Techno-economic evaluation and comparison of PAC-MBR and ozonation-UV revamping for organic micro-pollutants removal from urban reclaimed wastewater

The presence of sewage-borne Organic Micro-Pollutants (OMP) in Wastewater Treatment Plants (WWTP) effluents represents an increasing concern when water is reclaimed for irrigation or even indirect potable reuse. During eighteen months, an innovative hybrid water reclamation scheme based on a Membrane Biological Reactor (MBR) enhanced with Powder Activated Carbon (PAC) was operated at pilot-scale (70 m3/d) in order to compare it with state-of-the art Wastewater Reclamation System (WWRS) also revamped with a final step of ozonation-UV. Removal of persistent OMP, water quality and treatment costs were evaluated and compared for the different treatment schemes. OMP removal efficiency results for the different schemes concluded that established technologies, such as physico-chemical and filtration systems as well as MBR, do not remove significantly (>15%) the most recalcitrant compounds. The upgrading of these two systems through the addition of ozonation-UV step and PAC dosing allowed improving average recalcitrant OMP removal to 85±2 and 75±5 %, respectively. In term of costs, PAC-MBR represents an increase of 37 % of costs regarding conventional systems but presents improvements of 50 % reduction in space and water quality. On the other hand, ozonation requires up to a 15% increase of foot-print; nevertheless, represents lower costs and lower carbon footprint. Ozonation-UV seems to be the best option for upgrading existing facilities, while PAC- MBR should be considered when space represents a critical limitation and produced water is reused for high water quality purposes.Postprint (author's final draft

Análisis, biodisponibilidad y vigilancia de contaminantes orgánicos hidrofóbicos en el medio acuático

[spa] En un periodo de tiempo determinado, solamente una fracción de la cantidad total de una sustancia química presente en la columna de agua o en el sedimento está en forma bioaccesible o biodisponible. Por otra parte, aun cuando la fracción disuelta de un contaminante puede ser muy baja y a veces indetectable, una exposición muy larga puede dar lugar a su acumulación por parte de los organismos. Esta cuestión es especialmente relevante para los contaminantes hidrofóbicos, que tienden a persistir en el ambiente uniéndose a las partículas de sedimento y a ser acumulados por la biota. Una determinación precisa del riesgo asociado a la presencia de estos contaminantes en el medio acuático debe partir de medidas que tengan en cuenta su disponibilidad espacial y temporal para los seres vivos en cada circunstancia. La tesis se enmarca en este contexto y se centra en dos grupos de contaminantes haloaromáticos: el histórico pesticida diclorodifeniltricloroetano (DDT) y sus productos de transformación (DDX, en conjunto) y los retardantes de llama difeniléteres polibromados (PBDE), incluidos más recientemente en la legislación. El objetivo general era el desarrollo y aplicación de métodos analíticos con los que medir sus concentraciones en las distintas fases o compartimentos del medio acuático que fuesen representativas exposición real de los organismos vivos. En la primera parte de la tesis, se empleó una técnica moderna para la extracción cuantitativa en sedimento y en peces, adecuada a los requisitos normativos actuales de exhaustividad para la vigilancia de contaminantes. Para ello, se optimizó un método analítico mediante extracción selectiva con líquidos presurizados (SPLE) acoplada a cromatografía de gases y espectrometría de masas (GC-MS) que permitió realizar una extracción y purificación simultánea de las muestras con una reducción importante del tiempo de análisis, la manipulación de la muestra y el uso de disolventes frente a métodos tradicionales. Los métodos optimizados fueron aplicados para el análisis de PBDE y DDX en muestras de sedimentos y peces procedentes de distintos puntos de la costa peninsular y en la cuenca del río Ebro. La metodología desarrollada permitió, además, la detección en estas muestras de hexabromociclododecano (HBCD), un retardante de llama que comenzaba a utilizarse como sustituto de los PBDE y cuya presencia en el medioambiente apenas había sido descrita en ese momento. El análisis de las muestras demostró las diferencias relativas con que los peces acumulan cada uno de los analitos respecto a sus cantidades en el sedimento. Posteriormente, se evaluaron dos tipos de técnicas biomiméticas que utilizan una fase sustituta para cuantificar el contaminante bioaccesible y bioacumulable en el medio. En primer lugar, la extracción exhaustiva de los contaminantes presentes en los sedimentos realizada mediante el método de SPLE fue comparada con la extracción acuosa con Tenax®, lo que permitió cuantificar la fracción susceptible de pasar a la fase disuelta en periodos concretos de tiempo o fracción bioaccesible. La existencia de fracciones residuales de contaminante que mantienen asociados a la fase particulada de manera casi irreversible, diferentes según los analitos, es una de las causas que contribuyen a la formación de los patrones diferenciales entre biota y sedimento. Por último, dentro de la línea de trabajo de técnicas biomiméticas, se evaluó la aplicabilidad de distintas versiones de un dispositivo de muestreo pasivo en fase experimental, el Chemcatcher®, capaz de acumular los PBDE y DDX disueltos en el medio y proporcionar una medida promediada en el tiempo. Los límites de detección obtenidos indican que este sistema podría ser apto para el monitoreo de estos contaminantes en cuerpos de agua muy contaminados como efluentes de depuradoras, pero no para determinar las concentraciones en que se suelen encontrar en aguas superficiales.[eng] In a given period of time, only a fraction of the total amount of a chemical present in the water column or in the sediment is bioaccesible or bioavailable. In turn, even though the dissolved fraction of a contaminant may be very low, sometimes undetectable, a long exposure can lead to accumulation by the organisms. This issue is especially relevant for hydrophobic contaminants, as they tend to persist in the environment bound to sediment particles and to be accumulated by biota. The thesis is focused on two groups of pollutants haloaromatics: the historical pesticide dichlorodiphenyltrichloroethane (DDT) and its transformation products, and the flame retardants polybrominated diphenyl ethers (PBDEs), most recently included in legislation. The overall objective was the development and application of analytical methods by which to measure their concentrations in different phases or compartments in the aquatic environment that take into account the spatial and temporal availability for living beings. In the first part of the thesis, a modern technique for quantitative extraction from sediment and fish, adapted to current regulatory requirements of exhaustiveness for monitoring of pollutants, was used. In order to do so, an analytical method by selective extraction with pressurized liquids (SPLE) coupled to gas chromatography and mass spectrometry (GC-MS) was optimized. Optimized methods were applied for the analysis of sediment and fish samples from different parts of the mainland coast and the Ebro river basin. The developed methodology also allowed detection of hexabromocyclododecane (HBCD), a flame retardant that was just beginning to be used as a substitute for PBDEs and whose presence in the environment had just been described in that time. Afterwards, two types of biomimetic techniques using a surrogate phase for measuring the bioavailable and bioaccumulative pollutant in the medium were evaluated. First, the exhaustive extraction of contaminants in the sediment carried by SPLE method was compared with the aqueous extraction with Tenax®, allowing to quantify the fraction susceptible of passing to the dissolved phase in specific time periods or bioaccessible fraction. Finally, within the line of work of biomimetic techniques, the applicability of different versions of an experimental passive sampling device, the Chemcatcher®, able to accumulate PBDEs and DDX dissolved in the medium and provide a time-averaged measure was assessed

