*2.4. Aqueous Inorganic Nitrogen-Based Pollutants*

This section has as its main objective the presentation of the mechanisms underlying the photocatalytic degradation reaction of nitrates ions (NO3 −) and the factors that lead to obtaining final products that do not affect the environment and life in general. In addition to the traditional physical treatment (adsorption, membrane filtration, ion exchange, reverse osmosis) and (electro)chemical treatment (conventional chemical denitrification, zero-valent metal nanoparticles, hydrogen driven catalytic denitrification, electrochemical reduction, electrocoagulation, electrodialysis) processes for nitrate removal [115,116], investigations related to nitrate controlling have been carried out in recent years on the possibility of using photocatalytic processes [117].
