Assessment of the nitritation and anammox processes for mainstream wastewater treatment

Resumen

The implementation of mainstream autotrophic nitrogen removal processes such as the combined partial nitritation and anammox processes will contribute to maximise the wastewater energy recovery converting the wastewater treatment plants (WWTPs) in net energy producers and enabling the wastewater reuse. Consequently, this thesis aims to assess the nitritation and anammox processes implementation at mainstream conditions characterised by its low temperature, low nitrogen concentration and high fluctuations of wastewater characteristics. Different reactor configurations, including one, two-stage and hybrid systems, were employed. Moreover, the treatment of diverse wastewaters like blackwater from a source-separation on-site system and municipal wastewater were studied, being specially focused on overcoming the nitrite oxidizing bacteria development that challenged the anammox based processes implementation. Special attention was paid to the production of effluents complying with the European discharge limits as well as the evaluation of the activities of the involved microbial populations.