Carbamazepine and diclofenac: removal in wastewater treatment plants and occurrence in water bodies

Monitoring of emerging contaminants of concern in the aquatic environment: a review of studies showing the application of effect-based measures

Water scarcity is increasingly a global cause of concern mainly due to widespread changes in climate conditions and increased consumptive water use driven by the exponential increase in population growth. In addition, increased pollution of fresh water sources due to rising production and consumption of pharmaceuticals and organic chemicals will further exacerbate this concern. Although surface water contamination by individual chemicals is often at very low concentration, pharmaceuticals for instance are designed to be efficacious at low concentrations, creating genuine concern for their presence in freshwater sources. Furthermore, the additive impact of multiple compounds may result in toxic or other biological effects that otherwise will not be induced by individual chemicals. Globally, different legislative frameworks have led to pre-emptive efforts which aim to ensure good water ecological status. Reports detailing the use and types of effect-based measures covering specific bioassay batteries that can identify specific mode of actions of chemical pollutants in the aquatic ecosystem to evaluate the real threat of pollutants to aquatic lives and ultimately human lives have recently emerged from monitoring networks such as the NORMAN network. In this review, we critically evaluate some studies within the last decade that have implemented effect-based monitoring of pharmaceuticals and organic chemicals in aquatic fauna, evaluating the occurrence of different chemical pollutants and the impact of these pollutants on aquatic fauna with special focus on pollutants that are contaminants of emerging concern (CEC) in urban wastewater. A critical discussion on studies that have used effect-based measures to assess biological impact of pharmaceutical/organic compound in the aquatic ecosystem and the endpoints measurements employed is presented. The application of effect-based monitoring of chemicals other than assessment of water quality status is also discussed.

Degradation of diclofenac by Fe(II)-activated peracetic acid

In this study, peracetic acid (PAA) activated by Fe(II) was proposed to remove diclofenac (DCF) in polluted water. It was found that Fe(II)/PAA system could effectively remove DCF at neutral condition, which has a significant advantage over classical Fenton process. According to the result of scavenging experiment, both hydroxyl radical and peroxy radical were considered to be responsible for the degradation of DCF. The influence of several operational parameters including initial pH, Fe(II) dosage, PAA concentration and common water matrix on DCF removal were investigated. 80% DCF was removed at mild condition (pH 6-7) within 60 s, and its removal rate could be enhanced with the increase in Fe(II) dosage and PAA concentration. Presence of HCO3- and natural organic matter (NOM) was proved to have a significantly negative impact on DCF degradation. Four probable degradation pathways of DCF were proposed based on the detected reaction products, including hydroxylation, C-N bond cleavage, decarboxylation and dehydrogenation.

Environmental risk assessments of multiclass pharmaceutical active compounds: selection of high priority concern pharmaceuticals using entropy-utility functions

This research aimed to identify high-risk pharmaceutically active compounds (PhACs) by analyzing occurrence (O), persistence (P), bioaccumulation (B), and toxicity (T) of 62 drugs which are widely used in Iran. A comprehensive approach was taken in risk assessment of the selected PhACs and in their prioritization using multiple-criteria decision analysis (MCDA) such as utility functions and principal component analysis (PCA). In practice, assigning weight to each criterion (i.e., O, P, B, and T) for risk assessment of PhACs is a challenge. In this research, the impact of giving both equal and unequal weight to each criterion by using a quantitative entropy method was studied. For risk assessment, two exposure approaches (consumption rate and occurrence of PhACs) and three MCDA approaches (PCA and utility functions with and without equal weights for each criterion) were compared. The utility function using equal weights for all O, P, B, and T criteria showed that thioridazine, pimozide, chlorpromazine, sertraline, clomipramine, and aripiprazole were at the highest level of risk, with concern score of 0.75, 0.75, 0.67, 0.58, 0.58, and 0.58, respectively. Unequal weight approach included additional compounds such as fluoxetine, citalopram, and methadone as a priority. All three MCDA approaches showed that sedatives and antidepressants were prevalent PhACs in the risk-based priority lists. However, the exposure-based approaches showed antibiotics and analgesics as the pharmaceutical of the highest priority. Overall, selection of the high priority concern pharmaceuticals depends on the prioritization approach employed. However, the utility function using unequal weights is a more conservative and effective approach for prioritization.

Effect of superfine pulverization of powdered activated carbon on adsorption of carbamazepine in natural source waters

The purpose of this study is to investigate adsorptive removal of carbamazepine from natural source waters by superfine pulverized powdered activated carbon. Superfine pulverization is becoming an increasingly attractive approach to decrease the diffusion path of a target adsorbate molecule and improve the overall the kinetics of activated carbon adsorption. Here we report the impact of pulverization on powdered activated carbon characteristics, and carbamazepine adsorption behavior in distilled and deionized water and natural organic matter solutions. The superfine pulverization decreased the particle size of activated carbon by 50 folds and the specific surface area by 24%. In addition, the micropore volume of the activated carbon decreased from 0.23 cm³/g to 0.14 cm³/g, while mesopore and macropore volumes increased from 0.15 cm³/g and 0.11 cm³/g to 0.18 cm³/g and 0.48 cm³/g, respectively. In terms of surface chemistry, the oxygen and iron contents of the activated carbon increased notably after pulverization. Despite the decrease in surface area and increase in surface polarity, the pulverization improved the adsorption kinetics especially for short contact times i.e., < 6-h. In general, the dissolved organic carbon concentration negatively influenced the kinetic advantage of superfine pulverized activated carbon. Isotherm results indicated that the parent adsorbent has a higher adsorption capacity than superfine activated carbon in distilled and deionized water and in natural waters. This was attributed to the losses in specific surface area and favorable sorption sites inside micropores. Our literature analysis indicated that unlike the small molecular weight hydrophilic organic compounds, the pseudo-equilibrium adsorption capacity could be increased or at least not deteriorated for hydrophobic molecules (K_ow > 3). Therefore, superfine pulverization of PAC can serve as a promising approach to remove micropollutants from natural source waters with a kinetic advantage.

Magnetic Cellulose-Chitosan Nanocomposite for Simultaneous Removal of Emerging Contaminants: Adsorption Kinetics and Equilibrium Studies

The presence of pharmaceuticals in water systems threatens both terrestrial and aquatic life across the globe. Some of such contaminants are β-blockers and anticonvulsants, which have been constantly detected in different water systems. Various methodologies have been introduced for the removal of these emerging pollutants from different waters. Among them, adsorption using nanomaterials has proved to be an efficient and cost-effective process for the removal of pharmaceuticals from contaminated water. In this this study, a firsthand/time approach applying a recyclable magnetic cellulose-chitosan nanocomposite for effective simultaneous removal of two β-blockers (atenolol (ATN)) and propranolol (PRP) and an anticonvulsant (carbamazepine (CBZ)) is reported. A detailed characterization of the eco-friendly, biocompatible cellulose-chitosan nanocomposite with magnetic properties was performed at various rates of synthesis using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), and Fourier transform infrared (FTIR) spectroscopy. A N_2c adsorption-desorption test showed that the prepared nanocomposite is mesoporous, with a BET area of 112 m² g^-1. The BET isotherms results showed that the magnetic cellulose-chitosan nanocomposite has a pore size of 24.1 nm. The adsorption equilibrium of PRP and CBZ fitted with the Langmuir isotherm was consistent with the highest coefficient of determination (R² = 0.9945) and (R² = 0.9942), respectively, while the Sips model provided a better fit for ATN, with a coefficient of determination R² = 0.9956. The adsorption rate was accompanied by a pseudo-second-order kinetics. Moreover, the swelling test showed that up to 100 percent swelling of the magnetic cellulose-chitosan nanocomposite was achieved.

