Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA.
School of Environment and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, China.
Integr Environ Assess Manag. 2021 Jan;17(1):292-304. doi: 10.1002/ieam.4318. Epub 2020 Sep 17.
Recovering valuable nutrients (e.g., P and N) from waste materials has been extensively investigated at the laboratory scale. Although it has been shown that struvite precipitation from several manure sources contributes to nutrient management practices by recovering valuable nutrients and preventing them from reaching water bodies, it has not been widely applied in commercial (i.e., farm) scales. The purpose of this study is to evaluate the potential environmental impacts of the struvite recovery process from the liquid portion of the anaerobically digested dairy cow manure generated in Wisconsin, USA, dairy farms using life cycle assessment methodology for both bench- and farm-scale scenarios. The struvite precipitation process involves the use of additional chemicals and energy; therefore, investigating upstream impacts is crucial to evaluate the environmental costs and benefits of this additional treatment process. Results indicate that up to a 78% impact decrease in eutrophication potential can be achieved when P and N are recovered in the form of struvite and are applied in lieu of conventional fertilizers, rather than using the liquid portion of the anaerobically digested dairy manure as a fertilizer. Additionally, significant differences are identified in the majority of environmental impact categories when the struvite precipitation process is modeled and evaluated in a farm-scale setting. Future work should expand to evaluate the overall environmental impacts and trade-offs of struvite recovery application, including the anaerobic digestion system itself at the farm scale. Integr Environ Assess Manag 2021;17:292-304. © 2020 SETAC.
从废物中回收有价值的营养物质（例如磷和氮）已在实验室规模上进行了广泛研究。尽管已经表明，从几种粪肥来源沉淀鸟粪石有助于通过回收有价值的养分并防止它们进入水体来进行养分管理实践，但它尚未在商业（即农场）规模上广泛应用。本研究的目的是使用生命周期评估方法评估从美国威斯康星州奶牛场厌氧消化奶牛粪便的液体部分回收鸟粪石的过程对环境的潜在影响，包括实验室规模和农场规模两种情况。鸟粪石沉淀过程涉及使用额外的化学物质和能源；因此，调查上游影响对于评估这种额外处理过程的环境成本和收益至关重要。结果表明，当以鸟粪石的形式回收 P 和 N 并代替传统肥料施用于土壤中时，富营养化潜力最多可降低 78%，而不是将厌氧消化奶牛粪便的液体部分用作肥料。此外，当在农场规模上对鸟粪石沉淀过程进行建模和评估时，大多数环境影响类别中存在显著差异。未来的工作应扩展到评估鸟粪石回收应用的整体环境影响和权衡，包括农场规模上的厌氧消化系统本身。
