http://hdl.handle.net/2117/5301 Wed, 22 May 2013 12:07:56 GMT 2013-05-22T12:07:56Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/19104 Title: Application of the gas tracer method for measuring oxygen transfer rates in subsurface flow constructed wetlands Authors: Tyroller, Lina; Rousseau, Diederik P. L.; Santa, Santa; García Serrano, Joan Abstract: The oxygen transfer rate (OTR) has a significant impact on the design, optimal operation and modelling of constructed wetlands treating wastewater. Oxygen consumption is very fast in wetlands and the OTR cannot be determined using an oxygen mass balance. This problem is circumvented in this study by applying the gas tracer method. Experiments were conducted in an unplanted gravel bed (dimensions L × W × d 125 × 50 × 35 cm filled with a 30-cm layer of 10–11-mm gravel) and a planted horizontal subsurface flow constructed wetland (HSSFCW) (L × W × d 110 × 70 × 38 cm filled with a 30-cm layer of 3.5-mm gravel with Phragmites australis). Tap water saturated with propane as gas tracer (pure or commercial cooking gas, depending on the test) was used. The mass transfer ratio between oxygen and commercial propane gas was quite constant and averaged R = 1.03, which is slightly lower than the value of R = 1.39 that is usually reported for pure propane. The OTR ranged from 0.31 to 5.04 g O2 m−2 d−1 in the unplanted gravel bed and from 0.3 to 3.2 g O2 m−2 d−1 in the HSSFCW, depending on the hydraulic retention time (HRT). The results of this study suggest that the OTR in HSSFCW is very low for the oxygen demand of standard wastewater and the OTR calculations based on mass balances and theoretical stoichiometric considerations overestimate OTR values by a factor that ranges from 10 to 100. The gas tracer method is a promising tool for determining OTR in constructed wetlands, with commercial gas proving to be a viable low-cost alternative for determining OTR. Description: 5th. IWA International Young Water Professional 2010, qua atorga la International Water association Mon, 06 May 2013 12:38:26 GMT http://hdl.handle.net/2117/19104 2013-05-06T12:38:26Z Tyroller, Lina; Rousseau, Diederik P. L.; Santa, Santa; García Serrano, Joan no Treatment wetlands, Reed beds, Dissolved oxygen, Oxygen deficit, Oxygen transfer coefficient The oxygen transfer rate (OTR) has a significant impact on the design, optimal operation and modelling of constructed wetlands treating wastewater. Oxygen consumption is very fast in wetlands and the OTR cannot be determined using an oxygen mass balance. This problem is circumvented in this study by applying the gas tracer method. Experiments were conducted in an unplanted gravel bed (dimensions L × W × d 125 × 50 × 35 cm filled with a 30-cm layer of 10–11-mm gravel) and a planted horizontal subsurface flow constructed wetland (HSSFCW) (L × W × d 110 × 70 × 38 cm filled with a 30-cm layer of 3.5-mm gravel with Phragmites australis). Tap water saturated with propane as gas tracer (pure or commercial cooking gas, depending on the test) was used. The mass transfer ratio between oxygen and commercial propane gas was quite constant and averaged R = 1.03, which is slightly lower than the value of R = 1.39 that is usually reported for pure propane. The OTR ranged from 0.31 to 5.04 g O2 m−2 d−1 in the unplanted gravel bed and from 0.3 to 3.2 g O2 m−2 d−1 in the HSSFCW, depending on the hydraulic retention time (HRT). The results of this study suggest that the OTR in HSSFCW is very low for the oxygen demand of standard wastewater and the OTR calculations based on mass balances and theoretical stoichiometric considerations overestimate OTR values by a factor that ranges from 10 to 100. The gas tracer method is a promising tool for determining OTR in constructed wetlands, with commercial gas proving to be a viable low-cost alternative for determining OTR. http://hdl.handle.net/2117/18745 Title: Are ciliated protozoa communities affected by macrophyte species, date of sampling and location in horizontal sub-surface flow constructed wetlands? Authors: Puigagut Juárez, Jaume; Maltais-Laundry, Grabriel; Gagnon, Vincent; Brisson, Jacques Abstract: The effects of design and operational factors on the dynamics of ciliated protozoa in constructed wetlands (CWs) treating wastewater remain poorly known, although bacterivory by ciliates could have important implications for nutrient cycling in these systems. We conducted a greenhouse experiment with eight wetland mesocosms (1 m2) fed with synthetic wastewater to assess how macrophyte species (Phragmites australis, Phalaris arundinacea, and Typha angustifolia), location within CW (longitudinal, depth), and temporal fluctuations affect ciliate abundance and diversity. Urosoma similis was the most abundant taxon, but Hypotrichidae, Scuticociliates, Drepomonas revoluta, and Acineria uncinata were also abundant. Longitudinal location had the highest impact on ciliate dynamics, with more abundant and diverse communities in the initial section of wetlands. P. australis/T. angustifolia and P. arundinacea had the most and least favorable conditions for ciliates, respectively, but differences among macrophytes were mostly not significant. Ciliate abundance appeared to decline from August to November, most likely because of lower temperature and plant inputs of organic matter and oxygen. Depth had no apparent impact on ciliate dynamics, suggesting that sampling at multiple depths in CW is not necessary to adequately monitor ciliate communities. Overall, our results suggest that macrophytes, location, and date of sampling influenced ciliated dynamics but stress the need for direct