Modelització de l'estació depuradora d'aigües residuals de Granollers

Aquest document conté originàriament altre material i/o programari només consultable a la Biblioteca de Ciència i Tecnologia.Aquest projecte s'emmarca dins els sistemes de sanejament i forma part del projecte GEISTTAR finançat pel Ministerio de Economía y Competitividad (MINECO) (CTM2011-27163) liderat per la investigadora Maite Pijuan, el qual te l'objectiu d'estudiar la formació de gasos d'efecte hivernacle que es produeixen en Estacions Depuradores d'Aigües Residuals (EDARs), concretament en el reactor biològic. Una tasca dins el projecte, liderada per l'investigador Lluís Corominas, és la modelització de processos biològics en l'EDAR de Granollers per ajudar a entendre els mecanismes de degradació de matèria orgànica i nitrogen. Aquest treball estableix les bases per poder realitzar aquesta modelització en estat estacionari, seguint els passos proposats pel Good Modelling Practice (GMP) Task Group de la IWA. Els objectius específics que es proposen són l'anàlisi i estudi dels resultats del test de traçadors realitzat per l'Institut Català de Recerca de l'Aigua (ICRA) i realitzar una bona recopilació de dades sobre l'EDAR de Granollers per facilitar els estudis posteriors a aquest projecte

Control and optimization of an SBR for nitrogen removal: from model calibration to plant operation

En aquesta tesis s'ha desenvolupat un sistema de control capaç d'optimitzar el funcionament dels Reactors Discontinus Seqüencials dins el camp de l'eliminació de matèria orgànica i nitrogen de les aigües residuals. El sistema de control permet ajustar en línia la durada de les etapes de reacció a partir de mesures directes o indirectes de sondes. En una primera etapa de la tesis s'ha estudiat la calibració de models matemàtics que permeten realitzar fàcilment provatures de diferents estratègies de control. A partir de l'anàlisis de dades històriques s'han plantejat diferents opcions per controlar l'SBR i les més convenients s'han provat mitjançant simulació. Després d'assegurar l'èxit de l'estratègia de control mitjançant simulacions s'ha implementat en una planta semi-industrial. Finalment es planteja l'estructura d'uns sistema supervisor encarregat de controlar el funcionament de l'SBR no només a nivell de fases sinó també a nivell cicle.In this Thesis a control system has been developed which permits optimizing the performance of the Sequencing Batch Reactors (SBR) within the field of organic matter and nitrogen removal from the wastewater. This control system is based on the on-line adjustment of the length of the reaction phases using directly or indirectly the data acquired from the sensors. In a first stage of the Thesis the calibration of the activated sludge models is studied what permits obtaining models for testing different operating and control strategies. From the analysis of historical data several options for controlling the SBR are obtained and most suitable is tested using a simulation approach. Afterwards, the control strategy is implemented in a semi-industrial plant obtaining promising results. Finally, a proposal for a supervisory control system is presented which can be in charge of controlling the performance of the SBR not only at a phase level but also at cycle level

Do machine learning methods used in data mining enhance the potential of decision support systems? A review for the urban water sector

With sustainable development as their overarching goal, Urban Water System (UWS) managers need to take into account all social, economic, technical and environmental facets related to their decisions. Decision support systems (DSS) have been used widely for handling such complexity in water treatment, having a high level of popularity as academic exercises, although little validation and few full-scale implementations reported in practice. The objective of this paper is to review the application of artificial intelligence methods (mainly machine learning) to UWS and to investigate the integration of these methods into DSS. The results of the review suggest that artificial neural networks is the most popular method in the water and wastewater sectors followed by clustering. Bayesian networks and swarm intelligence/optimization have shown a spectacular increase in the water sector in the last 10 years, being the latest techniques to be incorporated but overtaking case-based reasoning. Whereas artificial intelligence applications to the water sector focus on modelling, optimization or data mining for knowledge generation, their encapsulation into functional DSS is not fully explored. Few academic applications have made it into decision making practice. We believe that the reason behind this misuse is not related to the methods themselves but rather to the disassociation between the fields of water and computer engineering, the limited practical experience of academics, and the great complexity inherently presentThe authors would like to acknowledge the People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme FP7/2007e2013 under REA agreement 289193 (SANITAS ITN). The authors thank the Spanish Ministry of Economy and Competitiveness (RYC-2013-14595, CTM2015-66892-R). The authors also acknowledge support from the Economy and Knowledge Department of the Catalan Government through the Consolidated Research Group (2014 SGR 291) - Catalan Institute for Water Research and (2014-SGR-1168)-LEQUIA-University of Giron

