http://hdl.handle.net/2117/1729 Thu, 23 May 2013 22:14:46 GMT 2013-05-23T22:14:46Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/16683 Title: Time series outlier and intervention analysis: Irrigation management influences on soil water content in silty loam soil Authors: Basem, Aljoumani; Sánchez Espigares, Josep Anton; Cañameras Riba, Núria; Josa March, Ramon; Monserrat, Joaquim Abstract: Understanding the field soil water regime is fundamental in scheduling irrigation as well as for monitoring water flow and solute transport. This study was carried out on variable interval irrigation and used time series analysis techniques to predict the soil water content at the interested depth by measuring one single depth in order to precisely determine the next irrigation time and its effect on soil water content at the interested depth. Volumetric water content of silty loam soil in Barcelona was measured in situ with capacitance soil moisture sensors at five depths within the root zone for a horticultural crop during its life cycle in 2010. The time series consisted of hourly measurements of soil water content and was transformed to a stationary situation. Subsequently, the transformed data were used to conduct analyses in the time domain in order to obtain the parameters of a seasonal autoregressive integrated moving average (ARIMA) model. In the case of variable interval irrigation, predicting the soil water content time series cannot be properly explained by the ARIMA model and its underlying normality assumption. By completing the ARIMA model with intervention analysis and outlier detection, the prediction of soil water content in variable interval irrigation can be made. The transfer function models were then used to predict water contents at depths of interest (0.20, 0.35, 0.50 and 0.60 m depths) as well as the average water content WAVG in the top 0.60 m soil profile by measuring water content at 0.10 m depth. As a result, the predictions were logical. Also, the next irrigation time and its effect on soil water content at the depth of interest were correctly estimated. To confirm results of the models, the experiment was repeated in 2011, and the predicted and observed values agree reasonably well. Description: Soil volumetric water content; Autoregressive integrated moving average (ARIMA); Outlier detection; Transfer function model Tue, 09 Oct 2012 11:01:57 GMT http://hdl.handle.net/2117/16683 2012-10-09T11:01:57Z Basem, Aljoumani; Sánchez Espigares, Josep Anton; Cañameras Riba, Núria; Josa March, Ramon; Monserrat, Joaquim no Autoregressive integrated moving average (ARIMA), Outlier detection, Soil volumetric water content, Transfer function model Understanding the field soil water regime is fundamental in scheduling irrigation as well as for monitoring water flow and solute transport. This study was carried out on variable interval irrigation and used time series analysis techniques to predict the soil water content at the interested depth by measuring one single depth in order to precisely determine the next irrigation time and its effect on soil water content at the interested depth. Volumetric water content of silty loam soil in Barcelona was measured in situ with capacitance soil moisture sensors at five depths within the root zone for a horticultural crop during its life cycle in 2010. The time series consisted of hourly measurements of soil water content and was transformed to a stationary situation. Subsequently, the transformed data were used to conduct analyses in the time domain in order to obtain the parameters of a seasonal autoregressive integrated moving average (ARIMA) model. In the case of variable interval irrigation, predicting the soil water content time series cannot be properly explained by the ARIMA model and its underlying normality assumption. By completing the ARIMA model with intervention analysis and outlier detection, the prediction of soil water content in variable interval irrigation can be made. The transfer function models were then used to predict water contents at depths of interest (0.20, 0.35, 0.50 and 0.60 m depths) as well as the average water content WAVG in the top 0.60 m soil profile by measuring water content at 0.10 m depth. As a result, the predictions were logical. Also, the next irrigation time and its effect on soil water content at the depth of interest were correctly estimated. To confirm results of the models, the experiment was repeated in 2011, and the predicted and observed values agree reasonably well. 