manipulative experiments of ciliate abundance, diversity, and composition conducted on a full annual cycle to better understand the impact of ciliates on nutrient cycling in CWs. This is especially true to determine if the associations found in our principal component analysis are robust. Tue, 09 Apr 2013 16:11:18 GMT http://hdl.handle.net/2117/18745 2013-04-09T16:11:18Z Puigagut Juárez, Jaume; Maltais-Laundry, Grabriel; Gagnon, Vincent; Brisson, Jacques no The effects of design and operational factors on the dynamics of ciliated protozoa in constructed wetlands (CWs) treating wastewater remain poorly known, although bacterivory by ciliates could have important implications for nutrient cycling in these systems. We conducted a greenhouse experiment with eight wetland mesocosms (1 m2) fed with synthetic wastewater to assess how macrophyte species (Phragmites australis, Phalaris arundinacea, and Typha angustifolia), location within CW (longitudinal, depth), and temporal fluctuations affect ciliate abundance and diversity. Urosoma similis was the most abundant taxon, but Hypotrichidae, Scuticociliates, Drepomonas revoluta, and Acineria uncinata were also abundant. Longitudinal location had the highest impact on ciliate dynamics, with more abundant and diverse communities in the initial section of wetlands. P. australis/T. angustifolia and P. arundinacea had the most and least favorable conditions for ciliates, respectively, but differences among macrophytes were mostly not significant. Ciliate abundance appeared to decline from August to November, most likely because of lower temperature and plant inputs of organic matter and oxygen. Depth had no apparent impact on ciliate dynamics, suggesting that sampling at multiple depths in CW is not necessary to adequately monitor ciliate communities. Overall, our results suggest that macrophytes, location, and date of sampling influenced ciliated dynamics but stress the need for direct manipulative experiments of ciliate abundance, diversity, and composition conducted on a full annual cycle to better understand the impact of ciliates on nutrient cycling in CWs. This is especially true to determine if the associations found in our principal component analysis are robust. http://hdl.handle.net/2117/17735 Title: Evaluating and comparing three community small-scale wind electrification projects Authors: Ferrer Martí, Laia; Garwood, Anna; Chiroque, José; Ramirez, Benito; Marcelo, Oliver; Garfi, Marianna; Velo García, Enrique Abstract: Electrificationsystemsbasedonrenewableenergyhaveprovensuitableforprovidingelectricity autonomouslytoruralcommunities.Amongthetechnicaloptionsavailable,windsystemsare increasinglygettingattention.InthenorthernmountainsofPeru,at3800m.a.s.l.,threecommunity wind electrificationprojectshavebeenimplemented.Thetechnicalsolutionsusedineachprojectare different:windvs.hybridphotovoltaic-windsystems;individualequipmentvs.microgrids.Thisstudy aims todescribe,evaluateandcomparethesethreesmall-scalecommunitywindelectrification projects.Theevaluationofthethreeprojectswascarriedoutbycomparingpreviousandpresent scenario;attentionhasbeenfocusedonprojectdesignandtechnicalaspects,socio-economicimpacts and sustainabilityandmanagementmodel.Thesethreeexamplesshedlightonboththeadvantages and disadvantagesofdifferenttechnologicaloptionsaswellasonappropriatecommunity-level managementmodels Wed, 13 Feb 2013 16:47:09 GMT http://hdl.handle.net/2117/17735 2013-02-13T16:47:09Z Ferrer Martí, Laia; Garwood, Anna; Chiroque, José; Ramirez, Benito; Marcelo, Oliver; Garfi, Marianna; Velo García, Enrique no Electrificationsystemsbasedonrenewableenergyhaveprovensuitableforprovidingelectricity autonomouslytoruralcommunities.Amongthetechnicaloptionsavailable,windsystemsare increasinglygettingattention.InthenorthernmountainsofPeru,at3800m.a.s.l.,threecommunity wind electrificationprojectshavebeenimplemented.Thetechnicalsolutionsusedineachprojectare different:windvs.hybridphotovoltaic-windsystems;individualequipmentvs.microgrids.Thisstudy aims todescribe,evaluateandcomparethesethreesmall-scalecommunitywindelectrification projects.Theevaluationofthethreeprojectswascarriedoutbycomparingpreviousandpresent scenario;attentionhasbeenfocusedonprojectdesignandtechnicalaspects,socio-economicimpacts and sustainabilityandmanagementmodel.Thesethreeexamplesshedlightonboththeadvantages and disadvantagesofdifferenttechnologicaloptionsaswellasonappropriatecommunity-level managementmodels http://hdl.handle.net/2117/17140 Title: Lagrangian simulation of suspended sediment in the swash zone Authors: Alsina Torrent, José Maria; Cáceres Rabionet, Iván; Sospedra Iglesias, Joaquim; Baldock, Tom E. Abstract: A numerical model is presented to simulate the sediment transport and beach morphology in the swash zone. The model resolves the non-linear shallow water equations in an Eulerian framework and then solves the advection-diffusion equation for turbulence and suspended sediment in a Lagrangian framework. A laboratory experimental data set under solitary broken waves has been used to validate the model ability to simulate the sediment mass trapped at different cross-shore positions. The model shows very good fit to experimental data illustrating the importance of sediment advection to predict correctly the sediment transport in the swash zone. Numerical simulations of a swash event in a natural beach show that sediment advection controls the cross-shore sediment transport distribution which is important to give realistic bed level evolution Mon, 17 Dec 2012 16:52:40 GMT http://hdl.handle.net/2117/17140 2012-12-17T16:52:40Z Alsina Torrent, José Maria; Cáceres