9420.pdf

Laboratory scale tests conducted by Riddle and Shikaze (1973) showed that BOD
removal of 0.022 kg/m 2
of disc surface per day is easily attainable on a salmon canning
plant effluent previously treated by DAF.
5.3.5.4 Activated Sludge
Full scale activated sludge treatment facilities are reported to be fairly common at
processing plants in, Japan (Okumura and Uetana, 1992). However, data on
performance and economics of applied activated sludge facilities is not available.
A state-of-the-art activated sludge biological nutrient removal pilot plant facility
incorporating two forms of disinfection has been operation for one year at a herring
processing plant in Denmark. The performance is encouraging but the economics are
not (NovaTec, 1993a).
Results of the pilot and bench scale tests of activated sludge treatment of fish processing
wastewater are reported in literature (Sasaki et al., 1980 (a), (b) and 1981, and Lin et al.,
1 979).
To the knowledge of the authors, no full or pilot scale activated sludge treatment plant at
a fish processing facilities exist in North America.
5.3.5.5 Anaerobic treatment
Anaerobic treatment is uneconomical mainly due to the moderate to low organic strengths
of the seafood processing wastewater and seasonal nature of most fish processing plant
operation. These relatively low concentrations do not permit high biomass generation and
retention capacity under normal hydraulic loadings and thereby limit the effectiveness of
conventional anaerobic treatment applications (Hudson et al., 1978).
Bench scale research of shellfish processing wastewater treatment by anaerobic packed
column by Hudson et al. (1978) showed that organic removal efficiencies near 80 % for
COD and 88 % for soluble BOD can be achieved. Effluent solids concentrations observed
were low, never exceeding 20 mg/L. Methane gas production was consistently greater
than 80 %
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