What is the wastewater?
Wastewater treatment is to collect and to process (or clean) by techniques of purification of wastewater contaminated, before they are discharged into the natural environment (soil, lagoon, river, or ocean). In effect, they are likely to pollute the latter.
There are 2 major types of sanitation : the consolidation stand-alone (individual or collective) and the public sewerage public
The wastewater treatment process consists of 3 main stages : the collection, treatment and discharge of water treated and cleaned in the natural environment.
a. The collection
The wastewater collection is done through a network of sanitation which is formed by a set of pipes called collectors. This network, which can be transported by gravity, by refoulement, under pressure or under vacuum wastewater to their treatment unit.
There are two types of network wastewater collection :
- Networks « unit » : they carry the wastewater and stormwater in the same network, sewerage
- Networks « divisive » : waste water and storm water are transported in separate networks.
b. The treatment
The treatment or cleaning aims to clean the wastewater so that they do not degrade the natural environments in which they will be rejected.
The mode of treatment varies depending on the type of sanitation facilities (individual or collective). It also depends on the degree of pollution and of natural environment in which they will be rejected. It is done by a sequence of steps involving the use of biological mechanisms and/or physico-chemical.
Individual sewage is carried out by means of septic tanks and/or boxes, fat, monitoring system infiltration.
The public sewerage is realized by means of sewage treatment plants that operate according to the category of waste water and discharge standards on organic principles or physico-chemical.
c. The evacuation of the treated water in the natural environment
It must be done without danger to the receiving environment. Once processed, the waters are discharged into the natural environment, where they will continue their natural process of treatment.
Sometimes, the water cleaned undergo additional processing in order to be reused for irrigation.
The public sewerage requires a fourth step, which is to manage the fate of by-products and waste-water treatment (refusal of screening, sludge, etc.)