Department of Land, Air and Water Resources, University of California, Davis, United States.
Department of Land, Air and Water Resources, University of California, Davis, United States.
Waste Manag. 2017 Jan;59:70-79. doi: 10.1016/j.wasman.2016.10.004. Epub 2016 Oct 15.
The process of composting is a source of greenhouse gases (GHG) that contribute to climate change. We monitored three field-scale green waste compost windrows over a one-year period to measure the seasonal variance of the GHG fluxes. The compost pile that experienced the wettest and coolest weather had the highest average CH emission of 254±76gCday dry weight (DW) Mg and lowest average NO emission of 152±21mgNday DW Mgcompared to the other seasonal piles. The highest NO emissions (342±41mgNday DW Mg) came from the pile that underwent the driest and hottest weather. The compost windrow oxygen (O) concentration and moisture content were the most consistent factors predicting NO and CH emissions from all seasonal compost piles. Compared to NO, CH was a higher contributor to the overall global warming potential (GWP) expressed as CO equivalents (CO eq.). Therefore, CH mitigation practices, such as increasing O concentration in the compost windrows through moisture control, feedstock changes to increase porosity, and windrow turning, may reduce the overall GWP of composting. Based on the results of the present study, statewide total GHG emissions of green waste composting were estimated at 789,000Mg of CO eq., representing 2.1% of total annual GHG emissions of the California agricultural sector and 0.18% of the total state emissions.
堆肥过程是温室气体（GHG）的来源之一，这些温室气体会导致气候变化。我们监测了三个现场规模的绿色废物堆肥垄沟，为期一年，以测量 GHG 通量的季节性变化。经历最潮湿和最凉爽天气的堆肥堆具有最高的平均 CH 排放量，为 254±76gC 干重（DW）Mg，与其他季节性堆相比，平均 NO 排放量最低，为 152±21mgNday DW Mg。经历最干燥和最热天气的堆肥堆的 NO 排放量最高（342±41mgNday DW Mg）。堆肥垄沟中的氧气（O）浓度和水分含量是预测所有季节性堆肥堆中 NO 和 CH 排放的最一致因素。与 NO 相比，CH 对整体全球变暖潜势（GWP）的贡献更高，以 CO 当量（CO eq.）表示。因此，通过控制水分来增加堆肥垄中的 O 浓度、改变原料以增加孔隙度以及翻堆等 CH 减排措施，可能会降低堆肥的整体 GWP。根据本研究的结果，全州绿色废物堆肥的总 GHG 排放量估计为 789000Mg 的 CO eq.，占加利福尼亚农业部门年总 GHG 排放量的 2.1%，占全州总排放量的 0.18%。
