Christina I. Kosma

Investigation of PPCPs in wastewater treatment plants in Greece: Occurrence, removal and environmental risk assessment

In the present work, an extensive study on the presence of eighteen pharmaceuticals and personal care products (PPCPs) in eight wastewater treatment plants (WWTPs) of Greece has been conducted. The study covered four sampling periods over 1-year, where samples (influents; effluents) from eight WWTPs of various cities in Greece were taken. All WWTPs investigated are equipped with conventional activated sludge treatment. A common pre-concentration step based on SPE was applied, followed by LC-UV/Vis-ESI-MS. Further confirmation of positive findings was accomplished by using LC coupled to a high resolution Orbitrap mass spectrometer. The results showed the occurrence of all target compounds in the wastewater samples with concentrations up to 96.65 μg/L. Paracetamol, caffeine, trimethoprim, sulfamethoxazole, carbamazepine, diclofenac and salicylic acid were the dominant compounds, while tolfenamic acid, fenofibrate and simvastatin were the less frequently detected compounds with concentrations in effluents below the LOQ. The removal efficiencies showed that many WWTPs were unable to effectively remove most of the PPCPs investigated. Finally, the study provides an assessment of the environmental risk posed by their presence in wastewaters by means of the risk quotient (RQ). RQs were more than unity for various compounds in the effluents expressing possible threat for the aquatic environment. Triclosan was found to be the most critical compound in terms of contribution and environmental risk, concluding that it should be seriously considered as a candidate for regulatory monitoring and prioritization on a European scale on the basis of realistic PNECs. The results of the extensive monitoring study contributed to a better insight on PPCPs in Greece and their presence in influent and effluent wastewaters. Furthermore, the unequivocal identification of two transformation products of trimethoprim in real wastewaters by using the advantages of the LTQ Orbitrap capabilities provides information that should be taken into consideration in future PPCP monitoring studies in wastewaters.

Occurrence and removal of PPCPs in municipal and hospital wastewaters in Greece

A monitoring study was carried out for the four seasons over 1-year monitoring period (March 2006-March 2007) to investigate the residues of 11 pharmaceuticals and personal care products (PPCPs) belonging to various therapeutic categories. The selected areas of the study were the municipal and hospital wastewater treatment plants (WWTPs) of Ioannina city, located in Western Greece. The most common pre-treatment technique for pharmaceuticals, solid-phase extraction (SPE), was used for the isolation and pre-concentration of the target analytes. The samples were screened using gas chromatography mass spectrometry (GC-MS). The results of the monitoring study, showed the occurrence of all target compounds in the wastewater samples. Concentrations in the municipal WWTP ranged between 0.3 and 164.4 microg/L in the influent and between 0.5 and 13.9 microg/L in the effluent. In the hospital WWTP concentrations ranged between 0.6 and 70.1 microg/L in the influent and between 0.5 and 14.6 microg/L in the effluent. Mean removal efficiencies ranged between 13% and 97% and between 9% and 87% for municipal and hospital WWTPs, respectively. Removal efficiencies were higher in the municipal WWTP than in the hospital WWTP.

Seasonal occurrence, removal, mass loading and environmental risk assessment of 55 pharmaceuticals and personal care products in a municipal wastewater treatment plant in Central Greece.

A comprehensive study, which contains the seasonal occurrence, removal, mass loading and environmental risk assessment of 55 multi-class pharmaceuticals and personal care products (PPCPs), took place in the wastewater treatment plant (WWTP) of Volos, Greece. A one year monitoring study was performed and the samples were collected from the influent and the effluent of the WWTP. Solid phase extraction was used for the pre-concentration of the samples followed by an LC-DAD-ESI/MS analysis. Positive samples were further confirmed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The maximum concentrations of the PPCPs varied between 21 ng/L and 15,320 ng/L in the influents and between 18 ng/L and 9965 ng/L in the effluents. The most commonly detected PPCPs were the diuretic furosemide, the beta-blockers atenolol and metoprolol, the analgesics paracetamol, nimesulide, salicylic acid and diclofenac and the psychomotor stimulant caffeine. The removal efficiencies ranged between negative and high removal rates, demonstrating that the WWTP is not able to efficiently remove the complex mixture of PPCPs. The estimated mass loads ranged between 5.1 and 3513 mg/day/1000 inhabitants for WWTP influent and between 4.1 to 2141 mg/day/1000 inhabitants for WWTP effluent. Finally, environmental risk assessment has been regarded a necessary part of the general research. According to the results produced from the calculation of the risk quotient on three trophic levels, the anti-inflammatory drug diclofenac and the antibiotics, trimethoprim and ciprofloxacin, identified to be of high potential environmental risk for acute toxicity, while diclofenac also for chronic toxicity.

