Publicado em "Heat transfer 1990 : proceedings of the Ninth International Heat Transfer Conference", Jerusalem, Israel, Vol. 5 (1990)Most of the fouling studies have been up to now focused
on the build up of deposits caused by only one foulant.
Although this type of research allows a more clear
identification of the mechanisms involved in the
formation of deposits, the study of more realistic situations
is now needed.
The paper reports the results of fouling tests where
different fouling agents were present in water: kaolin plus
magnetite particles, and bacteria (Pseudomonas
jl.uorescens) plus kaolin particles. Deposit formation was
monitored through heat transfer measurements. The tests
were performed with water flowing at several velocities and
the data were compared with previous results obtained
using a single foulant. in an attempt to determine possible
changes in the processes controlling the fouling rate.
Increased fouling resistances and rates were observed
when kaolin particles were suspended in the bacteria -
- water system.
The kaolin - magnetite interaction seems to decrease the
final amount of deposit and, at the same time, to increase
its mechanical strength.
Modifications in the metabolic processes or in the
adhesion forces may account for the observed changes