Determination of decabromodiphenyl ether in sediments using selective pressurized liquid extraction followed by GC-NCI-MS

5 pages, 3 figures, 2 tables.-- PMID: 14513196 [PubMed].-- Available online Sep 25, 2003.A method based on selective pressurized liquid extraction (SPLE) followed by gas chromatography–negative ion chemical ionization-mass spectrometry (GC–NCI-MS) has been evaluated for analysis of decabromodiphenyl ether (PBDE-209) in sediment samples. Instrumental operating conditions such as source temperature and system pressure were optimized in the NCI-MS system, giving an instrumental detection limit of 2 pg. The limit of determination of the entire SPLE–GC–NCI-MS procedure was around 50 pg g–1 dry weight (dw), with repeatability of replicates between 4 and 21% relative standard deviation. Application of the method to 13 different river and marine sediment samples collected in Spain revealed that levels of decabromodiphenyl ether ranged between 2 and 132 ng g–1 dry weight.This work was financially supported by the Ministerio de Ciencia y Tecnología (TRACOAL, PPQ2001–1805-C03–01).Peer reviewe

Potential chlorinated and brominated interferences on the polybrominated diphenyl ether determinations by gas chromatography-mass spectrometry

12 pages, 6 figures, 3 tables.-- PMID: 12967183 [PubMed].-- Printed version published Aug 8, 2003.The analysis of polybrominated diphenyl ether (PBDE) congeners by GC–MS was studied in terms of potential interferences. Different MS approaches were normally used for the PBDE analyses: negative ion chemical ionization (NICI-MS) and electron ionization (EI-MS). This paper studied the presence of potential interferences in each instrumental technique approach, principally those corresponding to different chlorinated compounds (PCBs, PCNs, etc.) as well as brominated compounds (PBBs, MeO-PBDEs, TBBPA, etc.). The two ionization modes are subjected to different types of interferences. In general, EI-MS is affected by chlorinated interferences, especially PCBs. NICI-MS eliminated chlorinated interferences but presented different brominated interferences, well resolved with the EI-MS approach.This research project was made possible by funding provided by the European Commission under the Energy, Environment and Sustainable Development programme (Standardised aquatic monitoring of priority pollutants by passive sampling (STAMPS), project number EVK1-CT2002-00119), and by the Spanish Ministerio de Ciencia y Tecnologia (TRACOAL, PPQ2001-1805-C03-01 and BQU2002-10946-E).Peer reviewe

