Suresnes water production plant
Not in China, but also interesting. A drinkable water production plant.
It is the plant of Suresnes, in the suburb of Paris. It belongs to the Eau et Force company, a Suez Environnement subsidiary. In France, the ‘Vigipirate’ security program makes the visit of a such plant difficult. It is based on protection against a terrorist attack. But thanks to my internship in the company, I had the right to attempt to a short tour on the site.
I aim to be a responsible of a water production plant. But the way to is hard as the management of that kind of building is complex. Good knowledge in Chemestry, Hydraulics et Automatism is required. But here is a condensed of what I dream to play with: blue, clear and pure water for people.
The plant is composed of two parts, which do the same work: the most recent was built in 1995 and the other in 1904! The water comes from…the Seine (the river passing through Paris)! The exhaure (pumping out point) is situated on the river bank at Suresnes. The water is lifted to 3 basins (photo) and you can observe that the water is pretty clear: it is pumped 4 meters under the surface of the river (there’s a less polluted water here). Then, the water is pre-ozoned a first time to kill the most biology (virus, bacteriaes, phungus and protozoas). Needed ozone is made in the building with oxygen and UV lamps. Then, it is insufflated in the water by membrane.
Photo 1: Bassin of Seine water
After clearing out the water biology, the organic pollution needs to be eliminated because that is what gives its color and smell to water. To do so, the settling technology is used. The problem is that kind of pollution is almost weight-less, which means it will take years to settle without adjonction of coagulant and flocculant. The plant uses two methods with two settling tanks: the Pulsator (on the older part of the plant – photo 2) using the pulsed bed sludge settling method and the Densadeg (on the most recent part of the plant – photo 3) using the lamellae settling method. Both are Degremon’s innovations.
Photo 2: Pulsator
Photo 3: Densadeg (principle)
The settled water is not totally cleared out of its residual flocs particles and nitrates: it needs to be filtered by biolite filtration. For the plant was built in two parts, one of them uses a common filtration by sand (photo 4) and the most recent uses a biolite filtration with bacteriae.
Photo 4: Sand filters tanks
Photo 5: Water after sand filtration
Ozonation aims to eliminate all pathogenic agents (cf. above). The step is not the only one that will desinfect the water. After the last filtration on activated carbon grains (ACG), a post-chlorination is required: it provides a residual agent that will assure a drinkable water (i.e without hazardious biologic particles) along the supplying network. The ACG filtration could be specific to each sort of organic contaminants the water contains (pesticides, taste or PAH) and ACG is mainly made with coal, coconut, wood.
Photo 6: Ozonation by membrane
Photo 7: ACG filtration tanks