生物炭和生物质灰对堆肥过程氨气/温室气体排放的影响OA

To address the issue of high greenhouse gas emissions in conventional composting,this study employs biochar and biomass ash(byproducts of biomass energy conversion)as additives,conducting a comparative analysis of their emis-sion reduction effects and underlying mechanisms.The results demonstrate that both biochar and biomass ash effectively ex-tended the duration of the thermophilic phase by 2～5 days and enhanced humification,leading to an increase in the humic acid to fulvic acid ratio by 2.1％～45.4％.Compared to the control group,the treatment groups with 1％biochar and bio-mass ash addition reduced CH4 emissions by 18.2％and 25.9％,N2O emissions by 16.5％and 21.2％,and NH3 emis-sions by 34.1％and 41.7％,respectively.The emission reduction effect was most pronounced at this application rate.No-tably,biomass ash demonstrated superior performance over biochar in mitigating emissions.Microbial community analysis revealed that biochar increased the relative abundance of Actinobacteria,while biomass ash enhanced both Actinobacteria and Firmicutes.Both additives significantly promoted the proliferation of humification-functional genera,including Thermo-bispora,Thermopolyspora,and Pseudoxanthomonas.The correlation analysis revealed that biochar could facilitate the trans-formation of organic carbon into humic acid by reducing moisture content and ammonium nitrogen content,thereby accelera-ting the humification process.Ultimately,this process mitigated the emissions of greenhouse gases and ammonia through the synergistic fixation of carbon and nitrogen.These phenomena may be attributed to the high specific surface area and abun-dant porous structure of biochar.Additionally,biomass ash could regulate the pH of the composting matrix,alter the NH4+-N/NH3 equilibrium,and induce shifts in microbial communities,thereby modulating the emissions of greenhouse gases and ammonia.This regulatory effect was likely associated with the strong alkalinity and rich mineral composition of biomass ash.These findings provide theoretical support for developing low-carbon composting technologies and advancing the green sustainable utilization of biomass energy conversion byproducts.