TREATMENT OF WASTE-WATER FROM A MULTI PRODUCT FOOD-PROCESSING COMPANY, IN UPFLOW ANAEROBIC SLUDGE BLANKET (UASB) REACTORS - THE EFFECT OF SEASONAL-VARIATION
Je. Schmidt et Bk. Ahring, TREATMENT OF WASTE-WATER FROM A MULTI PRODUCT FOOD-PROCESSING COMPANY, IN UPFLOW ANAEROBIC SLUDGE BLANKET (UASB) REACTORS - THE EFFECT OF SEASONAL-VARIATION, Pure and applied chemistry, 69(11), 1997, pp. 2447-2452
We have investigated the treatment of waste waters from a multi produc
t food-processing company using a UASB reactor concept. The company Fr
igodan processes over the season: peas, carrots, celery roots and leek
s, resulting in four different types of waste waters. Four lab-scale U
ASB reactors were started with the individual waste waters. The biomas
s was characterized after the reactors were adapted to the individual
waste water streams and steady state had been reached. Significant dif
ferences in both the activities of the different metabolic groups and
the numbers of bacteria in the different metabolic groups were found,
indicating that problems could occur when changing from one waste wate
r to another. To investigate this further, the waste waters were chang
ed between the different UASB reactors to allow as many different comb
inations of changes to be tested as possible. Significant decreases in
the overall efficiency were observed in the following cases: (1) When
changing from celery waste water to any other waste waters due to a s
ignificant increase in the organic loading rate of the reactor. (2) Wh
en leek waste water with high content of lipids and protein was fed to
the reactor. Criteria for treating of waste waters with seasonal vari
ations were developed.