Life cycle assessment of construction and renovation of sewer systems using a detailed inventory tool

Purpose: The objective was to provide comprehensive life cycle inventories for the construction and renovation of sewers. A detailed inventory was provided with multiple options of pipe materials, diameters and site-specific characteristics, and was embedded into the Excel ® -based tool SewerLCA. The tool allows for life cycle evaluation of different sewers. It was applied to determine the most important phases, processes, and related parameters involved in the construction and renovation of sewers from an environmental and economical perspective. Methods: Comprehensive life cycle inventories (LCIs) for sewers construction and renovation were obtained by first identifying all processes involved after interviewing construction experts and reviewing sewer construction budgets from a Catalan company; and second transforming the processes into masses of materials and energy usage using construction databases. In order to run the life cycle impact assessment (LCIA) the materials and energy typologies from the inventories were matched to their corresponding equivalents into available LCI databases. Afterwards the potential impacts were calculated through the use of LCIA characterization factors from ReCiPe. Life cycle assessment (LCA) was run several times to assess the construction of a 1-km-long sewer with varying pipe materials, life spans for each material, diameters, transport distances, site-specific characteristics, and pipe deposition options. Results and discussion: The environmental impacts generated by construction and renovation of a 1 km Polyvinylchloride (PVC) pipe with a diameter of 40 cm are mainly associated with pipe laying and backfilling of the trench. The evaluation of several pipe materials and diameters shows that the exclusion of renovation would underestimate the impacts by 38 to 82 % depending on the pipe materials and diameters. Including end-of-life phase for plastic pipe materials increases climate change (up to an extra 71 %) and human toxicity (up to an extra 147 %) impacts (among all diameters). The preferred pipe materials from an environmental point of view are precast concrete and High-Density Polyethylene (HDPE). Site-specific characteristics (specially the presence of rocky soil and asphalt placement) and material life span have a high influence on the overall environmental profile, whereas changes in transport distances have only a minor impact ( < 4 %). Conclusions: Environmental impacts during the construction and renovation of sewers are subject to differences in material type, site-specific characteristics and material life span. Renovation of sewers has a large influence on all potential environmental impacts and costs and, hence, should not be omitted in LCA studies. The treatment and disposal processes of plastic pipes at the end of their life has to be accounted in LCA studiesThe authors would like to thank Voltes S.L.U. for the technical support, Banc BEDEC, the Ramon and Cajal grant from Lluís Corominas RYC-2013-14595), Marie Curie Career Integration Grant PCIG9-GA-2011-293535 and Marie Curie SANITAS ITN Project GA 289193), Waterfate project (CTM2012-38314-C0201). Serni Morera’s FI scholarship (2015FI_B2 00071), STSMscholarship from EU-Cost Action Water2020 (ECOST-STSM-ES1202-110614-044095). LEQUIA and ICRA were recognized as consolidated research groups by the Catalan Government with codes 2014-SGR-1168 and 2014-SGR-291, respectivel

Connection of neighboring wastewater treatment plants: Economic and environmental assessment

This paper explores the potential of integrated management of neighboring wastewater treatment plants (WWTPs). The novelty lies in the integration of environmental aspects, with the application of life cycle assessment (LCA) methodology, together with economic criteria for the selection of best alternatives. A case study illustrates how the connection of neighboring wastewater systems by constructing an extra pipeline provides positive results in the economic assessment, and in the majority of the LCA categories used in the global environmental assessment. The consideration of local environmental constraints suggests that the usage of the connection should be limited to periods when the minimum ecological flow in the river section between the discharges of the two WWTPs is maintained. In this particular case, the scenario that promotes the usage of the connection between the two WWTPs (but with some restrictions in dry weather periods) is preferred because it provides cost savings of 45,053€·year-1 and satisfies environmental criteria. A scenario analysis has been conducted to evaluate the influence of the pipe length on both economic and environmental aspects and the influence of individual cost terms on the economic assessmentThe authors would like to thank Consorci per la Defensa de la Conca del Riu Bes os (CDCRB) (especially A. Freix o, C. Turon and J. Arr aez) for providing the case-study and the required data as well as the Spanish Ministry of Science and Innovation for funding (CTM-2009-13018 and RYC-2013-14595), and the European Union (ECOTECH-SUDOE Project SOE2/P2/E377, Marie Curie Career Integration Grant PCIG9-GA-2011-293535 and Marie Curie SANITAS ITN Project GA 289193). Serni Morera's FI scholarship and Voltes, S.L.U., for the technical advice and information for the inventory of the pipeline construction provided, are also acknowledged. LEQUIA and ICRA were recognised as consolidated research groups by the Catalan Government with codes 2014-SGR-1168 and 2014-SGR-291, respectivel

