Silvia Díaz-Cruz

Fate and removal of pharmaceuticals and illicit drugs in conventional and membrane bioreactor wastewater treatment plants and by riverbank filtration

Pharmaceutically active compounds (PhACs) and drugs of abuse (DAs) are two important groups of emerging environmental contaminants that have raised an increasing interest in the scientific community. A number of studies revealed their presence in the environment. This is mainly due to the fact that some compounds are not efficiently removed during wastewater treatment processes, being able to reach surface and groundwater and subsequently, drinking waters. This paper reviews the data regarding the levels of pharmaceuticals and illicit drugs detected in wastewaters and gives an overview of their removal by conventional treatment technologies (applying activated sludge) as well as advanced treatments such as membrane bioreactor. The paper also gives an overview of bank filtration practices at managed aquifer recharge sites and discusses the potential of this approach to mitigate the contamination by PhACs and DAs.

Occurrence of hydrophobic organic pollutants (BFRs and UV-filters) in sediments from South America

In the present study the occurrence of emerging hydrophobic organic pollutants in sediment samples from South America (Chile and Colombia) was investigated for the first time. Nineteen Chilean and thirteen Colombian sediment samples were analyzed in order to determine their content of brominated flame retardants (BFRs) (including PBDEs and emerging BFRs) as well as UV filters (UV-F). Samples were collected from neighboring aquatic ecosystems highly urbanized and industrialized in Colombia (Magdalena River area) and Chile (Biobio region). Different analytical procedures were applied depending on the selected analytes, based on chromatographic and mass spectrometric methodologies (GC-MS and LC-MS-MS). In general, concentration levels of both BFRs (up to 2.43 and 143ngg(-1) dw of PBDEs in Chile and Colombia, respectively) and UV-F (nd-2.96 and nd-54.4ngg(-1) dw in Chile and Colombia, respectively) were in the low range of published data, and the contribution of BFRs was higher than that of UV-F for almost all the sampled sediments.

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.

Review of emerging contaminants in aquatic biota from Latin America: 2002–2016

Although it is known that emerging contaminants are widespread all over the globe, there is a gap of information about their distribution in some geographical areas, such as Latin America. The present bibliographic work reviews the available literature about the presence of organic emerging contaminants in Latin American freshwater and marine biota between 2002 and 2016 and includes 23 works from Argentina, Brazil, Chile, Colombia, Mexico, and Nicaragua. In particular, the present review provides an overview of the occurrence of continuously present contaminants such as pharmaceuticals, personal care products, and pyrethroid insecticides, as well as the new groups of persistent organic pollutants, the halogenated flame retardants and the perfluoroalkyl substances. A wide overview is provided, considering not only occurrence data but also effects and potential transfer through the food chain. Environ Toxicol Chem 2017;36:1716-1727.

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.