FRONTSH1P_D5.4_LCA, s-LCA and LCC & main outcomes from CSS3

Deliverable D5.4 presents the sustainability assessment of Scenario 3.1 within Circular Systemic Solution 3 (CSS3), which focuses on the valorization of wastewater through a microalgae-based process. The assessment includes environmental, economic and social impact evaluations. Scenario 3.1 was compared against a conventional baseline scenario representing current wastewater treatment and disposal.

The Life Cycle Assessment results show that Scenario 3.1 significantly outperforms the baseline in most environmental impact categories. Notable improvements are observed in Abiotic Depletion – Fossil (–4.06 MJ vs +4.08 MJ), Global Warming Potential (0.33 kg CO₂ eq. vs 1.01 kg CO₂ eq.) and Acidification Potential (–3.72 × 10⁻³ kg SO₂ eq. vs 1.01 × 10⁻³ kg SO₂ eq.). Scenario 3.1 also yields net-negative results in eutrophication and ecotoxicity indicators, highlighting the system’s ability to reduce environmental burdens through the production of valuable bio-based outputs.

The Life Cycle Cost analysis reveals that, while the baseline incurs lower direct costs, Scenario 3.1 has the potential for long-term cost recovery through resource valorization. The main cost contributors in Scenario 3.1 are energy and input materials used in key stages such as harvesting and enzymatic hydrolysis.
The social Life Cycle Assessment evaluation indicates positive social performance for Scenario 3.1, particularly in relation to worker safety, job creation and technology development. Benefits are also observed for the local community and society at large, although minor gaps remain in areas such as certification uptake and public environmental engagement.

Overall, the results demonstrate that Scenario 3.1 offers a technically feasible and environmentally beneficial solution for wastewater treatment, with promising economic and social co-benefits. The findings support its potential scalability and contribution to sustainable regional transformation under the FRONTSH1P project.