68
R.H. Charlier and Th. Lonhienne
Although not well studied with regard to their precise effects, these
activities contribute to a further disturbance of the ecological balance.
2.6 Managing the Algal Problem
Globally considered, algae represent a source of problems, a target of
several nuisances, a decision and management tool, and a remedy for
some recent developments (Charlier 1991).
In 1983, the world production of algae reached 4 833 046 metric
tonnes of which 124 012 came from the EU, 7673 metric tonnes from the
former USSR and 1 575 650 from the Chinese People's Republic. Close to
4 million metric tonnes were composed of brown algae. Alginates are the
most common extracted product, followed by carageens, agar-agar and
far behind, furcelareens (from FAO data). Some other products used in
technology, foods, surgery and pharmacy are also extracted. Iodine extraction was halted roughly 40 years ago, while that of phycocolloids has
been on the increase for some decades.
Algae can be used in foods and feeds, in industry, agriculture, pharmacy, medicine, thalassotherapy, cosmetology, energy generation, water
purification and pollution abatement (Beavis and Charlier 1986; Charlier
et al. 1986). The last use has been attempted for example near Kiel,
Thessaloniki and Venice, and proposed for Brittany (Schramm 1991).
Seaweed biomass can also be used as a source of fuel or bioconversion
products, coastal protection and fertilization or composts; hence such
biomass can be used as an integrated system of production of food, feed,
fish, fuel and raw material. Bioconversion can be achieved by thermal
treatment, composting or methanization (Mancliere 1985; Morand et al.
1991). Methane production in a pollution abatement plant would be
possible (Schramm and Lehnberg 1984; Morand et al. 1991).
The experiment in the Danish Odense Fjord, where algae were harvested to remove nutrients from the water, and were then used for biogas
production, proved feasible and efficient, but showed that at current
energy prices, the undertaking was not economically profitable.
In Italy and France, researchers chose to methanize an Ulva-derived
juice rather than use the entire plant, a tenfold production was obtained
for an equal volume. The French opted for hydrolysis and pressing, the
Italians for centrifugation.
The French undertaking, financed by public and private funds, would
allow a 7-year investment return, for methanization, but pollution abate-
R.H. Charlier and Th. Lonhienne
Although not well studied with regard to their precise effects, these
activities contribute to a further disturbance of the ecological balance.
2.6 Managing the Algal Problem
Globally considered, algae represent a source of problems, a target of
several nuisances, a decision and management tool, and a remedy for
some recent developments (Charlier 1991).
In 1983, the world production of algae reached 4 833 046 metric
tonnes of which 124 012 came from the EU, 7673 metric tonnes from the
former USSR and 1 575 650 from the Chinese People's Republic. Close to
4 million metric tonnes were composed of brown algae. Alginates are the
most common extracted product, followed by carageens, agar-agar and
far behind, furcelareens (from FAO data). Some other products used in
technology, foods, surgery and pharmacy are also extracted. Iodine extraction was halted roughly 40 years ago, while that of phycocolloids has
been on the increase for some decades.
Algae can be used in foods and feeds, in industry, agriculture, pharmacy, medicine, thalassotherapy, cosmetology, energy generation, water
purification and pollution abatement (Beavis and Charlier 1986; Charlier
et al. 1986). The last use has been attempted for example near Kiel,
Thessaloniki and Venice, and proposed for Brittany (Schramm 1991).
Seaweed biomass can also be used as a source of fuel or bioconversion
products, coastal protection and fertilization or composts; hence such
biomass can be used as an integrated system of production of food, feed,
fish, fuel and raw material. Bioconversion can be achieved by thermal
treatment, composting or methanization (Mancliere 1985; Morand et al.
1991). Methane production in a pollution abatement plant would be
possible (Schramm and Lehnberg 1984; Morand et al. 1991).
The experiment in the Danish Odense Fjord, where algae were harvested to remove nutrients from the water, and were then used for biogas
production, proved feasible and efficient, but showed that at current
energy prices, the undertaking was not economically profitable.
In Italy and France, researchers chose to methanize an Ulva-derived
juice rather than use the entire plant, a tenfold production was obtained
for an equal volume. The French opted for hydrolysis and pressing, the
Italians for centrifugation.
The French undertaking, financed by public and private funds, would
allow a 7-year investment return, for methanization, but pollution abate-