Research On Modeling Of The Membrane Bioreactor System

Membrane bioreactor is becoming more and more popular in the area of wastewater treatment in the world. It is a kind of wastewater treatment technique which combines the membrane module and biological wastewater treatment process. In stead of the second precipitation tank, the membrane module functions as equipment to separate the water and sludge. The object of this research is the membrane bioreactor system. Compared with the traditional activated sludge wastewater treatment process, the membrane bioreactor has much more advantages. It is able to treat both municipal wastewater and industrial wastewater since it has higher sludge load than traditional activated sludge process. It also has other advantages such as requires smaller land, starts up faster and lower sludge production. So the membrane bioreactor will have a bright future in the area of wastewater.In this paper, the research achievements obtained by researchers home and abroad in membrane bioreactor were summarized, and the progress of membrane bioreactor in both experimental and modeling study as well as the main existing problems were given a concrete analysis and estimation, the reaction mechanism of wastewater treatment by membrane bioreactor was further investigated.Most of the existing models of membrane bioreactor are experiential and they are "black box models". These models do not have a precise result of simulation since they can not reveal the internal reaction process and the mechanism of wastewater treatment by membrane bioreactor. Through combining the process of activated sludge waste water treatment and the process of filtration in membrane module, this research established a mathematic model of membrane bioreactor system. This model can be used to simulate varies kinds of membrane bioreactor system since it takes following into consideration: the process of mass transfer in the membrane bioreactor, the process of microorganism reaction, the process of filtration and also the effect of operation conditions such as volume and quality of input wastewater, character of activated sludge and the temperature. The kinetics parameters and function parameters are also confirmed and the model was verified by two examples.The result of the model verification shows that this model is able to simulate the process in a membrane bioreactor well and to predict the condensation of waste in the reactor and in the outlet with a satisfying precision. Therefore, this model can help researchers analyzing the internal microbiological process in the membrane bioreactor,...