Life cycle assessment of biosolids land application and evaluation of the factors impacting human toxicity through plants uptake

Abstract

Due to the increasing environmental concerns in the wastewater treatment sector, the environmental impacts of organic waste disposal procedures require careful evaluation. However, the impacts related to the return of organic matter to agricultural soils are difficult to assess. The aim of this study is to assess the environmental impacts of land application of two types of biosolids (dried and composted, respectively) from the same wastewater treatment plant in France, and to improve the quantification of human toxicity. A Life Cycle Assessment (LCA) was carried out on a case study based on validated data from an actual wastewater treatment plant. Numerous impacts were included in this analysis, but a particular emphasis was laid on human toxicity via plant ingestion. For six out of the height impact categories included in the analysis, the dried biosolids system was more harmful to the environment than the composting route, especially regarding the consumption of primary energy. Only human toxicity via water, soil and air compartments and ozone depletion impacts were higher with the composted biosolids