Distribution and interaction between selected pharmaceuticals and hydrogeochemistry in Guadalhorce aquifer(South of Spain)

Management of water resources implies the study of their quality and in recent times one of the main drawbacks is the presence of non-regulated products, the so-called "Emerging Contaminants (EC)". Currently the study of these contaminants is among the research priorities of the main organizations dedicated to the protection of public and environmental, such as OMS, EPA or the EU Commission health. The list of emerging contaminants include a wide variety of products both industrial and domestic applications, whose harmful effects include toxicity, bioaccumulation, and even endocrine disruption. Conventional wastewater treatment technologies are not efficient at removing many of these contaminants, so effluents and reuse become one of the most significant sources of contamination, even many emerging pollutants are only partially degraded and are even more toxic byproducts than the parent compounds. This research is focused in the Guadalhorce porous aquifer (Malaga, south of Spain), to study the distribution of EC and the interaction with the hydrogeochemistry. 14 EC (Ibuprofen, Hydrochlorothiazide, Salicilic Acid, Triclosan, Menfenamic Acid, Carbamazepine, Trimethoprim, Ofloxacin, Cafeine, Metotrexato, Metronidazole, Sulfadiazine, Sulfamethazine and Sulfamethoxazole) and 36 paramaters including electrical conductivity, T, pH, DO, major ions (Cl-, SO42-, HCO3-, NO3-, Ca2+, Mg2+, Na+, K+), metals (B, Al, Fe, Mn, Cd, Pb, Zn, As and Se) and isotopes (d2H-H2O, d18O-H2O, d34S-SO42-) were controlled in a single field sampling (June 2012). Relationships between certain pollutants by its focus of origin are studied. Ibuprofen and Menfenamic acid follow the same pattern since they have the same use as anti-inflammatory agents and origin, mainly related to urban centers, which is important in the Guadalhorce area close to the mouth. Some possible explanations are the close situation of the Waste Water Treatment Plant of Malaga, numerous discharges of wastewater, irrigations with reused and non-reused water, among others. Nearby to the upper part of the aquifer, where farms and livestock are concentrated, pharmaceuticals for veterinary use are frequent. Furthermore, a relationship between certain emerging contaminants and hydrogeochemical characteristics present in the groundwater masses is observed, noting that ibuprofen, for example, has an indirect correlation to the temperature and concentration of certain ions such as chlorine and lead present in water masses. So it may be said that the distribution and concentration of emerging contaminants is not only affected by the number of pollution sources but also by the hydrogeochemical characteristics of the aquifer.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Variaciones estacionales de tensioactivos aniónicos en sedimentos estuáricos del río Guadalete (Cádiz, España)

