Salgado B.,Dow Chemical Company |
Majamaa K.,Dow Chemical Company |
Sanz J.,Veolia Water Solutions and Technologies |
Molist J.,Agencia Catalana de lAigua
Desalination and Water Treatment | Year: 2013
Within the current and future world's water scarcity, the reuse of treated waste water for specific applications offers an appealing alternative to conventional fresh water sources that cannot meet the expectations, mostly in terms of quantity. Spain is no exception to this global situation, with a constantly increasing population, in combination with growing water demand for applications such as production industry, exportation oriented agriculture, tourism development, and booming construction, access to sufficient quantities of fresh water is currently a rising concern. Camp de Tarragona (ACA) Water Reclamation Project is a prime example how water scarcity can be solved regionally by reclaiming water that would otherwise be discharged to the sea. The new reclamation plant treats municipal secondary effluent from Tarragona and Salou/Vilaseca Wastewater Treatment Plants to supply process water for the petrochemical industry of Tarragona. The plant capacity is currently 19,000 m3/d (Phase I), and further expansions are planned for increases up to 29,000 m3/d (Phase II) and even to 55,000 m3/d (Phase III) in the coming years. This additional supply would replace the water currently taken from the Ebro River, thus releasing this volume for drinking water supply to the population. Utilizing such a process, the industrial growth in water scarce regions can be supported and industry sustainability is increased further. A pipeline connects the two different Wastewater Treatment Plants (WWTPs), 10 km apart from each other, and feeds secondary treated effluent to the reverse osmosis (RO) pretreatment process. The pretreatment consists of ballasted flocculation, followed by disc filtration, sand filtration, and multimedia filtration prior feeding it to the two pass RO system. Final permeate treatment is done by UV light and chlorine disinfection, prior releasing water to the distribution system. This paper will review the detailed design of the plant, as a scale-up of pilot plant results, as well as the RO membranes performance data obtained during the start-up of the installation. RO performance is evaluated in detail taking into account the performance differences when different combinations of raw water sources were used. This paper will also explain in detail the preservation of the installation by means of 5-Chloro-2-Methyl-2H-Isothiazol-3-one/2-Methyl-2HIsothiazol-3-one (CMIT/MIT), during a medium term stop of the plant. © 2013 Desalination Publications.
Carafa R.,URS Corporation |
Faggiano L.,University of Girona |
Real M.,URS Corporation |
Munne A.,Agencia Catalana de lAigua |
And 5 more authors.
Science of the Total Environment | Year: 2011
In compliance with the requirements of the EU Water Framework Directive, monitoring of the ecological and chemical status of Catalan river basins (NE Spain) is carried out by the Catalan Water Agency.The large amount of data collected and the complex relationships among the environmental variables monitored often mislead data interpretation in terms of toxic impact, especially considering that even pollutants at very low concentrations might contribute to the total toxicity.The total dataset of chemical monitoring carried out between 2007 and 2008 (232 sampling stations and 60 pollutants) has been analyzed using sequential advanced modeling techniques. Data on concentrations of contaminants in water were pre-treated in order to calculate the bioavailable fraction, depending on substance properties and local environmental conditions.The resulting values were used to predict the potential impact of toxic substances in complex mixtures on aquatic biota and to identify hot spots. Exposure assessment with Species Sensitivity Distribution (SSD) and mixture toxicity rules were used to compute the multi-substances Potentially Affected Fraction (msPAF).The combined toxicity of the pollutants analyzed in the Catalan surface waters might potentially impact more than 50% of the species in 10% of the sites.In order to understand and visualize the spatial distribution of the toxic risk, Self Organising Map (SOM), based on the Kohonen's Artificial Neural Network (ANN) algorithm, was applied on the output data of these models. Principal Component Analysis (PCA) was performed on top of Neural Network results in order to identify main influential variables which account for the pollution trends. Finally, predicted toxic impacts on biota have been linked and correlated to field data on biological quality indexes using macroinvertebrate and diatom communities (IBMWP and IPS). The methodology presented could represent a suitable tool for water managers in environmental risk assessment and management. © 2011 Elsevier B.V.