The difference between energy consumption and energy cost: Modelling energy tariff structures for water resource recovery facilities

The objective of this paper is to demonstrate the importance of incorporating more realistic energy cost models (based on current energy tariff structures) into existing water resource recovery facilities (WRRFs) process models when evaluating technologies and cost-saving control strategies. In this paper, we first introduce a systematic framework to model energy usage at WRRFs and a generalized structure to describe energy tariffs including the most common billing terms. Secondly, this paper introduces a detailed energy cost model based on a Spanish energy tariff structure coupled with a WRRF process model to evaluate several control strategies and provide insights into the selection of the contracted power structure. The results for a 1-year evaluation on a 115,000 population-equivalent WRRF showed monthly cost differences ranging from 7 to 30% when comparing the detailed energy cost model to an average energy price. The evaluation of different aeration control strategies also showed that using average energy prices and neglecting energy tariff structures may lead to biased conclusions when selecting operating strategies or comparing technologies or equipment. The proposed framework demonstrated that for cost minimization, control strategies should be paired with a specific optimal contracted power. Hence, the design of operational and control strategies must take into account the local energy tariffThe authors would like to thank the Spanish Ministry of Economy and Competitiveness for funding (RYC-2013-14595 and CTM2012-38314-C02-01), and the European Union Marie Curie Career Integration Grant PCIG9-GA-2011-293535. ICRA was recognised as consolidated research groups by the Catalan Government with the code 2014-SGR-291. The usefulness of the energy cost model is now being demonstrated within the framework of the R3water project funded by EU (FP7, Grant agreement no: 619093

Using data from monitoring combined sewer overflows to assess, improve, and maintain combined sewer systems

Using low-cost sensors, data can be collected on the occurrence and duration of overflows in each combined sewer overflow (CSO) structure in a combined sewer system (CSS). The collection and analysis of real data can be used to assess, improve, and maintain CSSs in order to reduce the number and impact of overflows. The objective of this study was to develop a methodology to evaluate the performance of CSSs using low-cost monitoring. This methodology includes (1) assessing the capacity of a CSS using overflow duration and rain volume data, (2) characterizing the performance of CSO structures with statistics, (3) evaluating the compliance of a CSS with government guidelines, and (4) generating decision tree models to provide support to managers for making decisions about system maintenance. The methodology is demonstrated with a case study of a CSS in La Garriga, Spain. The rain volume breaking point from which CSO structures started to overflow ranged from 0.6. mm to 2.8. mm. The structures with the best and worst performance in terms of overflow (overflow probability, order, duration and CSO ranking) were characterized. Most of the obtained decision trees to predict overflows from rain data had accuracies ranging from 70% to 83%. The results obtained from the proposed methodology can greatly support managers and engineers dealing with real-world problems, improvements, and maintenance of CSSsSupport for this project was provided by the ENDERUS Project (CTM-2009-13018) and the predoctoral grant FPI BES-2010-039247, founded by the Spanish Ministry of Science and Innovation. Lluís Corominas received the postdoctoral Juan de la Cierva grant (JCI-2009-05604) from the Government of Spain and the Career Integration Grant (PCIG9-GA-2011-293535) from the EU. The authors also acknowledge the support from the Economy and Knowledge Department of the Catalan Government through the Consolidated Research Group (2014 SGR 291)–Catalan Institute for Water Researc

Is river rehabilitation economically viable in water-scarce basins?

