Atenolol Research Articles

Enhancing photocatalytic degradation of beta-blocker drugs using TiO2 NPs/zeolite and ZnO NPs/zeolite as photocatalysts: optimization and kinetic investigations

This study delves into the development and optimization of photocatalysts, namely ZnO NPs/Zeolite and TiO2 NPs/Zeolite, for the degradation of two beta-blocker drugs, including Atenolol (AT) and Metoprolol (ME). Structural and morphological analyses of the catalysts were conducted, and optimal conditions for drug degradation were determined using a Box-Behnken design. The results underscored the significant influence of pH, catalyst amount, drug concentration, and H2O2 concentration on the degradation process using ZnO NPs/Zeolite and TiO2 NPs/Zeolite as the catalysts. The optimal values of drug concentration, pH, catalyst amount, and H2O2 concentration, were determined to be 32 and 33 mg L−1, 4.2 and 4.6, 428 and 386 mg, and 2.6 and 2.5 mM utilizing ZnO NPs/Zeolite and TiO2 NPs/Zeolite as the catalyst, respectively. Following optimization, the kinetics of the photodegradation process were investigated, revealing promising rates and half-life times for both drugs. The pseudo-first-order rate constants for Atenolol and Metoprolol degradation were 0.064 ± 0.007 min−1 and 0.065 ± 0.004 min−1 with ZnO NPs/Zeolite and 0.071 ± 0.007 min−1 and 0.071 ± 0.006 min−1 with TiO2 NPs/Zeolite, respectively. Furthermore, ZnO NPs/Zeolite and TiO2 NPs/Zeolite demonstrated reusability up to 5 and 6 times, respectively, without significant activity loss. The comparative analysis highlighted the superior performance of TiO2 NPs/Zeolite over ZnO NPs/Zeolite, attributed to lower consumption, shorter degradation time, improved reusability, and compatibility with milder acidic conditions. Overall, the research showcases the potential of ZnO NPs/Zeolite and TiO2 NPs/Zeolite as an effective and sustainable solution for removing Metoprolol and Atenolol contaminants.

The fate of atenolol in wastewater treatment plants of representative densely urban agglomerations in China.

Atenolol (ATL) that can decrease heart rate and reduce renin release is extensively used in the treatment of hypertension, angina, and other diseases. ATL's popularity has therefore drawn attention to its environmental behavior and potential impacts. Wastewater treatment plants (WWTPs) are the main collection point for ATL entering the water environment, highlighting the necessity of studying its fate in the environment. In this study, five WWTPs with different processes in China's representative densely urban agglomerations (Pearl River Delta [PRD] region) were selected as certain representative sampling sites to investigate the fate of ATL in the WWTPs over four seasons. Results showed that ATL concentration in the influent of these WWTPs was 146.5-918.6ng/L and the corresponding concentration in the effluent was 43.0-534.1ng/L, achieving a certain degree of removal. The seasonal ATL removal performance varied greatly among these WWTPs, Liede, Tai Po, and Sha Tin WWTPs showed better removal stability. Meanwhile, the average ATL removal rates in Tai Po (83.36%) and Sha Tin (81.67%) were higher than those in the Futian (71.24%), Liede (55.44%), and Stonecutters Island WWTPs (44.96%). The primary treatment capacity of Futian WWTP was better than that of Tai Po and Sha Tin WWTPs in removing ATL, while the performance of secondary treatment was opposite. Moreover, Zahn-Wellens test demonstrated that ATL could be almost completely degraded after 30 days and some protonated molecules (e.g., m/z 145 and m/z 190) metabolites were formed, indicating that degradation may play a role in ATL removal in WWTPs.

Fe oxide modification of yerba mate waste-derived biochar and activated biochar via three methodologies: Effects of material surface properties on the Fe oxides grown and implications for paracetamol and atenolol sorption

