Abstract
The Rietvlei water treatment plant has recently (1988) been upgraded and redesigned
to accommodate dissolved air flotation and filtration (DAFF) in the same process unit.
The reason for this drastic change was the eutrophication of the raw water which
made conventional sedimentation before filtration impossible due to the high algal
content of the water. Rietvlei is the first treatment plant in South Africa that makes
permanent use of DAFF at full-scale.
After operating for a number of years it was possible to identify areas where the
operation of this process could possibly be improved. This study was directed at
these areas and it was shown that
flocculation conditions in the baffled flocculation channel can be satisfactory
predicted with the use of the Bratby reactor and the Argaman/Kaufman
flocculation model,
flocculation can be significantly improved with the aid of a nonionic
polyelectrolyte...
M. Ing. (Civil Engineering)