规模养猪场粪便堆肥处理生命周期评价实例分析

A Case Study on Life Cycle Assessment of Pig Manure Compost Production in a Pig Farm

以北京郊区某规模化养猪场现有堆肥系统为例,运用生命周期评价方法,以养猪场现行堆肥工艺为参比,以4种不同翻堆频率条件下的条垛式堆肥工艺作为备选方案,对该养猪场粪便不同堆肥处理情景的环境影响进行系统对比分析。结果表明,每处理1 t新鲜猪粪的化石能源损耗潜力为80.8～221.5 MJ;堆肥氨挥发排放对系统总酸化效应和富营养化效应贡献率均达96%以上;CO^2和N2O等温室气体排放对总温室效应的贡献分别为58%～88%和8%～35%。能源投入和气体排放是猪粪堆肥生命周期环境影响的关键因素,实践生产中应注重使用清洁能源,并结合工艺特点采用氨挥发与温室气体减排技术,减少堆肥生产过程的环境污染。

We evaluated the environmental burdens of one existing composting system and four alternative composting systems with different turning frequencies in Beijing area using life cycle assessment（LCA ）. The results showed that resources consumption and atmospheric e- missions played important roles in the environmental impacts of pig manure composting process. For these five composting options, fossil en- ergy of 80.8 to 221.5 MJ was needed to compost one ton of pig manure. During composting, ammonia emissions contributed more than 96% to the acidification potential（ AP ） and eutrophication potential（EP ）. Carbon dioxide and N20 from the pig farms contributed to about 58% to 88% and 8% to 35% of the total global warming potential, respectively. Of the alternative options, the options with turning frequen- cy of 1 to 2 times per week with diesel-powered turning machine should be recommended for pig manure composting because of the lower environmental impacts.