EN
The activated sludge process is one of the major biological wastewater treatment techniques. The physical properties of the activated sludge flocs are interesting for numerous practical reasons, including activated sludge mass transfer phenomena, biomass flocculation, solid-liquid separation, sludge thickening and dewatering. Application of the advanced measuring techniques, such as image analysis system, and development of specific experimental methods including sample preparation (embedding procedures and microtome sectioning) as well as multi-exposure photography with stroboscope illumination source, can provide complex information about flocs and may lead to a better understanding of the activated sludge process and more effective control of the process performance. In this paper, the results of a recent study concerning the physical properties and structure of the activated sludge flocs are presented.