home    about    browse    search    latest    help 
Login | Create Account

Effects of electrokinetic and ultrasonication pre-treatment and two-step anaerobic digestion of biowastes on the nitrogen fertiliser value by injection or surface banding to cereal crops

Nyang'au, Jared Onyango; Møller, Henrik Bjarne and Sørensen, Peter (2023) Effects of electrokinetic and ultrasonication pre-treatment and two-step anaerobic digestion of biowastes on the nitrogen fertiliser value by injection or surface banding to cereal crops. Journal of Environmental Management, 326, p. 116699.

[thumbnail of Nyang'au et al., 2023_Effects of electrokinetic and ultrasonication pre-treatment and two-step anaerobic digestion of biowastes on the nitrogen fertiliser value by injection or surface banding to cereal crops.pdf] PDF - Published Version - English
1MB


Summary

Biogas production from anaerobic digestion (AD) of biowastes is restricted by the recalcitrant nature of many
substrates, and this may also reduce the fertiliser value of the produced digestate. The degradability of substrates
can potentially be enhanced by physico-chemical pre-treatments before AD, and/or the degradation can be
increased by a longer digestion time. In this study, we evaluated the effects of electrokinetic (high voltage) and
ultrasonication pre-treatments of biowastes in a two-step AD process on nitrogen fertiliser replacement value
(NFRV) of digestates obtained from two biogas plants with contrasting hydraulic retention time (HRT) in the
primary AD step. The fertiliser value was tested by direct injection to spring barley and surface-banding to winter
wheat, and the ammonium N was 15N-labelled to evaluate ammonia losses. The electrokinetic pre-treatment step
significantly (p < 0.05) increased the NH4+-N/total N in the digestates before the second AD step but had an
insignificant effect on the fertiliser value in winter wheat and spring barley. Ultrasonication pre-treatment had
also no significant effect on the fertiliser value. The two-step AD significantly (p < 0.001) increased 15N recoveries
and mineral fertiliser equivalence of labelled ammonium-N in winter wheat and reduced ammonia
losses, with a significant effect (p < 0.001) observed in digestates sourced from a shorter HRT biogas reactor. The
fertiliser equivalence of labelled ammonium-N in the digestates was 80–88% after injection, indicating relatively
low N immobilisation with all the digestates. NFRV in the crops was mainly explained by the NH4+-N/total N
ratio, C/N ratio and dry matter content of the digestates. The findings suggest that electrokinetic and ultrasonication
pre-treatments combined with a second AD step have no considerable impact on the fertiliser value of
digestates, whereas a second AD step significantly reduced ammonia losses after application by surface-banding
in winter wheat.


EPrint Type:Journal paper
Agrovoc keywords:
Language
Value
URI
English
fertilisers -> fertilizers
http://aims.fao.org/aos/agrovoc/c_2867
English
biogas
http://aims.fao.org/aos/agrovoc/c_9262
English
manure management
http://aims.fao.org/aos/agrovoc/c_2ed1deb4
English
manures (fertilizers) -> organic fertilizers
http://aims.fao.org/aos/agrovoc/c_4592
Subjects: Crop husbandry > Composting and manuring
Environmental aspects > Air and water emissions
Research affiliation: Denmark > AU - Aarhus University > Faculty of Science and Technology > Department of Agroecology
Denmark > Organic RDD 6 > Fertihood
Horizon Europe or H2020 Grant Agreement Number:860127
ISSN:03014797
DOI:10.1016/j.jenvman.2022.116699
Deposited By: Sørensen, Senior scientist Peter
ID Code:45693
Deposited On:21 Mar 2023 09:12
Last Modified:21 Mar 2023 09:12
Document Language:English
Status:Published
Refereed:Peer-reviewed and accepted

Repository Staff Only: item control page

Downloads

Downloads per month over past year

View more statistics