Environmental impacts associated with the biological treatment and agricultural use of organic waste. Assessment of knowledge for the global environmental assessment of the supply chains

Abstract

The organic recovery of biodegradable waste intuitively appears to be environmentally sound. However, this assumption in favour of biological waste management is not easy to justify objectively, owing both to the choice of comparison criteria to consider and to the valuation of these criteria. The work presented here aimed at gathering the basic data necessary to perform global environmental assessments (like life cycle analysis) of biological waste treatment. As much as possible, all potential impact categories, along with all different stages of treatment were taken into account, including the stage following land application. The study consisted, firstly in collecting in literature obtainable data on the consumption and rejects of matter and energy associated to this different stages, and secondly in compiling the data retained for each impact factor in a form directly useable in environmental assessment tools. Globally, considering the huge sensitiveness of impact factors to the nature of substrates and to the treatment and background conditions (temperature, soil type), the available data appear to be much too scarce, both in term of on-site data acquisition and of the understanding of the underlying mechanisms.