Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2025
Forfattere
Begüm Bilgiç Judit Sandquist Svein Jarle Horn Lu Feng Cecilie Græsholt Asmira Delic Roger Antoine Khalil Michal SposobSammendrag
Digestate, a key byproduct of anaerobic digestion (AD), holds residual methane potential (RMP) that must be stabilized or recovered to prevent greenhouse gas emissions after field use. Thermal hydrolysis (TH), typically a pretreatment for AD, improves biogas production. This study assesses RMP in digestates from food waste (FW) and sewage sludge (SS) biogas plants, treated with TH at 160 and 190 °C. For the liquid fraction, FW digestate at 160 °C yielded 1.5 times more methane than untreated digestate, while SS digestate showed a threefold increase. The solid fraction of FW digestate at 160 °C had 1.4 times higher methane yield than untreated, but SS digestate produced less methane after TH. Adding sulfuric acid after TH increased phosphate release but reduced methane production in both digestates. Overall, TH as a post-treatment enhanced organic content release into the liquid fraction, enhancing methane yield, while acid addition improved phosphorus solubility, thereby enhancing digestate's nutrient value.
Sammendrag
Upgrading biogas to biomethane could contribute to sustainable energy production, yet H2S may reduce the process efficiency and gas quality. This work examined the impact of H2S on biomethanation in batch assays and in continuous trickle bed reactor (TBR). The batch assay (not biofilm based) was conducted to quickly determine the threshold H2S concentration and to evaluate the inoculum's response to repeated H2S exposure. In contrast, the TBR experiment aimed to explore the role of biofilm-based biomethanation in mitigating H2S inhibition. Batch assays revealed significant inhibition, especially at higher H2S concentrations (3 %) and thermophilic temperatures (51 °C). In the batch assay, presence of H2S resulted in up to 30 % reduction in CH4 yield, decreasing from 229 to 160 NmL/Lreactor. Additionally, the CH4 content declined by 12 %, from 49 to 43 %. In contrast, TBRs showed resilience where TBRs fed with H2S-rich biogas produced effluent gas with 83.5 % CH4, similar to control (81.0 %). 16S rRNA analysis highlighted shifts toward sulphate reducing and sulphur oxidizing bacteria under H2S exposure, while acetogenic and syntrophic acetate-oxidizing bacteria increased in the control. This suggests potential competition for available substrates when subjected to H2S. These findings highlight that H2S significantly inhibits non-biofilm-based biomethanation, as seen in batch assays, although moderate acclimation was observed. However, biofilm-based process, e.g TBRs, effectively mitigate H2S toxicity, ensuring efficient biogas upgrading to biomethane.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Sweet cherry fruit in Norway is sold to the domestic market for fresh consumption. Gradually the self-fertile and high yielding cultivar ‘Lapins’ has become dominant and in the 2024 season, cv. Lapins made up 60% of the total sweet cherry volume. The production of sweet cherry in Norway is located around three main packinghouses with minor to no differences in ripening time dependent on the weather conditions of the year. Situations with too much fruit on the market at the same time have been experienced, and fruit with a longer possible distribution time have been demanded from the packinghouses. In postharvest experiments, deliveries to the same packinghouse the same day exposed to exactly the same treatments were compared and differed in fungal decay from less than 5% to 60% after simulated shelf life. The dominating fungal decay was Mucor rot and grey mold. The risk of fungal decay pre- and postharvest on fruit grown in a humid climate (500 to 1700 mm annual precipitation) increases with high humidity under the plastic cover, with fruit-to-fruit contact in clusters, with incidence of non-developing or damaged fruit, and with minimal effect of the plant protection program. In order to improve the market situation in Norway, postharvest treatments alone are probably not enough. A holistic approach is needed through introduction of new cultivars with high yield potential that ripen over a longer period of time and are thoroughly tested in real scale experiments simulating distribution. A major challenge will be how to motivate growers to plant cultivars with potentially less income than possible with the self-fertile, high yielding cv. ‘Lapins’.
Sammendrag
Sweet cherries are grown in areas with suitable local climatic conditions up to 60°N in Norway. All orchards have high density planting systems and are rain covered. The most common system now is multibay high tunnels systems where the trees are under plastic cover from the bloom to the end of the harvest. All orchards are fertigated and the production is aimed to supply the fresh fruit domestic market with high quality fruit from early July and to the end of August. At NIBIO Ullensvang, western Norway a large number of sweet cherry cultivars and advanced selections from worldwide breeding programmes have been evaluated continuously since 1959 and several cultivars have been recommended from this programme for commercial production during the last decades. During the last six years approximately fifty cultivars and advanced selections grafted on the rootstock Gisela 6 have been tested. Important objectives were to obtain large and precocious yields, with important quality parameters like fruit size, fruit firmness, soluble solids, fresh appearance, good flavour and resistance against irrigation induced cracking. Based on the results from the recent testing program, the following cultivars are currently recommended for the fresh fruit market: a) for early season: ‘Adelka’, ‘Pacific Red’, ‘Sweet Aryana’ and ‘Bellise’, b) for mid-season: ‘Brooks’, ‘Giant Red’, ‘Grace Star’ and ‘Folfer’ c) for late season: ‘Van’, ,’SPC 342’, ‘LaLa Star’, Royal Edie’, ‘Tamara’ ‘Lapins’, ‘Royal Helen’, ‘Regina’ and ‘Sweetheart’.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Injeong Kim Lone Ross Gry Alfredsen Olov Karlsson Elif Kaynak Oisik Das Dennis Jones George I. Mantanis Dick SandbergSammendrag
Scots pine (Pinus sylvestris L.) sapwood was modified using maleic anhydride (MA) and sodium hypophosphite (SHP) to improve its durability against wood-deteriorating fungi, mechanical strength, and fire retardancy (thermal stability). The modification significantly reduced mass loss caused by wood-decaying fungi (Trametes versicolor, Rhodonia placenta, and soft rot fungi) due to the formation of cross-links between wood, MA, and SHP, which limited the moisture uptake and altered the chemical structure of wood. On the other hand, the modification did not provide improved resistance to fungi growth on the wood surface, which indicated that the modification had little impact on the accessibility of nutrients on the surface. A bending test showed that the modulus of elasticity (MOE) was not affected by the treatment, whilst the modulus of rupture (MOR) decreased to half the value of untreated wood. Thermal resistance was improved, as demonstrated by micro-scale combustion calorimeter testing, where the total heat release was halved, and the residue percentage nearly doubled. These results indicate that phosphonate protects the modified wood via the formation of a protective char layer on the surface and the formation of radical moieties. Based on the results, wood modified with MA and SHP shows potential for possible use in outdoor, non-loadbearing structures.
Forfattere
Gunnhild Jaastad Ingunn Øvsthus Trude Magnussen Erik J. Joner Pierre-Adrien Rivier Ivar Pettersen Jorunn Børve Tage ThorstensenSammendrag
Det er ikke registrert sammendrag
Forfattere
Gunnhild JaastadSammendrag
Det er ikke registrert sammendrag
Forfattere
Gunnhild JaastadSammendrag
Det er ikke registrert sammendrag