Application of Simultaneous Partial Nitrification and Anammox Process for Treatment of High Strength Nitrogen Containing Optoelectronic Wastewater

In this study, nitrogen removals from two different optoelectronic wastewaters were reported using anammox as the main reaction. CANON (Completely Autotrophic Nitrogen Removal over Nitrite) process was applied to remove nitrogen from high strength ammonium containing optoelectronic wastewater (WW1). The other optoelectronic wastewater (WW2) contains low COD (chemical oxygen demand) along with ammonia, therefore simultaneous partial nitrification, anammox and denitrification (SNAD) process was applied to remove both nitrogen and COD. Two lab scale sequencing batch reactors (SBRs) with working volume of 18 L and 2.5 L, respectively were operated over 16 months in different stages to treat WW1 and WW2, respectively. Essential nutrients and trace elements were also added in the influent wastewaters to support the anammox growth. Nitrogen loading rate (NLR) was gradually increased from 10 g-N m−3 d−1 to 909 g-N m−3 d−1 and 16 g-N m−3 d−1 to 480 g-N m−3 d−1 in SBR-18 and SBR-2.5, respectively. The SBR-18 was successfully run about 1 month to treat WW1 without dilution and an average 90% of total nitrogen (TN) removal was achieved in SBR-18. In case of SBR-2.5, the system successfully treated 89 g-COD m−3 d−1 and 428 g-N m−3 d−1, respectively, with 79% and 93% of COD and TN removal efficiencies in later stages. The influence of nutrients supplemented to the optoelectronic wastewater (WW2) on the performance of SNAD process and anammox activity was also evaluated in SBR-2.5. The SBR-2.5 was run without supplementing Ca2+, Mg2+ and Fe2+ to the WW2 from day 472-497. However, no specific changes in the reactor performance (nitrogen and COD removal efficiencies) and specific anammox activity (SAA) were observed. It is suggested that the optoelectronic wastewater could be treated by SNAD process without supplementing the additional nutrients.