The combined use of metrics of biological quality and biomarkers to detect the effects of reclaimed water on macroinvertebrate assemblages in the lower part of a polluted Mediterranean river (Llobregat River, NE Spain)
Prat N.,University of Barcelona |
Rieradevall M.,University of Barcelona |
Barata C.,CSIC - Institute of Environmental Assessment And Water Research |
Munne A.,Agencia Catalana de lAigua
Ecological Indicators | Year: 2013
The main purpose of this paper is to evaluate whether introducing reclaimed water to the lower part of the Llobregat River has an effect on the macroinvertebrate community assemblage and the biomarker responses of the caddisfly larvae Hydropsyche exocellata. Therefore, a before-and-after experiment was carried out at two locations, upstream and downstream of the discharge effluent. At both of the stations, quantitative benthic samples were taken using a Surber net. Several biological metrics were calculated to evaluate the biological quality. For the biomarker study, the population condition of the caddisfly H. exocellata was analysed. In both sites, as a result of physicochemical water conditions, the macroinvertebrate communities are dominated by taxa that are tolerant to pollution, and the ecological status of both sites is always poor. The discharge of the reclaimed water did not affect the composition and abundance of the dominant taxa, but the few intolerant species that were found upstream before the experiment disappeared downstream. Consequently, most of the metrics indicating the level of biological impairment had slightly lower values after the introduction of the treated water, even though the ecological status was always poor. Nevertheless, significant and specific toxic effects on the collected H. exocellata larvae were observed using biomarkers. The effects included oxidative stress-related responses, such as decreased antioxidant enzyme activities and increased levels of lipid peroxidation. Therefore, indications of additional stress to the populations of the caddisfly H. exocellata were found using several biomarkers, which can indicate a potential further deterioration of the ecological status of the river. In polluted rivers, such as the Llobregat, structural indicators are unable to indicate further impairment and biomarkers may be used as an useful tool to detect then the environmental impoverishment. The combination of both kinds of indicators is necessary for the establishment of the ecological status of a system, following the indications of the Water Framework Directive (WFD). © 2012 Elsevier Ltd. All rights reserved.
Vera I.,University of Concepción |
Garcia J.,University of Barcelona |
Saez K.,University of Concepción |
Moragas L.,Agencia Catalana de lAigua |
Vidal G.,University of Concepción
Ecological Engineering | Year: 2011
In Catalonia (Spain), a variety of different systems have been built to naturally treat liquid residues from small communities. Some of these wastewater treatment plants (WWTPs) include constructed wetlands with horizontal subsurface flow (HSSF) as secondary treatment. The present study described and characterized the performance of 11 WWTPs with secondary HSSF constructed wetland systems after an initial operating period of 8 years. The effluent concentrations of Biochemical Oxygen Demand (BOD5), Total Suspended Solids (TSS), Total Nitrogen (TN) and Total Phosphorous (TP) were statistically analyzed, and removal efficiencies for all WWTPs including all stages in treatment were calculated. The accumulated probability functions of those parameters were evaluated to determine the influence of two different types of polishing units on the overall performance: (a) only lagoon systems and (b) lagoon systems with HSSF. The statistical analysis indicates good performance for BOD5 and TSS. In the first case, mean concentrations below 25mg/L were found in 9 of the 11 plants analyzed and removal efficiencies between 78 and 96% were observed. In the second case, mean concentrations below 35mg/L were found in 8 of the 11 plants, and removal efficiencies were between 65 and 88%. For the nutrients, the removal efficiency for TN and TP were in the range of 48-66% and 39-58%, respectively. Additionally, the analysis of the influence of the polishing units did not show a significant improvement (α>0.05) for any parameter in the wetland systems without a subsequent polishing unit. However, in the wetland systems with a polishing unit of HSSF, a significant improvement (α<0.05) was found for the effluent's BOD5, TN and TP concentrations but with no significant contribution in TSS management. © 2010 Elsevier B.V.
