Wastewater treatment consists of a series of physical, chemical and biological processes that eliminate pollutants from water so that humans can make use of it.
The purification of waste water from towns and cities or industries is undertaken in a Waste Water Treatment Plant (WWTP).
In the WWTP, purification processes are performed (like those that occur naturally in the river basin) in a concentrated and automated way.
Below you will find an explanation for each of the different water treatment processes. Each process has a specific objective according to the purification stage. It is important to note that the composition of the water, circumstances and end use or destination may require variations on conventional water treatments.
Pre-treatment is common to all water treatments, whether it is wastewater treatment, drinking water purification or desalination, and its aim is to avoid large fragments such as branches causing breakdowns in the water treatment plant.
Primary treatment serves to eliminate floating and suspended solids, sand, fats and oils.
Secondary treatment generally comprises different types of biological treatment of water, the general aim of which, as we have seen, is to eliminate organic material.
Tertiary treatment focuses on eliminating pathogens, although it also succeeds in reducing suspended solids and waste organic material. This type of wastewater treatment is highly recommended where water needs to be reused for watering public gardens or farming, without causing any risk to human health.
ACCIONA undertakes the management of end-to-end services which involve all the stages involved in water treatment: readying it for human consumption, supplying it to the population, then cleaning up urban and industrial waste water. The company also takes care of invoicing end users.