丙酸盐对厌氧氨氧化生物膜系统的影响及机制研究OA

Anaerobic ammonium oxidation(ANAMMOX)process has a good application prospect in nitrogen removal from wastewater due to its low energy consumption and high cost-effectiveness.However,it could be affected by different types of organic matters when treating the actual wastewater.In this work,when the low concentration of propionate(30 mg/L)was added into the ANAMMOX biofilm system,the propionate was prior to participate in the partial denitrification process,and ANAMMOX activity was inhibited slightly,with the reaction rate decreasing from 7.24 mg/(L·h)to 5.56 mg/(L·h).When the concentration of propionate in the system increased to 60 mg/L,the performance changed with the initial nitrate concentration in the system.Under the low concentration of initial nitrate(＜15 mg/L),the propionate involved in the partial denitrification via nitrate,and the whole denitrification via nitrite;the activity of ANAMMOX bacteria was further inhibited.Under the high initial nitrate concentration(above 30 mg/L),the propionate mainly involved in the partial denitrification via nitrate.Based on the effect of propionate,the influent concentration of this ANAMMOX system was optimized,leading to the total nitrogen removal efficien-cyreaching about 94％.Candidatus_Kuenenia and Candidatus_Brocadia were identified as the dominant ANAMMOX bacteria.With the increasement of propionate concentration,the relative abundance of Candidatus_Kuenenia and Candidatus_Brocadia decreased from 8.83％and 1.78％to 2.88％and 0.20％,respectively.However,the relative abundance of denitrifying bacteria Thauera increased from 0 to 19.39％.When the system was fed with the optimal influent,the relative abundance of Candidatus_Kuenenia and Candidatus_Brocadia increased slightly to 6.76％and 0.30％,respectively,and the relative abundance of Thauera decreased to 14.82％.This studyaimed to provide theoretical guidance for the practical application and optimization of ANAMMOX process in wastewater treatment.