Uggetti E.,University of Barcelona |
Ferrer I.,University of Barcelona |
Molist J.,Agencia Catalana de lAigua |
Garcia J.,University of Barcelona
Water Research | Year: 2011
Sludge treatment wetlands (STW) emerge as a promising sustainable technology with low energy requirements and operational costs. In this study, technical, economic and environmental aspects of STW are investigated and compared with other alternatives for sludge management in small communities (<2000 population equivalent). The performance of full-scale STW was characterised during 2 years. Sludge dewatering increased total solids (TS) concentration by 25%, while sludge biodegradation lead to volatile solids around 45% TS and DRI24h between 1.1 and 1.4 gO2/kgTS h, suggesting a partial stabilisation of biosolids. In the economic and environmental assessment, four scenarios were considered for comparison: 1) STW with direct land application of biosolids, 2) STW with compost post-treatment, 3) centrifuge with compost post-treatment and 4) sludge transport to an intensive wastewater treatment plant. According to the results, STW with direct land application is the most cost-effective scenario, which is also characterised by the lowest environmental impact. The life cycle assessment highlights that global warming is a significant impact category in all scenarios, which is attributed to fossil fuel and electricity consumption; while greenhouse gas emissions from STW are insignificant. As a conclusion, STW are the most appropriate alternative for decentralised sludge management in small communities. © 2010 Elsevier Ltd.
Ibanez C.,IRTA Aquatic Ecosystems |
Alcaraz C.,IRTA Aquatic Ecosystems |
Caiola N.,IRTA Aquatic Ecosystems |
Rovira A.,IRTA Aquatic Ecosystems |
And 6 more authors.
Science of the Total Environment | Year: 2012
The lower Ebro River (Catalonia, Spain) has recently undergone a regime shift from a phytoplankton-dominated to a macrophyte-dominated system. This shift is well known in shallow lakes but apparently it has never been documented in rivers. Two initial hypotheses to explain the collapse of the phytoplankton were considered: a) the diminution of nutrients (bottom-up); b) the filtering effect due to the colonization of the zebra mussel (top-down). Data on water quality, hydrology and biological communities (phytoplankton, macrophytes and zebra mussel) was obtained both from existing data sets and new surveys. Results clearly indicate that the decrease in phosphorus is the main cause of a dramatic decrease in chlorophyll and large increase in water transparency, triggering the subsequent colonization of macrophytes in the river bed. A Generalized Linear Model analysis showed that the decrease in dissolved phosphorus had a relative importance 14 times higher than the increase in zebra mussel density to explain the variation of total chlorophyll. We suggest that the described changes in the lower Ebro River can be considered a novel ecosystem shift. This shift is triggering remarkable changes in the biological communities beyond the decrease of phytoplankton and the proliferation of macrophytes, such as massive colonization of Simulidae (black fly) and other changes in the benthic invertebrate communities that are currently investigated. © 2011 Elsevier B.V.
Otero N.,University of Barcelona |
Soler A.,University of Barcelona |
Corp R.M.,Agencia Catalana de lAigua |
Mas-Pla J.,University of Girona |
And 2 more authors.
Journal of Hydrology | Year: 2011
The Tordera Desalination Plant located in Blanes (NE Spain) has seawater intake through 10 beach wells located a few meters inland on the shoreline at the Tordera River Delta. Between October 2002 and October 2003, the extracted groundwater showed a decrease in conductivity, especially in the wells located in the northern area, prompting the present study. A multi-isotopic approach (δD, δ18OH2O, 3H, δ34SSO4, 87Sr/86Sr and 228Ra/226Ra) coupled with chemical data was applied in order to assess the origin of the water collected for the desalination plant and to quantify the extent of freshwater collection from the Tordera aquifer, when applicable. Three multi-piezometers located in the Tordera aquifer were also sampled in order to characterize the freshwater end-member. A seasonal survey was performed in order to assess the evolution of mixed freshwater-seawater intake. Tritium isotopes showed values ranging from 0.6 to 2.5TU indicating recent origin of the collected waters. This was further confirmed using radium isotopes (226Ra and 228Ra), as the 228Ra/226Ra activity ratio (AR) indicated a continuous input of seawater on a yearly time scale. The water extracted from the beach wells was at least 95% seawater, except for wells 8-10. The latter two were extracting up to 15% of freshwater from the Tordera aquifer system. From a methodological point of view, while δ34S of dissolved sulphate and the ratio 87Sr/86Sr are good tracers of seawater mixing with freshwaters, the isotopic composition of water (δD and δ18OH2O) and the Cl-/Br- ratio are conservative tracers that allow for quantifying the contribution of freshwater to the extracted water. Although slight variations linked to seasonality were observed in all wells during the 3-year study period (November 2003 to December 2006), wells 1 and 7 showed an increase in freshwater contribution from 4% to 11% and well 10 a decrease from 15% to 10% over this period. © 2010 Elsevier B.V.