A Review on the Removal of Carbamazepine from Aqueous Solution by Using Activated Carbon and Biochar

Carbamazepine (CBZ), one of the most used pharmaceuticals worldwide and a Contaminant of Emerging Concern, represents a potential risk for the environment and human health. Wastewater treatment plants (WWTPs) are a significant source of CBZ to the environment, polluting the whole water cycle. In this review, the CBZ presence and fate in the urban water cycle are addressed, with a focus on adsorption as a possible solution for its removal. Specifically, the scientific literature on CBZ removal by activated carbon and its possible substitute Biochar, is comprehensively scanned and summed up, in view of increasing the circularity in water treatments. CBZ adsorption onto activated carbon and biochar is analyzed considering several aspects, such as physicochemical characteristics of the adsorbents, operational conditions of the adsorption processes and adsorption kinetics and isotherms models. WWTPs usually show almost no removal of CBZ (even negative), whereas removal is witnessed in drinking water treatment plants through advanced treatments (even >90%). Among these, adsorption is considered one of the preferable methods, being economical and easier to operate. Adsorption capacity of CBZ is influenced by the characteristics of the adsorbent precursors, pyrolysis temperature and modification or activation processes. Among operational conditions, pH shows low influence on the process, as CBZ has no charge in most pH ranges. Differently, increasing temperature and rotational speed favor the adsorption of CBZ. The presence of other micro-contaminants and organic matter decreases the CBZ adsorption due to competition effects. These results, however, concern mainly laboratory-scale studies, hence, full-scale investigations are recommended to take into account the complexity of the real conditions.

Exposure of Mytilus trossulus to diclofenac and 4'-hydroxydiclofenac: Uptake, bioconcentration and mass balance for the evaluation of their environmental fate

Diclofenac (DIC) is one of the most widely consumed drugs in the world, and its presence in the environment as well as potential effects on organisms are the subject of numerous recent scientific works. However, it is becoming clear that the risk posed by pharmaceuticals in the environment needs to be viewed more broadly and their numerous derivatives should also be considered. In fact, already published results confirm that the transformation products of NSAIDs including DIC may cause a variety of potentially negative effects on marine organisms, sometimes showing increased biological activity. To date, however, little is known about bioconcentration of DIC and DIC metabolites and the role of sex in this process. Therefore, the present study for the first time evaluates sex-related differences in DIC bioconcentration and estimates bioconcentration potential of DIC metabolite, 4-OH DIC, in the Mytilus trossulus tissues. In the experiment lasting 7 days, mussels were exposed to DIC and 4-OH DIC at concentrations 68.22 and 20.85 μg/L, respectively. Our study confirms that DIC can be taken up by organisms not only in its native form, but also as a metabolite, and metabolised further. Furthermore, in the present work, mass balance was performed and the stability of both studied compounds under experimental conditions was analysed. Obtained results suggest that DIC is more stable than its derivative under the tested conditions, but further analyses of the environmental fate of these compounds are necessary.

Four scenarios of environmental risk of diclofenac in European groundwater ecosystems

Groundwater is the largest source of liquid freshwater on Earth. Groundwater ecosystems harbor a rich biodiversity, mainly consisting of microbes and invertebrates that provide substantial ecological services. Despite its importance, groundwater is affected by several anthropic pressures, including pollution from pharmaceutical compounds. Diclofenac is the non-steroidal drug most widely detected in freshwaters, both in surface waters (e.g., rivers, streams, lakes etc.) and groundwaters. Unlike surface waters, the environmental risk of diclofenac in European groundwaters has not yet been assessed by the competent Authorities. The environmental risk assessment refers to the analysis of the potential risk that a chemical compound poses to a given environment by comparing its measured environmental concentrations to its predicted no-effect concentration. In this study, we explored four environmental risk scenarios in European groundwaters using different methodologies. We obtained diverse risk expectations, some indicative of a moderately diffuse environmental risk for concentrations of diclofenac ≥42 ng/L and others indicative of a widespread environmental risk for concentrations ≥5 ng/L. The difference among the four scenarios mainly related to the methods of calculating the predicted no-effect concentration of diclofenac. We discussed the four scenarios in order to identify the most realistic risk expectations posed by diclofenac to European groundwater ecosystems.

Biomarkers for assessing chronic toxicity of carbamazepine, an anticonvulsants drug on Pangasianodon hypophthalmus (Sauvage, 1878)

In recent times, carbamazepine (CBZ) as an anticonvulsants drug has raised attention because of its safety concern in the aquatic environment. The present study aimed to evaluate the sub-lethal effects of CBZ (1%, 0.1 % and 0.01 % of 96 h LC₅₀) on P. hypophthalmus for 60 days based on haematological, biochemical, and genotoxicity biomarkers. Chronic exposure of CBZ altered blood profiles (total erythrocyte count, packed cell volume, haemoglobin) and serum biomarkers such as alkaline phosphates, cholesterol, lactate dehydrogenase and transaminase enzymes. Oxidative stress biomarkers such as superoxide dismutase (SOD) and catalase (CAT) activity were also substantially affected in all treatments. Genotoxicity study revealed the formation of micronucleus in erythrocytes of exposed fish. Integrated Biomarker Response (IBR) study showed cholesterol, serum glutamic oxaloacetic transaminase (SGOT) in serum and SOD, CAT in liver tissue are the best organ-based enzyme biomarkers. The present report concludes that an environmentally realistic concentration of CBZ can pose a serious threat to aquatic organisms.

Degradation of carbamazepine by UVA/WO3/hypochlorite process: Kinetic modelling, water matrix effects, and density functional theory calculations

The rapid recombination of electron/hole pairs is a major setback in the application of WO₃-based photocatalysis in water treatment. In this study, hypochlorite (ClO^-) was used as an electron acceptor to enhance the photocatalytic degradation of carbamazepine (CBZ) using UVA-excited WO₃. The results showed that CBZ degradation in the UVA/WO₃/ClO^- system followed a pseudo-first order reaction kinetic model. The addition of 0.1 mM ClO^- to the UVA/WO₃ system at pH values of 8.2 and 6.2 increased the rate constant (k_obs) of the degradation process 5.3- and 11.5-fold, respectively. Further, increasing the WO₃ dosage or decreasing the initial CBZ concentration resulted in an increase in k_obs. However, at high concentrations, ClO^- inhibited CBZ degradation. Based on the kinetic model, it could be suggested that ClO played a dominant role in the degradation process. Furthermore, the water matrix effects were as follows: the optimal pH was 6.2; humic acid, chloride, bicarbonate, and ammonium exhibited inhibitory effects on CBZ degradation; and sulfate ion significantly enhanced the degradation. Density functional theory (DFT) calculations indicated a strong affinity between ClO^- and the WO₃ surface. Specifically, the electrical energy per order that was associated with the use of ClO^- varied in the range of 0.100-1.617 kWh/m³. In summary, this study shows that ClO^- is an excellent electron acceptor for excited WO₃, while clarifying the CBZ degradation-enhancing effect of ClO^- as well as the kinetic model and DFT calculations. These findings can be employed in the degradation of recalcitrant contaminants in a cost-effective manner, while being significant for the development of more effective catalysts of UV-assisted advanced oxidation processes.