This work presents, for the first time, the development of magnetic composites using activated biochar (BC-Act) derived from yerba mate waste. It includes an analysis of the effect of the activation process on the formation of iron oxides using the most applied methodologies, an aspect that has not been studied before. Three methodologies have been considered for Fe oxides grown: coprecipitation (COP), impregnation-pyrolysis (IP), and alkaline oxidation in the presence of nitrates (AOPN). The materials with magnetic response and good enough BET area have been used to sorb Paracetamol (PCT) and Atenolol (ATE) from aqueous solutions. The activation process has resulted in the formation of mesopores, an increase of surface area due to the destruction/release of impurities, the transformation of whewellite to calcite, and changes in magnetic behavior. These changes seem to affect the formation of Fe oxides. The COP and IP methods allow the development of magnetic composites based on BC-Act, BC-Act-COP and BC-Act-IP, with saturation magnetization of 3.1 Am2/kg and 1.5 Am2/kg, respectively, attributed to magnetite/maghemite formation and a minimal distance for manipulation by a magnetic field of 12.1 mm and 7.9 mm, respectively. These distances must be considered when developing efficient removal systems using magnetic composites. PCT was sorbed faster and more efficiently than ATE, associated with its smaller molecular size. This presents a valuable contribution to environmental sustainability and advancements in water purification, highlighting the dual advantage of converting the widely available waste product, predominantly found in South America, into an effective sorbent with magnetic characteristics, capable of removing pharmaceutical contaminants from aqueous solutions. This is done in the circular economy, avoiding the final deposition of yerba mate waste in landfills, increasing their lifespan, and safeguarding other natural and non-renewable resources, such as clays, whose preservation rather than exploitation improves environmental quality and saves energy.

Simultaneous degradation of pharmaceuticals and personal care products in hospital wastewater using ozone under ultraviolet irradiation

The discharge of Pharmaceuticals and personal care products (PPCPs) from industries and hospitals are responsible for the contamination of water body with slow or non-degradable toxic compounds. The removal of these contaminants required advanced treatment process because of unable to treat by conventional wastewater treatment process. In this study, the degradation of PPCP compounds, including caffeine (CAF), atenolol (ATL), carbamazepine (CBZ), sulfamethoxazole (SMX), trimethoprim (TMP), and acetaminophen (ACT) was evaluated under exposure to 1.0 and 1.5 mg/L dissolved ozone (O3), both with and without ultraviolet (UV) irradiation (254 nm). Using liquid chromatography with tandem mass spectrometry, we determined that the removal efficiency for the targeted contaminants exceeded 95 % within just 20 min of exposure to both 1.0 and 1.5 mg/L O3. However, when treated with UV light alone, the removal efficiency was limited at 3 %–11 %. A combination treatment involving dissolved 1.5 mg/L O3 and UV light led to over 97 % removal within 7 min. This outcome was attributed to hydroxylation reactions, aromatic ring opening, oxidation, and mineralization facilitated by the HO and peroxide generated through the photolysis of O3. The degradation rate of PPCP compounds followed pseudo-first-order kinetics and showed a decrease in the presence of humic acid and hospital wastewater further decreased it. Moreover, O3/UV treatment generated lower-weight degradation products. The toxicity analysis revealed that these transformation products exhibited environmental benignity and minimal health risks which O3/UV treatment potentially minimizes the presence of harmful byproducts. These findings provide a foundation for developing combined hybrid systems for PPCP containing wastewater, containing membrane filtration with ozonation system.

Novel Catalyst-free Activation of Chlorine by Visible Light for Micropollutant Abatement

This study systematically investigated the direct activation of chlorine by visible light emitting diode (Vis-LED). Vis-LED could effectively activate chlorine to degrade micropollutants with degradation efficiency and pseudo-first-order degradation rate constant range of 64.3%-100% and 0.0340-0.195min-1, respectively. Quenching experiments and modeling results suggested that reactive chlorine species (RCS, including ClO•, Cl2•-, and Cl•) and hydroxyl radical (•OH) were involved in the degradation of atenolol (ATL). The contribution ratio of ClO•, free available chlorine, Cl•, Cl2•-, and •OH to ATL degradation were 58.7%, 17.4%, 15.6%, 1.8%, and 5.9%, respectively, in Vis-LED448/chlorine process. Moreover, the innate quantum yields of HClO and ClO- decreased from 0.229 and 0.0206 to 0.0489 and 0.0109mol·Einstein-1, respectively, as the wavelength increased from 448 to 513nm, leading to a decrease in ATL degradation, which was consistent with the model results. Experimental and modeling results have confirmed that ATL degradation decreased when pH increased from 4.0 to 9.0. Cl- had little effect on the degradation of ATL, while HA and HCO3- affected ATL degradation by scavenging reactive species and/or shielding effect. The concentration of disinfection by-products decreased with the increase of wavelength and pH. In summary, Vis-LED/chlorine is an efficient water treatment process even without a catalyst.

