min, which suggested that high degradation rate and mineralization efficiency on CBZ could be achieved by employing Fe2+ as a catalyst. Based on the intermediate products identified by Ultra Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS), the possible degradation pathways were proposed. Finally, the growth inhibition assay with Escherichia coli (E. coli) showed that the toxicity of plasma/Fe2+-treated CBZ solution decreased and a relatively low solution toxicity could be achieved. Thus, the plasma/catalyst could be an effective technology for the degradation of pharmaceuticals in aqueous solutions.

The role of iron-doped g-C3N4 heterogeneous catalysts in Fenton-like process investigated by experiment and theoretical simulation

The Fenton-like process provides a promising method to produce reactive radicals for the degradation of refractory organic pollutants in environmental remediation. In this study, the iron-doped g-C3N4 (CNF) coupled with H2O2 was applied to enhance the degradation of carbamazepine (CBZ). And the role of CNF was elucidated by experiment and density functional theory (DFT) calculations. The largest CBZ removal efficiency of 99.02% was achieved in acid condition (pH = 3) with the addition of 0.5 g/L 14% CNF and 50 mM H2O2. Thirteen intermediates were identified based on high performance liquid chromatography coupled with mass spectrometer (LCMS) and DFT calculations. The degradation products of CBZ were mainly protein-like materials with a low humification degree. During the degradation process, H2O2 was preferentially adsorbed on the active Fe-O site of CNF by hydrogen bonding, hence the promoted electron transfer from H2O2 to Fe(III) contributed to the generation of Fe(II). Certain deformation of H2O2 was observed that the O-O bond length increased to about 1.51 Å. As a result, large amounts of radical species (·OH) were generated by H2O2 decomposition, which was responsible for attacking the CBZ molecules and proceeding the degradation reaction.

Fe-Cu binary oxide loaded zeolite as heterogeneous Fenton catalyst for degradation of carbamazepine at near-neutral pH

In this study, Fe-Cu binary oxide was loaded on zeolite (Fe/Cu/zeolite) to be used as heterogeneous Fenton catalyst, and the catalytic degradation of carbamazepine (CBZ) were optimized at near-neutral pH. The results showed that the Fe and Cu oxide, mainly Fe2O3, Fe3O4, and CuO nanoparticles, were uniformly distributed on the surface of zeolite particles. Under the optimized conditions, Fe/Cu/zeolite could completely degrade CBZ when initial pH ranged from 3 to 7, and the removal efficiency of CBZ still remained above 74% even though the initial pH increased to near 10. After 8 times' repeated use, the Fe/Cu/zeolite exhibited an over 95% removal efficiency of CBZ. The hydroxyl radicals (•OH) were verified to be the main active oxidants by quenching experiments and ESR testing. The XPS of the materials revealed that the high catalytic efficiency was attributed to the synergistic effect of Fe(III)/Fe(II) and Cu(II)/Cu(I) redox cycles. This catalyst can be used for the efficient degradation of organic pollutants in heterogeneous Fenton systems.

Preparation of millimeter-scale MIL-53(Fe)@polyethersulfone balls to optimize photo-Fenton process

Fe-MOFs are expected to be the candidates for heterogeneous Fenton catalysts due to their porous channel and high specific surface area feature. However because of their small size they are difficult to recycle, and the low Fe(II) concentration make them low efficiency for H2O2 activation. Herein, we report millimeter-scale polymer anchored porous MIL-53(Fe) composite balls with highly improved Fenton-like performance and easy recycling for the elimination of carbamazepine. It is prepared via MIL-polyethersulfone dope and solvent/water exchange method with organic ligand substitution strategy that affording SO and CO mixed-coordination. The degradation rate constant for MIL-53(Fe)@PES is 4 times that of pure MIL-53(Fe), while the degradation rate constant of photo Fenton is 79 times of dark one. The composite balls can be recovered by simple precipitation process and the removal efficiency of carbamazepine still reach 80% after 5 cycles of regeneration. The mechanism of photo-Fenton degradation of carbamazepine were proposed.

Removal of carbamazepine (CBZ) from synthetic urine by FeOCl-coated ceramic membrane: The study of kinetic modeling

Pharmaceuticals residual in the human urine are difficult to remove in the conventional wastewater treatment plants (WWTPs) and cause a serious environmental issue. Hence, we developed a FeOCl-coated ceramic membrane coupled with the Photo-Fenton system for direct removing pharmaceuticals from human urine. In this study, the removal efficiency of CBZ from hydrolyzed urine was higher than that from fresh urine. The apparent rate constant (kobs) of CBZ from hydrolyzed urine could reach 0.0163 min−1, 1.39 times higher than that from fresh urine (0.0117 min−1). Interestingly, this performance was not caused by the solution pH. The effect of substrates in the hydrolyzed urine was further explored, verifying that ammonia played a key role in quenching the hydroxyl radicals (•OH). The nitrogen reactive species (RNS) were then generated, resulting in that the kobs of CBZ from hydrolyzed urine sharply decreased, compared with the phosphate buffer solution (pH = 9). The quenching experiment was further to confirm that the RNS was primary reactive oxide species in the hydrolyzed urine. Based on the data of kinetic study and reported previously, competitive kinetic modeling was set up, which could successfully predict the removal efficiency of pharmaceuticals from hydrolyzed urine. The study provided a new method for removing pharmaceuticals residual in human urine and the kinetic modeling could be widely used to predict the removal of pharmaceuticals from human urine.