Ex–ante LCA for circular resource management of liquid digestate, by predictive modeling of algae–bacterial processes

Diego Penaranda, Francesca Casagli, Marjorie Morales, Fabrice Beline and Olivier Bernard

Journal of Industrial Ecology, 2025, vol. 29, issue 5, 1568-1582

Abstract: The simplest method for treating liquid digestate, which involves directly spreading it over local agricultural land, is facing scrutiny due to the challenges of transporting large volumes and the environmental risks posed by nitrogen and phosphorus pollutants. Improvements in liquid digestate treatment are necessary to mitigate these threats and support a growing circular economy. This study evaluates an advanced digestate treatment method that decouples hydraulic retention time (HRT) and solid retention time (SRT) in high‐rate algal/bacterial ponds (HRABPs). By combining life cycle assessment (LCA) with high‐fidelity modeling for HRABPs, this study simulates productivity and removal efficiencies under realistic climatological conditions, providing life cycle inventories for numerous large‐scale scenarios. To minimize environmental impacts while maximizing algal productivity and nitrogen intake in the algal biomass, 36 scenarios were simulated, considering different HRT, SRT, alkalinity addition, winter storage, and biomass post‐treatment hypotheses. The results demonstrate that microalgae treatment makes sense for valorizing liquid digestate, proving to be less impactful than direct land application. However, the LCA results also highlight the complexity of the issue. Low HRT (HRT = 5 days > SRT = 15 days) achieves the highest efficiency in nitrogen and phosphorus recycling but necessitates large production areas, leading to high environmental impacts. Mathematical modeling, coupled with LCA, can resolve these trade‐offs and guide the optimization and scaling‐up of climatology‐dependent systems.

Date: 2025
References: Add references at CitEc
Citations:

Downloads: (external link)
https://doi.org/10.1111/jiec.70050

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:bla:inecol:v:29:y:2025:i:5:p:1568-1582

Ordering information: This journal article can be ordered from
http://www.blackwell ... bs.asp?ref=1088-1980

Access Statistics for this article

Journal of Industrial Ecology is currently edited by Reid Lifset

More articles in Journal of Industrial Ecology from Yale University
Bibliographic data for series maintained by Wiley Content Delivery ().