Integrated multi-biomarker responses of juvenile rainbow trout (Oncorhynchus mykiss) to an environmentally relevant pharmaceutical mixture

Pharmaceuticals are emerging pollutants of concern for aquatic ecosystems where they are occurring in complex mixtures. In the present study, the chronic toxicity of an environmentally relevant pharmaceutical mixture on juvenile rainbow trout (Oncorhynchus mykiss) was investigated. Five pharmaceuticals (paracetamol, carbamazepine, diclofenac, naproxen and irbesartan) were selected based on their detection frequency and concentration levels in the Meuse river (Belgium). Fish were exposed for 42 days to three different concentrations of the mixture, the median one detected in the Meuse river, 10-times and 100-times this concentration. Effects on the nervous, immune, antioxidant, and detoxification systems were evaluated throughout the exposure period and their response standardized using the Integrated Biomarker Response (IBRv2) index. IBRv2 scores increased over time in the fish exposed to the highest concentration. After 42 days, fish exposed to the highest concentration displayed significantly higher levels in lysozyme activity (p < 0.01). The mixture also caused significant changes in brain serotonin turnover (p < 0.05). In short, our results indicate that the subchronic waterborne exposure to a pharmaceutical mixture commonly occurring in freshwater ecosystems may affect the neuroendocrine and immune systems of juvenile rainbow trout.

Simple and effective removal of psychiatric pharmaceuticals from wastewater treatment plant effluents by magnetite red mud nanoparticles

Psychological disorders due to the COVID-19 pandemic have increased the consumption of psychiatric pharmaceuticals on a global scale in last year. These compounds reach wastewater treatment plants (WWTP) through sewerage system and are not sufficiently removed by using conventional treatment process. Psychiatric drugs released with WWTP effluent may cause possible risks to the receiving aquatic environment. Also, two antidepressants have been included in the "watch list" in 2020. Therefore, simple and relatively cost effective removal of psychiatric drugs from wastewaters becomes important. Magnetite red mud nanoparticles (RM-NPs) synthesized was applied for the removal of psychiatric drugs (fluoxetine, paroxetine, carbamazepine, diazepam, and lorazepam) in WWTP effluent first time in this study. The adsorption of carbamazepine as a model compound was fitted well with pseudo-second-order kinetic model. The Freundlich isotherm model better represented the sorption data than the Langmuir model. High adsorption capacity (90.5 mg/g) was reached at 30 min contact time at pH 6.5-7.0 at 25 °C. The adsorption rate was described by the pseudo second order model and its rate control mechanism was controlled by film diffusion. The magnetite RM-NPs were efficiently used for the removal of carbamazepine from real WWTP effluents. The adsorption capacity and the magnetic separability of the regenerated magnetite RM-NPs were unaffected five cycles. Due to its simple application, low cost and high adsorption capacity, magnetite RM-NPs can be recommended as a better adsorbent comparing to commercial adsorbents to remove psychiatric drugs from WWTP effluents.

Recent Trends in Pharmaceuticals Removal from Water Using Electrochemical Oxidation Processes

Nowadays, the research on the environmental applications of electrochemistry to remove recalcitrant and priority pollutants and, in particular, drugs from the aqueous phase has increased dramatically. This literature review summarizes the applications of electrochemical oxidation in recent years to decompose pharmaceuticals that are often detected in environmental samples such as carbamazapine, sulfamethoxazole, tetracycline, diclofenac, ibuprofen, ceftazidime, ciprofloxacin, etc. Similar to most physicochemical processes, efficiency depends on many operating parameters, while the combination with either biological or other physicochemical methods seems particularly attractive. In addition, various strategies such as using three-dimensional electrodes or the electrosynthesis of hydrogen peroxide have been proposed to overcome the disadvantages of electrochemical oxidation. Finally, some guidelines are proposed for future research into the applications of environmental electrochemistry for the degradation of xenobiotic compounds and micropollutants from environmental matrices. The main goal of the present review paper is to facilitate future researchers to design their experiments concerning the electrochemical oxidation processes for the degradation of micropollutants/emerging contaminants, especially, some specific drugs considering, also, the existing limitations of each process.

β-Lactam Resistance Gene NDM-1 in the Aquatic Environment: A Review

New Delhi Metallo-β-lactamase-1 (NDM-1) offers carbapenem antibiotics resistance that creates an evolving challenge in treating bacterial infections. NDM-1-bearing strains were observed in surface waters around New Delhi in 2010 and after then identified globally. The usage of antibiotics may hasten the growth of the NDM-1-producing bacteria, which pose severe hazards to human and animal health. The emergence of the NDM-1 in the aquatic environment is turning out to be a growing concern worldwide. NDM-1 gene conferring resistance to a widespread class of antibiotics has been observed in bacteria disseminated in animal production wastewaters, hospital sewage, domestic sewage, industrial effluents, wastewater treatment plants, drinking water, surface water, and even in groundwater. This review recapitulates the currently published research studies on the prevalence and geographical distribution of the NDM-1 gene in the aquatic environment, its habitats, and healthcare risk associated with NDM-1-producing bacteria, in addition to molecular techniques employed to reveal the occurrence of the NDM-1 in the aquatic environment, including conventional polymerase chain reaction, real-time qPCR, DNA hybridization, and microarray-based methods.

Real-time heart rate monitoring system for cardiotoxicity assessment of Daphnia magna using high-speed digital holographic microscopy

Machine vision techniques for monitoring heart rates in aquatic bioassays have been applied to cardiotoxicity assessment. However, the requisite large data sizes and long calculation times make long-term observations of heart rates difficult. In this study, we developed a real-time heart rate monitoring system for individual Daphnia magna in a water chamber mounter that immobilizes their movement in 100 mL media. Heart rates are calculated from real-time, time-resolved relative phase information from digital holograms acquired with a 200 fps camera and parallel computation using a graphics processing unit. With this system, we monitored the real-time changes in the heart rates of individual D. magna specimens exposed to H₂O₂ as a positive control for reactive oxygen species (ROS) levels in an aquatic environment for 10 h, a period long enough to observe dynamic heart rate responses to the mounting process and exposure and to establish heart rate trends. An additional group analysis was conducted to compare to conventional cardiotoxicity assessment, with results of both assessments showing that the heart rates reduced according to ROS level by H₂O₂ exposure concentration. Notably, the results of our real-time dynamic heart rate monitoring in aquatic conditions indicated that establishing a relaxation heart rate before measurements could improve the accuracy of toxicity assessment. It is believed that the system developed in this study, achieving the simultaneous measurement, analysis, and display of reconstructed results, will find wide application in other aquatic bioassays.