Performance Evaluation of Horizontal Flow Constructed Wetland for Removal of Pharmaceuticals from Synthetic Wastewater

The removal efficiency of pharmaceutical compounds in wastewater treatment can be significantly influenced by seasonal variations and the presence of vegetation. This study evaluates the removal efficiencies of five pharmaceutical compounds – Cefadroxil (CFL), Ciprofloxacin (CIP), Cefpodoxime (CFD), Atenolol (ATN) and Avil-25 (AVL) – in non-planted (CW2) and planted (CW1) constructed wetlands across various parameters including Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solids (TSS), Alkalinity, Nitrate, and Phosphate during winter and summer seasons. Results indicate that CW1 consistently outperforms CW2 in all parameters and seasons. For example, CW1 achieved 54.28% BOD removal for CFL in winter compared to CW2's 39.67%, with summer values reaching 79.6% and 69.7%, respectively. The superior performance of CW1 was also observed for COD and other parameters, with phosphate removal reaching 94% in summer. The results of HPLC analysis indicated that CW1 showed better removal efficiencies of Cefadroxil (56.94%), Ciprofloxacin (90%), and Avil-25 (99.7%) than CW2. Even though Cefpodoxime showed low removal efficiency in both systems, CW1 still performed slightly better (13.99% vs. 0.7%). Atenolol removal was particularly notable in CW1 (93.79%), significantly outperforming CW2. Hazard quotient assessments revealed lower risks associated with pharmaceutical residues in CW1. For example, Ciprofloxacin's hazard quotient was reduced from 16% in CW2 to 10% in CW1, underscoring the effectiveness of vegetation in mitigating environmental risks. Atenolol showed a significant hazard quotient reduction from 2% in CW2 to less than 0.5% in CW1, while Avil-25's hazard quotient was negligible in CW1 compared to 4% in CW2. It was also concluded that vegetation positively influenced the treatment efficacy of constructed wetlands for pharmaceuticals with reduced eco-toxicity and the associated risks.

Eco-friendly simultaneous estimation of atenolol and losartan potassium in spiked human plasma via synchronous fluorescence with sustainability assessment.

A green, sensitive, and fast spectrofluorimetric technique for the simultaneous determination of atenolol (ATN) and losartan potassium (LSR) was developed. The proposed technique relied on the implementation of a first derivative synchronous fluorescence spectroscopy for the determination of the investigated drugs simultaneously without pretreatment procedures. The synchronous fluorescence of both drugs was measured in methanol at Δλ of 100 nm, and the first derivative peak amplitudes (1D) were measured at 321 nm for ATN and 348 nm for LSR, each at the zero-crossing point of the other. The method was rectilinear over the concentration ranges of 100-1000 ng/mL and 50-500 ng/mL for ATN and LSR, respectively. The proposed technique was successfully applied for the determination of the studied drugs in their laboratory-prepared mixture and pharmaceutical formulations, demonstrating high mean recoveries of 100.54% for ATN and 100.62% for LSR, without interference from common excipients. The results were in good agreement with those obtained by the comparison method. Three recent greenness assessment tools, the Eco-Scale tool, the Green Analytical Procedure Index (GAPI) metric, and the Analytical GREEnness metric approach, were employed to affirm the greenness of the proposed method. The developed method was proven to be eco-friendly.

Matching periodate peak absorbance by far UVC at 222 nm promotes the degradation of micropollutants and energy efficiency

Periodate (PI)-based advanced oxidation processes have gained increasing interest. This study for the first time elevates the light-activation capacity of PI by using far UVC at 222 nm (UV222/PI) without extra chemical inputs. The effectiveness and the underlying mechanisms of UV222/PI for the remediation of micropollutants were studied by selecting atenolol (ATL) as a representative. PI possessed a high molar absorption coefficient of 9480–6120 M−1 cm−1 at 222 nm in the pH range of 5.0–9.0, and it was rapidly decomposed by UV222 with first-order rate constants of 0.0055 to 0.002 s−1. ATL and the six other organic compounds were effectively degraded by the UV222/PI process under different conditions with the fluence-based rate constants generally two to hundred times higher than by UVA photolysis. Hydroxyl radical and ozone were confirmed as the major contributors to ATL degradation, while direct photolysis also played a role at higher pH or lower PI dosages. Degradation pathways of ATL were proposed including hydroxylation, demethylation, and oxidation. The high energy efficiency of the UV222/PI process was also confirmed. This study provides a cost-effective and convenient approach to enhance PI light-response activity for the treatment of micropollutants.

