[Nitrogen Removal Performance of ANAMMOX Process with K Addition in Saline Surroundings].

In view of the poor performance of biological nitrogen removal in saline wastewater treatment, nitrogen removal of anaerobic ammonium oxidation(ANAMMOX) with K addition was studied. The results showed that K addition could strengthen nitrogen removal performance. The effect of K on ANAMMOX process was mainly divided into four stages. In the adaptive phase(0-2 mmol·L), sudden addition of K destroyed the original equilibrium reaction, but ultimately ANAMMOX bacteria could adapt to the presence of K. Because K had no obvious effects on anaerobic ammonia oxidation bacteria, the removal rates of NH-N and NO-N slightly increased. In the ascension phase(2-8 mmol·L), K played a role in promoting anaerobic ammonia oxidation biological systems, with increasing concentration of K, the removal rates of NH-N and NO-N significantly increased. In the stabilization phase(8-20 mmol·L), the nitrogen removal rate decreased, but was still higher than the control without K addition. In the inhibition phase(more than 20 mmol·L), K largely inhibited anaerobic ammonia oxidation, and its denitrification efficiency was lower than 0 mmol·L. In the whole cycle, when the concentration of K was 8 mmol·L, it achieved the best effect, the average removal rates of NH-N and NO-N were 89.24% and 84.87%, and NRR was 1.113 kg·(m·d).