Empresa Portuguesa Das Aguas Livres SA

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Sanches S.,IBET Institute Biologia Experimental e Tecnologica | Sanches S.,New University of Lisbon | Penetra A.,Empresa Portuguesa das Aguas Livres S.A. | Rodrigues A.,Empresa Portuguesa das Aguas Livres S.A. | And 8 more authors.
Separation and Purification Technology | Year: 2013

The combination of low pressure ultraviolet photolysis and nanofiltration proved to be extremely efficient for the treatment of drinking water since several emerging pesticides spiked in surface water were found to be highly removed. The concentration of the by-products formed and estrogenic activity of the nanofiltration permeate was found to be always very low during operation, showing that the by-products formed during photolysis were efficiently retained by the nanofiltration process. Moreover, the need to further treat/dispose the retentate and the respective costs are also likely to decrease. The combined process is promising to remove the selected micropollutants and formed by-products while reducing the chlorine doses needed to achieve water disinfection, therefore decreasing also the formation of disinfection by-products. © 2013 Elsevier B.V. All rights reserved.


De Jesus Gaffney V.,University of Lisbon | Cardoso V.V.,Empresa Portuguesa das Aguas Livres S.A. | Rodrigues A.,Empresa Portuguesa das Aguas Livres S.A. | Ferreira E.,Empresa Portuguesa das Aguas Livres S.A. | And 2 more authors.
Quimica Nova | Year: 2014

A method was developed for the analysis of 31 pharmaceutical compounds in Lisbon's drinking water system, using solid-phase extraction (SPE) and ultraperformance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). The method was validated through estimation of the linearity range, method detection and quantification limits, matrix effects, precision and accuracy. The method detection and quantification limit ranges were 0.009-10 and 0.03-33 ng/L, respectively. Analytes were quantified in water samples collected from the EPAL (Empresa Portuguesa das águas Livres S.A.) supply system. Carbamazepine, atenolol, sulfadiazine, sulfamethazine, sulfapyridine, sulfamethoxazole, acetaminophen, caffeine and erythromycin were quantified in the analysed samples.


Sanches S.,Institute Of Biologia Experimental E Tecnologica Ibet | Sanches S.,New University of Lisbon | Leitao C.,New University of Lisbon | Penetra A.,Empresa Portuguesa das Aguas Livres S.A. | And 7 more authors.
Journal of Hazardous Materials | Year: 2011

The widely used low pressure lamps were tested in terms of their efficiency to degrade polycyclic aromatic hydrocarbons listed as priority pollutants by the European Water Framework Directive and the U.S. Environmental Protection Agency, in water matrices with very different compositions (laboratory grade water, groundwater, and surface water). Using a UV fluence of 1500mJ/cm 2, anthracene and benzo(a)pyrene were efficiently degraded, with much higher percent removals obtained when present in groundwater (83-93%) compared to surface water (36-48%). The removal percentages obtained for fluoranthene were lower and ranged from 13 to 54% in the different water matrices tested. Several parameters that influence the direct photolysis of polycyclic aromatic hydrocarbons were determined and their photolysis by-products were identified by mass spectrometry. The formation of photolysis by-products was found to be highly dependent on the source waters tested. © 2011 Elsevier B.V.


Pereira V.J.,IBET | Pereira V.J.,New University of Lisbon | Marques R.,IBET | Marques M.,IBET | And 3 more authors.
Water Research | Year: 2013

The effectiveness of free chlorine for the inactivation of fungi present in settled surface water was tested. In addition, free chlorine inactivation rate constants of Cladosporium tenuissimum, Cladosporium cladosporioides, Phoma glomerata, Aspergillus terreus, Aspergillus fumigatus, Penicillium griseofulvum, and Penicillium citrinum that were found to occur in different source waters were determined in different water matrices (laboratory grade water and settled water). The effect of using different disinfectant concentrations (1 and 3 mg/l), temperatures (21 and 4 °C), and pH levels (6 and 7) was addressed. The sensitivity degree of different fungi isolates to chlorine disinfection varied among different genera with some species showing a higher resistance to disinfection and others expected to be more prone to protection from inactivation by the water matrix components. When the disinfection efficiency measured in terms of the chlorine concentration and contact time (Ct) values needed to achieve 99% inactivation were compared with the Ct values reported as being able to achieve the same degree of inactivation of other microorganisms, fungi were found to be more resistant to chlorine inactivation than bacteria and viruses and less resistant than Cryptosporidium oocysts. © 2012 Elsevier Ltd.


