Le système insensé qui consiste à tirer la chaîne pour se débarasser de nos excréments dans les cours d'eau qui sont la source de notre eau potable me motive d'aller à la quête de solutions innovatrices au problème des égoûts. Pour les gens du milieu, les eaux usées d'une résidence familiale sont de 2 classes: les eaux noires des toilettes et les eaux grises des éviers, douches, bains, laveuses à linge et à vaisselle.
Des chercheurs des Pays-Bas examinent les différentes façons de recycler les eaux grises car celles-ci sont 75% de l'eau utilisée dans une maison, mais le filtrage de certains chimiques qui viennent de produits de soins personnels et de beauté sont un problème tout particulier. Les agents antibactériens comme le triclosan et l'agent de conservation propylparaben sont particulièrement difficiles à se débarasser.
L'ingrédient éthylhexyl méthoxycinnamate dans les crèmes solaires a tendance à accroître la concentration potentielle des perturbateurs oestrogéniques dans l'eau traitée. (il faut consulter le site "Sabotage Hormonal" pour se rendre compte de l'étendue et les effets de ces produits polluants et toxiques http://www.sabotage-hormonal.org/ ).
On espère un jour réutiliser les eaux grises recyclées de la maison familiale pour les toilettes, arroser les pelouses et les jardins.
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"Recycling Household Gray Water
With many parts of the world suffering from scarce freshwater, recycled household water represents a prodigious potential resource. Some researchers envision neighborhood treatment systems to someday reuse homes' so-called "gray water," the wastewater from sinks and baths. Dutch scientists have now tested these methods and find that despite some success in removing pollutants derived from personal care products, further improvements are needed.
Although homes have just one sewer line, conservationists see two distinct kinds of water flowing into it: Toilets generate so-called "black water," whereas sinks, washing machines, and showers produce gray water. Because this gray water constitutes about 75% of household water usage, experts think it's a promising target for local reclamation.
Although gray water has a lighter pollutant load than wastewater from toilets, it still contains chemicals found in personal care products, such as the antibacterial agent triclosan and the preservative propylparaben. Researchers have been developing systems to someday treat gray water within neighborhoods, or perhaps even in individual homes, so it can be reused to flush toilets or irrigate lawns and gardens.
In the laboratory, (Dutch environmental scientist)Hernández Leal and colleagues subjected gray water samples to the typical biological treatments used in sewage facilities: They added sewage sludge to the water, and the sludge's microbes chewed up organic chemical contaminants for 12 hours.
The researchers then analyzed the treated water for 18 compounds from personal care products using gas chromatography/mass spectrometry. The sludge treatments removed about 80% of most of the contaminants, but the treated water still contained organic pollutants at low microgram-per-liter levels, which are problematic. For example, at 3.8 µg/L, the sunblock ingredient ethylhexyl methoxycinnamate contributes to the treated water's overall potential as an estrogenic disruptor."
Excerpts from article written by Steven C. Powell published in Chemical & Engineering News here: http://pubs.acs.org/cen/news/88/i32/8832news7.html
I find it's so wasteful to flush the toilet in the rivers we draw our drinking water from, I'm still looking for better alternatives to the sewer solution.
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