Management of acute carbamazepine poisoning:A narrative review

Standard management protocols are lacking and specific antidotes are unavailable for acute carbamazepine(CBZ)poisoning.The objective of this review is to provide currently available information on acute CBZ poisoning,including its management,by describing and summarizing various therapeutic methods for its treatment according to previously published studies.Several treatment methods for CBZ poisoning will be briefly introduced,their advantages and disadvantages will be analyzed and compared,and suggestions for the clinical treatment of CBZ poisoning will be provided.A literature search was performed in various English and Chinese databases.In addition,the reference lists of identified articles were screened for additional relevant studies,including non-indexed reports.Nonpeer-reviewed sources were also included.In the present review,154 articles met the inclusion criteria including case reports,case series,descriptive cohorts,pharmacokinetic studies,and in vitro studies.Data on 67 patients,including 4 fatalities,were reviewed.Based on the summary of cases reported in the included articles,the cure rate of CBZ poisoning after symptomatic treatment was 82%and the efficiency of hemoperfusion was 58.2%.Based on the literature review,CBZ is moderately dialyzable and the recommendation for CBZ poisoning is supportive management and gastric lavage.In severe cases,extracorporeal treatment is recommended,with hemodialysis as the first choice.

Intranasal administration of carbamazepine-loaded carboxymethyl chitosan nanoparticles for drug delivery to the brain

Epilepsy is considered as a common and diverse set of chronic neurological disorders and its symptoms can be controlled by antiepileptic drugs(AEDs). The presence of p-glycoprotein and multi-drug resistance transporters in the blood-brain barrier could prevent the entry of AEDs into the brain, causing drug resistant epilepsy. To overcome this problem, we propose using carboxymethyl chitosan nanoparticles as a carrier to deliver carbamazepine(CBZ) intranasally with the purpose to bypass the blood-brain barrier thus to enhance the brain drug concentration and the treatment efficacy. Results so far indicate that the developed CBZNPs have small particle size(218.76 ± 2.41 nm) with high drug loading(around 35%) and high entrapment efficiency(around 80%). The in vitro release profiles of CBZ from the NPs are in accordance with the Korsmeyer-peppas model. The in vivo results show that both encapsulation of CBZ in nanoparticles and the nasal route determined the enhancement of the drug bioavailability and brain targeting characteristics.

Carbamazepine solubility enhancement in tandem with swellable polymer osmotic pump tablet: A promising approach for extended delivery of poorly water-soluble drugs

Elementary osmotic pump(EOP)is a unique extended release(ER)drug delivery system based on the principle of osmosis.It has the ability to minimize the amount of the drug,accumulation and fluctuation in drug level during chronic uses.Carbamazepine(CBZ),a poorly water-soluble antiepileptic drug,has serious side effects on overdoses and chronic uses.The aim of the present study was to design a new EOP tablet of CBZ containing a solubility enhancers and swellable polymer to reduce its side effects and enhance the patient compliance.Firstly,a combination of solubilizing carriers was selected to improve the dissolution of the slightly soluble drug.Then,designing the new EOP tablet and investigating the effect of different variables of core and coat formulations on drug release behavior by single parameter optimization and by Taguchi orthogonal design with analysis of variance(ANOVA),respectively.The results showed that CBZ solubility was successfully enhanced by a minimum amount of combined polyvinyl pyrrolidone(PVP K30)and sodium lauryl sulfate(SLS).The plasticizer amount and molecular weight(MW)together with the osmotic agent amount directly affect the release rate whereas the swellable polymer amount and viscosity together with the semi-permeable membrane(SPM)thickness inversely influence the release rate.In addition,the tendency of following zero order kinetics was mainly affected by the coat components rather than those of the core.Further,orifice size does not have any significant effect on the release behavior within the range of 0.1 mm to 0.8 mm.In this study we report the successful formulation of CBZ-EOP tablets,which were similar to the marketed product Tegretol CR 200 and able to satisfy the USP criterion limits and to deliver about 80%of CBZ at a rate of approximately zero order for up to 12 h.

