Environmental Benefits and Burdens of Phosphorus Recovery from Municipal Wastewater
Environmental Benefits and Burdens of Phosphorus Recovery from Municipal Wastewater
复制标题
DOI：
10.1021/es505102v
复制
发表时间：
2015-07-21
影响因子：
11.4
通讯作者：
Leslie, Gregory
中科院分区：
文献类型：
--
作者：
Bradford-Hartke, Zenah;Lane, Joe;Leslie, Gregory
采用生命周期评价法(LCA)比较了4个集中式和2个分散式城市污水系统磷回收的环境效益和负担。在集中式系统中，除陆地生态毒性和淡水富营养化影响类别外，从固体脱水液中以鸟粪石形式回收的磷产生了环境效益，电力和化学品的使用被运营节省和避免了化肥生产所抵消。然而，以化学为基础的磷回收通常需要比避免使用化肥所抵消的资源更多的资源，从而造成净环境负担。在分散式系统中，通过尿源分离回收磷降低了全球变暖和臭氧消耗潜力，但由于将未经处理的尿液应用到陆地上，增加了陆地生态毒性和盐碱化潜力。总体而言，矿物枯竭和富营养化是磷回收的有据可查的论点；然而，磷回收不一定带来净环境效益。虽然避免化肥生产确实会减少潜在的影响，但磷回收并不一定能抵消在这一过程中消耗的资源。生命周期评价结果表明，选择合适的磷回收方法除考虑富营养化和矿物质消耗的影响外，还应考虑当地条件和其他环境影响，包括全球变暖、臭氧消耗、毒性和盐碱化。
The environmental benefits and burdens of phosphorus recovery in four centralized and two decentralized municipal wastewater systems were compared using life cycle assessment (LCA). In centralized systems, phosphorus recovered as struvite from the solids dewatering liquid resulted in an environmental benefit except for the terrestrial ecotoxicity and freshwater eutrophication impact categories, with power and chemical use offset by operational savings and avoided fertilizer production. Chemical-based phosphorus recovery, however, generally required more resources than were offset by avoided fertilizers, resulting in a net environmental burden. In decentralized systems, phosphorus recovery via urine source separation reduced the global warming and ozone depletion potentials but increased terrestrial ecotoxicity and salinization potentials due to application of untreated urine to land. Overall, mineral depletion and eutrophication are well-documented arguments for phosphorus recovery; however, phosphorus recovery does not necessarily present a net environmental benefit. While avoided fertilizer production does reduce potential impacts, phosphorus recovery does not necessarily offset the resources consumed in the process. LCA results indicate that selection of an appropriate phosphorus recovery method should consider both local conditions and other environmental impacts, including global warming, ozone depletion, toxicity, and salinization, in addition to eutrophication and mineral depletion impacts.