Manammox – mainstream anammox at Sjölunda WWTP
Paper i proceeding, 2014
The next revolution in biological nutrient removal at municipal wastewater treatment plants (WWTPs) is fully autotrophic nitrogen removal. Extensive pilot tests at Sjölunda WWTP in Malmö, Sweden, are ongoing for implementing Manammox (mainstream anammox) in the existing plant, which already today separates COD and nitrogen removal. The Manammox concept is based on a combined process where nitritation-anammox is operated in moving-bed biofilm reactors for sludge liquor treatment and treatment of mainstream wastewater with exchange of biofilm carriers between the two systems. Almost complete ammonium oxidation and more than 80% nitrogen reduction was reached in the sludge liquor system and up to 60% in the main stream process. Quantitative PCR showed almost the same composition of the bacterial population with high abundance of anammox bacteria and ammonia-oxidising bacteria in all reactors and that the exchange of carriers did not effectively suppress the nitrite-oxidising bacteria in the system. Optimal choice of the oxygen supply for the process seems to be crucial for further increase of the nitrogen reduction in the mainstream.