Simultaneous pressurized liquid extraction and clean-up for the determination of metabolites in complex environmental solid matrices

Occurrence of priority and emerging organic contaminants in cold-water corals and their habitat: A case study in La Herradura Bay (Spain)

Coastal ecosystems are heavily anthropized areas impacted by discharge of chemical pollutants. We present for the first time the occurrence of a wide number of such chemicals in surface water, sediment, suspended particulate matter, and corals from a protected Mediterranean setting, La Herradura Bay (Spain). A seasonal monitoring sampling campaign was conducted in 2021 (winter and summer). This bay is a marine biodiversity hot spot and home for endangered cold-water corals species (Astroides calycularis and Dendrophyllia ramea). Up to 94 target analytes were present in marine samples, with pharmaceuticals being the predominant compound class (up to 37 ng L-1 in seawater and 775 ng g-1 in sediments), especially during the winter season. Uncontrolled untreated wastewater discharges in combination with hydrodynamics dominating in the area seemed to be the major source of contaminants towards the coral colonies inhabiting the bay, which accumulate pharmaceuticals (up to 154 ng g-1), personal care products (UV filters and synthetic fragrances), polycyclic aromatic hydrocarbons, and organophosphate flame retardants, showing log BAFs up to 6.6. Such values were slightly higher in D. ramea than A. calycularis, but not statistically significant differences were observed (p-value >0.05). Further research is encouraged to assess possible damage to cold-water coral species exposed to multiple contaminants.

Assessment of trace organic chemicals in anaerobically digested sludge and their partitioning behaviour: Simultaneous Soxhlet chemical extraction and quantification via LC-MS/MS analysis

The increasing number of trace organic contaminants (TrOCs) detected in anaerobically digested sludge (ADS) is triggering increasing concern on its circular-economy reuse practices. A large scientific effort has been performed to define their concentration limits, partition behaviour, and innovative technologies for their removal, which require the definition of versatile and economically sustainable analytical methodologies. In this study, a Soxhlet extraction method coupled with LC-MS/MS analysis was developed to simultaneously determine 32 TrOCs in ADS, 11 of them being quantified in this matrix for the first time. The targeted TrOCs were selected based on the European Urban Wastewater Treatment Directive, and on their frequency of detection in municipal wastewater and/or sludge and chemical diversity. The use of methanol as solvent allowed good recovery efficiencies from ADS solid phase, with an extraction time of 3.5 h and without the need for subsequent clean-up procedures. The targeted LC-MS/MS method enabled high-sensitivity quantification of TrOCs in the liquid phase. At least 25 out of the 32 target compounds were detected in ADS samples from two wastewater treatment plants in Germany, providing their concentration data and highlighting the influence of TrOCs characteristics and sludge properties on contaminant partition coefficients (KD). The experimental outcomes highlight the versatility of the Soxhlet method, which is effective in extracting compounds characterized by diverse properties and structures, and opens new perspectives for the analysis of various substrates. This could support the European Sewage Sludge Directive, expanding its application to soils and cultivated foods and offering insights into TrOCs transfer among different substrates and their influence when used as fertilizer, aiding in the efficient definition of risk assessment methodologies and regulatory concentration limits.

Determination of pharmaceuticals and metabolites in sludge and hydrochar after hydrothermal carbonization using sonication-QuEChERS extraction method and UHPLC LTQ/Orbitrap MS

Pharmaceuticals (PhACs) are an important group of emerging contaminants that are released continuously in the environment from wastewater treatments plants (WWTPs). They can produce biological effects even though at very low concentrations. Conventional WWTPs are not able to remove or degrade completely emerging pollutants resulting in the presence of PhACs in sewage sludge after wastewater treatment. PhACs are found in sludge at low ppb-ppt levels, and their analysis and detection is a difficult task due to the complexity of sewage sludge matrices. Hydrothermal carbonization is currently being proposed as a suitable conversion technology for sewage sludge management to recover valuable products and to be used for soil amendment. In this work, a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based methodology with a dispersive solid-phase extraction (d-SPE) clean-up followed by ultra-high-performance liquid chromatography coupled with high-resolution linear ion trap-Orbitrap mass spectrometry (UHPLC-LTQ/Orbitrap MS), operated in positive ionization mode, was adopted to investigate 33 multiclass pharmaceuticals in sewage sludge and in hydrochar produced after hydrothermal carbonization. The analytical method was first optimized studying various extraction parameters and finally validated in terms of linearity, recovery, intra and inter-day precisions, expanded uncertainty (%U)/Horrat ratio at three spiking levels, matrix-effects (ME), process efficiency (PE), and limits of detection and quantification. The developed methodology fulfilled all analytical requirements and was finally applied to sludge samples from the WWTP of Ioannina city where a group of antibiotics was detected at concentrations up to 15 ng g^-1 and psychiatric drugs such as amisulpride, clozapine, and citalopram were detected at higher concentration levels up to 205, 87.4 and 63.2 ng g^-1, respectively. The method was also applied to hydrothermally treated sludge sample under different reaction conditions. Most of the antibiotic compounds were not detected, and several psychiatric drugs such as mirtazapine, bupropion, valsartan, diazepam, and caffeine were found at concentrations below the LOQ.