Monitoring the complex occurrence of pesticides in the Llobregat basin, natural and drinking waters in Barcelona metropolitan area (Catalonia, NE Spain) by a validated multi-residue online analytical method

The European Directive 98/83/CE legislates the presence of pesticides in drinking water, but apart from a few compounds, nothing is said about which pesticides should be monitored. Nevertheless, water companies need to go beyond the accomplishment of the legislation and find out pesticide contamination in all sources of water in order to manage the hazard assessment, and to guarantee safe drinking water to all the population. The aim of this work was to develop an analytical multi-residue method for circa 100 compounds. The method analyses previously monitored compounds in Barcelona city and its metropolitan area, as well as many emerging pesticides and some transformation products. An on-line sample extraction (0.75 mL) coupled to fast UHPLC-MS/MS method was developed. Good linearity (r2 > 0.995, with less residuals than 15%), accuracies and precisions under 25%, and acceptable expanded uncertainties were obtained for most of the monitored compounds, according to ISO/IEC 17025, obtaining limits of quantification between 5 and 25 ng/L for all compounds. A monitoring campaign on natural and treated waters in the Barcelona metropolitan area was carried out during 2016–2017. Results showed that pesticide contamination at the low stretch of Llobregat River and in its aquifer is severe. The maximum concentrations were in the range of few μg/L for carbendazim, DEET, diuron and propiconazole, and in the range 0.1–0.5 μg/L for bentazone, imidacloprid, isoproturon, simazine, metazachlor, methomyl, terbutryn and tebuconazole. However, the efficiency of advanced treatments in the DWTPs involved in drinking water production in the Barcelona metropolitan area allows the complete removal of pesticides and a safe water production for consumers. The method shows a good analytical performance for most compounds with a fast sample preparation and analysis. In addition, it has updated the knowledge about the occurrence of pesticides in the Barcelona city area.We are grateful to Dr. Francesc Ventura for his critical revision of this work and to J. Martín-Alonso, M. Paraira, V. García-Tarriño, A. Cabeza and M. Ganzer for their knowledge and comments about the Llobregat River basin and drinking water distribution system. We are also grateful to all co-workers of the Analytical Organic Chemistry Department to deal with the daily work and for their time spent to move forward this study, as well as to the Sampling Department co-workers. This work has received funding from European Union's Horizon 2020 Research and Innovation Programme under grant agreement No. 727450. This presentation only reflects the authors' views and the Commission is not responsible for any use that may be made of the information it contains.Peer reviewe

Evaluation of two aquatic passive sampling configurations for their suitability in the analysis of estrogens in water

The presence of estrogens in the aquatic environment has been the target of several studies in the last decade. Newly developed passive sampling techniques for polar organic chemicals show great promise for the assessment of long-time exposure of aquatic organisms to emerging contaminants. In the present work, two configurations of the Chemcatcher® passive sampler have been tested for their applicability to the analysis of seven estrogens in water. Accumulation experiments in the laboratory, to calculate the uptake rates, and a field trial show that the polar configuration of this device may be used for the efficient sampling and determination of estrogens in water. Time weighted average concentrations were determined in the field trial and compared with spot sampling concentrations. The detection of estriol using passive sampling, although not found with spot sampling, clearly demonstrates the value of this technique in assessing relevant concentrations of estrogens in the aquatic media.This work has been financially supported by the European Union under the STAMPS (EVK1-CT2002-00119) project and by the Spanish Ministry of Science and Innovation through the projects CEMAGUA (CGL2007-64551/HID), SCARCE (Consolider-Ingenio 2010 CSD2009-00065) and SOSTAQUA (led by Aguas de Barcelona and founded by CDTI in the framework of the Ingenio 2010 Programme under the CENIT call), and reflects the author's view. The EU is not liable for any use that may be made of the information contained in it. Many thanks to Arturo Faura, Lluis Tirapu and Antoni Ginebreda from the Catalonian Water Agency for helping with the choice of the sampling sites and for the use of their facilities, as well as for providing the water parameters monitored with SAIH and XACQA. Marina Kuster gratefully acknowledges the I3P Program (Itinerario integrado de inserción profesional; co-financed by CSIC and European Social Funds) for a predoctoral grant. Merck (Darmstadt, Germany) is acknowledged for the gift of SPE and LC columns.Peer reviewe