Soil-less Soil Study - A Sustainable Solution for Green Infrastructure Soil Media - Part 1, Life Cycle Assessment
Physical Sciences and Mathematics
The management of waste glass is of great concern worldwide due to its non-combustible and non-putrescible nature. Additionally, there is an urgent need for more sustainable alternatives and sources for aggregate, as the world is running out of quarried sand for use in construction. The Soil-less Soils Project, which is currently being run by the Philadelphia-based landscape architecture firm, OLIN, in partnership with the University of Pennsylvania and Temple University, is located at the nexus of two pressing environmental issues associated with urban development: a scarcity of sand and an overabundance of post-consumer glass. To solve these problems, the research initiative aims to develop and test a low-carbon footprint, rapidly renewable manufactured soil mix for use in green infrastructure and urban planting applications. The principle components of the mix are Class A biosolids and fine-ground recycled glass cullet. While the primary goals of the Soil-less Soils Project are environmental, the use of glass, an inert material, in place of mineral aggregate may also provide benefits in terms of soil function and uniformity in designed landscapes. To assess the environmental impacts of the substitution of natural sand with glass fines in the Soil-less Soil mix, a comparative cradle-to-gate life cycle analysis (LCA) was performed on the two materials. This is the first ever LCA study on recycled aggregates from waste glass in the landscape architecture industry, which was based on both the database and the first hand data. The results reveal that compared with the conventional sand, recycled aggregates produced from waste glass reduce 67% greenhouse gases (GHGs) emission with a saving of 48% water usage. The positive outcomes of the study will provide guidance on maximizing waste glass recycling and encourage the use of waste glass in the green infrastructure application.