Nitrogen Removal Controlled by an Ammonium-Analyser at the North Pest Wastewater Treatment Plant

Abstract

At the North Pest Wastewater Treatment Plant, a nutrient removal process has been in operation since 2011. New tanks have been built, which can receive approximately half of the pre-settled wastewater. A predenitrification system has been planned and built both to the old and new lines. Due to the relatively small anoxic zones, periodic aeration was initiated first in the new line to achieve the lowest possible effluent total nitrogen concentration. Because of its positive impact, the operation of periodic aeration was initiated in the old line as well. Ammonium-analysers are used to control the aeration periods. Due to this process, the plant can provide a very low total nitrogen effluent value (below 10 mg dm-3 on average) as well as save energy and operational costs.