The presence and longitudinal and temporal distributions of the two main anionic surfactants, linear alkylbenzene sulfonates (LAS) and alkyl ethoxysulfates (AES), were monitored in surface sediments from the Guadalete estuary, located in the north of the Bay of Cadiz (SW of Spain). Seasonal samplings were performed for two years at three different stations; one of them located up-stream near the discharge outlet of a wastewater treatment plant (WWTP). A control station was also sampled in a tidal channel within the boundaries of a natural park adjacent to the estuary. LAS and AES concentration values ranged from 196 to 2864 ng g-1 and from 147 to 557 ng g-1, respectively, the lowest values corresponding to the control station and the highest ones found near the WWTP outlet. A general decrease in the concentrations of both surfactants was found in summer, when degradation processes are faster, whereas the highest concentrations were detected during the wet months, when temperature decreases and rainwater exceeds the WWTP capacity, so untreated wastewater is discharged directly into the river. Due to differential sorption and degradation processes, the relative distribution of LAS homologues in sediments showed higher percentages for those having longer alkyl chains, whereas AES homologues with an even carbon unit number in the alkyl chain and AES ethoxymers with fewer ethylene groups were predominant. No hazard for aquatic organisms was foreseen at the concentrations found for both surfactants along the estuary.Se ha realizado un seguimiento de la presencia y las distribuciones temporal y longitudinal de los dos tensioactivos aniónicos más usados -sulfonato de alquilbenceno lineal (LAS) y alquil etoxisulfatos (AES)- en sedimentos superficiales del estuario del río Guadalete, localizado al norte de la Bahía de Cádiz (SO de España). Para ello se llevaron a cabo muestreos estacionales durante dos años en tres estaciones diferentes, una de ellas localizada río arriba y en las inmediaciones de la zona de descarga de una estación depuradora de aguas residuales (EDAR). También se muestreó una estación control en un caño mareal situado dentro de los límites de un parque natural cercano al estuario. El rango de concentraciones de LAS y AES encontrado estuvo comprendido entre 196 y 2864 ng g-1 y entre 147 y 557 ng g-1 respectivamente, correspondiendo los valores más bajos a la estación control y los más altos a aquella situada cerca de la descarga de la EDAR. En términos generales, se detectó un descenso en las concentraciones de ambos tensioactivos durante el verano, cuando los procesos degradativos alcanzan mayor velocidad, mientras que las concentraciones más altas correspondieron a los meses con mayores precipitaciones, cuando se registra un descenso en la temperatura y tienen lugar descargas de agua residual sin tratar a causa de la saturación de la EDAR. Debido a procesos de adsorción y degradación diferencial, la distribución relativa de homólogos de LAS en el sedimento mostró un porcentaje mayor para aquellos con mayor longitud de cadena alquílica, mientras que los homólogos de AES con número par de carbonos en dicha cadena y los etoxímeros con menor número de grupo etoxilados fueron predominantes. No se detectó ningún riesgo para los organismos acuáticos teniendo en cuenta las concentraciones encontradas en el estuario para ambos tensioactivos

Assessment of a wide array of contaminants of emerging concern in a Mediterranean water basin (Guadalhorce river, Spain): Motivations for an improvement of water management and pollutants surveillance

This study investigates the occurrence and distribution of 185 organic contaminants (regulated pollutants and contaminants of emerging concern; CECs) in surface and groundwater of the Guadalhorce River basin (southern Spain) providing the most detailed dataset regarding organic pollution presented so far in this area. Up to 63 contaminants were detected in a monitoring campaign conducted in March 2016. Most contaminants were detected more frequently in surface water where they generally present higher concentrations suggesting the prevalence of wastewater discharges into streams as the main pollutant sources. In general, hydrophobic CECs presented the highest frequencies of detection and concentrations, which can be a consequence of several factors: (1) hydrophobic compounds show a higher retardation factor, which result, along with a continuous contaminant input, in a widespread and homogeneous distribution. In contrast, hydrophilic contaminants are more easily transported by water flows towards the lower basin and potentially accumulate as driven by groundwater flow and because of low renewal rates in the detrital aquifers caused by re-pumping and irrigation return flows in agricultural lands; (2) hydrophobic CECs studied in this research are mainly personal care products and organophosphate esters flame retardants and plasticizers, which are present in many different products and are used in large amounts; Also, (3) use of biosolids (reclaimed sewer sludge) as fertilizer for crops is potentially an additional diffuse source of organic pollutants in the study area contributing to a widespread distribution, especially for hydrophobic compounds. Obtained results highlight the need to better define the potential risk of non-regulated contaminants in water resources as well as the great impact of untreated wastewater discharges

Estudio de contaminantes emergentes en acuíferos detríticos de la cuenca hidrográfica del Río Guadalhorce (Málaga)

