bachelorThesis
Determinação do fluxo crítico e fluxo limite em membrana de microfiltração utilizada no pós-tratamento de esgoto doméstico
Fecha
2016Registro en:
OLIVEIRA, Amanda Tobias Costa de. Determinação do fluxo crítico e fluxo limite em membrana de microfiltração utilizada no pós-tratamento de esgoto doméstico. 2016. 24 f. TCC (Graduação) - Curso de Engenharia Civil, Departamento de Engenharia Civil, Universidade Federal do Rio Grande do Norte, Natal, 2016.
Autor
Oliveira, Amanda Tobias Costa de
Resumen
The threshold flux and limiting flux concepts represent an important advance in membrane
technology, for they allow the identification of optimal operating conditions for fouling
control, one of the main obstacles in membrane application for water and wastewater
treatment. In this study, the pressure-step method was applied to a microfiltration membrane
system fed with anaerobic filter’s effluent in order to determine the threshold and limiting
fluxes. Throughout the experiments, the pressure was gradually increased to a maximum
value and then it was decreased to the initial value, while the permeate flux was measured.
Three fouling parameters were defined and calculated from the pressure-step tests results:
average flux in the step (Jm), fouling rate (dJ/dt) and initial flux increase (ΔJ0). The results
showed smaller flux values, for the same pressure, in the descending phase than in the
ascending phase, indicating the formation of a irreversible fouling layer. Furthermore, Jm did
not reach a stabilization plateau, which would indicate the limiting flux. Since the crossflow
velocity could not be kept constant, the fouling rate (dJ/dt) decreased with pressure increase,
affecting the ΔJ0 results, which would indicate the threshold flux. It was concluded that it is
not possible to determine the threshold flux and the limiting flux without constant crossflow
velocity.