Nitrogen availability in digestates from full-scale biogas plants following soil application as affected by operation parameters and input feedstocks

TY - JOUR

T1 - Nitrogen availability in digestates from full-scale biogas plants following soil application as affected by operation parameters and input feedstocks

AU - Nyangáu, Jared Onyango

AU - Sørensen, Peter

AU - Møller, Henrik Bjarne

PY - 2023/12

Y1 - 2023/12

N2 - Biogas operation parameters are usually optimised to enhance biogas yields while ignoring digestate quality. This study evaluated the effects of varying operation parameters and input feedstocks used in co-digestion with manure on digestate properties and N turnover in soil for 80 days. Net inorganic N release (% of N input) from digestates varied significantly (p < 0.001) due to their contrasting properties. Temperature, hydraulic retention time (HRT), manure type and input feedstocks significantly influenced soil inorganic N release. Animal slurry co-digested with energy crops had the highest average net soil inorganic N release at 67 %, while co-digestion with straw-based feedstock had the lowest at 56 %. Feedstock type greatly influenced the choice of digesting temperature and HRT, with most energy crop-based feedstocks digested at <50 days HRT. Digestate properties NH4+ -N/total N, C/N and total carbon concentration significantly influenced net inorganic N release in soil. A better understanding of the effects of biogas operation variables on nutrient availability and digestate fertilising properties could help design and optimise the anaerobic digestion process to increase biogas yields and N fertiliser value of the digestates.

AB - Biogas operation parameters are usually optimised to enhance biogas yields while ignoring digestate quality. This study evaluated the effects of varying operation parameters and input feedstocks used in co-digestion with manure on digestate properties and N turnover in soil for 80 days. Net inorganic N release (% of N input) from digestates varied significantly (p < 0.001) due to their contrasting properties. Temperature, hydraulic retention time (HRT), manure type and input feedstocks significantly influenced soil inorganic N release. Animal slurry co-digested with energy crops had the highest average net soil inorganic N release at 67 %, while co-digestion with straw-based feedstock had the lowest at 56 %. Feedstock type greatly influenced the choice of digesting temperature and HRT, with most energy crop-based feedstocks digested at <50 days HRT. Digestate properties NH4+ -N/total N, C/N and total carbon concentration significantly influenced net inorganic N release in soil. A better understanding of the effects of biogas operation variables on nutrient availability and digestate fertilising properties could help design and optimise the anaerobic digestion process to increase biogas yields and N fertiliser value of the digestates.

KW - Mineralisation

KW - Anaerobic digestion

KW - Fertiliser value

KW - optimisation

KW - Net inorganic N release

KW - Optimisation

UR - http://www.scopus.com/inward/record.url?scp=85175047293&partnerID=8YFLogxK

U2 - 10.1016/j.biteb.2023.101675

DO - 10.1016/j.biteb.2023.101675

M3 - Journal article

SN - 2589-014X

VL - 24

JO - Bioresource Technology Reports

JF - Bioresource Technology Reports

M1 - 101675

ER -