ABSTRACT
First of all, centrifuges were applied in food processing and mineral separation and later in the chemical industry. When environmental engineers realized the possible use of the centrifuge in the field of sludge treatment, centrifuges had already reached an advanced stage of development. In general, centrifuges can treat a large quantity of sludge and requires relatively a smaller space. The latter may be of interest where space is limited, and in the case of future extension. Centrifuges are now extremely versatile in regard to adjustment of sludge characteristics (by correct choice of operating parameters as well as by varied equipment and accessories). Only a few categories of centrifuges are available for the dewatering and thickening of wastewater sludges: the scroll discharge solid bowl centrifuge, the disc-type centrifuge, and the imperforate basket centrifuge. All of them belong to the class of sedimentation centrifuges.