Actualmente existe un creciente interés por los contaminantes emergentes, en especial por los productos farmacéuticos y de cuidado personal (PPCPs), ya que son contaminantes que han pasado inadvertidos a lo largo de los años debido a sus bajas concentraciones, pero que presentan efectos perjudiciales para la salud y el medio ambiente, algunos de ellos se comportan, incluso, como disruptores endocrinos. Estos compuestos, en su mayoría, no regulados en la legislación, han sido hallados en aguas superficiales, subterráneas, sedimentos e incluso en aguas de abastecimiento. Este trabajo se centra en las aguas subterráneas de la cuenca del río Guadalhorce, determinando la distribución de los PPCPs, y la relación que presentan con las fuentes de contaminación existentes en el área de estudio.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Screening and Distribution of Contaminants of Emerging Concern and Regulated Organic Pollutants in the Heavily Modified Guadalhorce River Basin, Southern Spain

Emerging pollutants have aroused an increasing concern due to their ubiquitous presence in the environment and harmful potential. Both emerging (e.g., pharmaceuticals and personal care products) and regulated organic pollutants pose a serious threat to water quality and their presence and spatial distribution are complicated to address as they can derive from several factors: distribution of point and diffuse sources, environmental conditions, hydrogeological features of the region and inherent properties of the considered contaminants. In this study, a ground and surface water monitoring campaign was conducted in the three main detritic groundwater bodies of an extensive and heavily modified river basin in order to draft an initial description of the occurrence and distribution of a wide range of organic contaminants. In total, 63 out of 185 target pollutants were detected. An attempt to understand the importance of different factors governing the distribution of some of the most frequently found pollutants was made. Antibiotics spatial distribution is potentially influenced by the hydrogeological functioning of the basin modified by hydraulic infrastructures (reflected by hydrochemistry and environmental tracers delta H-2 and delta O-18), not directly related to the distribution of potential sources. The presence of other organic pollutants does not reflect an evident correlation with flow pathways. Differences in contaminant occurrence are potentially attributed to the way pollutants are released into the environment as well as physico-chemical properties

Post-treatment of real municipal wastewater effluents by means of granular activated carbon (GAC) based catalytic processes: A focus on abatement of pharmaceutically active compounds

Pharmaceutically active compounds (PhACs) widely present in urban wastewater effluents pose a threat to ecosystems in the receiving aquatic environment. In this work, efficiency of granular activated carbon (GAC) - based catalytic processes, namely catalytic wet peroxide oxidation (CWPO), peroxymonosulfate oxidation (PMS/GAC) and peroxydisulfate oxidation (PDS/GAC) at ambient temperature and pressure were studied for removal of 22 PhACs (ng L-1 level) that were present in secondary effluents of real urban wastewater. Concentrations of PhACs were measured using Ultra Performance Liquid Chromatography - Triple Quadrupole Mass Spectrometry (UPLC-QqQ-MS/MS). Catalytic experiments were conducted in discontinuous mode using up-flow fixed bed reactors with granular activated carbon (GAC) as a catalyst. The catalyst was characterized by means of N-2 adsorption-desorption isotherm, mercury intrusion porosimetry (MIP), elemental analysis, X-ray fluorescence spectroscopy (WDXRF), X-ray diffraction (XRD), thermal gravimetry and differential temperature analyses coupled mass spectrometry (TGA-DTA-MS). Results indicate that the highest efficiency in terms of TOC removal was achieved during CWPO performed at optimal operational conditions (stoichiometric dose of H2O2; TOC removal similar to 82%) followed by PMS/GAC (initial PMS concentration 100 mg L-1; TOC removal similar to 73.7%) and PDS/GAC (initial PDS concentration 100 mg L-1; TOC removal similar to 67.9%) after 5 min of contact time. Full consumption of oxidants was observed in all cases for CWPO and PDS/GAC at contact times of 2.5 min, while for PMS/GAC it was 1.5 min. In general, for 18 out of 22 target PhACs, very high removal efficiencies (> 92%) were achieved in all tested processes (including adsorption) performed at optimal operational conditions during 5 min of contact time. However, moderate (40 - 70%) and poor (< 40%) removal efficiencies were achieved for salicylic acid, ofloxacin, norfloxacin and ciprofloxacin, which can be possibly attributed to insufficient contact time. Despite high efficiency of all studied processes for PhACs elimination from urban wastewater effluent, CWPO seems to be more promising for continuous operation. (C) 2021 Elsevier Ltd. All rights reserved.Authors are grateful to staffmembers of Viikinmaki Wastewater Treatment Plant (Helsinki, Finland) for collaboration. D.Sc. Juan Jose Rueda-Marquez is thankful for financial support from Academy of Finland within the project "Combination of Advanced Oxidation Processes and Photobiotreatment for Sustainable Resource Recovery and Wastewater Reuse". D.Sc. Irina Levchuk is grateful for financial support obtained from KAUTE saatio(grant number: 201800116). D.Sc. Ana Rey is grateful for financial support from Ministerio de Economia y Competitividad (MINECO)Agencia Estatal de Investigacion (AEI) of Spain through the project CTQ2015-73168-JIN, co-financed by the European Funds for Regional Development (FEDER, UE). D. Sc. Javier Moreno-Andres is grateful for the financial support by the European Union under the 2014-2020 ERDF Operational Programme and by the Department of Economy, Knowledge, Business and University of the Regional Government of Andalusia. Project reference: FEDER-UCA18-108023