Purslane protects against the reproductive toxicity of carbamazepine treatment in pilocarpine-induced epilepsy model

Objective: To investigate the protective effect of purslane with carbamazepine treatment.Methods: Male albino rats were modulated by pilocarpine to be epileptic.Both the normal and epileptic rats were treated with carbamazepine, purslane or carbamazepine plus purslane, with separate non-treated control groups for both normal and epileptic rats.Results: The data from the current study showed amelioration in amino acids and electrolytes in the epileptic rats treated with purslane and carbamazepine, with this amelioration occurring without decreasing the fertility hormones(testosterone,dehydroepiandrosterone, luteinizing hormone and follicle stimulating hormone).Purslane treatments also prevented the increase in estradiol.The decreased epileptic hyperexcitability with purslane was evidenced by decreased glial fibrillary acidic protein and lipid peroxidation.Conclusions: Natural products like purslane could be used with the highly repetitive drugs like carbamazepine to reduce or prevent its side-effects.

Formulation of unidirectional release buccal patches of carbamazepine and study of permeation through porcine buccal mucosa

Objective:To achieve transbuccal release of carbamazepine by loading in unidirectional release mucoadhesive buccal patches.Methods:Buccal patches of carbamazepine with unidirectional drug release were prepared using hydroxypropyl methyl cellulose,polyvinyl alcohol,polyvinyl pyrrolidone and ethyl cellulose by solvent casting method.Water impermeable backing layer(Pidilite?Biaxially-oriented polypropylene film)of patches provided unidirectional drug release.They were evaluated for thickness,mass uniformity,surface pH and folding endurance.Six formulations FA2,FA8,FA10,FBI,FB14 and FB16(folding endurance above 250)were evaluated further for swelling studies,ex vivo mucoadhesive strength,ex vivo mucoadhesion time,in vitro drug release,ex vivo permeation,accelerated stability studies and FTIR and XRD spectral studies.Results:The ex vivo mucoadhesion time of patches ranged between 109 min(FA10)to 126 min(FB14).The ex vivo mucoadhesive force was in the range of 0.278 lo 0.479 kg/m/s.The in vitro drug release studies revealed that formulation FA8 released 84%and FB16 released 99.01%of drug in140 min.Conclusions:The prepared unidirectional buccal patches of carbamazepine provided a maximum drug release within specified mucoadhesion period and it indicates a potential alternative drug delivery system for systemic denvery of carbamazepine.

Solubility measurement and thermodynamic modeling of carbamazepine(form III)in five pure solvents at various temperatures

In this work,the solubilities of carbamazepine(CBZ)(form III)in ethyl acetate,methyl acetate,ethylene glycol,chloroform and cyclohexylamine were determined by laser monitoring techniques at pressure above sea level,and the solubility data of CBZ(form III)in different pure solvents were fitted by the Modified Apelblat model andλh model.The result shows that the solubility of CBZ(form III)in five solvents increases as temperature rises,and the solubility in chloroform was the largest.The experimental solubility values of CBZ(form III)in ethyl acetate,methyl acetate,chloroform and cyclohexylamine were in better agreement with the simulated fitting values of theλh model.For ethylene glycol,the r value was much larger than the other four solvents,and it can be seen from theλh model that ethylene glycol was closer to the ideal solution system than the other four solvents.

Effects of topiramate and carbamazepine on thyroid hormone level in adults with epilepsy

