Term: Wastewater treatment plant

Wastewater treatment plant

Wastewater treatment or sewage treatment is the process that removes the majority of the contaminants from waste-water or sewage and produces both a liquid effluent suitable for disposal to the natural environment and a sludge. To be effective, sewage must be conveyed to a treatment plant by appropriate pipes and infrastructure and the process itself must be subject to regulation and controls. There are many and various forms of treatment processes. The site where the processes are conducted is called a wastewater treatment plant (WWTP). The flow scheme (see figure 1) of a conventional WWTP is generally the same in all countries and exists our of following physical-chemical elements:

•Mechanical treatment;
•Influx (Influent)
•Removal of large objects
•Removal of sand

Biological treatment;
•Oxidation bed (oxidizing bed) or Aerated systems
•Post precipitation

•Chemical treatment (this step is usually combined with settling and other processes to remove solids, such as filtration.