Exploring synergistic interactions of ethyl acetate removal and community ecology using magnetite-entrapped biofilters.

Emissions of ethyl acetate (EA) exhaust from industrial sources can cause environmental and health risks. EA can be effectively removed by biological filtration with low operating costs and promising good benefits. This study demonstrated the synergistic effect of using magnetite and pebbles as bio-packing in promoting microbial activity and microbial abundance for EA degradation. The biofilter filled with magnetite and pebbles exhibits the most efficient removal of EA, average removal efficiency >90% (Inlet load: 120.19 ± 9.33 g/(m·h), Empty bed residence time: 60s). Meanwhile, magnetite promoted the increase of Adenosine Triphosphatase (ATP) and Lactate Dehydrogenase (LDH) concentrations compared to the control group, with maximum concentrations of 1.31 μM/L and 0.024 U/10 cell, respectively. Furthermore, the presence of magnetite promoted the structural diversity of microbial community (Rhodoblastus, Xanthobacter, Saccharibacteria_genera_incertae_sedis and Acidocella. A first-attempt mechanism of ethyl acetate degradation was proposed to reveal interactions of microbial communities in magnetite biofilter columns, by stimulating microbial community diversification to promote the above-mentioned dominant species bioremediation.