Comprehensive pilot plant studies have been conducted over a period of six years in connection with the upgrading of the Lynetten Wastewater Treatment Plant to nutrient removal. The studies showed already at an early state that the nitrification process was inhibited. Short-term and long-term effects in connection with the running-in of the nitrogen removal processes, were investigated in two situations,- with and without inoculation with adapted sludge from a reference pilot plant. The floc formation, sludge accumulation and the establishment of full nitrification and denitrification developed in the same way in the two tests. The development of the nitrification capacity, however, differed to a significant extent. Compared with the nitrification capacity at the reference plant, the nitrification capacity in the test involving inoculation was reached approximately 2 month after the start-up as opposed to 7.5 months in the test without inoculation.

This content is only available as a PDF.