Aquascope Facts

Nutrients from sewage

Dumping sewage
This is how we dumped sewage into the North Sea as late as the 80´s, but is now forbidden.

Sewage contains a great many nutrients, and a great deal of it ends up in the sea. Sewage is commonly delivered to a sewage plant where it is cleaned to varying degrees before it is released into the environment. At some sewage plants, treatment methods are very simple, whereas others use very refined methods. The resulting sludge is often burnt or deposited in quarries.
Unfortunately certain cities like Brussels in Belgium release their sewage directly into rivers, where it quickly reaches the North Sea. Several coastal towns in Britian release sewage from pipelines that reach several kilometres out into the sea. In the Netherlands, the sewage is minimally treated before it is released, for example, from a 11 km long pipeline reaching out into the North Sea from The Hague.
    Some of the resulting sludge from the treatment process is used as fertilizer on arable land. One of the disadvantages with this method is that the sludge is often deposited on the fields at the wrong time of the year so the nutrients leak out into the groundwater and rivers and eventually out into the sea. The sludge also can contain traces of poisons that finally end up in agricultural products. It would be much better if this sewage sludge could be effectively recycled. Hopefully this problem will be solved, but there are those that believe this is impossible as long as we continue using the present methods of treating sewage and large scale centralized handling.
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A splendid outing ?
Problems and expectations
”It was better before"
Seawater and soluble salts
The sea moves
Coastal waters are close to us
What is eutrofication?
Sources of over-fertilization
How the open masses of water are effected
How shallow bays are effected
What can we do?
Alga harvest

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Bo Johannesson | Martin Larsvik | Lars-Ove Loo | Helena Samuelsson