Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
Sci Total Environ. 2020 Aug 20;731:139157. doi: 10.1016/j.scitotenv.2020.139157. Epub 2020 May 5.
This study investigated the interplay effects of key operational factors on maturity, gaseous emissions, and energy efficiency during composting of livestock manure digestate. Orthogonal experiments were conducted with three factors: digestion duration (15, 30, 45 days), corn stalk addition (15%, 25%, 35%, wet weight based), and aeration rate (0.12, 0.24, 0.48 L kg dry matter (DM) min). Results showed that digestion duration was the main factor influencing the compost germination index (GI), greenhouse gases (GHGs) emission, and net energy. Digestion duration of 30 days was favored for compost GI and GHG reduction, while digestion duration of 45 days exhibited 18% higher daily net energy. Increasing corn stalk addition and aeration rates improved compost GI, but increased energy consumption. Corn stalk addition of 25% and aeration rate of 0.24 L kg DM min could ensure desirable compost maturity and save energy consumption. Thus, digestion for 30 days, 25% corn stalk addition, and aeration rates of 0.24 L kg DM min can be potentially implemented in industry for environmental and cost efficient composting of digestate.
本研究探讨了关键操作因素在堆肥过程中对家畜粪便消化物的成熟度、气态排放物和能源效率的相互作用影响。采用正交试验设计了三个因素：消化时间（15、30、45 天）、玉米秸秆添加量（15%、25%、35%，基于湿重）和曝气率（0.12、0.24、0.48 L kg 干物质（DM）min）。结果表明，消化时间是影响堆肥发芽指数（GI）、温室气体（GHGs）排放和净能量的主要因素。30 天的消化时间有利于堆肥 GI 和 GHG 减排，而 45 天的消化时间则使每日净能量提高了 18%。增加玉米秸秆添加量和曝气率可提高堆肥 GI，但会增加能源消耗。玉米秸秆添加量为 25%和曝气率为 0.24 L kg DM min 可确保达到理想的堆肥成熟度并节省能源消耗。因此，30 天的消化时间、25%的玉米秸秆添加量和 0.24 L kg DM min 的曝气率可能会在工业上用于环境和成本效益高的消化物堆肥。
