It was observed respectively by optical microscope and SEM (scanning electron microscope) that bacteria, filamentous fungi, protozoan and metazoan were adhered on the surface of the sludge, and the microorganism of the floe in the forms of micro-colones.

• 光学显微镜和扫描电子显微镜观察发现，污泥表面附着有各种球菌、杆菌、丝状菌以及原、后生动物，凝絮体中微生物以微群落形式分布。