As for water treatment processes, the problems are numerous and varied. According to UNEP (United Nations Environment Program), 2,000 million tons of water are polluted daily due to waste and warns that without urgent action to improve the management of these two million tons of waste that pollutes the waters, the situation will worsen.

This does not only affect the health of millions of people, especially the poorest, but also affects the marine ecosystems, in such a way that there is 245,000 km2 of marine dead zones, and to the climate, due to methane emissions that contribute to global warming. Besides, Spain is exposed each year to millionaire fines imposed by the European Union for non-compliance with current regulations.

In order to adopt solutions, it is necessary to know the possible causes and sources of contamination of the water environment. Aquatic pollution can be punctual (in the event that it is produced by a specific and identifiable emission source affecting a specific area) or diffuse (when the origin is not clearly defined and large areas are affected in which multiple sources of pollution coexist). issue). In general, we can consider as sources of contamination of the water environment, the urban sewagethe industrialthe agricultural/livestock, and the atmospheric contributions..

Likewise, we can classify the basic contaminants that can be found in natural waters into 4 groups:

• Organic pollutants, such as pesticides, hydrocarbons or surfactants.
• Radioactive contaminants, both natural and anthropogenic in origin.
• Biological contaminants, such as bacteria, fungi or viruses, all of which carry diseases.
• Inorganic contaminants, such as heavy metals.