Oliveira B.R.,IBET Institute Biologia Experimental e Tecnologica | Barreto Crespo M.T.,IBET Institute Biologia Experimental e Tecnologica | Barreto Crespo M.T.,New University of Lisbon | San Romao M.V.,IBET Institute Biologia Experimental e Tecnologica | And 5 more authors.
Water Research | Year: 2013

Fungi are known to occur ubiquitously in the environment. In the past years, the occurrence of filamentous fungi in the aquatic environment has been a subject of growing interest. This study describes the occurrence of various fungal genera in different drinking water sources being Penicillium and Trichoderma the most representative ones (30% and 17%, respectively). Also, 24 fungal species that have not been previously described in the aquatic environment are reported in this study, being once again the major species from the Penicillium genera. This study therefore contributes to the knowledge on the richness of fungi diversity in water. 68% of the described species were found to be able to grow at 30°C but only Aspergillus fumigatus, Aspergillus viridinutans and Cunninghamella bertholletiae were able to grow at the higher temperature tested (42°C). 66% of the species that were able to grow at 30°C have spore sizes below 5μm which enables them to cause breathing infections. These were therefore identified as potential pathogenic species. © 2013 Elsevier Ltd.


Pereira V.J.,Institute Biologia Experimental e Tecnologica IBET | Pereira V.J.,New University of Lisbon | Fernandes D.,Institute Biologia Experimental e Tecnologica IBET | Carvalho G.,Institute Biologia Experimental e Tecnologica IBET | And 5 more authors.
Water Research | Year: 2010

A comparison of different isolation techniques and culture media for detection of filamentous fungi and yeasts in the aquatic environment revealed that the use of membrane filtration with the media dichloran rose bengal chloramphenicol (DRBC) optimized fungi detection in terms of abundance and variety in three untreated water sources with very different characteristics (surface water, spring water, and groundwater). The diversity of the fungi population captured by direct DNA extraction of fungi collected by membrane filtration was compared with the isolates obtained after selective growth using different culture media through amplification of the internal transcribed spacer gene and denaturing gradient gel electrophoresis (DGGE). The Czapek-Dox agar, Sabouraud dextrose agar, and DRBC media showed closer similarities to those obtained by the uncultured biomass for the different water sources. Based on these data and the best enumeration results, DRBC is recommended for the assessment of fungi in water sources using culture-based methods. DGGE was also used to monitor temporal variations in the fungal population structure and showed that each water matrix possessed a distinct population profile as well as that changes in the fungal community can be expected in the different matrices throughout the year. © 2010 Elsevier Ltd.


Penetra A.,Empresa Portuguesa Das Aguas Livres S.A. | Vale Cardoso V.,Empresa Portuguesa Das Aguas Livres S.A. | Ferreira E.,Empresa Portuguesa Das Aguas Livres S.A. | Benoliel M.J.,Empresa Portuguesa Das Aguas Livres S.A.
Water Science and Technology | Year: 2010

Contamination of surface and groundwater sources with pesticide residues has been of great concern for a long time and it is a major challenge for the preservation and sustainability of the environment. In order to accomplish the requirements of the European Directive 98/83/EC, we developed and validated an analytical method based on the combination of gas chromatography and tandem quadrupole mass spectrometry (GC-MS/MS) using solid-phase extraction as sample preparation. In this work nine pesticides were studied: molinate, simazine, atrazine, terbuthylazine, diazinon, alachlor, metalaxyl, metolachlor and pendimethalin. In order to get the best sensitivity and selectivity for each pesticide, several parameters of the tandem mass spectrometry were optimized using the MRM mode. Good linearity of the detector response was found for all pesticides at concentrations within the tested working range, with linear determination coefficients higher than 0.9988. Recoveries studies in several matrices with different fortification levels were performed, with recoveries between 77 and 115% with RSD lower than 9.5%. The MQLs obtained for these compounds were between 0.013 μg L -1 and 0.022 μg L -1, which were much lower than the maximum level established by the European legislation. © IWA Publishing 2010.


