Water treatment, purification plants
In olden times, and unfortunately, even in the present day in many countries, water is consumed without previously having been treated and used water is disposed of by discharges.
Fortunately for human health and for the environment, water is being treated more and more often before consumption, then after use and before disposal. Sometimes water destined for irrigation is also treated, although to a lesser degree.
This is why we have treatment plants, also called purification plants, when it concerns used water. Here you will find filters, settling tanks, biological or secondary treatment tanks, pumping and water circulation installations etc.
Due to the development of regulations, which are justified by better health protection, they have become more and more complex in order to eliminate excess mineral salts, bacteria or undesirable organic matter. This is also an area which is constantly evolving, in which biology is very much in evidence.