Effects of aeration conditions on nitrogen removal performance and microbial community changes in biological aerated filter with iron-based composite packing
WEI Chenzheng1,2, LIU Ying1,2, REN Jilong1,2, MA Hongjing1,2, WU Yinghai1, HAN Rui1,2*
1.College of Marine Technology and Environment, Dalian Ocean University, Dalian 116023, China; 2.Key Laboratory of Environment Controlled Aquaculture (KLECA), Ministry of Education, Dalian 116023, China
Abstract: In order to investigate the nitrogen removal performance of biological aerated filter (BAF), mariculture wastewater and characteristics of microbial communities on packings were investigated under different aeration conditions. The BAF was treated by three methods with different aeration conditions (24 h continuous aeration. 12 h intermittent aeration, and 0 h aeration) and filled with composite immobilized bio-packings prepared by mixing polypropylene carbonate (PPC) gel hydrophilic packing and sponge iron with mass ratio of 3∶1 at water temperature of (30.0±0.5)℃, hydraulic load rate (HLR) of 1.2 m3/(m2·d), carbon to nitrogen ratio of 3∶1 and pH (7.0±0.5). The results showed that there were high removal rate of ammonia nitrogen in the 12 hours aeration group. There was higher microbial community diversity index including Shannon, Chao1 and ACE in sponge iron group than that in other treatments, indicating that the maximal microbial diversity and abundance was observed in the treatment. There was higher relative abundance of the bacterial genus with denitrification ability, including Acinetobacter and Delftia in sponge iron packing and Photobacterium in PPC packing in this treatment than that in other treatments. It was found that the iron-based composite filler BAF enriched more denitrifying bacteria under the condition of 12 h intermittent aeration, which makes the biological aerated filter have good denitrification performance and saves more energy consumption. The findings will provide a theoretical basis for improving the denitrification performance of BAF and analyzing of the microbial community structure of bio-packings in the system.
2021, Vol. 36 
