Concentrations Of Diclofenac Research Articles

TiO2-reduced graphene oxide nanocomposites for the trace removal of diclofenac

Solar photocatalysis using TiO2-reduced graphene oxide (T-RGO) nanocomposite as catalyst is explored for the removal of the last traces of diclofenac (DCF) pollutant from water. T-RGO nanocomposites of different compositions were synthesised by a modified process involving solvothermal treatment of titanium isopropoxide and graphene oxide (GO) in isopropanol medium. The prepared catalysts have been characterised by powder X-ray diffraction, infrared spectroscopy, Raman spectroscopy, transmission electron microscopy, photoluminescence emission spectroscopy, UV–Vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy and N2 adsorption–desorption measurements. The degradation of DCF is highly facile under solar irradiation in the presence of T-RGO with more than 98% of the 25 mg/L DCF aqueous solution getting degraded in 60 min followed by complete mineralisation in 100 min. Relevant reaction parameters such as catalyst loading, RGO content in the composite, concentration of DCF and the influence of pH on the degradation of the pollutant were identified and optimised. Reaction intermediates were identified by using LC–MS technique. The degradation followed Langmuir–Hinshelwood mechanism and pseudo first order kinetics. The stability and reusability of the catalyst are established. The efficiency of the catalyst in various real water matrices has also been proved thereby affirming its potential for commercial applications.

Distribution of micropollutants in estuarine and sea water along the Portuguese coast

This work provides the first spatial distribution report of micropollutants (MPs) in the entire Portuguese coast, comprising the ocean shore (sea water, SW) and whenever possible the nearest river discharging on it (estuarine water, EW). This surface water monitoring programme aimed to assess the spatial distribution of 37 MPs with a wide chemical nature, including some substances prioritized by the European Union Directive 39/2013/EU and contaminants of emerging concern targeted in the Watch List of Decisions 495/2015/EU and 840/2018/EU. The risk quotients were estimated in each sampling point for the detected MPs. High concentrations of diclofenac, tramadol and carbamazepine were determined, the latter with medium to high risk for algae. Some pharmaceuticals and perfluorooctanesulfonic acid (PFOS) were broadly distributed, maybe due to the direct discharge into the sea. Atrazine and alachlor were found in the majority of the samples, with alachlor levels often considered as medium to high risk.

Nanocellulose-Based Patches Loaded with Hyaluronic Acid and Diclofenac towards Aphthous Stomatitis Treatment.

Nanostructured patches composed of bacterial nanocellulose (BNC), hyaluronic acid (HA) and diclofenac (DCF) were developed, envisioning the treatment of aphthous stomatitis. Freestanding patches were prepared via diffusion of aqueous solutions of HA and DCF, with different concentrations of DCF, into the wet BNC three-dimensional porous network. The resultant dual polysaccharides-based patches with a nanostructured morphology present thermal stability up to 200 °C, as well as good dynamic mechanical properties, with a storage modulus higher than 1.0 GPa. In addition, the patches are non-cytotoxic to human keratinocytes (HaCaT cells), with a cell viability of almost 100% after 24 h. The in vitro release profile of DCF from the patches was evaluated in simulated saliva, and the data refer to a diffusion- and swelling-controlled drug-release mechanism. The attained results hint at the possibility of using these dual polysaccharides-based oral mucosal patches to target aphthous stomatitis.

Influence of aquatic colloids on the bioaccumulation and biological effects of diclofenac in zebrafish (Danio rerio)

Natural aquatic colloids play an important role in the migration, transformation of pollutants in the environment, but their potential effects are often ignored in ecotoxicology research. In this study, diclofenac (DCF) was selected as a typical drug to study the effects of natural colloids on the bioaccumulation and biotoxicity in juvenile zebrafish (Danio rerio) exposed to an environmentally relevant concentration (1μg/L) and a high concentration (100μg/L) of DCF. The results showed that the presence of colloids accelerated and enhanced the accumulation of DCF in zebrafish muscle and viscera, and the effects are greater at the environmentally relevant concentration of DCF. However, the colloids enhanced the burden in the head in the environmentally relevant concentration group, but reduced it in the high concentration group. This observation may be related to the occurrence of variations in the contribution of the adsorption forms of DCF and the colloids depending on different DCF concentrations. At the same time, the presence of colloids can significantly induce AChE activity of DCF in the brain and alter swimming activity and shoaling behaviour of the individuals, however no significant effects on the attack and shock behaviour were observed. These findings indicate that the combination of natural colloids and pollutants may change with pollutant concentrations, thereby altering the bioaccumulation and biological effects in aquatic organisms.

