Cultural eutrophication control through water reuse

The increasing use of mineral fertilisers over the last decades has contrib uted to the appearance of numerous cases of water eutrophication, a new for m of water pollution. The starting point of eutrophication is the increase of nutrient concentration (nitrogen and phosphorus) in a water mass, which is subsequently followed by an uncontrolled growth of primary producers and episodes of oxygen depletion due to microbial decomposition of algal organ ic matter. The excess nutrient loads reaching surface waters are usually as sociated to discharges from anthropogenic activities, which normally involv e direct water usage instead of reuse of reclaimed effluents. Agriculture a ctivities and livestock breeding are two of the main nutrient sources respo nsible for water eutrophication, as well as human - urban and industrial wa stewater discharges. Wastewater reclamation and reuse can be a suitable str ategy for preserving the quality of natural waters, by suppressing effluent discharges and the associated nutrient contributions to receiving waters. Reuse of reclaimed water for agricultural and landscape irrigation as well as for environmental enhancement offers an adequate strategy for preserving natural water systems from eutrophication.