Rabionet, Iván; Sospedra Iglesias, Joaquim; Baldock, Tom E. no A numerical model is presented to simulate the sediment transport and beach morphology in the swash zone. The model resolves the non-linear shallow water equations in an Eulerian framework and then solves the advection-diffusion equation for turbulence and suspended sediment in a Lagrangian framework. A laboratory experimental data set under solitary broken waves has been used to validate the model ability to simulate the sediment mass trapped at different cross-shore positions. The model shows very good fit to experimental data illustrating the importance of sediment advection to predict correctly the sediment transport in the swash zone. Numerical simulations of a swash event in a natural beach show that sediment advection controls the cross-shore sediment transport distribution which is important to give realistic bed level evolution http://hdl.handle.net/2117/17041 Title: Bacterial transformation and biodegradation processes simulation in horizontal subsurface flow constructed wetlands using CWM1-RETRASO Authors: Llorens Ribes, Esther; Saaltink, Maarten Willem; Poch, Manel; García Serrano, Joan Abstract: The performance and reliability of the CWM1-RETRASO model for simulating processes in horizontal subsurface flow constructed wetlands (HSSF CWs) and the relative contribution of different microbial reactions to organic matter (COD) removal in a HSSF CW treating urban wastewater were evaluated. Various different approaches with diverse influent configurations were simulated. According to the simulations, anaerobic processes were more widespread in the simulated wetland and contributed to a higher COD removal rate [72–79%] than anoxic [0–1%] and aerobic reactions [20–27%] did. In all the cases tested, the reaction that most contributed to COD removal was methanogenesis [58–73%]. All results provided by the model were in consonance with literature and experimental field observations, suggesting a good performance and reliability of CWM1-RETRASO. According to the good simulation predictions, CWM1- RETRASO is the first mechanistic model able to successfully simulate the processes described by the CWM1 model in HSSF CWs. Tue, 27 Nov 2012 17:25:43 GMT http://hdl.handle.net/2117/17041 2012-11-27T17:25:43Z Llorens Ribes, Esther; Saaltink, Maarten Willem; Poch, Manel; García Serrano, Joan no The performance and reliability of the CWM1-RETRASO model for simulating processes in horizontal subsurface flow constructed wetlands (HSSF CWs) and the relative contribution of different microbial reactions to organic matter (COD) removal in a HSSF CW treating urban wastewater were evaluated. Various different approaches with diverse influent configurations were simulated. According to the simulations, anaerobic processes were more widespread in the simulated wetland and contributed to a higher COD removal rate [72–79%] than anoxic [0–1%] and aerobic reactions [20–27%] did. In all the cases tested, the reaction that most contributed to COD removal was methanogenesis [58–73%]. All results provided by the model were in consonance with literature and experimental field observations, suggesting a good performance and reliability of CWM1-RETRASO. According to the good simulation predictions, CWM1- RETRASO is the first mechanistic model able to successfully simulate the processes described by the CWM1 model in HSSF CWs. http://hdl.handle.net/2117/17040 Title: CWM1 implementation in RetrasoCodeBright: first results using horizontal subsurface flow constructed wetland data, Chemical Engineering Journal Authors: Llorens Ribes, Esther; Saaltink, Maarten Willem; García Serrano, Joan Abstract: Constructed Wetland Model No. 1 (CWM1) processes were implemented within RetrasoCodeBright (RCB) to simulate hydraulics and reactive transport as well as the main biodegradation and transformation processes in horizontal subsurface flow constructed wetlands (SSF CWs). New values for some stoichiometric and kinetic coefficients were determined in the calibration step in order to obtain more realistic biochemical transformation and degradation processes. The model was checked and then tested for a horizontal SSF CW operating with different hydraulic loading rates [20, 36 and 45 mm/d]. Modifications to the CWM1 formulation had a negligible effect on the good fitting of measured and simulated data. However, changes in stoichiometric and kinetic parameters positively affected performance. Bacterial concentrations defined as initial conditions proved to be a variable requiring attention in the calibration. In terms of pollutant concentrations in effluent, simulated data corresponded well with data measured in most cases evaluated. The quality of the results obtained suggests that CWM1-RETRASO, the resulting model, is a potential tool for studying hydraulics, reactive transport and the main biochemical transformation and degradation processes for organic matter, nitrogen and sulphur in horizontal SSF CWs. Tue, 27 Nov 2012 17:22:47 GMT http://hdl.handle.net/2117/17040 2012-11-27T17:22:47Z Llorens Ribes, Esther; Saaltink, Maarten Willem; García Serrano, Joan no Constructed Wetland Model No. 1 (CWM1) processes were implemented within RetrasoCodeBright (RCB) to simulate hydraulics and reactive transport as well as the main biodegradation and transformation processes in horizontal subsurface flow constructed wetlands (SSF CWs). New values for some stoichiometric and kinetic coefficients were determined in the calibration step in order to obtain more realistic biochemical transformation and degradation processes. The model was checked and