Biological sewage treatment plant BNR

Biological Nutrient Removal (BNR) is a process used for nitrogen and phosphorus removal from wastewater before it is discharged into surface or ground water. The rising concentration of harmful nutrient compounds – specifically nitrogen and phosphorus – in municipal wastewater treatment plant discharge causes cultural eutrophication (nutrient enrichment due to human activities) in surface waters. Summer algal blooms are a familiar example of this eutrophication, and can present problems for ecosystems and people alike: low dissolved oxygen, fish kills, murky water, and depletion of desirable flora and fauna.