Supramolecular Interaction of Atenolol and Propranolol with β-Cyclodextrin Spectroscopic Characterization and Analytical Application.

Atenolol (ATE) and propranolol (PRO) inclusion complexes with β-cyclodextrin have been investigated in aqueous solution. The aqueous solution was examined and characterized using UV-vis, fluorescence spectroscopy, and 1H NMR. The physical mixture was characterized using FTIR. The existence of inclusion complexes is confirmed by observing changes in spectroscopic properties. The ATE complex with β-CD exhibited an interaction as host and (β-CD) as a guest in a 1:1 ratio, with an inclusion constant K of 2.09 × 10-3 µM-1, as determined by the typical double-reciprocal graphs. Similarly, the PRO complex with β-CD exhibited an interaction as host and (β-CD) guest in 1:1 and 1:2 stoichiometry at the same time; the inclusion constants were K1 = 5.80 × 10-5 µM-1 and K2 = 4.67 × 10-8 µM-1, as determined by typical double-reciprocal graphs. The variables influencing the formation of the inclusion complexes were investigated and optimized. Based on the enhancement in fluorescence intensity due to the formation of inclusion complexes, spectrofluorometric methods were developed and validated for determination of each drug's pharmaceutical formulation. The quantification of the fluorescence intensity for ATE and PRO was conducted at λex/λem 226/302 nm and λex/λem 231/338 nm, respectively. Under the optimal reaction circumstances, linear relationships with good correlation coefficients of 0.9918 and 0.99 were found in the concentration ranges of 0.3-1.7 μM, and 0.1-1.1 μM for ATE and PRO, respectively. The limits of detection (LODs) were found to be 0.13 and 0.01 μM for ATE and PRO, respectively. The suggested approach was effectively applied to the analysis of both drugs' pharmaceutical formulations.

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

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

Development of a RP-HPLC method for simultaneous determination of atenolol, metoprolol tartrate and phenol red for in-situ rat intestinal perfusion studies

Single-pass intestinal perfusion (SPIP) method is a widely used experimental model to determine the intestinal permeability of drugs. These studies are performed in the presence of a reference standard (metoprolol, MT) and a zero permeability marker (phenol red, PR). Therefore, it is important to develop a validated method for simultaneous determination of the investigated compound along with MT and PR. The aim of this study was to develop a reversed phase high-performance liquid chromatography (RP-HPLC) method with UV-detection for the simultaneous determination of atenolol (ATN), MT, and PR in the perfusion medium used in SPIP experiments. Separation of compounds were performed using an InertSustain C18 (250 × 4.6 mm, 5 µm) HPLC column at 35 °C. The mobile phase was a mixture of acetonitrile and phosphate buffer (pH 7.0, 12.5 mM) in gradient elution, and was delivered at a flow rate of 1 mL/min. The acetonitrile ratio of the mobile phase increased linearly from 10 to 35 % over 15 min. The injection volume was 20 µL, and ATN, MT and PR were detected at 224 nm. The retention times under optimum HPLC conditions were 5.028 min, 12.401 min, and 13.507 min for ATN, MT and PR, respectively. The developed RP-HPLC method was validated for selectivity, specificity, calibration curve and range, accuracy and precision, carry-over effect, stability, reinjection reproducibility, recovery and robustness. The method was linear for ATN (0.76–50 μg/mL), MT (1.14–50 μg/mL), and PR (0.47–20 μg/mL) with determination coefficients of 0.9999, 0.9994 and 0.9998, respectively. The results obtained for all validation parameters of the developed RP-HPLC method met the required limits of the ICH M10 Guideline.

