000000881 001__ 881
000000881 035__ $$a21094 
000000881 037__ $$aROMDOC-THESIS-2016-369
000000881 041__ $$arum
000000881 100__ $$aIlie, Mihaela
000000881 245__ $$aContribuţii la studiul degradării biologice a substanţelor organice poluante 
000000881 260__ $$c2009-10-24
000000881 520__ $$aABSTRACT This paper deals with a subject of great topicality and significant complexity in the field of wastewater treatment its general aim being the environmental protection. The biological treatment has been imposed as technology for organic matters removal from wastewater, due to the advantage of reaction development under natural environment conditions. In the field of processes, plants and equipment designed for wastewater treatment, there are many problems unsolved both theoretically and practically. In these plants there are spread polyphased mixtures that involve knowledge from different scientific fields: mechanics, hydrodynamics, chemistry, biology, energetics, etc. Due to the complexity of phenomena that occur within hydraulic plants of this type, that involve the intervention of factors with a different nature, only some problems solved in more simple hypotheses that allow a scientific approach, are known. Obtaining new solutions by process modelling and simulation shows a special importance and significance in this context. Physical, chemical and biological processes that occur within aeration tanks from the treatment plants are extremely complex, their mathematical modelling being very difficult. Research activities performed in this field deal with bacterial environment development, as well as the influence that chemical and physical factors have on those specific for breaking down the organic matters existing in water, but hydro-dynamical factors are neglected, although these processes occur in the aqueous environment. This paper managed, by studying aspects related to organic matter breaking down, to create some mathematical models that join, in an original manner, the processes from the aeration tank: dissolved oxygen dispersion, hydrodynamic conditions and consumption within the cellular metabolism, of oxygen existing in the aqueous environment. In comparison with models shown in the technical literature and analyzed in the present paper, the achieved ones consider also the aqueous environment with the turbulence generated and induced by oxygenation equipment, by values of Nusselt criterion, aspect that brings a significant original contribution. Simulation of oxygen concentration values by running the mathematical model within FlexPDE program led to results comparable to those obtained within the experimental research activity, aspect that allowed the theoretical model validation. Thus, the model becomes more close to the reality of the process that occurs in the aeration tank, that might allow the automatic control and handling of processes that directly base on correlation between physical, chemical and biochemical factors.
000000881 6531_ $$aApe reziduale -- Epurare -- Nămol activ -- Teză de doctorat
000000881 6531_ $$aSimulare cu modele matematice -- Teză de doctorat
000000881 8560_ $$ff_costache@library.pub.ro
000000881 8564_ $$uhttp://romdoc.upb.ro/record/881/files/$$zAccess to Fulltext
000000881 980__ $$aTHESIS