Characters of biofilm and its microorganism population in biological aerobic filter

Utilizing biological aerobic filter for treating simulated domestic waste water to study the character of biofilm pattern, biomass and microorganism activity change in the reactor at steady-state operation, and to analyze the spatial change rule of biofilm and microorganism population. The biofilm pattern, colour and thickness of the biological aerobic filter possessed the characteristics of gradual change along water flow. While the biofilm density distributed not evenly upwards vertically, and the part near the carrier surface had larger porosity. The biomass tended to decrease gradually along water flow. The biofilm activity change appeared obvious characteristics of reversed V shape. The composition of microorganism population was various. The food chain was long and cross each other. The system nutrition structure was complicate. The microorganism population of high nutrition occupied higher ratio. The range of utilizing the bottom matter was large. Dominant microorganism population of different metabolism type might form along the water flow.