Resolution of overlapping spectra using chemometric manipulations of UV-spectrophotometric data for the determination of Atenolol, Losartan, and Hydrochlorothiazide in pharmaceutical dosage form

Simultaneous determination of atenolol (ATN), losartan potassium (LOS), and hydrochlorothiazide (HCZ) in presence of HCZ impurity B was conducted by chemometric approaches and radial basis function network (RBFN) using UV-spectrophotometry without preliminary separation. Three chemometric models namely, classical least-squares (CLS), principal component regression (PCR), and partial least-squares (PLS) along with RBFN were utilized using the ternary mixtures of the three drugs. The multivariate calibrations were obtained by measuring the zero-order absorbance of the mixtures from 250 to 270 nm at the interval of 0.2 nm. The models were built covering the concentration range of (4.0 to 20.0), (3.8 to 20.2), and (0.9 to 50.1) μg mL−1 for ATN, LOS, and HCZ, respectively. The regression coefficient was calculated between the actual and predicted concentrations of the 3 drugs using CLS, PCR, PLS and RBFN. The accuracy of the developed models was evaluated using the root mean square error of prediction (RMSEP) giving satisfactory results. The proposed methods were simple, accurate, precise and were applied efficiently for the quantitation of the three components in laboratory-prepared mixtures, and in dosage form showing good recovery values. In addition, the obtained results were compared statistically with each other using ANOVA test showing non-significant difference between them.

Performance and mechanistic studies of rapid atenolol degradation through peroxymonosulfate activation by V, Co, and bamboo carbon catalyst.

Developing the Co-based catalysts with high reactivity for the sulfate radical (SO4-·)-based advanced oxidation processes (SR-AOPs) has been attracting numerous attentions. To improve the peroxymonosulfate (PMS) activation process, a novel Co-based catalyst simultaneously modified by bamboo carbon (BC) and vanadium (V@CoO-BC) was fabricated through a simple solvothermal method. The atenolol (ATL) degradation experiments in V@CoO-BC/PMS system showed that the obtained V@CoO-BC exhibited much higher performance on PMS activation than pure CoO, and the V@CoO-BC/PMS system could fully degrade ATL within 5min via the destruction of both radicals (SO4-· and O2-··) and non-radicals (1O2). The quenching experiments and electrochemical tests revealed that the enhancing mechanism of bamboo carbon and V modification involved four aspects: (i) promoting the PMS and Co ion adsorption on the surface of V@CoO-BC; (ii) enhancing the electron transfer efficiency between V@CoO-BC and PMS; (iii) activating PMS with V3+ species; (iv) accelerating the circulation of Co2+ and Co3+, leading to the enhanced yield of reactive oxygen species (ROS). Furthermore, the V@CoO-BC/PMS system also exhibited satisfactory stability under broad pH (3-9) and good efficiency in the presence of co-existing components (HCO3-, NO3-, Cl-, and HA) in water. This study provides new insights to designing high-performance, environment-friendly bimetal catalysts and some basis for the remediation of antibiotic contaminants with SR-AOPs.

Miscanthus x giganteus biochar: Effective adsorption of pharmaceuticals from model solution and hospital wastewater

This study investigated the adsorption of pharmaceuticals, including atenolol (AT), 17-α-ethinylestradiol (EE2), and sulfamethoxazole (SMX), in model solutions and in the effluent from a hospital wastewater treatment plant. The pharmaceuticals were adsorbed on biochar prepared from Miscanthus x giganteus biomass obtained from the phytoremediation of contaminated or marginal soil. The feedstock was pyrolyzed at 360 °C (M-3) and 500 °C (M-5). The representation of functional groups, specific surface area, porosity, and pore volume were lower for M-5. Pore diameters were comparable, but their depth decreased for M-5. The specific surface area and porosity surface area of M-5 were 30 times higher after 4 h of shaking compared to properties without shaking. The biochar leachate pH was 9.8 ± 1.0 (M-3), and 11.1 ± 1.1 (M-5). No desorption of potentially risk organic compounds was detected. M-3 was generally a better adsorption material. The removal of EE2, AT and SMX was greater than 90%, 70% and 30 % respectively after 4 h in model waters. There was no evidence of a linear relationship between the sorption efficiency of pharmaceuticals and the biochar dose. Sorption experiments with real wastewater from a hospital wastewater treatment plant demonstrated high removal rates of monitored pharmaceuticals, including e.g. SMX (80%), trimethoprim (91%), venlafaxine (100%), clarithromycin (96%), tramadol (93%), diclofenac (86%). It was proven that the efficiency of the adsorption process is influenced not only by the dose or physico-chemical properties of the biochar, but also by the initial concentration of the pharmaceutical and its properties. The presence of other components of real wastewater, which can cause competitive sorption and overlapping of active centers on the surface of the biochar, also decreased the efficiency. The results demonstrate that both biochars are suitable for tertiary or quaternary water treatment for pharmaceutical removal. Due to the lower energetic, and therefore economic, costs of pyrolysis, a lower pyrolysis temperature can be preferred.