then tested for a horizontal SSF CW operating with different hydraulic loading rates [20, 36 and 45 mm/d]. Modifications to the CWM1 formulation had a negligible effect on the good fitting of measured and simulated data. However, changes in stoichiometric and kinetic parameters positively affected performance. Bacterial concentrations defined as initial conditions proved to be a variable requiring attention in the calibration. In terms of pollutant concentrations in effluent, simulated data corresponded well with data measured in most cases evaluated. The quality of the results obtained suggests that CWM1-RETRASO, the resulting model, is a potential tool for studying hydraulics, reactive transport and the main biochemical transformation and degradation processes for organic matter, nitrogen and sulphur in horizontal SSF CWs. http://hdl.handle.net/2117/15843 Title: Minimizing phosphorus discharge from aquaculture earth ponds by a novel sediment retention system Authors: Lefrançois, Philippe; Puigagut Juárez, Jaume; Chazarenc, Florent; Comeau, Yves Abstract: Freshwater fish farms in Quebec are facing stringent phosphorus discharge limits of 4.2 kg P per tonne of fish produced. Most phosphorus in fish farm effluents is found in particulate form (uneaten food, feces, etc.). Physical separation systems such as microscreens, filter beds, Cornell-type circular tanks and settling tanks have been proposed to remove solids from raceway and recirculation fish farm effluents but these technologies are relatively expensive and labour intensive for small pond based production facilities, as mostly found in Quebec. A novel sediment retention system (SRS), consisting of a 1m3 truncated pyramid, was installed at the bottom of an earth pond, below a surface aerator. The objective of this study was to determine the feasibility of collecting and removing sediments by using the SRS and to determine its particulate phosphorus removal efficiency. Solids accumulated in the SRS were quantified and characterised weekly, for 10 weeks. Fish production, food supply, rain events and fish harvesting were also monitored over the course of the study period. The total solids (TS) accumulation rate in the SRS was, on average, 4.0 kg/d with a volatile solids fraction of 7.8% and the P accumulation rate was, on average, 12.4 g P/d. The P removal efficiency obtained with the SRS was 24% of the total P not taken up by fish (effluent P, PEFF). Assuming that 50% of the PEFF was in the particulate form, the removal efficiency of the SRS was 47%. Lab-scale results correlated with the P mass balance calculations to show that sediments from earth ponds can play an active role in the sorption of soluble phosphorus. Approximately 30% of the P removed from the SRS was attributed to previous sorption/precipitation of soluble P into inorganic forms. The Langmuir model fitted the sorption isotherm of phosphorus onto earth pond soil and the maximum sorption constant obtained was 1.3mg P/g soil. Fish harvesting was identified as the main external factor affecting sediments and phosphorus accumulation in the SRS. It was concluded that an SRS located under the aerator surface is a suitable and efficient strategy to collect and remove particulate phosphorus generated from fish production in earth ponds. Description: Aquacultural Engineering Society Superior Paper Award Fri, 11 May 2012 18:48:56 GMT http://hdl.handle.net/2117/15843 2012-05-11T18:48:56Z Lefrançois, Philippe; Puigagut Juárez, Jaume; Chazarenc, Florent; Comeau, Yves no Phosphorus removal, Solids capture, Fish farm Freshwater fish farms in Quebec are facing stringent phosphorus discharge limits of 4.2 kg P per tonne of fish produced. Most phosphorus in fish farm effluents is found in particulate form (uneaten food, feces, etc.). Physical separation systems such as microscreens, filter beds, Cornell-type circular tanks and settling tanks have been proposed to remove solids from raceway and recirculation fish farm effluents but these technologies are relatively expensive and labour intensive for small pond based production facilities, as mostly found in Quebec. A novel sediment retention system (SRS), consisting of a 1m3 truncated pyramid, was installed at the bottom of an earth pond, below a surface aerator. The objective of this study was to determine the feasibility of collecting and removing sediments by using the SRS and to determine its particulate phosphorus removal efficiency. Solids accumulated in the SRS were quantified and characterised weekly, for 10 weeks. Fish production, food supply, rain events and fish harvesting were also monitored over the course of the study period. The total solids (TS) accumulation rate in the SRS was, on average, 4.0 kg/d with a volatile solids fraction of 7.8% and the P accumulation rate was, on average, 12.4 g P/d. The P removal efficiency obtained with the SRS was 24% of the total P not taken up by fish (effluent P, PEFF). Assuming that 50% of the PEFF was in the particulate form, the removal efficiency of the SRS was 47%. Lab-scale results correlated with the P mass balance calculations to show that sediments from earth ponds can play an active role in the sorption of soluble phosphorus. Approximately 30% of the P removed from the SRS was attributed to previous sorption/precipitation of soluble P into inorganic forms. The Langmuir model fitted the sorption isotherm of phosphorus onto earth pond soil and the maximum sorption constant obtained was 1.3mg P/g soil. Fish harvesting was identified as the main external factor affecting sediments and phosphorus accumulation in the SRS. It was concluded that an