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/2117/15838 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/2117/13666 Title: Digestión anaerobia de subproductos de la industria cárnica Authors: Palatsi Civit, Jordi; Rodríguez-Abalde, Ángela; Fernández García, Belén; Flotats Ripoll, Xavier Wed, 26 Oct 2011 09:43:50 GMT http://hdl.handle.net/2117/13666 2011-10-26T09:43:50Z Palatsi Civit, Jordi; Rodríguez-Abalde, Ángela; Fernández García, Belén; Flotats Ripoll, Xavier no http://hdl.handle.net/2117/13619 Title: Codigestion of cow and guinea pig manure in low-cost tubular digesters at high altitude Authors: Garfi, Marianna; Ferrer Martí, Laia; Pérez Bort, Irene; Flotats Ripoll, Xavier; Ferrer Martí, Ivet Fri, 21 Oct 2011 12:59:03 GMT http://hdl.handle.net/2117/13619 2011-10-21T12:59:03Z Garfi, Marianna; Ferrer Martí, Laia; Pérez Bort, Irene; Flotats Ripoll, Xavier; Ferrer Martí, Ivet no http://hdl.handle.net/2117/13603 Title: Effects of tillage systems in dryland farming on near-surface water content during the late winter period Authors: Josa March, Ramon; Hereter Quintana, Agnès Abstract: Tillage systems modify, at least temporarily, some of the physical properties of soil, such as soil porosity. Tillage also has an indirect effect on soil water content throughout the growth cycle, particularly in areas with a Mediterranean climate. This paper presents the results of monitoring the water content in the topsoil (0–0.20 m) of three adjacent plots during February to May cycles starting in 1994–1995 and ending in 1998–1999. Each of the plots had a surface area of 2700 m2, an 8% slope and Calcic Cambisol soil. Starting in 1994, three different tillage systems were applied: conventional tillage, which is typical of the area (CT); minimum tillage (MT); and no-tillage (NT). Two vertical 200 mm TDR probes were permanently installed in each plot and measurements were taken every week. The results show that, under an NT system, the soil had significantly higher water content than the other two soil plots. However, this increased quantity of water did not denote increased crop production; on the contrary, these preliminary data point to a decrease in crop production. Thu, 20 Oct 2011 14:30:33 GMT http://hdl.handle.net/2117/13603 2011-10-20T14:30:33Z Josa March, Ramon; Hereter Quintana, Agnès no Tillage systems modify, at least temporarily, some of the physical properties of soil, such as soil porosity. Tillage also has an indirect effect on soil water content throughout the growth cycle, particularly in areas with a Mediterranean climate. This paper presents the results of monitoring the water content in the topsoil (0–0.20 m) of three adjacent plots during February to May cycles starting in 1994–1995 and ending in 1998–1999. Each of the plots had a surface area of 2700 m2, an 8% slope and Calcic Cambisol soil. Starting in 1994, three different tillage systems were applied: conventional tillage, which is typical of the area (CT); minimum tillage (MT); and no-tillage (NT). Two vertical 200 mm TDR probes were permanently installed in each plot and measurements were taken every week. The results show that, under an NT system, the soil had significantly higher water content than the other two soil plots. However, this increased quantity of water did not denote increased crop production; on the contrary, these preliminary data point to a decrease in crop production. http://hdl.handle.net/2117/13488 Title: Gestión y tratamiento de deyecciones ganaderas (III) Authors: Flotats Ripoll, Xavier Tue, 11 Oct 2011 15:05:00 GMT http://hdl.handle.net/2117/13488 2011-10-11T15:05:00Z Flotats Ripoll, Xavier no http://hdl.handle.net/2117/13487 Title: Gestión y tratamiento de deyecciones ganaderas (II) Authors: Flotats Ripoll, Xavier Tue, 11 Oct 2011 15:01:15 GMT http://hdl.handle.net/2117/13487 2011-10-11T15:01:15Z Flotats Ripoll, Xavier no http://hdl.handle.net/2117/13486 Title: Gestión y tratamiento de deyecciones ganaderas (I) Authors: Flotats Ripoll, Xavier Tue, 11 Oct 2011 14:54:52 GMT http://hdl.handle.net/2117/13486 2011-10-11T14:54:52Z Flotats Ripoll, Xavier no http://hdl.handle.net/2117/12850 Title: Feasibility study of the anaerobic digestion of dewatered pig slurry by means of polyacrylamide Authors: Campos Pozuelo, Elena; Almirall, Marta; Martínez-Almela, Jesus; Palatsi Civit, Jordi; Flotats Ripoll, Xavier Fri, 01 Jul 2011 10:03:07 GMT http://hdl.handle.net/2117/12850 2011-07-01T10:03:07Z Campos Pozuelo, Elena; Almirall, Marta; Martínez-Almela, Jesus; Palatsi Civit, Jordi; Flotats Ripoll, Xavier no http://hdl.handle.net/2117/12847 Title: Organic waste: a resource to be managed Authors: Flotats Ripoll, Xavier Fri, 01 Jul 2011 08:06:32 GMT http://hdl.handle.net/2117/12847 2011-07-01T08:06:32Z Flotats Ripoll, Xavier no http://hdl.handle.net/2117/12679 Title: Simulación del proceso de digestión anaerobia y producción de biogás. Identificación de parámetros Authors: Flotats Ripoll, Xavier; Rodríguez-Abalde, Ángela; Fernández