Focus and challenges

Sustainable Nitrogen’s focus is on residues such as livestock slurries, AD digestates, waste water treatment slurries and landfill leachates. 

Sustainable Nitrogen will investigate how technologies can be developed, adapted and integrated into energy and nutrient recovery systems to mitigate the environmental impact arising on disposal of these difficult ammoniacal waste/residue streams.  

Methodologies and objectives

Sustainable Nitrogen will leverage results from previous research by tcbb RESOURCE to scale-up a method for efficient separation of solids from ammoniacal slurry/sludge streams, sufficiently clarifying the liquor filtrates to a standard that:
(i) facilitates downstream nitrogen (N) (and other contaminant) recovery, and
(ii) de-waters solids to facilitate cost-effective supply for centralised (optimal) energy/nutrient recovery. 

Sustainable Nitrogen will investigate specific technology adaptations required to optimise energy recovery from nitrogen-charged solids via anaerobic digestion (AD) or advanced thermal technologies and will investigate measures required to convert recovered nitrogen and phosphorus (P) into safe, saleable fertilisers, ideally in forms that mitigate loss and environmental impact when recycled back to land.

Sustainable Nitrogen will review methods for recovery of residual nitrogen from filtrate liquors, facilitating nutrient recycling and rendering the effluents to a standard that minimises environmental impact on discharge. It will investigate how these technologies can also be adapted to remove chemical or other contaminants, facilitating deployment for processing a wider variety of waste streams.

Business models and commercial frameworks

Sustainable Nitrogen will outline the business models and commercial frameworks required to underpin commercial deployment, reducing the cost and mitigating environmental impact of waste/ residue management, to make measurable contributions to Water Quality Framework, Air Quality Framework and 2030 Energy and Climate Change Framework objectives.

The system can potentially mobilise some of Ireland’s largest available low-cost (no-cost) biomass resources to contribute towards energy de-carbonisation, as well as treating the waste streams to mitigate atmospheric/water/greenhouse gases emissions that otherwise arise from current disposal methods.

The collaboration

Sustainable Nitrogen is a collaboration between tcbb RESOURCE and NUI Galway’s Dept. of Microbiology (Prof. Vincent O'Flaherty's Microbial Ecology Lab, affiliated to the Ryan Institute), and supported by research funding from Ireland’s Environmental Protection Agency (EPA).

The roadmap

Sustainable Nitrogen will pursue a route to identify pressures on the environment and on policy, to inform policy, and to develop solutions. A visualisation of this roadmap is available to download from here:

Keywords:
Waste water, nutrient removal, landfill leachate, advanced thermal technologies, anaerobic digestion, fertiliser, filtration, nitrification, ammonia, greenhouse gas emissions 

Follow the journey

Follow the Sustainable Nitrogen journey here and on Twitter @SustainableNn