Toxic effects of diclofenac on gills, liver and kidney of Cyprinus carpio (Linnaeus, 1758)

Diclofenac, the anti-inflammatory drug, is found in natural water bodies all over the world. Toxicological researches of diclofenac report harmful effects on aquatic species even at low concentrations. The aim of the present study is to determine whether diclofenac affects the gills, livers and kidneys of common carp (Cyprinus carpio). In order to evaluate the toxic effects of diclofenac as NASIDs in fish, common carps (Cyprinus carpio) were exposed to diclofenac concentrations of 1.25 mg/L, 2.5 mg/L and 5 mg/L. Over a 21-day experiment period, diclofenac effects on the fishes were investigated by weekly histopathological observations. The histopathological examinations of diclofenac on the exposed fishes revealed alterations of the kidneys pertaining to hyaline droplet, increase in interstitial cells, shrinkage of glomeruli, and the presence of melanomacrophages and necrosis of epithelial cells of tubules. In the gills, the predominant finding consisted of epithelial hyperplasia, telangiectasia, clubbing, lamellar fusion, and increase of mucosal cells. Histopathological alterations were also observed in the liver, including the presence of melanomacrophages, degeneration, vacuolation of hepatocytes, and necrosis. Comparatively, the most alterations were found in the gills and the liver. On the contrary, the gills, livers and kidney sections of two control groups exhibited normal architecture. The study’s results revealed that diclofenac could be harmful for Cyprinus carpio (as one of the main species in Caspian Sea).

Topical Diclofenac, an Efficacious Treatment for Osteoarthritis: A Narrative Review.

Multiple head-to-head trials have demonstrated that topical nonsteroidal anti-inflammatory drugs (NSAIDs), including topical diclofenac, provide at least equivalent analgesia, improvement in physical function, and reduction of stiffness compared with oral NSAIDs in osteoarthritis and have fewer systemic adverse events. While efficacy of topical diclofenac in osteoarthritis is well established, understanding of the time to onset of action, duration of effect, and the minimum effective concentration is limited. Factors likely to influence these parameters include drug penetration and localization. Diclofenac concentrations in the joint tissues are likely to be more relevant than plasma concentrations. However, although diclofenac penetrates and is retained in these “effect compartments” at the site of inflammation and drug activity, no specific minimum effective concentration of diclofenac in plasma or synovial tissue has been identified. Recent evidence suggests that a reduction in inflammatory markers may be a better predictor of efficacy than plasma concentrations. This narrative review explores existing evidence in these areas and identifies the gaps where further research is needed. Based on our findings, topical NSAIDs such as diclofenac should be considered as a guideline-supported, generally well-tolerated, and effective first-line treatment option for knee and hand OA, especially for older patients and those who have comorbid conditions and/or risk factors for various systemic (gastrointestinal, hepatic, renal, or cardiovascular) adverse events associated with oral NSAIDs, particularly at high doses and with long-term use.Electronic supplementary materialThe online version of this article (10.1007/s40744-020-00196-6) contains supplementary material, which is available to authorized users.

Occurrence and environmental risks of nonsteroidal anti-inflammatory drugs in urban wastewater in the southwest monsoon region of India.

