Carbon footprint of chlorination and photocatalytic tertiary wastewater treatments

¹ Department of Chemical Engineering, University of Balamand, 100 Tripoli, Lebanon
² Department of Industrial and Building Engineering, University of Lleida, 08700 Igualada, Spain
³ Aqualia, Lleida WWTP, Cami Sot de Fontanet, 29, 25197 Lleida, Spain
⁴ Department of Chemistry, Physics and Environmental and Soil Sciences (DQFAS), University of Lleida, 25198 Lleida, Spain

^* Corresponding author: Makram.Bachawati@balamand.edu.lb

Abstract

This study depicts a comparative carbon footprint analysis of two tertiary wastewater treatment methods: chlorination and photocatalytic. It integrates data from an extensive literature review and an on-site investigation conducted at the Aqualia plant in Spain. The analysis employed a Life Cycle Assessment (LCA) methodology using SimaPro software to assess the carbon footprint of each treatment method. Data was collected from various literature sources and the Aqualia plant. Results indicate that the chlorination process exhibits a lower carbon footprint than the photocatalytic process. Notably, the electricity requirements of the photocatalytic treatment contribute significantly to its higher carbon emissions. The literature review and the data collected from the Aqualia plant consistently support the finding that the energy-intensive nature of the photocatalytic process leads to more significant carbon emissions. Despite the higher treatment efficiency of the photocatalytic process, the analysis reveals that the chlorination process remains a more environmentally favorable choice regarding carbon footprint. The substantial electricity demand of the photocatalytic process offsets its efficiency benefits, resulting in higher carbon emissions. In conclusion, while photocatalytic treatment demonstrates superior wastewater treatment efficiency, a holistic consideration of environmental impacts is crucial. These insights provide valuable guidance for stakeholders in the wastewater treatment industry, supporting adopting sustainable practices that prioritize reducing carbon emissions.