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

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

Deterministic and probabilistic health risk assessment for exposure to non-steroidal anti-inflammatory drugs in an Indian river

This study presents deterministic and probabilistic human health risk assessment using Monte Carlo simulations on exposure to an Indian river, Kaveri, which has been contaminated by non-steroidal anti-inflammatory drugs (NSAIDs). The NSAIDs of concern are naproxen, ibuprofen, aspirin, ketoprofen, and diclofenac. We have considered three exposure scenarios (water ingestion, dermal exposure, and fish ingestion) for four different age groups (0-5, 6-10, 11-18, and 19-70 years). Deterministic risk assessment revealed teenagers to be the most sensitive receptors and water ingestion to be the most crucial pathway contributing to maximum health risk (79 to 86%). Based on the results of Monte Carlo simulations, it was found that the probability of exceeding the deterministic mean risks ranged from 17 to 39% for different exposure routes. High end risk estimates such as 95th percentiles and maximum values of HQ for the entire population did not exceed the USEPA allowable risk. This implies that the NSAIDs at the detected concentrations in the Kaveri river may not pose adverse health effects even in the worst-case scenario. Among the five NSAIDs, diclofenac was found to be the major contributor for health risk. Moreover, the concentration of diclofenac was just one order less than the estimated site-specific threshold concentrations. From sensitivity analysis, the most and the least impactful parameters were found to be water ingestion rate and fish ingestion rate respectively.

The degradation pathways of carbamazepine in advanced oxidation process: A mini review coupled with DFT calculation

Degradation pathway is important for the study of carbamazepine (CBZ) removal in advanced oxidation processes (AOPs). Generally, degradation pathways are speculated based on intermediate identification and basic chemical rules. However, this semiempirical strategy is sometimes time-consuming and baseless. To improve the situation, a mini meta-analysis was first conducted for the degradation pathways of CBZ in AOPs. Then, the rationality of the pathways was analyzed by Density Functional Theory (DFT) calculation. Results show that the degradation pathways of CBZ in various AOPs has high similarity, and the reactive sites predicted by Fukui function fitted well with the data retrieved from literatures. In addition, molecule configuration of degradation intermediates was found to play a very important roles on degradation pathway. The study reveals that computational chemistry is a useful tool for degradation pathway speculation in AOPs.

Comparison of advanced biological treatment and nature-based solutions for the treatment of pharmaceutically active compounds (PhACs): A comprehensive study for wastewater and sewage sludge

Passing of pharmaceutical residues into environment in an uncontrolled manner as a result of continuous increase in drug consumption across the globe has become a threatening problem for the ecosystems and almost all living creatures. In this study, diclofenac (DCF), carbamazepine (CBZ), 17β-estradiol (17β-E2) and 17α-ethynylestradiol (EE2) belonging to different therapeutic classes were investigated simultaneously in advanced biological treatment and nature-based treatments during 12-months sampling campaign. In this context, behavior patterns of pharmaceutically active compounds (PhACs) throughout the both wastewater and sludge lines in advanced biological wastewater treatment plant (WWTP), wastewater stabilization pond (WSP) and constructed wetland (CW) were discussed in detail based on each treatment processes seasonally. Furthermore, statistically evaluated data obtained in full-scale WWTPs were compared with each other in order to determine the valid removal mechanisms of these pharmaceutical compounds. While DCF and CBZ were detected very intensively both in the wastewater and sludge lines of the investigated WWTPs, steroid hormones,17β-E2 and EE2, were determined below the LOQ value in general. Annual average removal efficiencies achieved in studied WWTPs for DCF ranged between -23.3% (in CW) and 75.2% (in WSP), while annual average removal rates obtained for CBZ varied between -20.7% (in advanced biological treatment) and 10.0% (in CW). It has been found that DCF was highly affected by different wastewater treatment processes applied in the WWTPs compared to CBZ which showed extraordinary resistance to all different treatment processes. Although calculated in different rates for each compounds, biodegradation/biotransformation and sorption onto sewage sludge were determined as the main removal mechanisms for PhACs in plants. Although showed a similar behavior in the sludge dewatering unit (decanter) present in the advanced biological WWTP, quite different behaviors observed in the anaerobic digester for DCF (up to 15% decrease) and CBZ (up to 95% increase). Sorption and desorption behaviors of DCF and CBZ were also evaluated in the sludge treatment processes found in advanced biological WWTP. Percentages of originated extra annual average of pharmaceutical loads were calculated as 0.64% and 0.90% for DCF and CBZ, respectively in the advanced biological WWTP due to the sidestream caused by the sludge dewatering unit.

Screening priority indicator pollutants in full-scale wastewater treatment plants by non-target analysis

Wastewater treatment plants (WWTPs) are the main sources of emerging contaminants (ECs) in aquatic environment. However, the standards for limiting emerging pollutants in effluent are extremely lacking. We investigated the occurrence and removal of emerging pollutants in 16 WWTPs in China using non-target analysis. 568 substances screened out were divided into 9 kinds including 167 pharmaceuticals, 113 natural substances, 85 pesticides, 86 endogenous substances, 64 chemical raw materials, 14 personal care products, 17 food additives, 6 hormones and 16 others. And they were divided into 5 fates. Pesticides and pharmaceutical compounds seemed to be the most notable categories, the kinds detected in each sample is the largest compared with other compounds. Besides, the average removal rate of pesticides and pharmaceuticals in all WWTPs were the lowest, at 9.54% and 23.77%, respectively. Priority pollutants were screened by considering distribution of pollutants with different fates. Pollutants with the same fate especially "consistent" in different WWTPs had attracted attention. 4 potential priority pollutants including metoprolol, carbamazepine, 10, 11-dihydro-10, 11-dihydroxycarbamazepine and irbesartan were proposed. And it was found that the 4 compounds, "consistent suspects" and "consistent non-targets" had similar rankings of removal rate in 16 WWTPs, which can reflect the performance of different WWTPs.

First surveillance of SARS-CoV-2 and organic tracers in community wastewater during post lockdown in Chennai, South India: Methods, occurrence and concurrence

Surveillance of SARS-CoV-2 and organic tracers (OTs) were conducted in the community wastewater of Chennai city and the suburbs, South India, during partial and post lockdown phases (August-September 2020) as a response to the coronavirus disease 2019 (COVID-19) pandemic. Wastewater samples were collected from four sewage treatment plants (STPs), five sewage pumping stations (SPSs) and at different time intervals from a suburban hospital wastewater (HWW). Four different methods of wastewater concentrations viz., composite (COM), supernatant (SUP), sediment (SED), and syringe filtration (SYR) were subjected to quantitative real time-polymerase chain reaction (qRT-PCR). Unlike HWW, STP inlet, sludge and SPS samples were found with higher loading of SARS-CoV-2 by SED followed by SUP method. Given the higher levels of dissolved and suspended solids in STPs and SPSs over HWW, we suspect that this enveloped virus might exhibit the tendency of higher partitioning in solid phase. Cycle threshold (Ct) values were < 30 in 50% of the HWW samples indicating higher viral load from the COVID-19 infected patients. In the STP outlets, a strict decline of biochemical oxygen demand, >95% removal of caffeine, and absence of viral copies reflect the efficiency of the treatment plants in Chennai city. Among the detected OTs, a combination of maximum dynamic range and high concurrence percentage was observed for caffeine and N1 gene of SARS-CoV-2. Hence, we suggest that caffeine can be used as an indicator for the removal of SARS-CoV-2 by STPs. Our predicted estimated number of cases are in line with the available clinical data from the catchments. Densely distributed population of the Koyambedu catchment could be partly responsible for the high proportion of estimated infected individuals during the study period.