Municipal wastewater treatment plants (MWWTPs) are considered to reduce the amount of pollutants that enter water reservoirs as a result of wastewater disposal. An assessment of the occurrence and removal of pharmaceutical compounds, mainly nonsteroidal anti-inflammatory drugs (NSAIDs), in wastewater from the Kavoor MWWTP (southwest monsoon region), India, is presented in this paper. The performance of the MWWTP was monitored in the summer (May) and monsoon (September) periods. The highest inlet concentrations of diclofenac, naproxen, ibuprofen, ketoprofen, and acetylsalicylic acid in the wastewater were observed in May and were 721.37, 2132.48, 2109.875, 2747.29, and 2213.36μg/L, respectively. The ketoprofen content was found to be higher than that of other NSAIDs in the influent in both seasons, whereas the diclofenac content was found to be the lowest. The removal efficiency (RE) of the target NSAIDs in the Kavoor secondary treatment plant varied from 81.82-98.92% during the summer season. During the monsoon season, the influent NSAID concentration level dropped, probably because of infiltration in old sewer pipes. In addition, a 100% RE was achieved for all the target NSAIDs in the wastewater of the MWWTP. The results showed that secondary treatment plants have the potential to remove NSAID compounds from municipal sewage with consistent performance. The environmental hazards caused by the accumulation of such compounds in water reservoirs are due to open discharge. The environmental risk levels of these compounds were also studied by the environmental risk assessment (ERA) using the European Agency for Evaluation of Medicines approach.

Optimization, equilibrium, adsorption behavior and role of surface functional groups on graphene oxide-based nanocomposite towards diclofenac drug

Aquatic contamination of diclofenac (DCF), an emergent non-steroidal anti-inflammatory drug (NSAIDs), can result in adverse effects to many ecosystems through biomagnification. Hence, introducing effective remediation techniques to sequester the pharmaceutical wastes is highly fundamental to prevent their accumulation in the environment. Generally, adsorption has been presented as a green and efficient approach. Herein, we report the characterization and application of the novel magnetic nanocomposite (GO@CoFe2O4) derived from cobalt-based ferrite (CoFe2O4) and graphene oxide (GO) for DCF adsorption. For the optimization procedure, the response surface methodology (RSM) was adopted to investigate the impacts of DCF concentration (1.6–18.4 mg/L), DCF dosage (0.08–0.92 g/L), and solution pH (2.6–9.4) to find the optimum conditions for DCF removal, at 10.5 mg/L, 0.74 g/L, and pH 4, respectively. For the adsorption experiments, the kinetic, isotherm, thermodynamic, and intraparticle diffusion models were systematically studied. Moreover, we have elucidated the role of functional groups on the surface of GO@CoFe2O4 in enhancing the adsorption of DCF drug. With good removal efficiency (up to 86.1%), high maximum adsorption capacity (32.4 mg/g), GO@CoFe2O4 can be a potential candidate to eliminate DCF drug from water.

First Electrochemical Sensor (Screen-Printed Carbon Electrode Modified with Carboxyl Functionalized Multiwalled Carbon Nanotubes) for Ultratrace Determination of Diclofenac.

A simple, sensitive and time-saving differential-pulse adsorptive stripping voltammetric (DPAdSV) procedure using a screen-printed carbon electrode modified with carboxyl functionalized multiwalled carbon nanotubes (SPCE/MWCNTs-COOH) for the determination of diclofenac (DF) is presented. The sensor was characterized using optical profilometry, SEM, and cyclic voltammetry (CV). The use of carboxyl functionalized MWCNTs as a SPCE modifier improved the electron transfer process and the active surface area of sensor. Under optimum conditions, very sensitive results were obtained with a linear range of 0.1–10.0 nmol L−1 and a limit of detection value of 0.028 nmol L−1. The SPCE/MWCNTs-COOH also exhibited satisfactory repeatability, reproducibility, and selectivity towards potential interferences. Moreover, for the first time, the electrochemical sensor allows determining the real concentrations of DF in environmental water samples without sample pretreatment steps.