SRS located under the aerator surface is a suitable and efficient strategy to collect and remove particulate phosphorus generated from fish production in earth ponds. http://hdl.handle.net/2117/15842 Title: Mesophilic and thermophilic anaerobic biodegradability of water hyacinth pre-treated at 80 °C Authors: Ferrer Martí, Ivet; Campos Pozuelo, Elena; Flotats Ripoll, Xavier; Palatsi Civit, Jordi Abstract: Water hyacinth (Eichornia crassipes) is a fast growing aquatic plant which causes environmental problems in continental water bodies. Harvesting and handling this plant becomes an issue, and focus has been put on the research of treatment alternatives. Amongst others, energy production through biomethanation has been proposed. The aim of this study was to assess the anaerobic biodegradability of water hyacinth under mesophilic and thermophilic conditions. The effect of a thermal sludge pre-treatment at 80 C was also evaluated. To this end, anaerobic biodegradability tests were carried out at 35 C and 55 C, with raw and pre-treated water hyacinth. According to the results, the thermal pre-treatment enhanced the solubilisation of water hyacinth (i.e. increase in the soluble to total chemical oxygen demand (COD)) from 4% to 12% after 30 min. However, no significant effect was observed on the methane yields (150–190 L CH4/kg volatile solids). Initial methane production rates for thermophilic treatments were two fold those of mesophilic ones (6–6.5 L vs. 3–3.5 L CH4/kg COD day). Thus, higher methane production rates might be expected from thermophilic reactors working at short retention times. The study of longer low temperature pre-treatments or pre-treatments at elevated temperatures coupled to thermophilic reactors should be considered in the future. Fri, 11 May 2012 18:43:39 GMT http://hdl.handle.net/2117/15842 2012-05-11T18:43:39Z Ferrer Martí, Ivet; Campos Pozuelo, Elena; Flotats Ripoll, Xavier; Palatsi Civit, Jordi no Water hyacinth (Eichornia crassipes) is a fast growing aquatic plant which causes environmental problems in continental water bodies. Harvesting and handling this plant becomes an issue, and focus has been put on the research of treatment alternatives. Amongst others, energy production through biomethanation has been proposed. The aim of this study was to assess the anaerobic biodegradability of water hyacinth under mesophilic and thermophilic conditions. The effect of a thermal sludge pre-treatment at 80 C was also evaluated. To this end, anaerobic biodegradability tests were carried out at 35 C and 55 C, with raw and pre-treated water hyacinth. According to the results, the thermal pre-treatment enhanced the solubilisation of water hyacinth (i.e. increase in the soluble to total chemical oxygen demand (COD)) from 4% to 12% after 30 min. However, no significant effect was observed on the methane yields (150–190 L CH4/kg volatile solids). Initial methane production rates for thermophilic treatments were two fold those of mesophilic ones (6–6.5 L vs. 3–3.5 L CH4/kg COD day). Thus, higher methane production rates might be expected from thermophilic reactors working at short retention times. The study of longer low temperature pre-treatments or pre-treatments at elevated temperatures coupled to thermophilic reactors should be considered in the future. http://hdl.handle.net/2117/15841 Title: Sources of contamination and modelled pollutant trajectories in a Mediterranean harbour (Tarragona, Spain) Authors: Mestres Ridge, Marc; Sierra Pedrico, Juan Pablo; Mösso Aranda, César; Sánchez-Arcilla Conejo, Agustín Abstract: The proximity of commercial harbours to residential areas and the growing environmental awareness of society have led most port authorities to include environmental management within their administration plan. Regarding water quality, it is necessary to have the capacity and tools to deal with contamination episodes that may damage marine ecosystems and human health, but also affect the normal functioning of harbours. This paper presents a description of the main pollutant sources in Tarragona Harbour (Spain), and a numerical analysis of several pollution episodes based on the Port Authority’s actual environmental concerns. The results show that pollution generated inside the harbour tends to remain confined within the port, whereas it is very likely that oil spills from a nearby monobuoy may affect the neighbouring beaches. The present combination of numerical models proves itself a useful tool to assess the environmental risk associated to harbour activities and potential pollution spills. Fri, 11 May 2012 18:39:29 GMT http://hdl.handle.net/2117/15841 2012-05-11T18:39:29Z Mestres Ridge, Marc; Sierra Pedrico, Juan Pablo; Mösso Aranda, César; Sánchez-Arcilla Conejo, Agustín no Water pollution, Numerical models, Risk management, Harbours, Tarragona The proximity of commercial harbours to residential areas and the growing environmental awareness of society have led most port authorities to include environmental management within their administration plan. Regarding water quality, it is necessary to have the capacity and tools to deal with contamination episodes that may damage marine ecosystems and human health, but also affect the normal functioning of harbours. This paper presents a description of the main pollutant sources in Tarragona Harbour (Spain), and a numerical analysis of several pollution episodes based on the Port Authority’s actual environmental concerns. The results show that pollution generated inside the harbour tends to remain confined within the port, whereas it is very likely that oil spills from a nearby monobuoy