Research On The Effect Of Sality And Humic Acid To Anammox Performance And Its Strengthening Mechanism

In this paper,the individual and combined effect of salinity and humic acid on anammox bacteria was studied.The combined impact of salinity and humic acid on anammox performance and microbial was also discussed,which revealed the operating performance and the problems of the treatment process.It provides a new solution for the treatment of high-salt and high-humic acid wastewater based on the performance robustness and nitrogen removal by coupling anammox with denitrification in a corncob-dosed reactor.Through the research of this paper,the following results were obtained:?1?Unacclimated anammox bacteria will be inhibited not only under the conditionsof individual salinity and humic acid,but more severe under the combined circumstance of salinity and humic acid.The degree of inhibition in nitrogen removal performance of the system was as followed:individual humic acid<individual salinity<combined salinity and humic acid.By analyzing the nitrogen removal efficiency,microbial activity,and relevant indexes of the extracellular polymeric substances?EPS?in the reactors,the reasons for the difference between the individual inhibition and combined inhibition of salinity and humic acid were analyzed.?2?The anammox could gradually adapt to the circumstances of high-salinity and humic acid after acclimating for a certain period of time,the system's nitrogen removal performance was gradually restored,and a stable nitrogen removal efficiency could be maintained.Therefore,it is feasible to use anammox process to treat high-salt and high-humic acid wastewater.However,it took a long time to acclimate anammox bacteria,and it was difficult to fully recover the microbial activity after the combined inhibition was caused by salinity and humic acid.A statistical analysis of the total nitrogen removal efficiency during the entire operation showed that there was a significant difference in the total nitrogen removal performance between the combined group,the individual group,and the blank group?P<0.05?.The combined inhibition of salinity and humic acid was more severe than individual inhibition.This suggests that for successful application of anammox in high salinity and humic acid wastewater treatment,it is essential to consider the synergistic inhibition caused by salinity and humic acid.?3?Nitrite?NO₂^--N?,a substrate for anammox bacteria,was also a potential inhibitor due to its strong negative effect on microbial activity.The utilization rate of NO₂^--N could be decreased in the presence of salinity and humic acid,resulting in the accumulation of NO₂^--N in the system,which would further threat the anammox performance.In this paper,corncob was used as the solid carbon source for the first time to be applied in the anammox process.The coupling of anammox with denitrification in a corncob-dosed reactor was successfully achieved,which reduced the excess NO₂^--N in the system.At the same time,as a solid-phase carrier,corncob was a suitable biofilm carrier for the enrichment of anammox bacteria,which increased the stability and the impact resistance of the system.It provides a new solution for the treatment of high-salinity and high humic acid wastewater through anammox process.