BACKGROUND: It has been demonstrated that traditional antiepileptics, such as phenytoin, carbamazepine (CBZ), phenobarbital, etc., can result in the decrease of thyroid hormone of epileptic patients. However, there is still no sufficient evidence for the studies about the effect of new-type antiepileptics, such as topiramate (TPM), on thyroid hormones. OBJECTIVE: To observe the effects of TPM and CBZ on the level of thyroid hormones in serum of adults with epilepsy. DESIGN: A comparative observation. SETTING: Department of Neurology, Sichuan Provincial People's Hospital. PARTICIPANTS: Totally 100 outpatients or inpatients newly diagnosed to have epilepsy were selected from the Department of Neurology, Sichuan Provincial People's Hospital from July 2003 to August 2005, including 60 males and 40 females, aged 18-70 years. All the patients were accorded with the standard for the classification of epilepsy set by International League Against Epilepsy (ILAE) in 1981; Had been Informed and agreed with the detection; Had no history of thyroid gland disease; Had not taken any drugs could affect the thyroid function. Meanwhile, 40 adult healthy examinees were selected from our hospital as the control group, including 24 males and 16 females, aged 18-65 years. METHODS: ① The 100 epileptic patients were randomly divided into TPM group (n =50) and CBZ group (n =50), and they were treated with TPM (Xian-Janssen Pharmaceutical, Ltd.; Batch number: 03AS032, Norm: 25 mg/tablet) and CBZ (Shanghai Sunve Pharmaceutical Co., Ltd.; Batch number: 030201, Norm: 100 mg/tablet) respectively. The initial dosage of TPM was 25 mg per day, increased by 25 mg every week, the objective dosage of 100-200 mg per day was maintained when the symptoms were satisfactorily controlled. The dosage of CBZ was 6-8 mg/kg per day. All the patients were administrated for 1 year. ② The serum levels of total thyroxine (TT4), free thyroxine (FT4), total triiodothyronine (TT3), free triiodothyronine (FT3) and thyroid stimulating hormone (TSH) in the epileptic patients were detected by means of chemiluminescence before treatment and at 3, 6 and 12 months after treatment respectively. ③Standards for judging curative effects: Controlled by without seizure, the frequency of seizure reduced by ≥ 75% was taken as significant effect, reduced by 50%-74% as effect, and reduced by < 49% as invalid, whereas increased by more than 20% was taken as aggravation. ④ The intergroup and intragroup differences of the measurement data were compared by the analysis of variance and paired t test respectively. MAIN OUTCOME MEASURES: Serum levels of thyroid hormones before treatment and at different time points after treatment of TPM and CBZ. RESULTS: All the 100 epileptic patients and 40 healthy subjects were involved in the analysis of results. ① Changes of serum levels of thyroid hormones: The serum levels of TT3, TT4, FT3, FT4 and TSH were close between the epileptic patients and normal subjects before treatment (P > 0.05). In the CBZ group, the serum levels of FT4 at 3, 6 and 12 months after treatment [(16.87±3.77), (16.34±3.98) , (16.97±3.95) pmol/L] were significantly decreased as compared with those before treatment [(18.00±3.54) pmol/L, t =2.74, 3.50, 2.26, P < 0.05]; The levels of TT3 at 3, 6 and 12 months [(2.09±0.54), (1.99±0.49), (1.84±0.47) nmol/L] were significantly decreased as compared with those before treatment [(2.22±0.63) nmol/L, t =2.73, 2.78, 5.18, P < 0.05]. The levels of TT3 at 6 and 12 months [(109.65±23.98), (107.72±23.90) nmol/L] were significantly decreased as compared with those before treatment [(118.98±28.48) nmol/L, t =3.11, 3.30, P < 0.05]. TT4 level in serum at 3 months and the levels of FT3 and TSH at each time point after CBZ treatment had no obvious changes as compared with those before treatment (P > 0.05). In the TPM group, the levels of thyroid hormones at each time point had no obvious changes as compared with those before treatment (P > 0.05). ② Curative effects: Of the 100 epileptic patients, it was controlled in 12 cases, significantly effective in 30 cases, effective in 39 cases and invalid in 19 cases, the total effective rate was 81% (81/100). CONCLUSION: CBZ treatment can lead to the decreases of thyroid hormones in adult epileptic patients. Epilepsy itself and TPM treatment cannot change the thyroid hormones in adult epileptic patients, which suggests that TPM treatment is safer for the thyroid function of adult epileptic patients.

A Study on the Degradation of Carbamazepine and Ibuprofen by TiO₂&ZnO Photocatalysis upon UV/Visible-Light Irradiation

The degradation of carbamazepine (CBZ) and ibuprofen (IBP) in aqueous matrices was investigated by TiO2 and ZnO photocatalysis initiated by UV-A and visible-light irradiation. Emphasis was given on the effect of operating parameters on the degradation effectiveness, such as catalyst type and loading (50 - 500 mg/L), initial drug concentration (10, 40, 80 mg/L) and wavelength of irradiation (200 - 600 nm). In an effort to understand the photocatalytic pathway for CBZ and IBP removal in terms of primary oxidants, the contribution of HO· was evaluated. With this scope, the radical-mediated process was suppressed by addition of an alcohol scavenger, isopropanol, (i-PrOH), described as the best free hydroxyl radical quencher. The photodegradation rate of the pharmaceuticals was monitored by high performance liquid chromatography (HPLC). According to the results, visible-light exposure, at λexc > 390 nm, takes place as a pure photocatalytic degradation reaction for both compounds. IBP was found to have overall high conversion rates, compared to CBZ. IBP oxidized fast under photocatalytic conditions, regardless the adverse effect of the increase of initial drug concentration, or low catalyst load, irradiation upon visible-light, by either titania or zinc oxide. Finally, addition of isopropanol showed a significant inhibition effect on the CBZ degradation, taken as an evidence of a solution-phase mechanism. In the case though of IBP degradation, the hole mechanism may be prevailing, suggested by the negligible effect upon addition of isopropanol indicating a direct electron transfer between holes (h+) and surface-bound IBP molecules. A plausible mechanism of IBP and CBZ photocatalysis was proposed and described.