Carbamazepine and Diclofenac Removal Double Treatment: Oxidation and Adsorption

In the present research, the effect of two hybrid treatments, ozone followed by powdered activated carbon (PAC) or PAC followed by ozone (O₃), was studied for the removal of two drugs present in water: diclofenac and carbamazepine. In the study, two initial concentrations of each of the contaminants, 0.7 mg L^-1 and 1.8 mg L^-1, were used. Different doses of PAC between 4-20 mg L^-1 were studied as variables, as well as different doses of O₃ between 0.056-0.280 mg L^-1. The evolution of the concentration of each contaminant over time was evaluated. From the results obtained, it was concluded that the combined treatment with ozone followed by PAC reduces between 50% and 75% the time required to achieve 90% removal of diclofenac when compared with the time required when only activated carbon was used. In the case of carbamazepine, the time required was 97% less. For carbamazepine, to achieve reduction percentages of up to 90%, O₃ treatment followed by PAC acted faster than PAC followed by O₃. In the case of diclofenac, PAC treatment followed by O₃ was faster to reach concentrations of up to 90%. However, to reach yields below 80%, O₃ treatment followed by PAC was more efficient.

Mechanisms of emerging pollutant Dechlorane Plus on the production of short-chain fatty acids from sludge anaerobic fermentation

The effect of emerging pollutant Dechlorane Plus (DPs), an organochlorine aliphatic flame retardant, on waste-activated sludge anaerobic fermentation was investigated, and the related mechanisms were revealed for the first time. The results of this experiment suggested that the presence of DPs had a significant inhibitory effect on sludge anaerobic fermentation to generate the intermediate valuable product short-chain fatty acids (SCFA), and when the DP content was 3034.1±101.7 mg/kg total suspended solids (TSS), the maximal output of SCFA was only 215.04 mg/g, which was 0.47 times of that in the blank. The underlying mechanism investigation indicated DPs promoted the disintegration of sludge, but inhibited the process of hydrolysis and acidification. DPs inhibited the release of soluble bound extracellular polymers (SB-EPS) in sludge. The analysis of microbial community characteristics indicated that DPs reduced the level of Firmicutes and Actinobacteriathe, which were the key acid producing bacteria. At the genus level, DPs reduced the relative abundance of Proteiniclasticum and Mycobacteriumwas.

Electrochemical degradation of DCF by boron-doped diamond anode: degradation mechanism, pathways and influencing factors

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been widely detected in wastewater and surface water, indicating that the removal of NSAIDs by wastewater treatment plants was not efficient. Electrochemical advanced oxidation technology is considered to be an effective process. This study presents an investigation of the kinetics, mechanism, and influencing factors of diclofenac (DCF) degradation by an electrochemical process with boron-doped diamond anodes. Relative operating parameters and water quality parameters are examined. It appears that the degradation follows the pseudo-first-order degradation kinetics. DCF degradation was accelerated with the increase of pH from 6 to 10. The degradation was promoted by the addition of electrolyte concentrations and current density. Humic acid and bicarbonate significantly inhibited the degradation, whereas chloride accelerated it. According to the quenching tests, hydroxyl radicals (•OH) and sulfate radicals contributed 76.5% and 6.5%, respectively, to the degradation. Sodium sulfate remains a more effective electrolyte, compared to sodium nitrate and sodium phosphate, suggesting the quenching effect of nitrate and phosphate on •OH. Major DCF transformation products were identified. According to the degradation products detected by liquid chromatography-mass spectrometry, hydroxylation and decarboxylation are the main pathways of DCF degradation; while dechlorination, chlorination, and nitro substitution are also included in this electrochemical degradation process.

Fabrication of Bi4O5Br2 photocatalyst for carbamazepine degradation under visible-light irradiation

Bi₄O₅Br₂ with irregular flake shape was synthesized by a facile and energy-saving hydrolysis method. Its band gap energy (E_g) was 2.1 eV. The formation mechanism was proposed. The Bi₄O₅Br₂ exhibited superb visible-light-induced photocatalytic activity (>90%) toward the oxidation of carbamazepine. The kinetics rate constant (k) attained 0.0196 min^-1. The effect of Bi₄O₅Br₂ dosage, initial solution pH value, and inorganic anions on carbamazepine degradation was investigated. During the oxidation process, photogenerated holes (h⁺) and superoxide radical anions (•O₂^-) were the main active species. Based on the reaction intermediates results determined through a combined system of liquid chromatography and mass spectrometry, a possible reaction mechanism was speculated. The degree of contamination of carbamazepine solution after treatment was evaluated through the teratogenic effect experiment. After 120 min of visible light exposure, the carbamazepine solution is free of pollution. Also, the as-synthesized Bi₄O₅Br₂ maintains good chemical stability and could be reused in the photodegradation process, indicating its potential in practical applications.

Boosting pharmaceutical removal through aeration in constructed wetlands

This work evaluated the removal efficiency of 13 wastewater-borne pharmaceuticals in a pilot constructed wetland (CW) operated under different aeration strategies (no aeration, intermittent and continuous). Aeration improved the removal of conventional wastewater parameters and the targeted micropollutants, compared to the non-aerated treatment. Reduction of chemical oxygen demand (COD) and total nitrogen (TN) was slightly higher applying intermittent aeration than applying continuous aeration, the opposite was observed for the investigated pharmaceuticals. Seven targeted compounds were found in influent wastewater, and five of them (acetaminophen, diclofenac, ketoprofen, bezafibrate and gemfibrozil) were efficiently removed (> 83%) in the aerated systems. The overall risk of the investigated samples against aquatic ecosystems was moderate, decreasing in the order influent > no aeration > intermittent aeration > continuous aeration, based on the hazard quotient approach. Lorazepam, diclofenac and ketoprofen were the pharmaceuticals that could contribute the most to this potential environmental impact of the CW effluents after discharge. To the authors' knowledge this is the first sound study on the removal and fate of ketoprofen, bezafibrate, and lorazepam in aerated CWs, and provides additional evidence on the removal and fate of acetaminophen, diclofenac, gemfibrozil, and carbamazepine in this type of bioremediation systems at pilot plant scale.

Degradation of diclofenac sodium using Fenton-like technology based on nano-calcium peroxide

A nano-calcium peroxide (nCaO₂) powder with a purity of 89.1% was prepared using an improved traditional method. Then, the as-prepared nCaO₂ was used as the source of hydrogen peroxide (H₂O₂) for the Fenton-like degradation of diclofenac sodium (DCF). The results showed that nCaO₂ performed better for DCF removal when compared to nCaO₂ prepared by a conventional method and commercial calcium peroxide (CaO₂). Further experimental results indicated that 97.5% of DCF could be removed in 180 min at a nCaO₂/Fe²⁺-EDTA/DCF molar ratio of 16/8-8/1, which was more efficient than in the H₂O₂/EDTA-Fe²⁺/DCF and nCaO₂/Fe²⁺/DCF systems. The best removal rate of DCF was at pH 6.0, unlike previous claims that stated that the lower the pH in the buffer system, the better the degradation of DCF. In addition, the influence of water quality parameters, such as Cl^-, NO₃^-, SO₄^2-, HCO₃^-, and humic acid (HA), on DCF removal were evaluated. A free radical masking experiment revealed the existence of hydroxyl radical (OH), superoxide radical (O₂^-) and singlet oxygen (¹O₂), and indicated that the degradation of DCF was mainly due to oxidation caused by OH. Electron paramagnetic resonance (EPR) studies for different systems and different active oxygen species were carried out, and it was further confirmed that OH radicals have high intensity in the Fenton-like system based on nCaO₂. EPR results also showed that the addition of EDTA can promote the production of OH. According to the identification of the dominant reactive species and GC-MS, the possible theoretical DCF degradation pathways were proposed.