Degradation of venlafaxine using TiO2/UV process: Kinetic studies, RSM optimization, identification of transformation products and toxicity evaluation

The photochemical degradation of the antidepressant drug venlafaxine (VNF) by UV/TiO2 process was investigated in the present study. Prescreening experiments were conducted to study the effects of main parameters affecting the photocatalytic process. In addition, the effects and interactions of most influenced parameters were evaluated and optimized by using a central composite design model and a response surface methodology. Results indicated that VNF was quickly removed in all the irradiation experiments and its degradation was mainly affected by the studied variables (catalyst dose, initial VNF concentration and pH), as well as their interaction effects. Parallel to kinetic studies, the transformation products (TPs) generated during the treatment was investigated using LC coupled to low and high resolution mass spectrometry. Based on identification of the main TPs, tentative transformation pathways were proposed, including hydroxylation, demethylation and dehydration as major transformation routes. Τhe potential risk of VNF and its TPs to aqueous organisms was also investigated using Microtox bioassay before and during the processes. The obtained results showed an increment in the acute toxicity in the first stages and a continuously decreasing after then to very low values reached within 240min of the photocatalytic treatment, demonstrating that UV/TiO2 can lead to the elimination of parent compound and the detoxification of the solution.

Occurrence of pharmaceuticals in surface waters: analytical method development and environmental risk assessment

The present work illustrates the development of an analytical method, based on offline solid phase extraction (SPE) followed by liquid chromatography–electron spray ionisation–single quadrupole mass spectrometry (LC-ESI-MS) for the simultaneous determination of pharmaceuticals belonging to various therapeutic classes (analgesics/anti-inflammatories, lipid regulators, antibiotics, antiepileptics, antipsychotics, psychomotor stimulants, glucocorticoid steroids, disinfectants, beta-blockers, H2 receptor antagonists and oestrogens) in surface waters. The method developed was applied for the analysis of pharmaceutical residues in surface waters from different sampling points along the aquatic systems of Lake Pamvotis and the River Kalamas, close to the city of Ioannina (Epirus, Greece), while the monitoring programme was carried out during the four seasons of the year. According to the results obtained, the majority of the compounds were detected in discrepant concentrations. The concentrations for all the compounds ranged from levels below quantification limit to 3506 ng/L, with caffeine and salicylic acid being the ubiquitous compounds. The results of the monitoring contributed substantially to the knowledge on the occurrence of pharmaceuticals in Greece and more specifically in surface waters of the region of Epirus. Regarding the environmental risk due to the presence of target compounds in surface waters, this was estimated calculating risk quotients (RQs) for different aquatic organisms (algae, daphnids and fish). The results denoted a possible threat for the aquatic environment, rendering in this way the RQ method as a helpful tool for a first approach. Extensive study is needed for triclosan, salicylic acid, sulfamethoxazole and erythromycin in order to better correlate their occurrence and potential toxic effects in aquatic life and humans.

Analysis, occurrence, fate and risks of proton pump inhibitors, their metabolites and transformation products in aquatic environment: A review

Proton pump inhibitors (PPIs) which include omeprazole, esomeprazole, lansoprazole, pantoprazole and rabeprazole, are extensively used for the relief of gastro-intestinal disorders. Despite their high worldwide consumption, PPIs are extensively metabolized in human bodies and therefore are not regularly detected in monitoring studies. Very recently, however, it has been shown that some omeprazole metabolites may enter and are likely to persist in aquatic environment. Hence, to fully assess the environmental exposures and risks associated with PPIs, it is important to better understand and evaluate the fate and behavior not only of the parent compound but also of their metabolites and their transformation products arising from biotic and abiotic processes (hydrolysis, photodegradation, biodegradation etc.) in the environment. In this light, the purpose of this review is to summarize the present state of knowledge on the introduction and behavior of these chemicals in natural and engineering systems and highlight research needs and gaps. It draws attention to their transformation, the increase contamination by their metabolites/TPs in different environmental matrices and their potential adverse effects in the environment. Furthermore, existing research on analytical developments with respect to sample treatment, separation and detection of PPIs and their metabolites/TPs is provided.

Photochemical transformation and wastewater fate and occurrence of omeprazole: HRMS for elucidation of transformation products and target and suspect screening analysis in wastewaters

Omeprazole is one of the world-wide most frequently prescribed and administered pharmaceuticals in humans for the relief of gastro-intestinal disorders. Despite its high worldwide consumption, omeprazole is rarely detected in urban wastewaters and environmental waters. On the other hand, its human urinary metabolites and transformation products formed through abiotic processes in the environment have been recently documented. Despite these available data, however, there is still a lack of information on the extent of environmental fate and occurrence, on elimination mechanisms and efficiencies in waste water treatment plants. In this study, the relevance of photodegradation processes on the environmental persistence of omeprazole under simulated and solar irradiation was investigated. Photodegradation experiments were performed in distilled water, lake, river and seawater, and revealed that the different matrix in natural waters significantly affect the photolytic behavior of the investigated compound. Overall, the results highlight that photodegradation process by solar irradiation significantly contributes to omeprazole degradation and elimination from the aquatic environment. TPs formed through the process were identified and elucidated by using liquid chromatography high resolution mass spectrometry. In total seven TPs were identified, among of which four were also detected as hydrolysis TPs. The Microtox bioassay showed that solar photolysis is efficient to detoxify omeprazole and its TPs in aqueous solutions. Finally, a systematic investigation was conducted in order to provide information on removal efficiency and occurrence of omeprazole and its metabolites/TPs in 8 WWTPs in North West Greece by performing target and suspect screening analysis. The findings revealed the presence of both parent compound and metabolites/TPs in wastewaters. Given, however, the scarce detection of omeprazole at fairly low concentration levels, from analytical and environmental point of view, further attention should be given to metabolites/TPs instead of the parent compound.