María Jesús García-Galán

Occurrence and in-stream attenuation of wastewater-derived pharmaceuticals in Iberian rivers

A multitude of pharmaceuticals enter surface waters via discharges of wastewater treatment plants (WWTPs), and many raise environmental and health concerns. Chemical fate models predict their concentrations using estimates of mass loading, dilution and in-stream attenuation. However, current comprehension of the attenuation rates remains a limiting factor for predictive models. We assessed in-stream attenuation of 75 pharmaceuticals in 4 river segments, aiming to characterize in-stream attenuation variability among different pharmaceutical compounds, as well as among river segments differing in environmental conditions. Our study revealed that in-stream attenuation was highly variable among pharmaceuticals and river segments and that none of the considered pharmaceutical physicochemical and molecular properties proved to be relevant in determining the mean attenuation rates. Instead, the octanol-water partition coefficient (Kow) influenced the variability of rates among river segments, likely due to its effect on sorption to sediments and suspended particles, and therefore influencing the balance between the different attenuation mechanisms (biotransformation, photolysis, sorption, and volatilization). The magnitude of the measured attenuation rates urges scientists to consider them as important as dilution when aiming to predict concentrations in freshwater ecosystems.

Multiresidue trace analysis of sulfonamide antibiotics and their metabolites in soils and sewage sludge by pressurized liquid extraction followed by liquid chromatography–electrospray-quadrupole linear ion trap mass spectrometry

The present study describes the development, validation and a practical application of a fully automated analytical method based on pressurized liquid extraction (PLE) followed by solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) for the simultaneous determination of 22 sulfonamides, including five acetylated metabolites, in sewage sludge and soil samples. Both matrix matched calibration curves and standard calibration curves were built in order to evaluate the potential matrix effects during analysis, and different internal standards were used to compensate these effects during quantification. The recovery efficiencies were found to be 60-130% for the majority of the sulfonamides in both matrices and at two spike levels. The intra-day and inter-day precisions, expressed by the relative standard deviation (RSD), were below 23%. The method limits of detection (MLODs) achieved were in the range 0.03-2.23 ng g(-1) for sewage sludge and 0.01-4.19 ng g(-1) for soil samples. The methodology was applied to evaluate the occurrence of the target sulfonamides in several sewage sludge and soil samples taken in different wastewater treatment plants (WWTPs) and agricultural areas. Results confirmed the wide presence of sulfonamides in both matrices, being sulfathiazole and sulfamethazine the sulfonamides most frequently detected in sewage sludge and soil samples, respectively. Maximum concentrations corresponded to sulfamethazine in both cases (139.2 ng g(-1) and 8.53 ng g(-1) for sewage sludge and soils respectively). Levels were generally lower in soils. Three of the five acetylated metabolites were detected in sewage sludge and two of them in soils, at concentrations not higher than 9.81 ng g(-1).

Ecotoxicity evaluation and removal of sulfonamides and their acetylated metabolites during conventional wastewater treatment

The present study describes the evaluation of the risk posed by the occurrence of sulfonamides (SAs) in wastewaters. A fully automated analytical method based on on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry (on line SPE-LC-MS/MS) was developed, validated and applied for the analysis of sixteen SAs and, for the first time in wastewaters and sewage sludge, five of their acetylated metabolites. Influent and effluent samples from twenty two different wastewater treatment plants (WWTPs) in Catalonia (Spain) and sewage sludge from fifteen of them were analyzed; removal rates (RE%) and half-lives (t(1/2)) for each SA were calculated. The estimated correlations between RE% and to the hydraulic retention time (HRT) of the different plants indicated no clear influence of HRT on removals. Sulfamethoxazole (SMX), sulfapyridine (SPY) and their corresponding acetylated metabolites were detected with the highest frequencies of detection and at the highest concentrations. The ecotoxicity of both SPY and AcSPY was evaluated for the first time through bioluminescent inhibition assays, resulting in a higher toxicity being attributed to the metabolite. Finally, the potential environmental risk posed by the levels of SAs detected was evaluated calculating the hazard quotients (HQ) to different non-target aquatic organisms in treated wastewaters. SMX was the only SA posing a risk to algae, with an HQ>10.

Occurrence and Fate of Sulfonamide Antibiotics in Surface Waters: Climatic Effects on Their Presence in the Mediterranean Region and Aquatic Ecosystem Vulnerability

Surface water bodies are constantly exposed to pollutant inputs of different origin. Wastewater effluents discharge directly on the receiving natural streams, and are among the main entrance pathways for sulfonamides. Strong contrast between seasons, with the consequent fluctuations in the flow rates, and heavy contamination pressures from extensive urban, industrial, and agricultural activities are characteristics of water courses located in the Mediterranean area. The low base flows of Mediterranean rivers makes their hydrology cycle heavily dependent on wastewater inputs, and therefore removal efficiencies of wastewater treatment plants are key to the health of the aquatic ecosystem.

Biotechnology: A highly efficient tool for the current environmental challenges

Biotechnologies are nowadays widely spread in the environmental field to manage a broad range of polluted waters, soils and wastes like urban and industrial wastewaters, landfill leachate, animal waste and sludge of organic origin. Moreover, their application is highly suitable in developing countries due to their low investment costs and easy operation. Basic research and innovation on biotechnologies is currently contributing to tackle environmental challenges derived from human activities, such as climate change, chemical pollution and the exhaustion of fossil fuels. The International Society for Environmental Biotechnology (ISEB) is an interdisciplinary consortiumof scientists and engineers whodecided to join forces to promote environmental biotechnology. Since its creation in 1992, ISEB has organized 9 conferences with delegates from more than 30 different countries. The 10th ISEB Conference was held in Barcelona in 2016 as a follow-up of the previous ones: always considering environmental biotechnology as the way to address environmental problems from a wide perspective.

Occurrence of Polar Organic Pollutants in Groundwater Bodies of Catalonia

Currently, about half of the groundwater bodies in Catalonia present a bad status in terms of water quantity and chemical quality. The latter is linked to land use, since groundwater contamination originates from agricultural, industrial, and urban activities. This chapter reviews the monitoring programs performed in up to 18 groundwater bodies of Catalonia with the common objective of assessing the occurrence and fate of different polar organic contaminants (PolOPs) in the subsurface. They include the evaluation of polar pesticides and the veterinary antibiotics sulfonamides in rural areas and the study of pharmaceuticals, illicit drugs, and UV filters in urban areas. A review of the analytical methodologies used for the analysis of these compounds in groundwater has been provided, and PolOP concentrations measured have been discussed in terms of spatial and temporal variability and linked to potential contamination sources.

Fate and Occurrence of PhACs in the Terrestrial Environment

Abstract As a consequence of human pharmaceuticals being found in surface water, groundwater, and drinking water, a high interest is now focused in their fate and behavior in soil ecosystems. Irrigation with raw or reclaimed wastewaters and fertilization with contaminated manure or biosolids are the main entrance pathways of pharmaceuticals in soil systems. Their mobility or retention in the different soil horizons will depend on many and different variables, going from the physicochemical properties of the compound to the intrinsic characteristics of the soil. On the other hand, their biodegradability is directly related to their bioavailability in the soil solution. These data, together with information on their occurrences and concentrations, are necessary to discern their capacity to reach groundwater bodies and surface waters, as well as their potential ecotoxicity against different soil organism and human exposures.