may affect the neighbouring beaches. The present combination of numerical models proves itself a useful tool to assess the environmental risk associated to harbour activities and potential pollution spills. http://hdl.handle.net/2117/15838 Title: Start-up strategies of thermophilic anaerobic digestion of sewage sludge Authors: Gimenez-Lorang, Antonio; Ferrer Martí, Ivet; Flotats Ripoll, Xavier; Palatsi Civit, Jordi Abstract: The aim of the present work was to evaluate two different strategies to convert a continuous mesophilic anaerobic reactor into thermophilic, treating sewage sludge. The compared strategies were a single direct temperature change, from 358 to 558C, and a multi-step temperature change (358–438–508–558C). The single direct step strategy was shown to be as effective as the more conservative multi-step strategy, recovering the system efficiency after 20 days in terms of methane yield, although there was a higher volatile fatty acids accumulation and higher propionate/acetate ratio values during the temperature transition. From the results of the multi-step strategy it could be stated that the critical process performance during temperature transition occurred between 43 and 508C, which should be taken into account to define more accurate future transition strategies. Sewage sludge thermophilic vs mesophilic biodegradability was assessed by means of anaerobic biodegradability tests, and no significant statistical differences in biodegradability or methane yields were found. Fri, 11 May 2012 18:21:45 GMT http://hdl.handle.net/2117/15838 2012-05-11T18:21:45Z Gimenez-Lorang, Antonio; Ferrer Martí, Ivet; Flotats Ripoll, Xavier; Palatsi Civit, Jordi no anaerobic digestion, mesophilic, sewage sludge, thermophilic The aim of the present work was to evaluate two different strategies to convert a continuous mesophilic anaerobic reactor into thermophilic, treating sewage sludge. The compared strategies were a single direct temperature change, from 358 to 558C, and a multi-step temperature change (358–438–508–558C). The single direct step strategy was shown to be as effective as the more conservative multi-step strategy, recovering the system efficiency after 20 days in terms of methane yield, although there was a higher volatile fatty acids accumulation and higher propionate/acetate ratio values during the temperature transition. From the results of the multi-step strategy it could be stated that the critical process performance during temperature transition occurred between 43 and 508C, which should be taken into account to define more accurate future transition strategies. Sewage sludge thermophilic vs mesophilic biodegradability was assessed by means of anaerobic biodegradability tests, and no significant statistical differences in biodegradability or methane yields were found. http://hdl.handle.net/2117/15159 Title: Reliability, repeatability and accuracy of the falling head method for hydraulic conductivity measurements under laboratory conditions Authors: Pedescoll Albacar, Anna; Samsó Campà, Roger; Romero Morales, Enrique Edgar; Puigagut Juárez, Jaume; García Serrano, Joan Abstract: The aim of this study was to verify under lab conditions the reliability, repeatability and accuracy of the falling head method (FHM) for hydraulic conductivity measurements. TheFHMis a reliable procedure that has slight variations (less than 10%) in repeated measurements and turns out to be a reliable technique to record the hydraulic conductivities typically described for clogged and unclogged subsurface-flow constructed wetlands (from 4 to ca. 360 m/day). The accuracy of the method is acceptable considering difficulties in the measurement of hydraulic conductivity in highly conductive media. Accordingly, results show measurement deviations of 20% when compared with a laboratory constant head method for highly conductive media (higher than 250 m/day), and 80% for media with low hydraulic conductivity (lower than 50 m/day). The main conclusion of the present paper is that of the FHM is a reliable and repeatable technique for hydraulic conductivity measurements and it is accurate enough for on-site clogging assessment in full-scale constructed wetlands. Wed, 15 Feb 2012 12:45:10 GMT http://hdl.handle.net/2117/15159 2012-02-15T12:45:10Z Pedescoll Albacar, Anna; Samsó Campà, Roger; Romero Morales, Enrique Edgar; Puigagut Juárez, Jaume; García Serrano, Joan no The aim of this study was to verify under lab conditions the reliability, repeatability and accuracy of the falling head method (FHM) for hydraulic conductivity measurements. TheFHMis a reliable procedure that has slight variations (less than 10%) in repeated measurements and turns out to be a reliable technique to record the hydraulic conductivities typically described for clogged and unclogged subsurface-flow constructed wetlands (from 4 to ca. 360 m/day). The accuracy of the method is acceptable considering difficulties in the measurement of hydraulic conductivity in highly conductive media. Accordingly, results show measurement deviations of 20% when compared with a laboratory constant head method for highly conductive media (higher than 250 m/day), and 80% for media with low hydraulic conductivity (lower than 50 m/day). The main conclusion of the present paper is that of the FHM is a reliable and repeatable technique for hydraulic conductivity measurements and it is accurate enough for on-site clogging assessment in full-scale constructed wetlands. http://hdl.handle.net/2117/14979 Title: The new pelagic operational observatory of the catalan sea (OOCS) for the multisensor coordinated measurement of