The water is a rare and precious commodity that we absolutely have to preserve at any cost. However it is one of the most wasted resources of the world: indeed only the two percent of wastewater are recycled, while several countries are currently in an advanced state of drought and millions of people still have no access to drinking water. But since a few years people are starting to realize that water resources are not inexhaustible and that recycle it finally is a good solution. Especially as there are many simple and effective means of purifying water to make it suitable for daily consumption. Once the water is treated and reused, a huge quantity of sludge is left, that we also have to recycle.
Why it is important to recycle sludge?
Treating the sludge which is remaining after water purification allows to reduce its volume and make its store easier. It also allows to improve its consistence to store it easier in heaps. Moreover, the sludge is mostly made up of water and bacteria which develop very quickly and contaminate it. But the sludge is intended to be reused as a fertilizer for the fields and the cultures: so it has to be treated to prevent bacterial proliferation to maintain its properties.
How to treat the sludge?
Firstly it has to be thickened: it consists by adding dry matter and remove water to increase the sludge dessication. So the sludge is filtered through a sieve to let the liquid sink. Then it is dehydrated to get the most of solid matter as possible. After it is dried to remove all the water, by letting it evaporate. Then it is stabilized to stop the fermentation and prevent development of bad smells. Once the sludge is completely treated, it can be stored and sent to other places to be reused. Click to learn more about urban and industrial sludge.