Salgado R.,New University of Lisbon | Salgado R.,Polytechnic Institute of Setúbal | Pereira V.J.,Institute Biologia Experimental e Tecnologica IBET | Pereira V.J.,New University of Lisbon | And 12 more authors.
Journal of Hazardous Materials | Year: 2013

Pharmaceutical compounds such as ketoprofen, diclofenac and atenolol are frequently detected at relatively high concentrations in secondary effluents from wastewater treatment plants. Therefore, it is important to assess their transformation kinetics and intermediates in subsequent disinfection processes, such as direct ultraviolet (UV) irradiation. The photodegradation kinetics of these compounds using a medium pressure (MP) lamp was assessed in pure water, as well as in filtered and unfiltered treated wastewater. Ketoprofen had the highest time- and fluence-based rate constants in all experiments, whereas atenolol had the lowest values, which is consistent with the corresponding decadic molar absorption coefficient and quantum yield. The fluence-based rate constants of all compounds were evaluated in filtered and unfiltered wastewater matrices as well as in pure water. Furthermore, transformation products of ketoprofen, diclofenac and atenolol were identified and monitored throughout the irradiation experiments, and photodegradation pathways were proposed for each compound. This enabled the identification of persistent transformation products, which are potentially discharged from WWTP disinfection works employing UV photolysis. © 2012 Elsevier B.V.


Pereira V.J.,Institute Biologia Experimental e Tecnologica IBET | Pereira V.J.,New University of Lisbon | Ricardo J.,Institute Biologia Experimental e Tecnologica IBET | Galinha R.,Institute Biologia Experimental e Tecnologica IBET | And 3 more authors.
Photochemical and Photobiological Sciences | Year: 2013

Low pressure ultraviolet photolysis proved to be an efficient treatment to achieve inactivation of different yeast species (Candida sp., Cryptococcus carnescens, Metschnikowia viticola/Candida kofuensis, Rhodosporidium babjevae, Rhodotorula minuta, and Rhodotorula mucilaginosa) isolated from water sources with very different compositions. The sensitivity degree of various yeast isolates to UV treatment varied among different genera. Species isolated from surface water gained additional photoprotective resistance as a defence mechanism to be able to survive under constant sunlight conditions compared to the groundwater isolates. Yeasts were found to be more resistant to UV treatment than E. coli, Cryptosporidium, and Giardia. This journal is © The Royal Society of Chemistry and Owner Societies 2013.


Sanches S.,Institute Biologia Experimental e Tecnologica IBET | Sanches S.,New University of Lisbon | Penetra A.,Empresa Portuguesa das Aguas Livres S.A. | Rodrigues A.,Empresa Portuguesa das Aguas Livres S.A. | And 8 more authors.
Separation and Purification Technology | Year: 2012

This study addresses the efficiency of nanofiltration to remove different pesticides and hormones from different real water sources (surface water and groundwater) and the effect of the ionic composition of different water sources on the rejection of the target micropollutants. Ultrafiltration was performed prior to the nanofiltration process to remove particulate and large colloidal organic matter, that interfere in the rejection of micropollutants during nanofiltration, without affecting the concentration of ionic species and natural organic matter present in the water. The other aim of this study was to understand the role of adsorption on the rejection of the solutes selected, which was tested by conducting membrane pre-adsorption experiments using these micropollutants under static and dynamic conditions. High percent rejections (67.4-99.9%) were obtained for the pesticides and hormones, often independently of the water composition. Size exclusion and hydrophobic interactions were found to highly influence the rejections obtained. The lower rejections (57.5-83.5%) obtained for pentachlorophenol could be explained by its increased solubility at the waters' pH. The overall nanofiltration efficiency to remove the selected compounds was not found to be considerably affected by the pre-adsorption of the compounds on the membrane under static and dynamic conditions, except for 17α-ethinylestradiol, estrone, and estriol in surface water. © 2011 Elsevier B.V. All rights reserved.

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