García, Belén; Palatsi Civit, Jordi Tue, 31 May 2011 09:47:32 GMT http://hdl.handle.net/2117/12679 2011-05-31T09:47:32Z Flotats Ripoll, Xavier; Rodríguez-Abalde, Ángela; Fernández García, Belén; Palatsi Civit, Jordi no http://hdl.handle.net/2117/12483 Title: Effects of thermal pre-treatments on solid slaughterhouse waste methane potential Authors: Rodríguez-Abalde, Ángela; Fernández García, Belén; Silvestre, Gracia; Flotats Ripoll, Xavier Abstract: The effects of thermal pre-treatments on the biogas production potential of two solid slaughterhouse waste types (poultry and piggery slaughterhouse by-products) were assessed by means of batch experiments. Both animal by-products were characterized in terms of fat, protein and carbohydrate concentrations. The selected thermal pre-treatments, pasteurization (70 ºC for 60 min) and sterilization (133 ºC and 3 bars for 20 min), are included in the current European regulations for the disposal or use of animal byproducts. The pre-treatments produced notable improvements in organic matter solubilization, but had different effects on the anaerobic bioavailability of the treated substrates. The methane yield of the initial volatile solids did not increase significantly after pre-treatment when carbohydrate concentration was high, reaching a maximum of 0:48 m3 CH4 kg1 VS for the pasteurized poultry waste. However, this yield increased by up to 52.7% after pasteurization and 66.1% after sterilization for the lower carbohydrate concentration sample (piggery waste), reaching maxima of 0.88 and 0:96 m3 CH4 kg 1 VS , respectively. The maximum methane production rates, measured as the maximum slope of the accumulated methane production curve, per unit of initial biomass content, were also different. While this rate increased by 52.6% and 211.6% for piggery waste after pasteurization and sterilization, respectively, it decreased by 43.8% for poultry waste after pasteurization with respect to untreated waste. Compounds with low biodegradability that are produced by Maillard reactions during thermal pre-treatment could explain the low bioavailability observed for waste with a high carbohydrate concentration. Thu, 05 May 2011 15:35:42 GMT http://hdl.handle.net/2117/12483 2011-05-05T15:35:42Z Rodríguez-Abalde, Ángela; Fernández García, Belén; Silvestre, Gracia; Flotats Ripoll, Xavier no The effects of thermal pre-treatments on the biogas production potential of two solid slaughterhouse waste types (poultry and piggery slaughterhouse by-products) were assessed by means of batch experiments. Both animal by-products were characterized in terms of fat, protein and carbohydrate concentrations. The selected thermal pre-treatments, pasteurization (70 ºC for 60 min) and sterilization (133 ºC and 3 bars for 20 min), are included in the current European regulations for the disposal or use of animal byproducts. The pre-treatments produced notable improvements in organic matter solubilization, but had different effects on the anaerobic bioavailability of the treated substrates. The methane yield of the initial volatile solids did not increase significantly after pre-treatment when carbohydrate concentration was high, reaching a maximum of 0:48 m3 CH4 kg1 VS for the pasteurized poultry waste. However, this yield increased by up to 52.7% after pasteurization and 66.1% after sterilization for the lower carbohydrate concentration sample (piggery waste), reaching maxima of 0.88 and 0:96 m3 CH4 kg 1 VS , respectively. The maximum methane production rates, measured as the maximum slope of the accumulated methane production curve, per unit of initial biomass content, were also different. While this rate increased by 52.6% and 211.6% for piggery waste after pasteurization and sterilization, respectively, it decreased by 43.8% for poultry waste after pasteurization with respect to untreated waste. Compounds with low biodegradability that are produced by Maillard reactions during thermal pre-treatment could explain the low bioavailability observed for waste with a high carbohydrate concentration. http://hdl.handle.net/2117/12231 Title: La implicación ciudadana como factor clave para el éxito de los procesos de digestión anaerobia Authors: Flotats Ripoll, Xavier; Burgos, Esther; Tey, Laura; Fresno, Joan Mon, 04 Apr 2011 13:44:00 GMT http://hdl.handle.net/2117/12231 2011-04-04T13:44:00Z Flotats Ripoll, Xavier; Burgos, Esther; Tey, Laura; Fresno, Joan no http://hdl.handle.net/2117/11322 Title: Effects of two tillage techniques on soil macroporosity in sub-humid environment. Authors: Josa March, Ramon; Ginovart Gisbert, Marta; Solé, Albert Wed, 09 Feb 2011 13:49:25 GMT http://hdl.handle.net/2117/11322 2011-02-09T13:49:25Z Josa March, Ramon; Ginovart Gisbert, Marta; Solé, Albert no