Spatial variation of pharmaceuticals in the unit processes of full-scale municipal wastewater treatment plants in Korea

Several reports have elucidated the removal of pharmaceutical residues in municipal wastewater treatment plants (WWTPs). However, there remains a need to determine the spatial distribution of pharmaceuticals in the unit processes of full-scale municipal WWTPs. Herein, spatial variations of fifteen pharmaceuticals in the unit processes of four full-scale municipal WWTPs were assessed by analyzing both solid and liquid samples. Furthermore, different pathways of each pharmaceutical such as biodegradation, adsorption, deconjugation, and electrostatic interaction were investigated. Pharmaceutical mass loading were measured at various points for the different unit process and evaluated using liquid chromatography-tandem mass spectrometry. The average mass loading of acetaminophen and caffeine decreased tremendously in the first biological treatment process regardless of the process configuration. In contrast, a temporary increase was observed in the mass loading of ibuprofen in the anaerobic and/or anoxic processes, which was presumably caused by deconjugation. Additionally, the adverse effect of coagulation on ibuprofen removal was validated. The major removal mechanism for the selected antibiotics, except for sulfamethoxazole, was the adsorption by biosolids due to electrostatic interaction. Subsequently, a drastic decrease was observed in their mass loadings in the solid-liquid separation process of the WWTPs. The membrane bioreactor (MBR) shows excellent capability for mitigation of pharmaceuticals in municipal wastewater because it comprises a high concentration of biosolids that act as adsorbents. The evaluation of the spatial variations of the selected pharmaceuticals in different unit processes provides valuable information on their behavior and removal mechanisms.

Occurrence of pharmaceutical residues, personal care products, lifestyle chemicals, illicit drugs and metabolites in wastewater and receiving surface waters of Krakow agglomeration in South Poland

This is the first study of broad range of chemical classes CECs conducted in the upper Wisla river catchment including the biggest WWTPs in this region and surface waters. The list of compounds is extensive and the paper provides, for the first time, better understanding of environmental burden from PCPCs in Poland. Cumulative contribution of hypertension pharmaceuticals, nonsteroidal anti-inflammatory drugs (NSAIDs) and lifestyle chemicals was 89% and 95% in wastewater influent, and 75% in wastewater effluent at both WWTPs. Significant removal efficiencies, exceeding 90%, were found for parabens, UV filters, NSAIDs, steroid estrogens, plasticizers, antibacterials/antibiotics, stimulants and metabolites and lifestyle chemicals. The comparison of the average mass loads of CECs between the influent and effluent, has shown that 27% and 29% of all detected CECs were removed by less than 50%. An increase of concentrations of CECs in the effluent was observed for 18% and 20% of all detected CECs in Kujawy and Plaszow WWTPs, respectively. Negative mass balances of fexofenadine, venlafaxine, o-desmethyltramadol, ketamine and temazepam were noted within WWTPs, which are a result of dissolution of persistent contaminants accumulated in aggregates and/or back-transformation or de-conjugation of metabolites into parent compounds. 44 CECs were detected in surface waters located upstream and downstream of the WWTPs. The concentrations of compounds were largely dependent on the dilution factor of WWTP discharge. The risk quotation (RQ) values for compounds present in surface waters were calculated in relation to their potential for bioaccumulation. Among compounds with high potential for bioaccumulation, with log K_OW ≥ 4.5, diclofenac, atorvastatin and triclosan were found to be of high risk. Many CECs with high, moderate or even low environmental impact have shown high potential for bioaccumulation and should be considered as priority at the same risk level. Moreover, possible synergistic action is still of concern.

Constructed wetlands operated as bioelectrochemical systems for the removal of organic micropollutants

The removal of organic micropollutants (OMPs) has been investigated in constructed wetlands (CWs) operated as bioelectrochemical systems (BES). The operation of CWs as BES (CW-BES), either in the form of microbial fuel cells (MFC) or microbial electrolysis cells (MEC), has only been investigated in recent years. The presented experiment used CW meso-scale systems applying a realistic horizontal flow regime and continuous feeding of real urban wastewater spiked with four OMPs (pharmaceuticals), namely carbamazepine (CBZ), diclofenac (DCF), ibuprofen (IBU) and naproxen (NPX). The study evaluated the removal efficiency of conventional CW systems (CW-control) as well as CW systems operated as closed-circuit MFCs (CW-MFCs) and MECs (CW-MECs). Although a few positive trends were identified for the CW-BES compared to the CW-control (higher average CBZ, DCF and NPX removal by 10-17% in CW-MEC and 5% in CW-MFC), these proved to be not statistically significantly different. Mesoscale experiments with real wastewater could thus not confirm earlier positive effects of CW-BES found under strictly controlled laboratory conditions with synthetic wastewaters.

Enzymatic activity changes in striped catfish Pseudoplatystoma magdaleniatum, induced by exposure to different concentrations of ibuprofen and triclosan

The present study aimed to evaluate the effects of exposure for four months, with ibuprofen and triclosan at 25 and 50 μg/L in Striped catfish Pseudoplatystoma magdaleniatum, evaluated between sexes and exposure times. Biochemical biomarkers such as lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyltransferase, acetylcholinesterase, creatine kinase, lipid peroxidation, albumin, globulins, creatinine, and urea were evaluated. The results of this study suggest that both ibuprofen and triclosan at concentrations of 25 and 50 μg/L can cause alterations to P. magdaleniatum, interfering with the activity of certain enzymes associated with energy production, immune response, architecture, and cellular physiology. Also, we determined the current state of contamination in fish, the concentration of ibuprofen and triclosan in P. magdaleniatum muscle samples from the different places markets located on the banks of the main rivers of Colombia was quantified by UHPLC-QqQ-MS/MS, in three climatic periods; finding triclosan levels in the dry season in some of the sampling points compatible with enzyme-level alterations in this species.

A review of combined sewer overflows as a source of wastewater-derived emerging contaminants in the environment and their management

Emerging contaminants such as pharmaceuticals, illicit drugs and personal care products can be released to the environment in untreated wastewater/stormwater mixtures following storm events. The frequency and intensity of combined sewer overflows (CSOs) has increased in some areas due to increasing urbanisation and climate change. Therefore, this review provides an up-to-date overview on CSOs as an environmental source of emerging contaminants. Other than compounds with high removal, those chiral species subject to enantioselective changes (i.e. degradation or inversion) during wastewater treatment can be effective markers of CSO discharge in the environment. A proposed framework for the selection of emerging contaminants as markers of CSOs is outlined. Studies have demonstrated that CSOs can be the main source of emerging contaminants with high removal efficiency during wastewater treatment (e.g. > 90%). However, the impact of CSOs on the environment is location specific and requires decision-making on their appropriate management at catchment level. This process would be aided by further studies on CSOs which incorporate the monitoring of emerging contaminants and their effects in the environment with those more routinely monitored pollutants (e.g. pathogens and priority substances). Mitigation and treatment strategies for emerging contaminants in CSOs are also discussed.