Atenolol uptake from pharmaceutical sources onto carbon aerogel prepared by supercritical CO2 drying

Atenolol (ATL) is a popular medication which is widely used to treat hypertension and angina. It is often found in aqueous environments, posing potential risk to human health and ecological well-being. In this study, carbon aerogel was prepared by supercritical CO2 drying of resorcinol–formaldehyde resin subsequently carbonized at 600 °C in an inert atmosphere. This porous material was characterized by SEM, BET, FTIR, and XRD and used for the first time for the removal of ATL from aqueous solutions under varying experimental conditions. Carbon aerogel in the form of microbeads exhibited a relatively high specific surface area of 376.02 m2/g and median pore radius of 9.83 nm. The isotherm models of Langmuir, Freundlich, Temkin, Redlich-Peterson and Brouers-Sotolongo were used to interpret the equilibrium data. Although most of the applied models fitted the data well, the calculated values for maximum sorption capacity (qmax) showed a huge deviation when compared to experimental value of 76.66 mg/g. The pseudo-first and pseudo-second-order kinetic models, Chrastil’s model, and the intraparticle diffusion model were employed for fitting the kinetic data. The rate of the process was rapid with most of the uptake attained in the first 20 min of the contacting. The sorption optimum was achieved at pH pH 9.0 and for sorbent’s dosage of 750 mg/L. Reusability study of the spent aerogel conducted in seven cycles evidenced slight decrease of approximately 1 % in removal efficiency across the cycles indicating that the sorbent maintained its high effectiveness and stability throughout its usage.

Trace compounds in the urban water cycle in the Freiberg region, Germany

Trace compounds in the urban water cycle in the Freiberg region, Germany

Environmental risk assessment of selected pharmaceuticals in hospital wastewater in nothern Vietnam

Pharmaceuticals are progressively employed in both human and veterinary medicine and increasingly recognized as environmental contaminants. This study investigated the occurrence of selected pharmaceuticals in influent and effluent of wastewater treatment plants of 12 hospitals in Hanoi and 3 northern cities of Vietnam during dry and rainy seasons. In addition, environmental risk of pharmaceuticals in both hospital influents and effluents were evaluated based on risk quotients (RQs). Nine selected pharmaceutical compounds including sulfamethoxazole (SMX), naproxen (NPX), diclofenac (DCF), ibuprofen (IBU), acetaminophen (ACT), carbamazepine (CBM), iopromide (IOP), atenolol (ATN), and caffeine (CAF) were frequently detected in most influent and effluent wastewaters of 12 investigated hospitals. Detected compound levels exhibited a wide range, from as low as 1 ng/L for DCF to as high as 61,772 ng/L for ACT. Among these compounds, ACT, CAF, SMX, and IOP were consistently detected at substantial concentrations in both influents and effluents. This investigation also highlighted potential risks posed by SMX, ACT, and CAF residues present in influents and effluents of hospital wastewater treatment plants (WWTPs) to aquatic ecosystem. These finding are expected to provide scientific-based evidence for the development of hospital waste management and environmental management programs in Vietnam.

Role of bipyridyl in enhancing ferrate oxidation toward micropollutants

Enhancing Fe(VI) oxidation ability by generating high-valent iron-oxo species (Fe(IV)/Fe(V)) has attracted continuous interest. This work for the first time reports the efficient activation of Fe(VI) by a well-known aza-aromatic chelating agent 2,2′-bipyridyl (BPY) for micropollutant degradation. The presence of BPY increased the degradation constants of six model compounds (i.e., sulfamethoxazole (SMX), diclofenac (DCF), atenolol (ATL), flumequine (FLU), 4-chlorophenol (4-CP), carbamazepine (CBZ)) with Fe(VI) by 2 – 6 folds compared to those by Fe(VI) alone at pH 8.0. Lines of evidence indicated the dominant role of Fe(IV)/Fe(V) intermediates. Density functional theory calculations suggested that the binding of Fe(III) to one or two BPY molecules initiated the oxidation of Fe(III) to Fe(IV) by Fe(VI), while Fe(VI) was reduced to Fe(V). The increased exposures of Fe(IV)/Fe(V) were experimentally verified by the pre-generated Fe(III) complex with BPY and using methyl phenyl sulfoxide as the probe compound. The presence of chloride and bicarbonate slightly affected model compound degradation by Fe(VI) in the presence of BPY, while a negative effect of humic acid was obtained under the same conditions. This work demonstrates the potential of N-donor heterocyclic ligand to activate Fe(VI) for micropollutant degradation, which is instructive for the Fe(VI)-based oxidation processes.

