Enhancing nutrient recovery from food waste anaerobic digestate

James O'Connor; Bede S Mickan; Sun K Gurung; Kadambot H M Siddique; Matthias Leopold; Nanthi S Bolan

doi:10.1016/j.biortech.2023.129869

Enhancing nutrient recovery from food waste anaerobic digestate

Bioresour Technol. 2023 Dec:390:129869. doi: 10.1016/j.biortech.2023.129869. Epub 2023 Oct 14.

Authors

James O'Connor¹, Bede S Mickan², Sun K Gurung³, Kadambot H M Siddique³, Matthias Leopold³, Nanthi S Bolan⁴

Affiliations

¹ UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009, Australia; Cooperative Research Centre for High Performance Soil, Newcastle, Callaghan, NSW, 2308, Australia; The UWA Institute of Agriculture, The University of Western Australia, Perth, WA 6001, Australia. Electronic address: james.oconnor@research.uwa.edu.au.
² UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009, Australia; The UWA Institute of Agriculture, The University of Western Australia, Perth, WA 6001, Australia; Richgro Garden Products, 203 Acourt Rd, Jandakot, WA 6164, Australia.
³ UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009, Australia; The UWA Institute of Agriculture, The University of Western Australia, Perth, WA 6001, Australia.
⁴ UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009, Australia; Cooperative Research Centre for High Performance Soil, Newcastle, Callaghan, NSW, 2308, Australia; The UWA Institute of Agriculture, The University of Western Australia, Perth, WA 6001, Australia.

PMID: 37844804
DOI: 10.1016/j.biortech.2023.129869

Abstract

The study synthesised the raw liquid fraction of digestate into a nutrient rich solid digestate through acidification whilst preventing nitrogen loss through ammonium volatilisation during evaporation. To stabilise ammonium in the digestate, it was acidified with sulphuric, nitric, and phosphoric acid to produce solid digestate with ammonium sulphate, ammonium nitrate and ammonium phosphate, respectively. These treatments were compared against urea ammonium nitrate, raw digestate, and unacidified solid digestate. To evaluate the effect of these transformed digestate products in soil, a plant growth experiment (Kikuyu; Cenchrus clandestinus) was conducted, and characterised, plant growth, soil chemistry, and rhizosphere bacterial communities. Plant growth was enhanced by all digestate treatments compared to control and urea ammonium nitrate. Ammonium phosphate solid digestate plant growth was significantly higher than all other acidified treatments due to the high P content. Moreover, digestate-amended soil had elevated Proteobacteria and putative denitrification genes.

MeSH terms

Ammonium Compounds*
Anaerobiosis
Food
Nitrogen / chemistry
Nutrients
Refuse Disposal*
Soil / chemistry
Urea

Substances

ammonium phosphate
ammonium nitrate
urea nitrate
Soil
Nitrogen
Ammonium Compounds
Urea