Pharmaceutical and Personal Care Products in Different Matrices: Occurrence, Pathways, and Treatment Processes

The procedures for analyzing pharmaceuticals and personal care products (PPCPs) are typically tedious and expensive and thus, it is necessary to synthesize all available information from previously conducted research. An extensive collection of PPCP data from the published literature was compiled to determine the occurrence, pathways, and the effectiveness of current treatment technologies for the removal of PPCPs in water and wastewater. Approximately 90% of the compiled published papers originated from Asia, Europe, and the North American regions. The incomplete removal of PPCPs in different water and wastewater treatment processes was widely reported, thus resulting in the occurrence of PPCP compounds in various environmental compartments. Caffeine, carbamazepine, diclofenac, ibuprofen, triclosan, and triclocarban were among the most commonly reported compounds detected in water and solid matrices. Trace concentrations of PPCPs were also detected on plants and animal tissues, indicating the bioaccumulative properties of some PPCP compounds. A significant lack of studies regarding the presence of PPCPs in animal and plant samples was identified in the review. Furthermore, there were still knowledge gaps on the ecotoxicity, sub-lethal effects, and effective treatment processes for PPCPs. The knowledge gaps identified in this study can be used to devise a more effective research paradigm and guidelines for PPCP management.

Removal of Carbamazepine onto Modified Zeolitic Tuff in Different Water Matrices: Batch and Continuous Flow Experiments

Carbamazepine (CBZ) is the most frequently detected pharmaceutical residues in aquatic environments effluent by wastewater treatment plants. Batch and column experiments were conducted to evaluate the removal of CBZ from ultra-pure water and wastewater treatment plant (WWTP) effluent using raw zeolitic tuff (RZT) and surfactant modified zeolite (SMZ). Point zero net charge (pHpzc), X-ray diffraction (XRD), X-ray fluorescence (XRF), and Fourier Transform Infrared (FTIR) were investigated for adsorbents to evaluate the physiochemical changes resulted from the modification process using Hexadecyltrimethylammonium bromide (HDTMA-Br). XRD and FTIR showed that the surfactant modification of RZT has created an amorphous surface with new alkyl groups on the surface. The pHpzc was determined to be approximately 7.9 for RZT and SMZ. The results indicated that the CBZ uptake by SMZ is higher than RZT in all sorption tests (>8 fold). Batch results showed that the sorption capacity of RZT and SMZ in WWTP effluent (0.029 and 0.25 mg/g) is higher than RZT and SMZ (0.018 and 0.14 mg/g) in ultrapure water (1.6–1.8 fold). Batch tests showed that the equilibrium time of CBZ removal in the WWTP matrix (47 h) is much longer than CBZ removal in ultrapure water. The sorption capacity of RZT & SMZ in WWTP effluent (0.03, 0.33 mg/g) is higher than RZT and SMZ (0.02 and 0.17 mg/g) in ultrapure water (1.5–2 fold) using column test. This study has clearly demonstrated that the performance of RZT and SMZ is more efficient for the removal of CBZ from realistic wastewater than ultrapure water. It is evident that the surfactant modification of RZT has enhanced the CBZ removal in both matrices.

Matrix composition during ozonation of N-containing substances may influence the acute toxicity towards Daphnia magna

Micropollutants reach the aquatic environment through wastewater treatment plant effluents. Ozonation, applied in wastewater treatment for micropollutants abatement, can yield transformation products (TP), which might be of ecotoxicological concern. Previous studies on TP formation were mostly performed in ultrapure water. However, the water matrix can have a substantial influence and lead to unpredictable yields of TPs with toxicological potential. In this study the acute toxicity (immobilization) of the parent substances (isoproturon and metoprolol) and also of available TPs of isoproturon, metoprolol and diclofenac towards Daphnia magna (D. magna) were investigated. Further, the acute toxicity of TP mixtures, formed during ozonation of isoproturon, metoprolol and diclofenac was evaluated in the following systems: in the presence of radical scavengers (tert-butanol and dimethyl sulfoxide) and in the presence of hypobromous acid (HOBr), a secondary oxidant in ozonation. For all tested substances and TP standards, except 2,6-dichloroaniline (EC₅₀ 1.02 mg/L (48 h)), no immobilization of D. magna was detected. Ozonated pure water and wastewater did not show an immobilization effect either. After ozonation of diclofenac in the presence of dimethyl sulfoxide 95% (48 h) of the daphnids were immobile. Ozonation of parent substances, after the reaction with HOBr, showed no effect for isoproturon but a high effect on D. magna for diclofenac (95% immobilization (48 h)) and an even higher effect for metoprolol (100% immobilization (48 h)). These results emphasize that complex water matrices can influence the toxicity of TPs as shown in this study for D. magna.

Preparation and Characterization of Magnetic Polypyrrole Composite Microspheres Decorated with Copper (II) As A Sensing Platform for Electrochemical Detection of Carbamazepine

With a facile solvothermal technique, synthesis and application of Fe₃O₄@PPy–Cu^IIcomposite microspheres in the carbon ionic liquid matrix have been reported as highly sensitive sensors for voltammetric determination of Carbamazepine (CBZ). The morphology, crystal phase, and structure of synthesized nanocomposite were confirmed by routine methods, such as transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier translation infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Under the optimized conditions, differential pulse voltammetric (DPV) peak current was proportional to the CBZ concentration in the range of 0.05 to 25 μM with the detection limit (S/N = 3) of 32 nM. The storage stability of the modified electrode was also investigated which shows that the current responses remain about 95.2% of their initial values, indicating the appreciable storage stability of this sensor.The proposed electrode displayed excellent repeatability and it was satisfactorily used for determination of CBZ in real samples (urine, and serum samples) with high recovery.

Selective adsorption and enhanced photodegradation of diclofenac in water by molecularly imprinted TiO2

In the paper, molecularly imprinted TiO₂ was prepared by surface molecularly imprinted technology and liquid phase deposition method for preferential removal of persistent toxic pollutants from complex environmental water. Diclofenac was selected as the template molecule and target for photodegradation study. The characterization results of SEM, TEM, FTIR and XRD showed that the TiO₂ film with imprinted diclofenac was successfully synthesized on the surface of TiO₂ particles. Meanwhile, the adsorption and photodegradation experiments also indicated that the molecularly imprinted TiO₂ had larger adsorption capacity, better selectivity and higher photodegradation performance for diclofenac than non-imprinted TiO₂. The primary active species and degradation pathways during photodegradation process were also elucidated according to radical capture experiments and UPLC-MS-TOF technology. The prepared molecularly imprinted TiO₂ has the advantages of efficient removal ability, high stability and environmental protection, so it has a wide application value in water treatment and water environmental restoration, especially when involved persistent toxic pollutants.

In situ functionalization of a cellulosic-based activated carbon with magnetic iron oxides for the removal of carbamazepine from wastewater

The main goal of this work was to produce an easily recoverable waste-based magnetic activated carbon (MAC) for an efficient removal of the antiepileptic pharmaceutical carbamazepine (CBZ) from wastewater. For this purpose, the synthesis procedure was optimized and a material (MAC4) providing immediate recuperation from solution, remarkable adsorptive performance and relevant properties (specific surface area of 551 m² g^-1 and saturation magnetization of 39.84 emu g^-1) was selected for further CBZ kinetic and equilibrium adsorption studies. MAC4 presented fast CBZ adsorption rates and short equilibrium times (< 30-45 min) in both ultrapure water and wastewater. Equilibrium studies showed that MAC4 attained maximum adsorption capacities (q_m) of 68 ± 4 mg g^-1 in ultrapure water and 60 ± 3 mg g^-1 in wastewater, suggesting no significant interference of the aqueous matrix in the adsorption process. Overall, this work provides evidence of potential application of a waste-based MAC in the tertiary treatment of wastewaters. Graphical abstract.

