Integrierte Vermeidung und Verminderung der Umweltverschmutzung

Chapter 3
By-products from the filleting, skinning, cutting and canning steps are used for:
• production of foodstuffs, e.g. fish-meal, ingredients, surimi, polyunsaturated fatty acids,
gelatine and collagen
• production of animal feed, e.g. fish protein, fish silage, fish protein hydrolysate, petfood,
fish-oil and solubles
• production of fertilisers such as fish solubles and fish protein hydrosylate
• production of pharmaceuticals such as gelatine and collagen
• production of coatings, e.g. fish-oil and pearl essence, and adhesives such as fish glue
• production of leather.
Fluid lost from the fish may be treated anaerobically to produce biogas. Heads, shells, intestines
and scraps have different applications, such as:
• production of animal feed, e.g. fish-meal, crustacean meal for cats and antaxanthin for
aquaculture
• production of foodstuff, e.g. fish-meal, chitin and chitosan
• production of flocculants for waste water treatment, e.g. chitin and chitosan
• production of pharmaceuticals, e.g. chitin and chitosan.
Figure 3.3 shows consumption and emission levels of the process steps in fish canning.
LIQUID WASTE
IN
VOLUME/WEIGHT
POLLUTING
LOAD
COMPOSITION
WASTE
WATER
0.2 m 3 /t *COD: 350 - 1700 mg/l Washing water
0.5 - 1 m 3 /t
*Blood
*Suspended solids(0.3 - 2.3 g/l)
*COD:2500-5000mg/l
*Oil: 0.2 - 2.5 g /l
*Suspended solids(0.6- 2.5 g/l)
*Soluble proteins
*COD: 12000 - 50000 mg/l
*Cl 10 - 57 g/l
17 m 3 /t *COD: 3000 - 5000 mg/l
0.1 - 0.3 m 3 /t *COD: 15000 - 50000 mg/l
0.04 m 3 /t
3 - 7 m 3 /t
*Traces of oil or brine
*Detergents
*Traces of oil or brine (15 - 30 mg/l)
*Detergents
*COD: 30 - 100 mg/l
Washing water
Blood water
Cooking water
Washing water
Spillage of sauce,
oil and brine
Cans cleaning
water
Autoclaving water
FISH
CANNING
Grading
Filleting
Eviscerating
Cutting into pieces
With NaCl
Pre-cooking
Without NaCl
Manual skinning
and cutting
Canning
Cleaning cans
Autoclaving
The considered fishes are: tuna, mackerel, herring and sardine.
Small-sized fish species are precooked in the can before the can is filled with the brine-oil.
SOLID WASTE/
BY-PRODUCT
Heads
Offal
Tails
Skins
Red meat
Bone
Scraps
Figure 3.3: Consumption and emission levels of the process steps in fish canning
[134, AWARENET, 2002]
% SOLID
WASTE
IN WEIGHT
Rejected fishes 3
158 January 2006 RHC/EIPPCB/FDM_BREF_FINAL
20 - 40
15 - 20
5
TOTAL: 30 - 65 %
Solid by-products of the filleting, curing, salting and the smoking of fish have similar uses as
mentioned above for the canning of fish. Ash from shavings is generally disposed of with
municipal solid waste. Figure 3.4 shows the consumption and emission levels of the process
steps in filleting and preserving fish.