Two-Dimension Dynamic Simulations on Biofilm Forming and Developing

摘要

It played an important role for biofilm microstructure and morphology on wastewater biological treatments. Multi-species microorganisms were able to form varieties of biofilm on adaptive carriers, and the process of biofilm to form and develop on carriers was multi-dimensional and dynamic. In this article, substrate transfer, biofilm formation and development in a two-dimension space were dynamically simulated with a combined discrete-differential method. The micro structural and morphological characteristics, such as biofilm thickness, density and porosity, were obtained as model output by using this new-type model. Meanwhile, the effects of the growing time and initial inoculation number of microorganisms on biofilm microstructure and morphology were also discussed. Firstly, the thickness of biofilm was increasing along with the growing time of biomass extending. At the time of 30 h for biofilm formation and development, it was not completely covered for carrier by bio-mass , and the fluctuation of biofilm was very ambient; but at the time of 60 h, biomass had covered the carrier entirely, and the fluctuation of biofilm tended to gentleness. Secondly, as biomass growing time was 30 h, it was not covered completely for carrier by biomass with different initial inoculating number of 50, 150 and 250. And the covering degree of biomass was improving along with initial inoculating number increasing. Especially, as initial inoculating number was 250, it was nearly covered for carrier by biomass.