Decisions on river rehabilitation actions are often based on cost-benefit analyses taking into account the costs and benefits of the considered management actions, but ecosystem services are often not included as benefits, despite recent evidences on the effects of river rehabilitations on ecosystem services. A cost-benefit analysis integrating market and non-market costs and benefits was undertaken in this study to assess the economic feasibility of a river rehabilitation project in a water scarce region, the Yarqon River Rehabilitation project (Israel). In this case, the costs included both the capital costs of implementing rehabilitation measures (including maintenance costs) and the opportunity costs of water allocation (foregone benefits to farmers from water provisioning for agriculture). The benefits of rehabilitation included the net marginal benefits of the cultural ecosystem services at local scale (estimated with a hedonic pricing method), and at regional scale (estimated with a value function transfer), in addition to the habitat service gene-pool protection (estimated with a replacement cost method). Bearing in mind the uncertainties surrounding water resource management decisions, especially in water scarce areas, a sensitivity and risk analysis was conducted using an analysis that included both Monte Carlo simulations and the standardized regression coefficients method. The rehabilitation of the Yarqon River provided positive net present values (approximately $139 million in 30-year period). This was thanks to the provision of cultural ecosystem services and despite the high rehabilitation costs, and that the massive water reallocation involved high foregone benefits to farmers. Therefore, these results highlight that river rehabilitation in water scarce regions can be economically viable due to the social amenity demand for urban riversThis research was supported by EU-ITN SANITAS (ITN-289193), a Marie Curie European Reintegration Grant (PERG07-GA-2010-259219) and a Career Integration Grant (PCIG09-2011-293365) within the 7th European Community Framework Programme, and the RYC-2013-14595 from the Spanish Ministry of Economy and Competitiveness. Authors acknowledge the support from the Economy and Knowledge Department of the Catalan Government through Consolidated Research Group (2014 SGR 291) Catalan Institute for Water Researc

Water footprint assessment in wastewater treatment plants

Wastewater treatment plants (WWTPs) play an important role within the urbanwater cycle in protecting receiving waters from untreated discharges. However, WWTPs processes also affect the environment. Life cycle assessment has traditionally been used to assess the impact of direct discharges from WWTPs and indirect emissions related to energy or chemical production. The water footprint (WF) can provide complementary information to evaluate the impact of a WWTP regarding the use of freshwater. This paper presents the adoption of the Water Footprint Assessment methodology to assess the consumption of water resources in WWTPs by considering both blue and grey WFs. The usefulness of the proposed methodology in assessing the environmental impact and the benefits from WWTP discharge to a river is illustrated with an actual WWTP, which treats 4,000 m3$d 1, using three scenarios: no treatment, secondary treatment and phosphorus removal. A reduction of the water footprint by 51.5% and 72.4% was achieved using secondary treatment and chemical phosphorus removal, respectively, to fulfill the legal limits. These results indicate that when treating wastewater, there is a large decrease in the grey water footprint compared with the no-treatment scenario; however, there is a small blue water footprintThe authors would like to thank the Spanish Ministry of Science and Innovation (PCIN-2013-074) and the European Union (Marie Curie Career Integration Grant PCIG9-GA-2011-293535 and SANITAS ITN Project agreement 289193). Serni Morera was awarded an FI scholarship from the Catalan Government (2015FI_B2 00071). Lluís Corominas received the Career Integration Grant (PCIG9-GA-2011-293535) from the EU and the Ramon y Cajal Grant (RYC-2013-14595) from Spanish Government. LEQUIA has been recognized as a consolidated research group by the Catalan Government with code2014-SGR-1168. The authors also acknowledge the support from the Economy and Knowledge Department of the Catalan Government through the Consolidated Research Group (2014-SGR-291) e Catalan Institute for Water Researc

Life cycle assessment of urban wastewater systems: Quantifying the relative contribution of sewer systems

This study aims to propose a holistic, life cycle assessment (LCA) of urban wastewater systems (UWS) based on a comprehensive inventory including detailed construction and operation of sewer systems and wastewater treatment plants (WWTPs). For the first time, the inventory of sewers infrastructure construction includes piping materials and aggregates, manholes, connections, civil works and road rehabilitation. The operation stage comprises energy consumption in pumping stations together with air emissions of methane and hydrogen sulphide, and water emissions from sewer leaks. Using a real case study, this LCA aims to quantify the contributions of sewer systems to the total environmental impacts of the UWS. The results show that the construction of sewer infrastructures has an environmental impact (on half of the 18 studied impact categories) larger than both the construction and operation of the WWTP. This study highlights the importance of including the construction and operation of sewer systems in the environmental assessment of centralised versus decentralised options for UWSICRA authors also acknowledge the Marie Curie EU Reintegration grants 2010-RG-277050 and PCIG9-GA-2011-293535, the EU-ITN SANITAS (ITN – 289193), the Spanish government (CTM 2011-27163; RYC-2013-14595) and the support from the Economy and Knowledge Department of the Catalan Government through the Consolidated Research Group (2014 SGR 291