| Title |
Nutrient challenges with solid-phase anaerobic digestate as a peat substitute-Storage decreased ammonium toxicity but increased phosphorus availability |
| ID_Doc |
6601 |
| Authors |
Caspersen, S; Oskarsson, C; Asp, H |
| Title |
Nutrient challenges with solid-phase anaerobic digestate as a peat substitute-Storage decreased ammonium toxicity but increased phosphorus availability |
| Year |
2023 |
| Published |
|
| DOI |
10.1016/j.wasman.2023.04.032 |
| Abstract |
The solid fraction (SD) obtained after liquid - solid separation of anaerobic digestate is interesting as a potential fertilizer as well as a peat substitute in horticultural growing substrates. We investigated the effect of incubation of the SD obtained by screw-press separation of digestate produced from food waste and plant residues on potentially plant available mineral nutrients and plant growth. The NH4-N concentration was initially > 1000 mg L-1 but rapidly decreased, probably due to NH3 emission promoted by a high initial pH. No nitrate was detected during the first four weeks of incubation. The concentrations of potentially available P and Mg were closely related and strongly increased during incubation. The effect of adding 20 or 30 vol% of SD to a peat-based growing substrate on the growth of basil and lettuce was investigated before and after the incubation period. With the unincubated SD, the initial substrate NH4-N of 200-300 mg L-1 was potentially phytotoxic. Plant growth response ranged from inhibition to stimulation, probably reflecting variation in substrate ammonium status. After 96 days of incubation, ammonium concentrations had decreased with > 50% and basil growth was generally positively affected by addition of incubated SD. However, available P concentrations of 140-210 mg L-1 in the incubated substrates posed a high risk of P leakage. In conclusion, storage greatly reduced NH4-N con-centrations and phytotoxicity when the SD was used as a partial substituent for peat in a horticultural growing substrate. Measures are needed, however, to limit available P concentrations in high-P solid digestate fractions. |
| Author Keywords |
Available nutrients; Biogas effluent; CAT-extraction; Circular economy; Growing media; Lactuca sativa; Ocimum basilicum |
| Index Keywords |
Index Keywords |
| Document Type |
Other |
| Open Access |
Open Access |
| Source |
Science Citation Index Expanded (SCI-EXPANDED) |
| EID |
WOS:000990134900001 |
| WoS Category |
Engineering, Environmental; Environmental Sciences |
| Research Area |
Engineering; Environmental Sciences & Ecology |
| PDF |
https://doi.org/10.1016/j.wasman.2023.04.032
|