Seasonal effects of pre-aeration on microbial processes for nitrogen removal in constructed wetlands

摘要

Seasonal effects of pre-aeration on microbial nitrogen performance in constructed wetlands (CWs) involved with anaerobic ammonium oxidation (anammox) process were investigated in this study. Slow natural re-acration rate was the inhibiting factor for total nitrogen removal in CW without pre-aeration, and partial nitrification was the main way for nitrite generation. Besides partial nitrification, prcacration provided nitrite generation inCWs with an alternative way: nitrate reduction. Advantage of pre-aeration of influent was much different under various temperature ranges. Mean temperature of 15 degrees C seemed to be the turning point. With a mean temperature of or higher than 15 degrees C, nitrate in the influent effectively improved nitrogen removal in CWs. With a mean temperature lower than 15 degrees C, the nitrate reduction process in CWs was greatly inhibited. The benefit of pre-aeration was weak under this temperature range. Seasonal aeration pattern for the pre-treatment of HSSF CWs might be a more energy-saving alternative in in-suit domestic sewage treatment.