148 H. N. Sandvold et al.
investments for the industry in new hatcheries. These new hatcheries will all
be using new water treatment technologies (RAS) (Badiola et al., 2012;
Bergheim et al., 2009). Second, it means the volume of collected organic
waste will increase substantially (Del Campo et al., 2010). In 2017, 330
million smolts with an average weight of 150 g were produced in Norway,
generating 85,000 tons of sludge. These calculations assume a waste factor of
1.5 for the sludge (Del Campo et al., 2010). Increasing the smolt weight to
1 kg, which is now permitted, will increase the volume of stored sludge to
570,000 tons. Denmark’s capacity for waste generation is much smaller, at an
estimated 150 tons, but, as the innovation leader, this represents a scale where
new technologies for waste handling can be developed. Farmed salmon production capacity in Denmark is currently 3,000 tons per annum. This calculation assumes 4.5 kg per finished fish.
8.2.3 Organic waste in salmon production
The waste streams from salmon production will differ in shape and volume in
relation to the different phases in the production process. In Figure 8.1, the
different waste streams coming from the three different phases of salmon
farming are illustrated.
By- products from land- based hatcheries (first phase in Figure 8.1) consist
of feed residues and fish faeces. The sludge is over 97% water but it is generally free of salt in juvenile smolt production (Badiola et al., 2012; Bergheim
et al., 2009; Del Campo et al., 2010; Fivelstad, Bergheim, Hølland &
Fjermedal, 2004). In contrast, waste from adult salmon in grow- out farms
(second phase in Figure 8.1) will have salt content. The sludge is concentrated with a polymer and dewatered on a belt filter, which reduces the water
content to roughly 80% feed (Badiola et al., 2012). Centrifuge technology
can reduce the water concentration to under 70% feed (Kristensen et al.,
Figure 8.1 The organic waste streams along the production chain for salmon farming
(by-products).
investments for the industry in new hatcheries. These new hatcheries will all
be using new water treatment technologies (RAS) (Badiola et al., 2012;
Bergheim et al., 2009). Second, it means the volume of collected organic
waste will increase substantially (Del Campo et al., 2010). In 2017, 330
million smolts with an average weight of 150 g were produced in Norway,
generating 85,000 tons of sludge. These calculations assume a waste factor of
1.5 for the sludge (Del Campo et al., 2010). Increasing the smolt weight to
1 kg, which is now permitted, will increase the volume of stored sludge to
570,000 tons. Denmark’s capacity for waste generation is much smaller, at an
estimated 150 tons, but, as the innovation leader, this represents a scale where
new technologies for waste handling can be developed. Farmed salmon production capacity in Denmark is currently 3,000 tons per annum. This calculation assumes 4.5 kg per finished fish.
8.2.3 Organic waste in salmon production
The waste streams from salmon production will differ in shape and volume in
relation to the different phases in the production process. In Figure 8.1, the
different waste streams coming from the three different phases of salmon
farming are illustrated.
By- products from land- based hatcheries (first phase in Figure 8.1) consist
of feed residues and fish faeces. The sludge is over 97% water but it is generally free of salt in juvenile smolt production (Badiola et al., 2012; Bergheim
et al., 2009; Del Campo et al., 2010; Fivelstad, Bergheim, Hølland &
Fjermedal, 2004). In contrast, waste from adult salmon in grow- out farms
(second phase in Figure 8.1) will have salt content. The sludge is concentrated with a polymer and dewatered on a belt filter, which reduces the water
content to roughly 80% feed (Badiola et al., 2012). Centrifuge technology
can reduce the water concentration to under 70% feed (Kristensen et al.,
Figure 8.1 The organic waste streams along the production chain for salmon farming
(by-products).