Life Cycle Assessment for Circular Waste and Wastewater Treatment

Dear Colleagues,

Cities and industries are currently pivoting from the linear disposal of waste to circular waste-to-resource systems grounded in bioeconomy principles. Life cycle thinking supplies the much-needed system view—linking collection, sorting, conversion, use, and end-of-life—to reveal trade-offs in environmental performance, resource efficiency, costs, and social aspects.

This Special Issue therefore welcomes studies applying life cycle assessment (LCA), life cycle costing (LCC), social LCA (S-LCA), or integrated life cycle sustainability assessment (LCSA) to evaluate, compare, and improve circular pathways across biochemical (e.g., fermentation, anaerobic digestion, and enzymatic routes) and thermochemical platforms (e.g., pyrolysis, gasification, and hydrothermal processes). We particularly encourage work on valorizing organic wastes (OFMSW, sewage sludge, agro-industrial residues, seaweed, and digestate) and wastewater, as well as transforming inorganic and gaseous streams—CO₂, CO/H₂ syngas, and industrial or biogenic off-gases—into bio-based intermediates and products. Topics of interest include CO₂ utilization and carbon capture and use (CCU), power-to-biochemicals, and syngas fermentation/upgrading yielding marketable outputs (e.g., methanol, ethanol, higher alcohols, formic acid, urea, dimethyl ether, dimethylamine, organic acids, and platform chemicals).

Rigorous investigations should cover multifunctionality, CCU carbon accounting (temporal/geographical), uncertainty/sensitivity, scalability (lab–pilot–full), and spatial/temporal dynamics. We also welcome dredged-sediment bioremediation within circular strategies (co-treatment with organic residues and beneficial reuse) assessed by life cycle tools. Submissions must ensure clear functional units and boundaries, transparent inventories, justified allocation, and uncertainty analyses.

Representative topics include VFA platforms; PHAs; nutrient recovery (N/P/K) from waste and wastewater; wastewater treatment in a circular economy perspective; biogas/biomethane upgrading; solvent/chemical recycling of bio-based materials; hybrid bio–electro systems; thermochemical oils/char/syngas with biological/catalytic upgrading; and sediment bioremediation (biopiles and bio-electro-kinetic trains). Preference will be given to studies with pilot-/full-scale evidence, decision-support relevance, and open data/coding.

Dr. Alessio Castagnoli
Dr. Francesca Demichelis
Dr. Matia Mainardis
Guest Editors

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