Search results for "Modelling"
showing 10 items of 1353 documents
THE IDENTIFIABILITY ANALYSIS FOR SETTING UP MEASURING CAMPAIGNS FOR INTEGRATED WATER QUALITY MODELLING
2010
Identifiability analysis enables one the quantification of the number of model parameters that can be assessed by calibration with respect to a data set. Such a methodology is based on the appraisal of sensitivity coefficients of the model parameters by means of Monte Carlo runs. By employing the Fisher Information Matrix, the methodology is able to gain insights with respect to the number of model parameters that can be reliably assessed. The paper presents a study where identifiability analysis is used as a tool for the setting up of measuring campaigns for integrated water quality modelling. The analysis has been applied to a real case study characterized by a partially urbanized catchme…
EVALUATION OF DIFFUSE AND CONCENTRATED POLLUTION AT WATERSHED SCALE
2009
The study presents an integrated approach in order to analyse and quantify pollution dynamics at basin scale depending on concentrated and diffuse sources. More specifically, an integrated model for urban drainage system has been exploited in order to simulate the complex sewer network - wastewater treatment plant and receiving water body. Moreover, a quali-quantitative model has been developped in order to simulate the non-point sources pollutant (agricultural and zoo-technical) in term of water river discharges and nutrient, produced from the wash off of soils. Finally, different models have been coupled in order to reconstruct the whole pollutant load for the receiving water body and to …
Frontiers in Wastewater Treatment and Modelling FICWTM 2017
2017
Today, multidisciplinary is a key to solving issues in the water field. The works in several International Water Association (IWA) Specialist Groups have demonstrated the importance of both innovative technologies and mathematical modelling, and that the exchange of scientific and technical information among researchers and practitioners involved in these fields is crucial for effectively advancing knowledge. Mathematical modelling has the advantage of allowing scenario analysis before designing the real plant in order to ensure an optimized system. To foster the multidisciplinary collaboration among different water specialists, the dialogue is a must in order to better share specific knowl…
The GSA-GLUE approach for uncertainty assessment of an integrated MBR model
2012
In the recent literature, the uncertainty of wastewater treatment plant (WWTP) modelling has had relevant interest both for designers and operators. Indeed, the frequent data lacking and the need to improve process knowledge, in case of innovative technologies, make the use of mathematical models more uncertain. Therefore, the need to make model uncertainty more explicit is warmly recommended. However, only few applications of uncertainty analysis in the wastewater field have been carried out. In this work, the combination of the global sensitivity analysis (GSA) and the Generalized Likelihood Uncertainty Estimation (GLUE) is applied for the uncertainty assessment of a WWTP model, in order …
A new integrated MBR model for wastewater treatment: sensitivity and uncertainty analysis
2017
In this study a new integrated membrane bioreactor (MBR) model is proposed. The model is able to describe the main biological processes aimed at the carbon and the nutrients (nitrogen, N and phosphorus, P) removal coupled with the soluble microbial products (SMP) formation/degradation. Furthermore, the model describes the key physical processes and the interconnection between SMP and membrane fouling. The model was calibrated by adopting data measured during the monitoring of a University Cape Town (UCT) MBR pilot plant. A sensitivity analysis allowed the reduction of the number of model FACTORs to be calibrated from 122 to 45. A good correlation between measured and simulated data was obta…
II ADVANCED COURSE Innovative wastewater treatment and mathematical modeling
2017
Over the past years, the knowledge and understanding of biological wastewater treatment has advanced extensively and moved away from empirically-based approaches to a fundamentally-based 'first principles' approach that embrace: bio-chemistry, microbiology, mathematics, and physical, chemical and bioprocess engineering. Also, the wastewater treatment plant of the future will be a water resource recovery facility (WRRF), implying attention for quite different aspects of these large scale technologies. Many of these advances have matured to a degree that they have been codified into mathematical models able to describe and simulate diverse systems under different environmental conditions at e…
Mathematical modelling of biogas from municipal solid waste landfil
2016
Sanitary landfills for municipal solid wastes can be considered as large biological reactors where the organic fraction of municipal solid waste undergoes anaerobic digestion producing gas and liquid emissions. Leachate production from municipal sanitary landfills is currently recognized as a major environmental burden associated with municipal solid waste management and it may be responsible for local pollution of groundwater and soil. Moreover, the fate of the organic compounds within the landfill body is of primary importance since it directly influences the production of landfill gas. The aim of the paper is to propose an integrated mathematical model able to simulate, on one hand, the …
Uncertainty of a biological nitrogen and phosphorus removal model
2010
In the last few years, the use of mathematical models in wastewater treatment plant (WWTP) processes has become a common way to predict WWTP behaviour. However, mathematical models generally demand advanced input for their implementation that must be evaluated by an extensive data gathering campaign, which cannot always be carried out. This fact, together with the intrinsic complexity of the model structure, leads to model results that may be very uncertain. Quantification of the uncertainty is imperative. However, despite the importance of uncertainty quantification, only a few studies have been carried out in the wastewater treatment field, and those studies only included a few of the sou…
Notes about urban drainage systems in the ancient Rome
2012
The magnificence of Roman buildings is very well-known from historical books, notes etc.. In contraposition to this, generally speaking, less is known about the majesty of Roman sewer systems in terms of structures, facilities and the very advanced as well as rudimental complexity. The Roman sewers have been over-praised. Indeed, despite their longevity, they ignored basic sanitary principles as well as design rules. The Roman Empire is in many ways the highest point of sewage management in the ancient world. Famous for public baths and latrines with quite complex engineering, Rome also excelled in the use of covered drains for stormwater and waste-sewage, with some houses directly connecte…
Experimental characterization of asphalt for an elasto-visco-plastic constitutive model.
2007
This paper describes a range of uniaxial creep tests that have been undertaken for a proprietary polymer modified asphalt, the procedure used to determine the parameters required for an elasto-visco-plastic constitutive model. Uniaxial compressive creep testing and creep recovery testing have been undertaken over a range of temperatures and stress conditions. Procedures used to determine the model parameters from the test data are detailed and parametric equations are developed to describe the model parameters as functions of the test conditions. Particular attention is given to the determination of the parameters related to visco-plastic flow and damage accumulation at high strain levels. …