Traitement des déchets industriels dans les fours à ciment ou les incinérateurs : une comparaison environnementale

7. Conclusion - How can the results be interpreted and how reliable are they?

This assessment concludes that the environmental performance of thermal treatment of all 5 types of industrial wastes in cement kilns is better compared to thermal treatment in waste incinerators. This is true for the vast majority of environmental impact categories considered. More...


7.1 Are certain environmental impacts more important than others?

Drawing conclusions from a Life Cycle Assessment requires subjective choices by decision makers in terms of priority setting.

What is more important: the preservation of our water resources or the preservation of the ozone layer? There is no objective answer to such a question. For each impact category, the unit of measurement is different (CO2 equivalents for global warming, phosphate equivalents for eutrophication…). Many impact categories are interlinked. Ecosystems for instance are affected not only by toxic effects, but also by climate change, and changes in ecosystems will in turn have effects on human health and so forth.

Currently, climate change is high on the political agenda and could potentially be given greater priority. For climate change and for many other environmental impacts, this assessment reaches the conclusion that the use of waste in cement production to replace petcoke and raw materials is the better option. The subjective decision on what importance to give to different environmental impacts must rest with the decision makers.

ISO 14044, the international standard that specifies requirements and provides guidelines for Life Cycle Assessment (LCA) allows weighing as a method to facilitate the interpretation of results. However it prohibits weighing if a comparative Life Cycle Assessment is directed to the general public, which is the case of the present summary. More...


7.2 How would the results change if the waste or process were slightly different?

To make sure the results are valid even if the characteristics or the wastes or process where slightly different, a sensitivity analysis was conducted. The variables tested took into account the comments expressed by the panel of experts.

It checked how results would change

This analysis revealed that results would change slightly for different impact categories, but that the overall conclusions would still hold.

These conclusions do not depend on the choice of impact assessment method either; as two different methods were used – CML and Eco-indicator 99 - which point in the same direction for all waste streams. More...

Les droits d’auteur de la Structure à Trois Niveaux utilisée pour communiquer cette analyse du cycle de vie appartiennent à GreenFacts asbl/vzw.