Obtención de núcleos de granulación para la transición eficiente de sistemas de lodos activados a lodos aerobios granulares en plantas de tratamiento convencionales de Costa Rica

The implementation of Aerobic Granular Sludge (AGS) technology is among the most promising strategies for wastewater treatment due to its superior efficiency, excellent settleability, and high biomass retention. However, its large-scale application is limited by long maturation times, sensitivity to hydrodynamic disturbances, and dependence on strict operational conditions.
This project aims to obtain pre-formed granulation nuclei to enable an efficient transition from conventional activated sludge systems to aerobic granular sludge in wastewater treatment plants, promoting, under specific operational conditions, the rapid proliferation of microcolonies of polyphosphate-accumulating organisms (PAOs) and the consolidation of functional granules. The strategy focuses on using a carbon-based structure modified with divalent cations and revalorising agricultural residues, such as sugarcane leaves, to synthesise biochar through controlled pyrolysis. The use of sugarcane leaves as an abundant, low-cost raw material follows the principles of the circular economy.
These granulation nuclei will be modified with calcium, providing an essential structural anchoring mechanism for granule formation by reducing electrostatic repulsion at the cellular interface and facilitating the production of extracellular polymeric substances (EPS), thereby strengthening cell cohesion and the structural integrity of the granule. At the same time, these nuclei will be developed under substrate-based metabolic selection using propionate, which favours PAO metabolic pathways that enhance competitiveness and storage capacity, promoting the formation of dense microcolonies.
The experimental section will evaluate mechanisms of action and operational effectiveness through comparative SBR assays and monitoring of physicochemical variables, operational indices, and biological markers. The success criterion will be a significant reduction in maturation time and improved stability under load shocks, providing a replicable “seed” protocol transferable to conventional treatment plants and thereby reducing technological barriers to the implementation of AGS in municipal contexts.

Evaluar el efecto de núcleos de biocarbón modificados con calcio y bioactivados en la aceleración de la transición a sistemas de lodos granulares aeróbicos en plantas de tratamiento de aguas residuales.

1. Soluciones de ingeniería ambiental para el desarrollo sostenible