Preparation and evaluation of transnasal microemulsion of carbamazepine

The objective of this study was to develop novel transanasl microemulsion containing carbamazepine for treatment of epilepsy.Oleic acid was selected as oil while Tween 80 and propylene glycol were selected as surfactant and cosurfactant respectively based on solubility results.Optimized ratio of Tween 80:propylene glycol was selected after developing pseudoternary phase diagrams for different ratio and microemulsions were prepared.The prepared microemulsions were evaluated for globule size,viscosity,pH,conductivity and%transmittance.Exvivo diffusion study for optimized microemulsion was performed through sheep nasal mucosa wherein diffusion flux and permeability coefficients were determined.Further pharmacodynamic performance was evaluated in rats by electrically induced seizures.It was found that optimized microemulsion was stable and transparent with average globule size of 190 nm and diffusion flux of 75.77 mg cm
2 min
1 and showed no toxicity during histopathological evaluation on sheep nasal mucosa.Pharmacodynamic evaluation also indicated lesser intensity of seizures in rats treated with optimized formulation in comparison to rats treated with oral carbamazepine microemulsion and nasal carbamazepine solution which suggested carbamazepine transnasal delivery system as an effective alternate therapy for treatment of epilepsy.

On-Line Photoinduced Fluorescence for Carbamazepine Determination after Multivariate Optimization

This work presents a simple and sensitive flow injection fluorimetric method for the determination of carbamazepine (CBZ) in pharmaceutical samples. It is based on the fluorescence signal measurement of the product generated by photoinduced (λex = 251 nm;λem = 434 nm) using a flow injection manifold containing an online homemade photoreactor. In order to optimize the experimental setup, the variable conditions were studied using a multivariate optimization method, thus finding the set of optimum parameters according to the evaluated responses (sensitivity and sampling frequency) and minimizing the number of experiments performed. Under optimal experimental conditions, linear relationship with good correlation coefficient (0.9956) was found between the fluorescence intensity and CBZ concentration in the range of 0.13 - 40 μg·mL-1. The limit of detection was 0.04 μg·mL-1. The precision of the method was satisfactory;the values of relative standard deviations were better than 4.36%. The proposed method was validated and successfully applied to the determination of CBZ in pharmaceuticals with good accuracy;being the recovery values from 89.45% - 112.20%.

An Ultra-sensitive LC Method for the Simultaneous Determination of Paracetamol, Carbamazepine, Losartan and Ciprofloxacin in Bulk Drug, Pharmaceutical Formulation and Human Serum by Programming the Detector

An ultra-sensitive LC method for the simultaneous quantitation of paracetamol, carbamazepine, losartan and ciprofloxacin have been developed and validated following the ICH guidelines at isobestic point and by programming the detector at individual wavelength of each component. The components were eluted by 50:50 v/v acetonitrile-water (pH 3.0) using a Bondapak, C18 (10 μm, 25 × 0.46 cm) column at flow rate of 1.0 mL·min-1 with detection wavelength 240 nm at isobestic point and 245, 230, 206 and 272 nm for paracetamol, carbamazepine, losartan potassium and ciprofloxacin respectively by programming the detector. Linearity was found to be 0.5 - 24, 0.25 - 8.0, 0.4 - 12 and 0.75 - 10 μg·mL-1 (R2 > 0.999) with detection limits 99, 20, 30 and 6.0 ng·mL-1 respectively. Comparison study with time program method showed more sensitivity with calibration range of 0.4 - 12, 0.2 - 6.0, 0.1 - 3.0 and 0.25 - 8.0 μg·mL-1 (R2 > 0.999) and LOD values 29, 11, 2.0 and 5.0 ng·mL-1 respectively. Percent recoveries >98.37% from pharmaceutical formulation and human serum samples and RSD 2% for inter-day and intra-day assay were obtained. The method was found to be robust and can be successfully applied for the determination of studied drugs in, pharmaceutical formulations and human serum without interference of excipients or endogenous components of serum.

