Nowadays the ecology is central to the collective unconscious: people are starting to realize that the resources of the planet are not inexhaustible, and that we have to preserve them. But numerous rare commodities, like water, keep being wasted and overexploited: indeed, only the two percent of used waters are currently recycled and reused, while millions of people worldwide do not even have any access to drinking water! However there are many water treatment plants which are in charge of treating wastewater to make it suitable for the daily consumption. These water treatment plants are also responsible for treatment of sludge which is collected after water cleaning.
Why it is important to treat the sludge
The sludge has many fertilizing properties: indeed once treated, it can be reused as a fertilizer in the fields to boost the cultivation. However, the sludge which is collected during water treatment is not suitable for use: it has to be cleared from the impurities and the noxious chemical components which might contaminate the groundwater tables, and so the cultures. Moreover, as the sludge is mainly made up of water and bacteria, it is a very good environment for the development of microorganisms which cause bad smells. So the sludge has to be subject of a specific treatment before being reused.
Which process to treat the sludge?
Firstly the sludge has to be thickened to increase its dessication, that is its dry matter content, to be stored easier. Then it has to be dehydrated to remove water as far as possible, without making it totally solid. After it is completely dried out to reduce its volume, and stabilized as well: it consists in purifying it to eliminate the bacteria responsible for bad smells. Finally the sludge is able to be store and sent to other places to be reused. Click to learn more about urban and industrial sludge.