Comparative Life Cycle Assessment (LCA) of Two On-Site Small-Scale Activated Sludge Total Oxidation Systems in Plastic and Vibrated Reinforced Concrete

This study proposes a comparison of the environmental impacts calculated with the Life Cycle Assessment (LCA) methodology of two on-site small-scale activated sludge total oxidation systems in linear low-density polyethylene (LLDPE) and vibrated reinforced concrete (VRC). The plants were designed to ensure a treatment capacity of 5, 10, 20 and 30 equivalent inhabitants (PE). The main aim of the study was to evaluate the incidence of construction, disposal and operation phases on the total impacts evaluated with three different methods: ReCiPe 2008, Ecological Footprint and IPCC 2007 100 years. The most significant phase for both treatment lines was the use phase, which contributed more than 80% to the total impacts. The construction phase was the second most impactful phase with an incidence less than 25% for both systems and for all the considered impacts assessment methods. The plant in LLDPE was more eco-friendly than that in (VRC). The plant in VRC was always most impactful, even comparing each single phase of the life cycle and for all the treatment capacities taken into consideration. Finally, the obtained results were not dependent on the impact assessment method considered.