Toxic effects of environmentally realistic concentrations of diclofenac in organisms from two distinct trophic levels, Hediste diversicolor and Solea senegalensis

The use of pharmaceutical drugs has systematically increased, resulting in their environmental presence and exertion of effects on non-target aquatic organisms. Diclofenac (DCF) is an analgesic, anti-inflammatory and antipyretic drug, frequently found in the aquatic compartment. The present work analyzed the ecotoxicological effects of DCF in the marine polychaete Hediste diversicolor and in the marine fish Solea senegalensis. In addition, the putative toxic effects of DCF along a simulated food chain were studied, by feeding individuals of S. senegalensis with H. diversicolor previously exposed to DCF. Biomarkers of anti-oxidant defense (catalase, CAT), phase II metabolism (glutathione S-transferases, GSTs) and neurotoxicity (acetylcholinesterase, AChE) were quantified. The obtained results demonstrated that DCF did not affect CAT activity in organisms of both species directly exposed through the water, suggesting the absence of oxidative effects. In addition, organisms directly or indirectly exposed to DCF showed an increase of GSTs activities, suggesting an additional challenge to the metabolism of the exposed individuals. However, significant decreases in the activities of CAT and AChE were observed in fish fed with worms previously exposed to DCF. These data suggest that direct or indirect exposure to DCF may cause significant physiological modifications in aquatic organisms. In addition, exposure of wild organisms via contaminated food may lead to toxicological effects which may differ from alterations elicited by direct exposure. Such toxicological differences, between direct (waterborne) and trophic (via contaminated feed) exposures were qualitatively distinct, and need to be fully addressed when considering the consequences of environmental contamination by therapeutic drugs.

Adsorption of Diclofenac from Aqueous Solution Using Highly Meso porous Carbon

Synthetics of mesoporous carbon (MC) from biomass including sucrose was used as the carbon resource, and eutectic salt (KCl/NaCl) as the porogen agent for the preparation of S-MC (sucrose mesopores carbons). The resultant samples were examined by means of different techniques, including thermal analysis (TGA), FTIR, transmitted electron microscopy (TEM), X-ray diffraction (XRD) and BET measurements. Investigate the efficiency of adsorption of diclofenac by highly mesopores carbons using Ultraviolet–Visible spectroscopy. The final concentrations of diclofenac were measured using Ultraviolet–Visible spectroscopy at different conditions (pH, contact time, temperature, weight of adsorbate, weight of adsorbent).

A Review on Diclofenac Removal from Aqueous Solution, Emphasizing on Adsorption Method

Diclofenac is a drug with an analgesic effect that accumulates and results in adverse consequences if it enters the human body more than needed. Low concentrations of diclofenac have been detected in different water sources through leachates of landfills and agricultural areas, human and animal excreta expired drug discharge, and hospital effluents. To eliminate diclofenac from the aquatic environment, different removal methods such as membrane filtration, ozonation, advanced oxidation, Fenton oxidation, electrochemical oxidation, photocatalysis, soil aquifer treatment, ion exchange, and adsorption are studied. Adsorption is considered to be more effective and economical than other methods in case of wastewater treatment. In this review paper, studies on diclofenac removal applying different methods, especially adsorption, are inquired and the adsorbents are divided into two main categories; carbonaceous and other adsorbents. The effect of different parameters such as contact time, pH, adsorbent dosage, initial concentration, and temperature on the adsorption process in the related studies is also mentioned. Furthermore, the equilibrium isotherms, and the adsorption kinetics of the studies were also noted. By studying the literature, it was clear that the pH value was a key parameter among all because it has a main effect on the removal efficiency and it is dependent on the pKa of diclofenac and the pHZPC of the adsorbent.

