Nowadays the ecology is at the heart of the preoccupations: people are starting to realize that our planet is suffering from the excessive human activity, and they are trying to work on preserving the resources. This calls especially for recycling, and particularly one of the water: indeed people are often worried about reusing the wastewater, but they do not always know that the treatment whose the water is subject of in the water treatment plants enables it to be perfectly suitable for the daily consumption. Yet, it is absolutely essential to recycle the used waters: indeed, there are millions of people who do not still have any access to this rare commodity, and the 98 percent of the water which is used all over the world is not recycled.
Used water treatment
To be reused, the soiled water has to be the subject of a strict treatment: indeed, eight steps are necessary to purify the water and make it suitable for consumption. Firstly it is filtered through a sieve to remove the biggest sediments, then we remove the sands and the fatty substances. After it is treated with chlorine against bacteria, and aerated to bring it oxygen. Then it is sent on a sedimentation tank to allows the sediments to fall at the bottom. It is treated one more time with chlorine and ozone to eliminate the last pathogen and the noxious chemical compounds. Once treated, the urban and industrial sludge is collected to be treated as well.
The sewage sludge treatment
The sewage sludge has to be recycled too, particularly to fertilize the field. To achieve this, it has to become solid: so it is thickened to increase the dry matter, then it is dehydrated and finally completely dried out. After it is stabilized to prevent the development of bacteria responsible for bad smells. Then it is dried out one last time, and finally it can be stored and sent to other places to be reutilized.