A novel laboratory simulator developed for pitting studies in chlorine
dioxide bleaching was modified to investigate the effects of microbe
containing environments in the splash zones of paper and board machines.
Layers of dried chemical pulp were used to simulate deposits in splash zones.
Artificial white water was prepared using as main components stone
groundwood (sgw) and chemical pulp transferred from a paper machine. A
consortium of aerobic as well as anaerobic bacteria typical for paper and
board machine environments was used. Biofilm formation and the
electrochemical behavior of stainless steel were studied. Open circuit
potentials were recorded and polarization measurements were performed. The
biofilms formed were analyzed by microbial cultivation and by epifluorescence
microscopy. Sulfur compounds as well as the chloride and oxalate contents of
the artificial white water in the course of the experiments were analyzed
using capillary electrophoresis. Also some of the layers of chemical pulp
closest to the metal surface were analyzed after the test. The results showed
that the developed laboratory simulator was a valuable and versatile tool
for studying the microbiological and chemical effects on pitting corrosion
of stainless steel in conditions simulating the splash zone areas of paper
and board machines.
|Conference||10th International Symposium On corrosion in the Pulp and Paper Industry, ISCPPI |
|Abbreviated title||10th ISCPPI|
|Period||21/08/01 → 24/08/01|