Endocrine disruptive action of diclofenac and caffeine on Astyanax altiparanae males (Teleostei: Characiformes: Characidae)

Diclofenac (DCF) and caffeine (CAF) are persistent pharmaceuticals that occur in mixtures in the aquatic ecosystems causing effects in the reproductive physiology of aquatic organisms. This study evaluated the physiological reproductive responses of Astyanax altiparanae males exposed to nominal concentrations of DCF (3.08 mg L−1) and CAF (9.59 mg L−1) separately and combined, for 96 h. The steroids profile, estrogenic biomarker vitellogenin (vtgA), testes and liver morphology, and also mortality of males were assessed. DCF and CAF degradation was 5% of the initial concentration for 24 h. The LC50 of the DCF and CAF were 30.8 mg L−1 and 95.9 mg L−1, respectively. Males exposed to DCF and CAF exhibited a reduction of 17β-Estradiol (E2) concentration compared to control (CTL). Similarly, testosterone (T) was also reduced in the DCF treatment, but this response was not observed in 11-Ketotestosterone (11-KT). Males exposed to DCF + CAF combined did not exhibit differences in T, E2 and 11-KT steroids. The vtgA gene expression and the sperm concentration did not change among the treatments. Moreover, acute exposure revealed a hypertrophy of hepatocytes cells in the DCF and DCF + CAF treatments. In conclusion, DCF and CAF, isolated, exhibit an endocrine disruptive activity in A. altiparanae male, an opposite response observed with the mixture of both compounds that abolishes the endocrine disruptive effects. DCF seems to be more toxic for this species, altering also hepatocytes morphology.

Efficient electro-oxidation of diclofenac persistent organic pollutant in wastewater using carbon film-supported Cu-rGO electrode

Gradually increasing concentrations of diclofenac (DCF), a widely used anti-inflammatory drug, in water bodies is an emerging concern because of the persistent characteristics and harmful environmental impact of the drug molecule. In this study, electro-oxidation using a novel copper (Cu) - reduced graphene oxide (rGO) electrode is indicated to be an efficient technology for treating DFC-laden wastewater. The Cu-rGO dispersed carbon film (∼1 mm thickness) is synthesized by carbonization and H2-reduction of a phenolic polymeric film in situ dispersed with a Cu salt and GO. The synthesized self-standing carbon film electrode is used for electro-oxidation of aqueous DCF. Analytical microscopic techniques are used to study the physicochemical properties of the material. Cyclic voltammetry analysis shows the prepared electrode generating a high oxidative current response. Approximately 100% DCF degradation is measured within 1 h at 1 V constant biased potential. Dual roles of Cu-rGO are presented as rGO facilitating direct oxidation via enhanced electron mobility at the electrode surface and Cu nanoparticles (NPs) participating in indirect oxidation by generating OH radicals in aqueous phase. The Cu NPs show an over-potential of −0.5 V vs. Ag/AgCl (100 mM KCl) for oxygen evolution, indicating indirect oxidation of DCF. The high non-faradic current density of 4 mA cm−2 generated at the positive potential (1 V) indicates direct oxidation of DCF. This study clearly indicates electro-oxidation using the Cu-rGO-dispersed carbon film electrode to be an efficient technique for remediation of pharmaceutical pollutants-contaminated wastewater.

Hydrogel Matrix-Grafted Impedimetric Aptasensors for the Detection of Diclofenac

Driven by the growing concern about the release of untreated emerging pollutants and the need for determining small amounts of these pollutants present in the environment, novel biosensors dedicated to molecular recognition are developed. We have designed biosensors using a novel class of grafted polymers, surface-attached hydrogel thin films, on conductive transducers as a biocompatible matrix for biomolecule immobilization. We showed that they can be dedicated to the molecular recognition of diclofenac (DCL). The immobilization of the aptamer onto surface-attached hydrogel thin films by covalent attachment provides a biodegradable shelter, providing the aptamer with excellent environments to preserve its active and functional structure while allowing the detection of DCL. The grafting of the aptamer is obtained using the formation of amide bonds via the activation of carboxylic acid groups of the poly(acrylic acid) hydrogel thin film. For improved sensitivity and higher stability of the sensor, a high density of the immobilized aptamer is enabled. The aptamer-modified electrode was then incubated with DCL solutions at different concentrations. The performances of the aptasensor were investigated by electrochemical impedance spectroscopy. The change in charge-transfer resistance was found to be linear with DCL concentration in the 30 pM to 1 μM range. The detection limit was calculated to be 0.02 nM. The improvement of the limit of detection can be mainly attributed to the three-dimensional environment of the hydrogel matrix which improves the grafting density of the aptamer and the affinity of the aptamer to DCL.