atmospheric and oceanographic conditions Authors: Cruzado, Antonio; Bahamón Rivera, Nixon; Aguzzi, Jacopo; Bernardello, Raffaele; Ahumada Sempoal, Miguel Angel; Puigdefàbregas Sagristà, Joan; Cateura Sabrí, Jordi; Muñoz, Eduardo; Velasquez Forero, Zoila Abstract: The new pelagic Operational Observatory of the Catalan Sea (OOCS) for the coordinated multisensor measurement of atmospheric and oceanographic conditions has been recently installed (2009) in the Catalan Sea (41°39'N, 2°54'E; Western Mediterranean) and continuously operated (with minor maintenance gaps) until today. This multiparametric platform is moored at 192 m depth, 9.3 km off Blanes harbour (Girona, Spain). It is composed of a buoy holding atmospheric sensors and a set of oceanographic sensors measuring the water conditions over the upper 100 m depth. The station is located close to the head of the Blanes submarine canyon where an important multispecies pelagic and demersal fishery gives the station ecological and economic relevance. The OOCS provides important records on atmospheric and oceanographic conditions, the latter through the measurement of hydrological and biogeochemical parameters, at depths with a time resolution never attained before for this area of the Mediterranean. Twenty four moored sensors and probes operating in a coordinated fashion provide important data on Essential Ocean Variables (EOVs; UNESCO) such as temperature, salinity, pressure, dissolved oxygen, chlorophyll fluorescence, and turbidity. In comparison with other pelagic observatories presently operating in other world areas, OOCS also measures photosynthetic available radiation (PAR) from above the sea surface and at different depths in the upper 50 m. Data are recorded each 30 min and transmitted in real-time to a ground station via GPRS. This time series is published and automatically updated at the frequency of data collection on the official OOCS website (http://www.ceab.csic.es/~oceans). Under development are embedded automated routines for the in situ data treatment and assimilation into numerical models, in order to provide a reliable local marine processing forecast. In this work, our goal is to detail the OOCS multisensor architecture in relation to the coordinated capability for the remote, continuous and prolonged monitoring of atmospheric and oceanographic conditions, including data communication and storage. Accordingly, time series of measurements for a number of biological parameters will be presented for the summer months of 2011. Marine hindcast outputs from the numerical models implemented for simulating the conditions over the study area are shown. The strong changes of atmospheric conditions recorded in the last years over the area have altered the marine conditions of living organisms, but the dimension of the impact remains unclear. The OOCS multisensor coordinated monitoring has been specifically designed to address this issue, thus contributing to better understand the present environmental fluctuations and to provide a sound basis for a more accurate marine forecast system. Mon, 06 Feb 2012 15:06:01 GMT http://hdl.handle.net/2117/14979 2012-02-06T15:06:01Z Cruzado, Antonio; Bahamón Rivera, Nixon; Aguzzi, Jacopo; Bernardello, Raffaele; Ahumada Sempoal, Miguel Angel; Puigdefàbregas Sagristà, Joan; Cateura Sabrí, Jordi; Muñoz, Eduardo; Velasquez Forero, Zoila no Pelagic observatory, Oceanographic buoy, Multisensor coordinated monitoring, PAR, Operational oceanography, Submarine canyons, Numerical multiparametric modelling, Ocean forecast, Western Mediterranean Sea The new pelagic Operational Observatory of the Catalan Sea (OOCS) for the coordinated multisensor measurement of atmospheric and oceanographic conditions has been recently installed (2009) in the Catalan Sea (41°39'N, 2°54'E; Western Mediterranean) and continuously operated (with minor maintenance gaps) until today. This multiparametric platform is moored at 192 m depth, 9.3 km off Blanes harbour (Girona, Spain). It is composed of a buoy holding atmospheric sensors and a set of oceanographic sensors measuring the water conditions over the upper 100 m depth. The station is located close to the head of the Blanes submarine canyon where an important multispecies pelagic and demersal fishery gives the station ecological and economic relevance. The OOCS provides important records on atmospheric and oceanographic conditions, the latter through the measurement of hydrological and biogeochemical parameters, at depths with a time resolution never attained before for this area of the Mediterranean. Twenty four moored sensors and probes operating in a coordinated fashion provide important data on Essential Ocean Variables (EOVs; UNESCO) such as temperature, salinity, pressure, dissolved oxygen, chlorophyll fluorescence, and turbidity. In comparison with other pelagic observatories presently operating in other world areas, OOCS also measures photosynthetic available radiation (PAR) from above the sea surface and at different depths in the upper 50 m. Data are recorded each 30 min and transmitted in real-time to a ground station via GPRS. This time series is published and automatically updated at the frequency of data collection on the official OOCS website (http://www.ceab.csic.es/~oceans). Under development are embedded automated routines for the in situ data treatment and assimilation into numerical models, in order to provide a reliable local marine processing forecast. In this work, our goal is to detail the OOCS multisensor architecture in relation to the coordinated capability for the remote, continuous and prolonged monitoring of