Occurrence, detection and ecotoxicity studies of selected pharmaceuticals in aqueous ecosystems- a systematic appraisal

Pharmaceutical compounds (PCs) have globally emerged as a significant group of environmental contaminants due to the constant detection of their residues in the environment. The main scope of this review is to fill the void of information on the knowledge on the African occurrence of selected PCs in environmental matrices in comparison with those outside Africa and their respective toxic actions on both aquatic and non-aquatic biota through ecotoxicity bioassays. To achieve this objective, the study focused on commonly used and detected pharmaceutical drugs (residues). Based on the conducted literature survey, Africa has the highest levels of ciprofloxacin, sulfamethoxazole, lamivudine, acetaminophen, and diclofenac while Europe has the lowest of all these PC residues in her physical environments. For ecotoxicity bioassays, the few data available are mostly on individual groups of pharmaceuticals whereas there is sparsely available data on their combined forms.

Occurrence of the main metabolites of the most recurrent pharmaceuticals and personal care products in Mediterranean soils

The use of sewage sludge and wastewater in agricultural lands provide contaminants to soils. As a result, a large number of contaminants can be present in soils. Among others, pharmaceuticals and personal care products (PPCPs) are two of the most studied families of emerging contaminants in wastewater. However, there is scarce information about their behaviour in soils. Occurrence, fate and behaviour in soils of metabolites are even less known. In this work, the degradation of most recurrent PPCPs in the environment and their main metabolites has been evaluated using batch experiments in three typical Mediterranean soils. Batch experiments were carried out in a climatic chamber using spiked soils under Mediterranean climatic conditions. The studied compounds were five pharmaceutically active compounds (carbamazepine, ibuprofen, caffeine, sulfamethoxazole and diclofenac), two parabens (methylparaben and propylparaben) and twelve of their main metabolites. Studied PPCPs and metabolites showed different adsorption capacity onto the studied soils. As results, despite of the compounds were spiked at the same concentrations, different contents were measured at the beginning of the batch experiments. The soil 3 showed the lowest degradation rate for all studied compounds what could be related with the higher adsorption capacity of this soil. A decrease of the measured contents was observed for all studied compounds, except in the case of CBZ and EP-CBZ. No transformations of parent compounds into their metabolites or vice versa were observed, except in the case of Ibuprofen and its metabolites. Although the results showed overall short degradation times for the most of the compounds studied, the evaluation of the environmental risks of the PPCPs and their metabolites should not be underestimated.

Approach to the Dynamic of Carbamazepine and its Main Metabolites in Soil Contamination through the Reuse of Wastewater and Sewage Sludge

The release of pharmaceutically active compounds to the soils through the application of sewage sludge and the irrigation with wastewater, or even with surface water, is constant. The adsorption of these compounds onto the soil is one of the key factors affecting their fate in the environment and their potential environmental risks. In this work, the adsorption of carbamazepine (CBZ) and its metabolites, 3-hydroxy-carbamazepine (3OH-CBZ), carbamazepine-10,11-dihydro-10,11-epoxide (EP-CBZ), and 10,11-dihydro-10-hydroxycarbamazepine (10OH-CBZ), in three Mediterranean soils was evaluated using single-solute and four-solute experiments. The highest adsorptions were measured for 3OH-CBZ, followed by CBZ, EP-CBZ, and 10OH-CBZ, in that order. A high influence of the physicochemical characteristics of the compounds, pH, and soil characteristics in the adsorption of the studied compounds was observed and corroborated by the statistical analysis of the results. Moreover, a good fit was observed in the three isotherm models evaluated (linear, Freundlich, and Langmuir) in single-solute experiments (R² > 0.90). However, a decrease of the measured adsorptions and a worse fit to the isotherm models were observed in the case of multiple-solute experiments. This could be mainly due to the competition established between the studied compounds for the active sites of the soils.

Occurrence of the main metabolites of pharmaceuticals and personal care products in sludge stabilization treatments

In Europe, approximately 40% of sludge yearly produced in wastewater treatment plants (WWTPs) is applied in agricultural lands as organic amendment, especially in arid regions. Sludge tends to concentrate wastewater pollutants. Many of them are not removed by sludge stabilization treatments and, as a result, they could originate adverse effects on soils, vegetation, animals, and humans. Although sludge stabilization treatments play an important role in removal contaminants from sludge and, therefore, in preventing contaminant discharges onto soils, there is scarce information about the occurrence of these compounds in these treatments. This fact is especially acute for emerging pollutants and, particularly, their metabolites. In this work, seven pharmaceuticals and personal care products, and their main metabolites, have been monitored in five different stabilization treatments: anaerobic and aerobic digestion, dehydration, composting, and lagooning. Sixteen compounds were measured in the analysed samples. Their distribution was similar in primary sludge, in spite of the different geographic locations of the WWTPs, The distribution was in accordance with the metabolic ratios of most of the studied compounds. Different behaviour was observed depending on the compound, for example, CBZ, 3-OH-CBZ, DIC, and 4-OH-DIC were highly persistent in all studied stabilization technologies whereas CAF, PX showed high degradability. Most of the studied compounds were measured in the final product of the sludge stabilization processes evaluated. This fact shows the necessity to improve the knowledge about the presence of these compounds in sludge intended to be applied onto soil and about the potential ecotoxicological risks of these compounds.