Adsorption of Diclofenac from Aqueous Solution onto Carbon Xerogels: Effect of Synthesis Conditions and Presence of Bacteria

Different carbon xerogels (CXs) were synthesized by the polymerization of resorcinol (R) and formaldehyde (F) catalyzed by cesium carbonate (Cs), and by varying the molar ratio R/Cs. The CXs were labeled as XCs-100, XCs-500, XCs-1000, and XCS-2000, corresponding to the R/Cs ratio of 100, 500, 1000, and 2000, respectively. The surface chemistry of the CXs varied very slightly with the R/Cs ratio because the point of zero charge (pHPZC) and the concentrations of basic and acid sites were almost independent on the R/Cs ratio. The surface areas of the four CXs decreased slightly by increasing the R/Cs ratio; however, XCs-500 presented the highest volume of pores and mesopores and mesopore surface area. At a concentration of diclofenac (DCF) at equilibrium of 800 mg/L, the adsorption capacities of XCs-100, XCs-500, XCs-1000, and XCs-2000 towards DCF in aqueous solution were 132.0, 184.6, 126.5, and 126.4 mg/g, respectively. Hence, the adsorption capacity of XCs-500 was about 1.4 times larger than those of the other CXs. The adsorption capacity of XCs-500 was reduced by increasing the solution pH due to electrostatic interactions, whereas the adsorption capacity was increased by raising the temperature, confirming that the adsorption was endothermic. The bacteria Escherichia coli adhered to the surface of XCs-500 forming a biofilm, and the presence of bacteria enhanced 1.3 times the adsorption capacity of XCs-500 towards DCF from water solutions.

Penetration of topical diclofenac into synovial tissue and fluid of osteoarthritic knees: a multicenter, randomized, placebo-controlled, pharmacokinetic study.

Background:Topical diclofenac, a nonsteroidal anti-inflammatory drug, has proven efficacy and safety in the management of osteoarthritis pain. We investigated penetration of topical diclofenac into knee synovial tissue and fluid (primary objective) and evaluated relative exposure in the knee versus plasma (secondary objective).Methods:In this phase I, double-blind, multicenter study, patients scheduled for arthroplasty for end-stage knee osteoarthritis were randomly assigned 2:1 to 4 g diclofenac diethylamine 2.32% w/w gel (92.8 mg diclofenac diethylamine, equivalent to 74.4 mg diclofenac, per application) or placebo gel, applied to the affected knee by a trained nurse/designee every 12 h for 7 days before surgery. Diclofenac concentrations were measured in synovial tissue, synovial fluid and plasma from samples obtained during surgery ⩾12 h after last application. Treatment-emergent adverse events (TEAEs) were evaluated.Results:Evaluable synovial tissue or fluid samples were obtained from 45 (diclofenac n = 29; placebo n = 16) of 47 patients. All diclofenac-treated participants had measurable diclofenac concentrations in synovial tissue [geometric mean 1.57 (95% confidence interval (CI) 1.12, 2.20) ng/g] and fluid [geometric mean 2.27 (95% CI 1.87, 2.76) ng/ml] ⩾12 h after the last dose. Geometric mean (95% CI) ratio of diclofenac in synovial tissue:plasma was 0.32 (0.23, 0.45) and in synovial fluid:plasma was 0.46 (0.40, 0.54). TEAE rates were similar for diclofenac (55.2%) and placebo (58.8%); none were treatment related.Conclusions:Topical diclofenac diethylamine 2.32% w/w gel penetrated into the osteoarthritic knee after repeated application and remained detectable in synovial tissue and fluid at the end of the final 12 h dosing cycle.