atmospheric and oceanographic conditions, including data communication and storage. Accordingly, time series of measurements for a number of biological parameters will be presented for the summer months of 2011. Marine hindcast outputs from the numerical models implemented for simulating the conditions over the study area are shown. The strong changes of atmospheric conditions recorded in the last years over the area have altered the marine conditions of living organisms, but the dimension of the impact remains unclear. The OOCS multisensor coordinated monitoring has been specifically designed to address this issue, thus contributing to better understand the present environmental fluctuations and to provide a sound basis for a more accurate marine forecast system. http://hdl.handle.net/2117/14774 Title: Playas agotadas Authors: Jiménez Quintana, José Antonio Abstract: Impedimos el aporte de sedimentos y alteramos la dinámica natural costera. ¿Y todavía nos extraña que las playas se hallen en retroceso? Tue, 24 Jan 2012 14:38:33 GMT http://hdl.handle.net/2117/14774 2012-01-24T14:38:33Z Jiménez Quintana, José Antonio no Impedimos el aporte de sedimentos y alteramos la dinámica natural costera. ¿Y todavía nos extraña que las playas se hallen en retroceso? http://hdl.handle.net/2117/14758 Title: Future scenario simulations of wave climate in the NW Mediterranean sea Authors: Casas Prat, Mercè; Sierra Pedrico, Juan Pablo Abstract: In this study, 20-year wave climate simulations (1991-2010 and 2081-2100) were performed and analysed in the NW Mediterranean with a fine resolution of 1/8º. The forcing wind was obtained from the ENSEMBLES project, including 3-hourly resolution, daily mean and maximum winds. The validation of the reference situation was done by comparing the probability density function of the datasets. It showed a reasonable agreement between results from 3-hourly winds and buoy data and between results from daily mean wind and wave hindcast data, although the spreading of the distribution is underestimated and some spatial discrepancies were found. The general tendency of the mean significant wave height is to decrease with the exception of the Northern Catalan coast for which no significant variation was detected. A seasonal analysis revealed a change in the annual pattern. During spring and summer the mean significant wave height tends to increase in some areas whereas milder winter and autumn periods are expected. The analysis of the 95% cumulative significant wave height showed similar results but accentuated changes were found. Tue, 24 Jan 2012 09:14:50 GMT http://hdl.handle.net/2117/14758 2012-01-24T09:14:50Z Casas Prat, Mercè; Sierra Pedrico, Juan Pablo no In this study, 20-year wave climate simulations (1991-2010 and 2081-2100) were performed and analysed in the NW Mediterranean with a fine resolution of 1/8º. The forcing wind was obtained from the ENSEMBLES project, including 3-hourly resolution, daily mean and maximum winds. The validation of the reference situation was done by comparing the probability density function of the datasets. It showed a reasonable agreement between results from 3-hourly winds and buoy data and between results from daily mean wind and wave hindcast data, although the spreading of the distribution is underestimated and some spatial discrepancies were found. The general tendency of the mean significant wave height is to decrease with the exception of the Northern Catalan coast for which no significant variation was detected. A seasonal analysis revealed a change in the annual pattern. During spring and summer the mean significant wave height tends to increase in some areas whereas milder winter and autumn periods are expected. The analysis of the 95% cumulative significant wave height showed similar results but accentuated changes were found. http://hdl.handle.net/2117/14748 Title: Simulación de la onda de avenida por ruptura de tanque de enfriamiento Authors: Fuentes Mariles, Oscar Arturo; Arganis Juarez, Maritza Liliana; Bladé i Castellet, Ernest; Sánchez Juny, Martí; De Luna Cruz, Faustino; Cruz Gerón, Juan Ansberto; Mendoza Facundo, José Enedino; Aragón Hernández, José Luis Abstract: Se llevó a cabo la simulación de la ruptura del borde de un tanque de enfriamiento usando dos métodos: Uno de volúmenes finitos denominado CARPA y un algoritmo en diferencias finitas centradas. El algoritmo en volúmenes finitos CARPA utilizado con el pre y post procesador GiD mostró ser una herramienta muy poderosa en la animación de planicies de inundación, útiles en la interpretación de resultados tanto en el espacio como en el tiempo, para la protección civil, así como para definir las posibles zonas afectadas debido a fenómenos como el de la ruptura de bordos. Mon, 23 Jan 2012 17:32:06 GMT http://hdl.handle.net/2117/14748 2012-01-23T17:32:06Z Fuentes Mariles, Oscar Arturo; Arganis Juarez, Maritza Liliana; Bladé i Castellet, Ernest; Sánchez Juny, Martí; De Luna Cruz, Faustino; Cruz Gerón, Juan Ansberto; Mendoza Facundo, José Enedino; Aragón Hernández, José Luis no Se llevó a cabo la simulación de la ruptura del borde de un tanque de enfriamiento usando dos métodos: Uno de volúmenes finitos denominado CARPA y un algoritmo en diferencias finitas centradas. El algoritmo en volúmenes finitos CARPA utilizado con el pre y post procesador GiD mostró ser una herramienta muy poderosa en la animación de planicies de inundación, útiles en la interpretación de resultados tanto en el espacio como en el tiempo, para la protección civil, así como para definir las posibles zonas afectadas debido a fenómenos como el de la ruptura de bordos.