Effect of the anode material, applied current and reactor configuration on the atenolol toxicity during an electrooxidation process

Atenolol (ATL) is a beta-blocker pharmaceutical product which is excreted mainly unchanged and may represent a long-term risk for organisms present in the sea and in fresh water. Due to its low biodegradation rate, electrochemical advanced oxidation processes (EAOPs) can be used to remove this compound. In this work, ATL ecotoxicity was analyzed in the presence of sodium sulfate (Na2SO4), which is widely used as supporting electrolyte in EAOPs. Ecotoxicity values were expressed as the pollutant concentration that leads to a 50% inhibition of the root elongation of Lactuca sativa seeds in relation to the control (EC50(5 days)). The obtained values for ATL showed an EC50(5 days) of 1377 mg L−1 towards Lactuca sativa. When Na2SO4 was added, the toxicity of the sample increased but no synergy was detected between both compounds. With 2 g L−1 Na2SO4, ATL showed an EC50(5 days) of 972 mg L−1; and with 4 g L−1 Na2SO4 and higher concentrations, EC50 value for ATL was 0 mg L−1. Statistical tools were used to obtain the zones of the [ATL]-[Na2SO4] plane which are toxic towards Lactuca sativa.Solutions containing ATL and Na2SO4 were treated by electrooxidation. Two anode materials (a boron-doped diamond electrode and a microporous Sb-doped SnO2 ceramic one); three operation currents (0.4, 0.6 and 1 A); and two reactor configurations (one-compartment reactor and two-compartment reactor separated by a cation exchange membrane) were used. Lactuca sativa seeds and Vibrio fischeri bacterium tests were employed to evaluate the toxicity of the solutions before and after applying the electrooxidation process. In all the tests, the ecotoxicity of the treated sample increased. This fact is owing to the persulfate presence in the solution due to the sulfate electrochemical oxidation. Nevertheless, none of the final samples were toxic towards Vibrio fischeri because ecotoxicity values were lower than 10 TU; and, in the case of the one-compartment reactor, practically all of them were also non-toxic towards Lactuca sativa. The toxicity of the treated samples increased when using the two-compartment reactor in the presence of the BDD anode, and when the operation current was increased. This is attributed to the highest formation of persulfates. Amongst all the tests performed in this work, the lowest toxicity value (i.e., 3 TU) together with the complete mineralization and degradation degrees was achieved with the two-compartment reactor using the BDD anode and operating at 0.6 A.

DETERMINATION OF THE ANTIHYPERTENSIVE DRUGS CAPTOPRIL, ATENOLOL, AND METOPROLOL IN DOSAGE FORMS

Three antihypertensive drugs Captopril (CPL), Atenolol (ATL), and Metoprolol (MTL) have been estimated sensitively and selectively by a single spectrophotometric method using neutral red dye NLR. The method is based on oxidation of the drugs by known excess of N-bromosuccinamide (NBS) in the first reaction step followed by the oxidation of NLR dye with the exceed ed amount of NBS, as the concentration of the drug compounds increase, the color of the dye increase, the dye exhibits absorbance peak at 523 nm. The linearity range was from 1 to 10 µg/ml for the three drugs, the molar absorptivity values were 2.1164 × 105, 1.9202× 104, and 57.934× 104 l.mol-1.cm-1 for CPL, ATL, and MTL respectively, the sensitivity index of Sand’ll were 0.0102, 0.0138, and 0.01182 µg/cm2 for CPL, ATL, and MTL respectively. LOD values for the three drugs ranged from 0.00405 to 0.00547 and LOQ values were ranged from 0.0135 to 0.0182 respectively, the method exhibits good applicability to the dosage forms and high confidence as compared with standard method and standard addition method.