There are various biological nutrient removal

There are various biological nutrient removal (BNR) process configurations that vary depending on the nutrients to be removes. There are BNR systems that remove the total nitrogen only, other remove the total phosphorus only while others remove both nutrients. The appropriateness of any configuration used depends on the operator’s experience, effluent and influent equality and the already existing treatment process. BNR systems meant to remove the total nitrogen should have an aerobic zone that supports nitrification and an anoxic zone for denitrification purpose.