Spatial dynamics of biochemical fractions degradation, functional enzymatic activity and bacterial community within co-bioevaporation pile

Abstract

Co-bioevaporation is a cleaner and sustainable production for treating concentrated landfill leachate (CLL). Temperature gradient in a co-bioevaporation pile resulted in a relatively wet matrix near the top, but drier conditions near the bottom. That made the biochemical fractions degradation (except of lipids) greatest near the top and lowest near the bottom. The total degraded biochemical fractions reached 191.96, 170.8 and 156.12 mg g−1 TS (total solids), respectively in the top, middle and bottom sections of the pile. The highest enzymatic activity (including hydrolase and dehydrogenase) was observed in the top region, while the lowest was in the bottom region. The top region came to be dominated by thermophiles, particularly anaerobic Tepidimicrobium which accounted for 10.55% and 8.81%, respectively in the warming and peak temperature periods. Their activity as well as synergy with aerobes contributed to the higher enzymatic activity and faster degradation near the top of a co-bioevaporation pile. The dominant genera near the bottom were aerobic mesophiles or moderate thermophiles. These spatial variations were related to the spatial gradients in temperature, organics and moisture which form, as well as to oxygen availability.