The paper presents research results on rheological properties of a pre
cipitated waterwork sludge. The water content of the sludge studied va
ried from 100 to 85 per cent at temperatures of 273-293 K, respectivel
y. The sludge in question can be classified as a plastic-viscous fluid
, described by the Bingham model. Some empirical relations describing
the influence of the water content on tau(O) and eta(pl) have been fou
nd. The mentioned parameters were also affected by temperature. The pa
per describes in detail, technical applications such as the flow of sl
udge in pipes, as well the flow along the bottom of sedimentation tank
s. (C) 1997 IAWQ. Published by Elsevier Science Ltd.