Carbamazepine Induced Ebstein-Barr Virus Reactivation: A Rare Manifestation of Anticonvulsant Hypersensitivity Syndrome

Carbamazepine (CBZ) is an antiepileptic drug which has multiple mechanisms of action including stabilization of the inactivated stage of the voltage-gated sodium channels, potentiating gamma-amino butyric acid (GABA) receptors as a GABA antagonist, as well as the serotonin releasing affect. It is effective in neuropathic pain syndromes such as post-herpetic neuralgia and trigeminal neuralgia, as well as epilepsy. We presented a 29-year-old female patient with the diagnosis of trigeminal neuralgia (TN) who experienced a reactivation of the latent Ebstein-Barr Virus (EBV) infection in terms of anticonvulsant hypersensitivity syndrome after CBZ use, who gave her approval to publish her data. Since the clinical and serological findings of EBV re-infection resolved after the discontinuation of the drug, this clinical and serological manifestation was attributed to CBZ. Since common side-effects of CBZ are drowsiness, dizziness, headaches, skin reactions, cognitive dysfunctions, we reported an activation of EBV infection due to CBZ consumption as a rare side-effect of the drug.

Rapid Degrading Carbamazepine in a Novel Advanced Oxidation Process of Bisulfite Activated by Lithium Cobaltate Recovered from Spent Lithium-ion Battery

Maximizing the sustainable recycling of spent lithium-ion batteries(LIBs)shows economic and environmental significance.This study recovered lithium cobaltate(LiCoO_(2),LCO)from spent LIBs cathode powder.The recovered LCO was then combined with NaHSO_(3)to remove refractory organic pollutants of carbamazepine(CBZ)in water.The degradation of CBZ reached 80.0%within 60 min,by 1O_(2),SO_(4),OH and O_(2)^(-)generated in the LCO/NaHSO_(3)reaction.The electron transfer between Co(III)and Co(II)was beneficial to the generation of free radicals.The LCO/NaHSO_(3)degraded CBZ effectively in both secondary outlet water and tap water.However,high concentrations of inorganic ions(Cl^(−),HCO_(3)^(-),HPO_(4)^(2-),SO_(2)−4,NO_(3)^(-))and natural organic matter(humic acid,HA)could inhibit the degradation of CBZ.After three cycles,the stability of the LCO/NaHSO_(3)system was demonstrated by the maintained high efficiency in the degradation of CBZ.The obtained data indicate that the LCO/NaHSO_(3)system holds great application potential in the field of advanced oxidation degradation of pollutants.

Meta-analysis and sequential analysis of acupuncture compared to carbamazepine in the treatment of trigeminal neuralgia

BACKGROUND In this randomized controlled trial(RCT)comparing current acupuncture with carbamazepine for trigeminal neuralgia,meta-and sequential analyses were utilized.AIM To guide clinical decision making regarding the treatment of trigeminal neuralgia with carbamazepine.METHODS The RCT literature on needle comparison was searched in various Chinese biomedical databases including Chinese Biomedical Literature Database,Wanfang Data,VIP Database,as well as international databases such as Excerpt Medica Database,Cochrane Library,PubMed,and Web of Science,along with related clinical registration platforms such as World Health Organization International Clinical Trial Registry Platform,ChiCTR,and Clinical Trials up to 1 April 2020.Risk of bias was evaluated using the Cochrane Collaborative Risk Bias tool,primary outcome measures(pain reduction)were analyzed using STATA metaanalysis,outcome measures were analyzed using trial sequential analysis 0.9.5.10 Beta sequential analysis,GRADE was used to assess the evidence,and adverse reactions were documented.RESULTS This study analyzed 16 RCTs with a total of 1231 participants.The meta-analysis revealed a statistically significant difference in pain reduction between acupuncture and carbamazepine[standardized mean difference(SMD)=1.47;95%confidence interval(CI):0.99-1.95],although the quality of evidence was deemed to be of extremely low quality.Cumulative meta-analysis based on the year of publication indicated that carbamazepine treatment first demonstrated a statistically significant difference in pain reduction in 2014 and remained relatively stable over time[SMD=1.84;95%CI:0.22-3.47].Additionally,the number of adverse events associated with acupuncture was significantly lower compared to carbamazepine.CONCLUSION Acupuncture for trigeminal neuralgia is better than analgesia and safer than carbamazepine;however,firm conclusions still require a high-quality,multicenter,large-sample RCT to confirm these findings.