Structural control of the non-ionic surfactant alcohol ethoxylates (AEOs) on transport in natural soils

Surfactants, after use, enter the environment through diffuse and point sources such as irrigation with treated and non-treated waste water and urban and industrial wastewater discharges. For the group of non-ionic synthetic surfactant alcohol ethoxylates (AEOs), most of the available information is restricted to the levels and fate in aquatic systems, whereas current knowledge of their behavior in soils is very limited. Here we characterize the behavior of different homologs (C12-C18) and ethoxymers (E03, E06, and E08) of the AEOs through batch experiments and under unsaturated flow conditions during infiltration experiments. Experiments used two different agricultural soils from a region irrigated with reclaimed water (Guadalete River basin, SW Spain). In parallel, water flow and chemical transport were modelled using the HYDRUS-1D software package, calibrated using the infiltration experimental data. Estimates of water flow and reactive transport of all surfactants were in good agreement between infiltration experiments and simulations. The sorption process followed a Freundlich isotherm for most of the target compounds. A systematic comparison between sorption data obtained from batch and infiltration experiments revealed that the sorption coefficient (K-d) was generally lower in infiltration experiments, performed under environmental flow conditions, than in batch experiments in the absence of flow, whereas the exponent (beta) did not show significant differences. For the low clay and organic carbon content of the soils used, no clear dependence of K-d on them was observed. Our work thus highlights the need to use reactive transport parameterization inferred under realistic conditions to assess the risk associated with alcohol ethoxylates in subsurface environments. (C) 2020 The Authors. Published by Elsevier Ltd

Tracking sewage derived contamination in riverine settings by analysis of synthetic surfactants

A study has been made of the presence and reactivity of the most commonly used surfactants, both anionic (linear alkylbenzene sulfonates, LAS, and alkyl ethoxysulfates, AES) and non-ionic (alcohol polyethoxylates, AEOs, and nonylphenol polyethoxylates, NPEOs), in water and surface sediments from the middle stretch of the Guadalete River in SW Spain (12 stations). Average values were between 0.1 and 3.7 mg kg_1 in sediment, and between 0.2 and 37 mg L_1 in water. The sorption of surfactants was dominated by hydrophobic mechanisms, so those homologues having longer alkyl chains (e.g. C18AEO) showed higher relative percentages and concentrations in sediments compared with water. Local and sharply higher concentrations of these compounds were observed at three sampling stations (7, 9 and 12), indicating the occurrence of wastewater discharges into the river. By analysing the distributions of different surfactant homologues and their metabolites we were able to distinguish between sewage contamination from sources discharging treated and untreated wastewaters. Upstream (stations 1–2), LAS concentrations were below 30 mg L_1 and the composition of their degradation intermediates (sulfophenyl carboxylic acids, SPCs) (160 mg L_1) was dominated by short-chain homologues (C6–C9SPCs), indicating that the degradation of this surfactant is at an advanced stage. The highest concentration (487 mg L_1) of SPCs was detected near the effluent outlet of a sewage treatment plant (STP) (station 12). Sampling stations (7 and 9) affected by untreated wastewater discharges were the only ones showing the presence of the most reactive and biodegradable SPC isomers and homologues (e.g. C11SPC). Here, LAS reached the highest concentration values measured (>2 mg L_1), and showed a homologue distribution closer to that of commercial mixtures than LAS found at the other stations.Peer Reviewe