Bardina M.,Agencia Catalana de lAigua |
Honey-Roses J.,University of British Columbia |
Munne A.,Agencia Catalana de lAigua
Water Policy | Year: 2016
Compliance with the Water Framework Directive (WFD) of the European Union requires water managers to establish environmental flow regimes (EFR) in rivers across the continent. Few water agencies have examined the economic and social welfare impacts of implementing environmental flow requirements. We present the approach used by the Catalan Water Agency to calculate an EFR and estimate the economic implications of its implementation in the Ter River (Catalonia, NE Spain), altered by weirs for hydro-electric production. We analyze various implementation strategies and their associated economic costs and benefits, concluding that the restoration of environmental flows in the Ter River has reasonable costs and is likely to be a socially desirable policy with economic benefits exceeding costs. This paper provides an example of how a water agency can generate policyrelevant information on the social welfare impacts of implementing environmental flow policies as mandated by the WFD. © IWA Publishing 2016.
Flo E.,CSIC - Institute of Marine Sciences |
Garces E.,CSIC - Institute of Marine Sciences |
Manzanera M.,Agencia Catalana de lAigua |
Camp J.,CSIC - Institute of Marine Sciences
Estuarine, Coastal and Shelf Science | Year: 2011
The physicochemical and biological characteristics of coastal waters form a gradient extending from land to ocean. In the Mediterranean this gradient is particularly large, due to the sea's weak tides. Within coastal waters, those waters in contact with land are called coastal inshore waters (CIW), defined herein as between 0 and 200 m from the shoreline. Here we present the first physicochemical and biological characterization of CIW of the NW Mediterranean Sea. This case study is based on 19 years of data collected from coastal inshore (CIW; 0-200 m), nearshore (CNW; 200-1500 m), and offshore (COW; >1500 m) waters of the Catalan coast. Analyses of these data showed that the physicochemical and biological characteristics of CIW differ significantly from those of CNW and COW due to: (1) significantly higher concentrations of dissolved inorganic nutrients (nitrate = 11.07 μM, nitrite = 0.52 μM, ammonium = 6.43 μM, phosphate = 0.92 μM, silicates = 5.99 μM) and chlorophyll-a (=2.42 μg/L) in CIW than in either CNW or COW (in some cases up to one order of magnitude); (2) a greater variability of dissolved inorganic nutrients and chlorophyll-a in CIW than in CNW and COW, and (3) the presence of a mostly urban population and the effects of river inflows as a primary source of CIW variability but with minimal impact on CNW or COW. In addition, the risk of eutrophication was found to be highest in CIW, placing human and environmental interests at greater risk than in the outermost coastal waters. The results highlight the importance of considering the distinctive physicochemical and biological properties of CIW in future coastal waters studies. This is of major importance in assessments of eutrophication and coastal water quality, not only to identify the pressure-impact relationships but also to allow the timely detection of local environmental problems and thus avoid endangering the unique communities of CIW and ensuring the sustainability of human activities. In conclusion, CIW characterization is essential to integrate coastal zone management. © 2011 Elsevier Ltd.
Mas-Pla J.,University of Girona |
Font E.,University of Girona |
Astui O.,Agencia Catalana de lAigua |
Mencio A.,University of Girona |
Perez-Paricio A.,Agencia Catalana de lAigua
Applied Geochemistry | Year: 2013
Stream-aquifer relationships in mountain basins are of great relevance because they control the water balance and, with it, the amount of resources (whether surface water or ground water) available for ecological and human demands. In this paper, this relationship is studied using environmental isotopes (δ18O and δD) to identify the occurrence of stream recharge in the Arbúcies River basin (NE Spain). Isotopic data from 51 natural springs define the local altitudinal gradient. This function is weighted by the proportional area above each point, given by the hypsometric curve, in order to estimate the isotopic stream water content as the contribution of runoff from incremental elevations. Stream water isotopes from two surveys are compared with hypsometrically averaged isotopic values to check for the appropriateness of this approach. Results show that it is more suitable when subsurface flows from surface formations, such as alluvial deposits, are the main contributors to stream discharge than when it derives from a single rainfall event. The characterization of stream isotope values is used as a key factor in identifying stream leakage to an unconfined alluvial aquifer in the lower reach of the Arbúcies River. © 2012 Elsevier Ltd.