Performance and mechanism of carbamazepine removal by FeS-S_(2)O_(8)^(2–)process:experimental investigation and DFT calculations

As persulfate(S_(2)O_(8)^(2-))is being increasingly used as an alternative oxidizing agent,developing lowcost and eco-friendly catalysts for efficient S_(2)O_(8)^(2-)activation is potentially useful for the treatment of wastewater containing refractory organic pollutant.In this study,the degradative features and mechanisms of carbamazepine(CBZ)were systematically investigated in a novel FeS-S_(2)O_(8)^(2-)process under near-neutral conditions.The results exhibited that CBZ can be effectively eliminated by the FeS-S_(2)O_(8)^(2-)process and the optimal conditions were:250 mg/L FeS,0.5 mmol/L S_(2)O_(8)^(2-),and pH=6.0.The existence of Cl^(−)(1 and 50 mmol/L)has little influence on the CBZ elimination,while both HCO_(3)^(−) and HPO_(4)^(2−)(1 and 50 mmol/L)significantly suppressed the CBZ removal in the FeS-S_(2)O_(8)^(2-)process.CBZ could be degraded via a radical mechanism in the FeS-S_(2)O_(8)^(2-)process,the working radical species(i.e.,SO_(4)•−and•OH)were efficiently formed via the promoted decomposition of S_(2)O_(8)^(2-)by the surface Fe2+on the FeS and the dissolved ferrous ions in solution.Based on the identified oxidized products and Fukui index calculations,a possible degradation pathway of CBZ was speculated.More importantly,a two-stage oxidation mechanism of CBZ elimination was speculated in the FeS-S_(2)O_(8)^(2-)process,the activation of S_(2)O_(8)^(2-)by the surface-active Fe(II)of FeS dominated in the initial 5 min,while homogeneous oxidation reactions played more essential parts than others in the following reaction stage(5–60 min).Overall,this study demonstrated that the FeS-S_(2)O_(8)^(2-)process is capable of removing CBZ from water efficiently.

Biosorption of clofibric acid and carbamazepine in aqueous solution by agricultural waste rice straw

Due to their widespread use, clofibric acid （CA） and carbamazepine （CBZ） have been frequently detected simultaneously at relatively high concentrations in aquatic environments. In this study, agricultural waste rice straw was employed as a potentially low-cost, effective and easy-to-operate biosorbent （RSB） to remove CA and CBZ. The adsorption of both pharmaceuticals followed pseudo second-order kinetics, and intraparticle diffusion was an important rate-limiting step. The adsorption isotherms of both drugs were fit well with Freundlich model. The adsorption of CA onto RSB was exothermic and was more likely to be dominated by physical processes, while the adsorption of CBZ was endothermic. Solution pH was determined to be the most important factor for CA adsorption, such that the adsorption capacity of CA onto RSB increased with the decline of solution pH. In the lower range of solution pH below 3. l, the CA removal efficiency was enhanced with the increase of biosorbent dosage. The CBZ removal efficiency was enhanced with the increase of RSB dosage without pH control. The maximum adsorption capacities were 126.3 mg/g for CA and 40.0 mg/g for CBZ.

In situ construction of Z-scheme FeS_(2)/Fe_(2)O_(3) photocatalyst via structural transformation of pyrite for photocatalytic degradation of carbamazepine and the synergistic reduction of Cr(Ⅵ)

Pyrite is the most abundant sulfide semiconductor mineral with excellent optical properties.However,few reports have investigated its photocatalytic activity because of the low photogenerated carrier separation efficiency.In this work,a Z-scheme FeS_(2)/Fe_(2)O_(3)composite photocatalyst was fabricated in situ via structural transformation of pyrite through heat treatment.A remarkably enhanced photocatalytic performance was observed over the FeS_(2)/Fe_(2)O_(3)composite photocatalyst.Compared with the pristine pyrite,the degradation efficiency of carbamazepine(CBZ)reached 65%at the added hexavalent chromium(Cr(Ⅵ))concentration of 20 mg/L and the Cr(Ⅵ)was nearly completely reduced in the mixed system using FeS_(2)/Fe_(2)O_(3)within 30 min under simulated solar light irradiation.The enhanced photocatalytic activity can be attributed to the efficient separation and transfer of photogenerated carriers in the FeS_(2)/Fe_(2)O_(3)composite photocatalyst.This facilitated the generation of·OH,hole(h^(+))and·O_(2)^(-)species,which participated in the photocatalytic reaction with CBZ.Based on the measurement of the active species and electric properties,a Z-scheme electron transfer pathway was proposed for the FeS_(2)/Fe_(2)O_(3)composite photocatalyst.This work broadens the application potential of pyrite in environmental remediation.