Effects of exposure to pharmaceuticals (diclofenac and carbamazepine) spiked sediments in the midge, Chironomus riparius (Diptera, Chironomidae)

Human and veterinary pharmaceuticals and degradation products are continuously introduced into the environment. To date, there is a lack of information about the effects of pharmaceuticals in spiked toxicity tests with non-target organisms. In this study, we have evaluated the effects of exposure to two common pharmaceuticals in the midge Chironomus riparius in spiked sediment experiments. The selected pharmaceuticals are the nonsteroidal anti-inflammatory drug (NSAID): diclofenac (DF) and the anti-depressant drug carbamazepine (CBZ). In order to assess the effects of the pharmaceuticals, a chronic toxicity test with the midge was carried out. The endpoints survival, growth and developmental stage by means of biomass, were measured after 10 days, and emergence rates and sex-ratio (male/female) were measured after 21 days of exposure. Significant mortality was observed in organisms at day 10 with a 40% of larvae surviving in the highest exposure concentration of CBZ. DF decreased the emergence ratio with respect to the controls in organisms exposed at concentrations of 34.0 μg·g− 1 whereas CBZ reduced the growth of the midges (30,6% with respect to the control) and induced a significant change in sex-ratio at concentrations of 31.4 μg·g− 1. The results obtained in the present study indicate possible adverse effects on aquatic invertebrates, which should be taken into account for environmental risk assessment of pharmaceutical compounds in sediments.Authors would like to thank to Dr. A.M. Arias for the Chironomus larvae image employed in the graphical abstract and the Spanish Ministry of Economy and Competitiveness for its financial support through the project SCARCE (Consolider-Ingenio 2010 CSD2009-00065), NET-SCARCE (CTM2015-69780-REDC) and the PIE 20143E072 (CSIC). M.H. is supported by a Ramón y Cajal contract (RYC-2012-12217) from the Spanish Ministry of Economy and Competitiveness (MINECO). Ministry of Economy and Competitiveness and European Regional Development Fund (ERDF).Peer reviewe

Distribución y transporte de tensioactivos sintéticos no iónicos (AEOs) en la zona no saturada

En este trabajo se analiza el comportamiento de un etoxímero de tensioactivo sintético no iónico (alcoholes polietoxilados, AEOs) en condiciones no saturadas a partir de un ensayo de laboratorio mediante una célula de flujo. Se presentan los resultados de la simulación correspondientes a la aplicación del código HYDRUS y una primera aproximación del transporte del etoxímero seleccionado (C16AEO6EO). De acuerdo a los resultados de la modelación, estos reproducen satisfactoriamente los datos experimentales, mostrando para el C16AEO6EO altos índices de degradación y adsorción en el suelo. In this work the behavior of an ethoxymer of non-ionic synthetic surfactant (alcohol polyethoxylates, AEOs) is studied under unsaturated conditions from a laboratory test performed in a flow cell. A first approach to the transport of the selected ethoxymer (C16AEO6EO) using HYDRUS code is presented. The results from modeling reproduce the experimental data successfully, showing a high degradation rate as well as soil adsorption of C16AEO6EO.infiltration and the delay in runoff generation.Postprint (published version