Performance of sequencing batch reactors for nutrient removal using salsnes filter fine mesh sieves as a primary treatment

Abstract

This study investigated the performance of sequencing batch reactors (SBR) for nitrification and denitrification. Bench scale Salsnes Filter (SF) was used as a primary treatment to provide wastewater with different organic fractions to assess its impact on denitrification. Tests were performed using activated sludge seed and municipal primary wastewater from two different municipal wastewater treatment plants located around Oslo-Norway. Three batch reactors were used; the first one used unfiltered wastewater, the second one used wastewater filtered through 1.2µm, and the third one used wastewater filtered through 18µm SF fine mesh sieve without filter mat formation. Characterization of the influent and effluent was performed. The results showed that the performance of the three reactors were similar, with 94.84% TSS removed for Reactor 1, 92.73% for Reactor 2 and 81.95% for Reactor 3. The percentage of NH4-N removed was also similar: 98.78% for Reactor 1, 96.09% and 98.22% for Reactor 2 and 3 respectively. The denitrification rate was found to be higher for Reactor 1, however there was no significant difference between the three reactors.