A methodological proposal for the valuation in LCA applied to the biowastes management in Barcelona

A comparative LCA is made to valuate the environmental implications of six scenarios of biowastes management in Barcelona, one of them consists of a traditional controlled landfill, in which the 54% of biowaste is disposed directly without any previous treatment, for the rest of the scenarios, a controlled landfill by rectangular baling-wrapping technology is considered. Then the consumption of energy, water, land used and, air and water emissions were quantified in the inventory and the software TRACI was used to classify and to characterize the impacts. In the other side, a new method is established for the valuation of LCA based in Multi-attribute Value Theory (MAVT). In view of the fact that the impact categories are not relevant enough for a determined zone, we had to resort to the theory of fuzzy sub-sets in order to generate an index for each scenario. The results demonstrate that worse option for the biowaste management is the scenario where a conventional sanitary landfill is considered. The valuation within LCA through the proposed methodology responds, on one hand, to the consideration of subjective aspects, and, on the other hand, to the inclusion of subjective elements treated through the theory of fuzzy sub-sets.