Carbamazepine degradation by heterogeneous activation of peroxymonosulfate with lanthanum cobaltite perovskite:Performance,mechanism and toxicity

The widely used carbamazepine(CBZ)is one of the most persistent pharmaceuticals and suffers insufficient removal efficiency by conventional wastewater treatment.A synthesized Co-based perovskite(LaCoO3)was used to activate peroxymonosulfate(PMS)in order to degrade CBZ.Results showed that LaCoO3 exhibited an excellent performance in PMS activation and CBZ degradation at neutral pH,with low cobalt leaching.The results of FT-IR and XPS verified the high structurally and chemically stability of LaCoO3 in PMS activation.Electron spin resonance(ESR)analysis suggested the generation of radical species,such as sulfate radicals(SO4·-)and hydroxyl radicals(·OH).Radical quenching experiments further revealed the responsibility of SO4·-as the dominant oxidant for CBZ oxidation.Ten products were detected via the oxidation of CBZ,with the olefinic double bond attacked by SO4·-as the initial step.Hydroxylation,hydrolysis,cyclization and dehydration were involved along the transformation of CBZ.The toxicity of CBZ solution was significantly reduced after treating by PMS/LaCoO3.

Characterization and biodegradation kinetics of a new cold-adapted carbamazepine-degrading bacterium, Pseudomonas sp. CBZ-4

Carbamazepine is frequently detected in waters and hardly eliminated during conventional wastewater treatment processes due to its complicated chemical structure and resistance to biodegradation. A carbamazepine-degrading bacterium named CBZ-4 was isolated at a low temperature （10℃） from activated sludge in a municipal wastewater treatment plant. Strain CBZ-4, which can use carbamazepine as its sole source of carbon and energy, was identified as Pseudomonas sp. by the 16S rRNA gene sequence. The composition and percentage of fatty acids, which can reveal the cold-adaptation mechanism of strain CBZ-4, were determined. Strain CBZ-4 can effectively degrade carbamazepine at optimal conditions： pH 7.0, 10℃, 150 r/min rotation speed, and 13% inoculation volume. The average removal rate of carbamazepine was 46.6% after 144 hr of incubation. The biodegradation kinetics of carbamazepine by CBZ-4 was fitted via the Monod model. Vmax and Ks were found to be 0.0094 hr^-1 and 32.5 mg/L, respectively.

Construction of high-efficient visible photoelectrocatalytic system for carbamazepine degradation:Kinetics,degradation pathway and mechanism

This study aimed to construct a photoelectrocatalytic(PEC)reaction system based on the self-made reduced TiO_(2) NTAs(r-TNAs)photoanode and activated carbon/Polytetrafluoroethylene(AC/PTFE)cathode.It would be observed clearly that the degradation rate constant of carbamazepine(CBZ)over r-TNAs(photoanode)-AC/PTFE(cathode)PEC system(0.04961 min^(-1))was even higher than that of r-TNAs(photoanode)-Pt(cathode)PEC system(0.04602 min^(-1))with the assistance of visible light irradiation and+0.4 V external potential.Besides,in order to obtain optimized conditions,the influence of key parameters such as pH value,electric current density and electrolyte concentration were studied.Most impo rtantly,photoelectrochemical(PECH)properties,reactive oxide species contribution.OH formation rate and CBZ degradation pathway were determined.The results illustrated that the excellent PEC degradation performance depended on the excellent photocatalytic property of r-TNAs photoanode and electron transfer prope rty of photoelectrodes in r-TNAs(photoanode)-AC/PTFE(cathode)PEC system.Therefo re,the study demonstrated that the r-TNAs(photoanode)-AC/PTFE(cathode)PEC system could be expected to replace metal-catalyzed cathodes depending on its excellent PEC performance activity and low cost as well as the reaction system possessed objective and practical application prospect.