Livestock manure and digestate treatment to reduce emissions and produce struvite

Designing and implementing a prototype, at farm-scale system, capable of recovering struvite from agricultural digestate

STRUVITE is addressing challenges related to emissions and nutrient recovery from agro-livestock digestate. They aim to produce treated fractions with reduced emissions of ammonia and greenhouse gases, particularly methane and nitrous oxide, compared to the initial digestate, during both storage and field application phases.

Their activities include laboratory analysis and testing to develop and implement a prototype treatment system for efficient recovery of nitrogen and phosphorus as struvite from the digestate. Results show technical feasibility in recovering phosphorus and nitrogen, although challenges remained due to the high concentration of solids and organic matter in the digestate.

Furthermore, the group monitors emissions from the field application of treated digestate fractions, finding reduced nitrogen emissions compared to the initial digestate due to depleted nitrogen content in the treated supernatant fraction and the presence of nitrogen and phosphorus in saline form (struvite) in the precipitated fraction.