奶牛粪便翻堆式与槽式堆肥过程气体排放规律及养分损失原位监测

为探究奶牛粪便翻堆式与槽式堆肥过程中温室气体和氨气(NH₃)排放规律及养分损失情况,采用原位监测的方法,通过静态采气箱和气体在线监测设备,分别对奶牛粪便翻堆式和槽式堆体开展为期36 d的气体监测。结果表明,翻堆式堆肥过程中甲烷(CH₄)、氧化亚氮(N2_O)和NH₃排放主要集中于翻堆阶段;槽式堆肥过程中CH₄和NH₃排放主要集中于堆肥前期,N2_O排放则主要集中于堆肥中后期。堆体管理措施及物料特性显著影响堆肥气体的排放。翻堆式堆肥过程中翻堆对气体排放的影响大于堆肥理化因子如温度、含水率以及pH值;而槽式堆肥过程中,降低堆体的平均温度可同时减缓堆肥过程中CH₄、二氧化碳(CO₂)和NH₃的释放。从养分损失来看,翻堆式和槽式堆肥过程中碳素总损失量分别占堆肥物料初始总碳含量(TC)的27.16%和21.53%,其中约80%以上的碳素损失来自CO₂-C。而堆肥过程中氮素总损失量分别占堆肥物料初始总氮含量(TN)的18.67%和13.44%,其中约80%以上的氮素损失来源于NH₃N。该研究表明,在保证堆体物料腐熟的前提下,降低翻堆频率可显著减缓翻堆式堆肥过程中温室气体和NH₃的排放;降低槽式堆肥堆体的温度可显著减少堆肥过程中CH₄、CO₂和NH₃的排放。该研究结果对于减少堆肥过程气态污染物排放和养分损失,提高堆肥效率具有重要的指导意义。

The In-situ Monitoring of Gas Emissions and Nutrient Losses from Turning and Trough Composting of Dairy Manure

In order to investigate greenhouse gases,ammonia(NH₃)emissions and nutrient losses during turning and trough composting of dairy manure,we carried out 36-day measurement campaigns respectively on the turning and trough compost piles in two different dairy farms.Measurements were performed using the closed-chamber and on-line gas monitoring equipment.Results showed the emissions of CH₄,N2_Oand NH₃ were mainly coupled with turning activities during turning composting.The CH₄and NH₃ emissions mainly produced at early phase of through composting,but the N2_Oproduction typically occurred at the later stage.The composting management practices and material characteristics can significantly affect gas emissions.During turning composting,turning events could have greater effects on gas emissions than the physicochemical factors(temperature,moisture and pH value)of compost.Lowering temperature can simultaneously reduce CH₄,CO₂and NH₃ emissions from the trough composting.For the nutrient losses,the total carbon losses from the turning and trough composting accounted for 27.16%and 21.53%of the initial C content respectively,with more than 80%of gaseous carbon losses from CO₂-C.The total nitrogen losses during the composting process accounted for 18.67%and 13.44%of the initial nitrogen content for the turning and trough composts,and more than 80%of the nitrogen losses came from NH₃N.Our results indicated that reducing the frequency of turning events can significantly decrease greenhouse gases and NH₃ emissions from the turning compost under the premise of ensuring the maturity of materials.Lowering the temperature of the trough composting pile can significantly reduce the yields of CH₄,CO₂and NH₃.These results have important implications for improving the compost efficiency,decreasing environmental pollution and nutrient losses from the composting process.