Occurrence, seasonal variation and human exposure to pharmaceuticals and personal care products in surface water, groundwater and drinking water in Lagos State, Nigeria

Abstract The occurrence of 28 pharmaceuticals and personal care products (PPCPs) was investigated in 17 surface water samples (rivers, canals, and lagoons), 12 groundwater samples (wells and boreholes, which can also be consumed for drinking) and 8 drinking water samples (bottles and sachets) during dry and rainy seasons in Lagos state, Nigeria. The most prevalent compound detected in all samples was amoxicillin (an antibiotic) at median concentrations of 1614, 238 and 358 ng/L in surface water, ground water and drinking water, respectively. This is of concern due to potential impact on development of antibiotic-resistant microbial strains. Other frequently-detected compounds include acetaminophen, nicotine, ibuprofen, and codeine with detection frequencies of more than 70%. Investigation of seasonal variability revealed that glyburide, caffeine, naproxen and diclofenac concentrations were significantly (P

Influence of Diclofenac on Activated Sludge Bacterial Communities in Fed-Batch Reactors.

SUMMARYResearch backgroundThe occurrence and environmental toxicity of pharmaceuticals have recently attracted increasing attention. Diclofenac is a highly consumed non-steroidal anti-inflammatory drug, which is often detected in wastewaters, but investigations of its influence on bacteria are scarce.Experimental approachWe investigated the influence of this pharmaceutical on bacterial community in activated sludge exposed to increasing concentrations of diclofenac in fed-batch reactors over 41 days. Nitrification activity of the activated sludge was measured and changes in bacterial community structure were followed using culture-independent molecular method (terminal restriction fragment length polymorphism, T-RFLP) and by the cultivation approach.Results and conclusionsNitrification activity was not detectably influenced by the addition of diclofenac, while the main change of the bacterial community structure was detected only at the end of incubation (after 41 days) when diclofenac was added to artificial wastewater as the only carbon source. Changes in community composition due to enrichment were observed using cultivation approach. However, taxonomic affiliation of isolates did not match taxons identified by T-RFLP community profiling. Isolates obtained from activated sludge used as inoculum belonged to five genera: Comamonas, Arthrobacter, Acinetobacter, Citrobacter and Aeromonas, known for their potential to degrade aromatic compounds. However, only Pseudomonas species were isolated after the last enrichment step on minimal agar plates with diclofenac added as the sole carbon source.Novelty and scientific contributionOur results suggest that the selected recalcitrant and commonly detected pharmaceutical does not strongly influence the sensitive and important nitrification process of wastewater treatment. Moreover, the isolated strains obtained after enrichment procedure that were able to grow on minimal agar plates with diclofenac added as the only carbon source could serve as potential model bacteria to study bacterial diclofenac degradation.

Decomposition of pharmaceutical micropollutant – diclofenac by photocatalytic nanopowder mixtures in aqueous media: effect of optimization parameters, identification of intermediates and economic considerations

This study evaluates application of three different nanopowder mixtures for decomposition of diclofenac (DCF), one of frequently detected pharmaceutical in wastewater. Analyzed three photocatalytic mixtures ZnO/SnO2, ZnO/TiO2 and ZnO/In2O3 are for the first time used for diclofenac degradation. A set of experiments were performed in order to investigate influence of catalyst concentration (0.10–0.60 mg mL−1), initial concentration of diclofenac (0.002–0.010 mg mL−1) and pH value (5–9). The increase in the catalyst concentration leads to a decrease in the degradation rate constant, which is the most pronounced in the ZnO/TiO2 and ranges from 0.47 (6) min−1 to 0.25 (3) min−1. The influence of pH on efficacy shows completely different effects: ZnO/In2O3 is most effective in alkaline environments, ZnO/TiO2 in neutral environments, while ZnO/SnO2 efficiency is good in both alkaline and acidic environments. Initial concentrations of diclofenac showed a complex effect on the degradation rate. The four dominant intermediates were detected by LC MS/MS technique. In case of all three nanomaterials, intensive degradation was achieved in first 30 minutes. The economical analysis of photocatalytic treatment was provided where the preparation of nanomaterials does not demand high costs and with the highest diclofenac concentration, total operation costs are the lowest (77.14 US$/kWh).