Carbamazepine removal from low-strength municipal wastewater using a combined UASB-MBR treatment system

An Upflow Anaerobic Sludge Blanket reactor combined with a two-stage membrane bioreactor were operated for 193 days in order to evaluate the biological removal of carbamazepine (CBZ) from low-strength municipal wastewater. The system worked in three different organic load stages (0.7 ± 0.1 kg COD·m^-3·d^-1, 0.4 ± 0.1 kg COD·m^-3·d^-1 and 0.1 ± 0.0 kg COD·m^-3·d^-1) to assess the impact of the influent OLR on operational parameters such as anaerobic and aerobic sludge retention time (SRT), acidity, volatile fatty acids (VFAs), biomass activity or biogas production. The highest carbamazepine removals were achieved during the anaerobic stage (UASB reactor), reaching averages of 48.9%, 48.0% and 38.2% operating at high, medium and low OLR, respectively. The aerobic treatment (MBR) served as post-treatment, improving the removals, and the global UASB-MBR system reached averages of 70.0%, 59.6% and 49.8% when the influent was at medium and low OLR, respectively. The results demonstrate the potential of combined biological systems on the removal of recalcitrant pharmaceuticals.

Immunity and inflammatory responses in gilthead sea bream (Sparus aurata L.) exposed to sub-lethal mixture of carbamazepine, cadmium chloride and polybrominated diphenyl ether

Chemical contaminants such as industrial and urban by-products, pharmaceuticals, drugs metabolites and, plastics, are continuously found in the oceans, affecting its quality and organism's welfare. Although these compounds are found at concentrations ranged ng L^-1, there is an increasing concern about the potential adverse effects of the interactions among those substances present, simultaneously, in a mixture. In the present study, specimens of sea bream (Sparus aurata) were exposed, by food, to rising concentrations of a mixture of carbamazepine, polybrominated diphenyl ether-47 and cadmium chloride, for 15 days and then, maintained, with the same control diet, without contaminants, for other 15 days. Samples of skin mucus, serum, head-kidney, liver and intestine were sampled at 0, 15 and 30 days. Cellular immune parameters were evaluated on head-kidney, as well as humoral parameters were determined on skin mucus and serum. In addition, the expression of some genes, related to immunity, was analysed on liver and intestine. Both cellular and humoral response were affected at 15 days, showing slightly signs of recovery at 30 days. Besides, the expression of immune-related genes was highly affected, suggesting the development of inflammatory processes, as well as a reduction of immune parameters. Overall, the mixture of compounds severally affected the immune system of sea bream, suggesting a lower degree of recovery. The prolonged exposure to a mixture of these compounds could entail serious change on population immunity and, eventually, promote changes on marine biota.

Photocatalytic degradation of diclofenac using TiO2-CdS heterojunction catalysts under visible light irradiation

The present study reports the photocatalytic degradation of analgesic drug diclofenac using the hydrothermally prepared TiO₂-CdS heterojunction catalyst. The results suggest that the prepared catalysts exhibited excellent photocatalytic activity under visible light irradiation. The photodegradation kinetics were well fitted to the pseudo-first-order reaction. The apparent reaction rate constant for TC5 catalyst in the diclofenac degradation was 0.02316 min^-1. Mineralisation of diclofenac using TC5 photocatalyst was around 86% within 4 h of irradiation time. The operating parameters such as optimal catalyst dosage, apparent solution pH and the effect of initial diclofenac concentration were also studied using the TC5 catalyst. The role of active species in the degradation mechanism was elucidated and it was found that the hydroxyl radical is the main active species in the diclofenac degradation mechanism. The charge transfer between heterojunction catalysts is facilitated by direct Z-scheme heterojunction structure. The coupled photocatalysts also showed good photochemical stability and reusability over five successive reaction cycles. The tentative degradation pathway has been devised based on LC-MS peaks, and it is found that only m/z 224, m/z 178 and m/z 124 were persisted at the end of the reaction.

Removal of pharmaceuticals and personal care products using native fungal enzymes extracted during the ligninolytic process

Significant concentrations of pharmaceuticals and personal care products (PPCPs) have been detected in aquatic environment. Fungal enzymatic processes can oxidize these persistent PPCPs; thus, these processes have attracted considerable attention from the scientific community. Here, we evaluated the efficacy of the removal of PPCPs using native fungal enzymes derived from Bjerkandera spp. TBB-03 under various conditions. Among the eight lignocellulosic substrates, ash, which showed the highest laccase production, was selected as the sole enzyme inducer. TBB-03 laccase was found to exhibit remarkable stability under varied pH and temperature conditions. Acetaminophen and bisphenol A were effectively removed by TBB-03 laccase under various conditions, except at pH 8. Although TBB-03 laccase could not efficiently remove single-state sulfamethoxazole directly, a 22% of improvement in sulfamethoxazole removal was observed in the presence of acetaminophen. Overall, our proposed approach showed that Bjerkandera adusta TBB-03 can be potentially applied for further research regarding PPCP remediation.

The impact of chloride and chlorine radical on nitrite formation during vacuum UV photolysis of water

The impact of chloride ion and chlorine radical on the formation of nitrite was investigated under Vacuum-UV (VUV) photolysis of nitrate contaminating water. An increase in chloride concentration reduced nitrite formation in part due to the relatively high VUV absorption of chloride. The use of various radical scavengers, such as acetate and acetone, helped delineate the specific roles of hydroxyl radical (HO) and chlorine radical (Cl) in oxidation and VUV photolysis of nitrate, and the subsequent formation of nitrite. HO reduced nitrite formation due to its high reaction rate constant with nitrite. Nitrite formation in both chloride and dissolved organic carbon (DOC) containing solution depended primarily on their relative concentrations. Carbamazepine (CBZ) was also used to analyze the effect of Cl on both the degradation of CBZ and the formation of nitrite. Cl showed to significantly increase the degradation of CBZ, but it had little impact on the formation of nitrite. This paper, utilizing detailed experimental data combined with kinetic modeling and mechanistic analysis of VUV photolysis in the presence of chloride and nitrate, provides the necessary scientific guidance towards more effective and optimized applications of VUV technology for drinking water treatment.

On the Use of Mechanistic Soil-Plant Uptake Models: A Comprehensive Experimental and Numerical Analysis on the Translocation of Carbamazepine in Green Pea Plants

Food contamination is a major worldwide risk for human health. Dynamic plant uptake of pollutants from contaminated environments is the preferred pathway into the human and animal food chain. Mechanistic models represent a fundamental tool for risk assessment and the development of mitigation strategies. However, difficulty in obtaining comprehensive observations in the soil-plant continuum hinders their calibration, undermining their generalizability and raising doubts about their widespread applicability. To address these issues, a Bayesian probabilistic framework is used, for the first time, to calibrate and assess the predictive uncertainty of a mechanistic soil-plant model against comprehensive observations from an experiment on the translocation of carbamazepine in green pea plants. Results demonstrate that the model can reproduce the dynamics of water flow and solute reactive transport in the soil-plant domain accurately and with limited uncertainty. The role of different physicochemical processes in bioaccumulation of carbamazepine in fruits is investigated through Global Sensitivity Analysis, which shows how soil hydraulic properties and soil solute sorption regulate transpiration streams and bioavailability of carbamazepine. Overall, the analysis demonstrates the usefulness of mechanistic models and proposes a comprehensive numerical framework for their assessment and use.