Electron transfer and microbially-driven synergy boost nitrogen conversion in Fe-BTC/biochar-amended electrified composting

Electric field-assisted composting technology is a novel and efficient approach to composting; however, it has various challenges, such as the emission of nitrogenous gases and limited electrical conductivity. This compost set up electric field assisted aerobic compost (CK), biochar (BC) + electric field assisted aerobic compost (T2) and FeBTC/BC+ electric field assisted aerobic compost (T1) respectively, and carried out compost experiments for 27 days. Purpose to develop a novel additive Fe-BTC/BC and examine its effects on nitrogenous gas emissions during electric field-assisted composting. Incorporating Fe-BTC/BC reduced NH 3 and N 2 O emissions by 47.05% and 19.83%, respectively, compared with that of the control, and led to an increase in peak temperature from 66.4 ℃ to 71.2 ℃ and a shortened composting period from 16 d to 9 d. Microbiological analysis indicated that Fe-BTC/BC enhanced the abundance of nitrifying functional microbial community, such as Bacillus (from 24.09% to 27.18%), and reduced that of denitrifying functional microbial community (from 5.08% to 3.91%).RDA indicated that NH 3 emission is in connection with nitrifying microbial community ( Clostridium_sensu_stricto_1 , Corynebacterium ). In addition, reduction-oxidation (REDOX) activity was enhanced upon the addition of Fe-BTC/BC. These findings indicate that Fe-BTC/BC has a synergistic effect that improves nitrogen conversion efficiency by altering the abundance of microorganisms and accelerating electron transfer. This study provides an important scientific basis for the development of novel materials to reduce the emission of nitrogenous gases during electric field-assisted composting. • Novel material Fe-BTC/BC has been develop and apply during pig manure composting. • NH 3 and N 2 O were reduced by 47.05% and 19.83% after adding Fe-BTC/BC. • Fe-BTC/BC restrained the denitrifying functional microbe. • The material REDOX activity was boosted by adding Fe-BTC/BC. • The electron transfer rate between minerals and microorganisms were accelerated.