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.
Forfattere
Gunnhild Jaastad Ingunn Øvsthus Trude Magnussen Erik J. Joner Pierre-Adrien Rivier Ivar Pettersen Jorunn Børve Tage ThorstensenSammendrag
Det er ikke registrert sammendrag
Sammendrag
Since the 1950s, the use of plastics in agriculture has helped solving many challenges related to food production, while its persistence and mismanagement has led to the plastic pollution we face today. A variety of biodegradable plastic products have thus been marketed, with the aim to solve plastic pollution through complete degradation after use. But the environmental conditions for rapid and complete degradation are not necessarily fulfilled, and the possibility that biodegradable plastics may also contribute to plastic pollution must be evaluated. A two-year field experiment with biodegradable mulches (BDMs) based on polybutylene adipate terephthalate (PBAT/starch and PBAT/polylactic acid) buried in several agricultural soils in mesh bags showed that also under colder climatic conditions does degradation occur, involving fragmentation after two months and depolymerization by hydrolysis, as shown by Fourier-transform infrared spectroscopy. The phytopathogenic fungus Rhizoctonia solani was found to be associated with BDM degradation, and the formation of biodegradable microplastics was observed throughout the experimental period. Between 52 and 93 % of the original BDM mass was recovered after two years, suggesting that accumulation is likely to happen in cold climatic regions when BDM is repeatedly used every year. Mass loss followed negative quadratic functions, implying increasing mass loss rates over time. Despite the range of climatic and edaphic factors, with various agricultural practices and vegetable productions at the study locations, the parameters that significantly favored in situ BDM degradation were higher soil organic matter content and temperatures.
Forfattere
Jonas Schmidinger Sebastian Vogel Viacheslav Barkov Anh-Duy Pham Robin Gebbers Hamed Tavakoli Jose Correa Tiago R. Tavares Patrick Filippi Edward J. Jones Vojtech Lukas Eric Boenecke Joerg Ruehlmann Ingmar Schroeter Eckart Kramer Stefan Paetzold Masakazu Kodaira Alexandre M.J.-C. Wadoux Luca Bragazza Konrad Metzger Jingyi Huang Domingos S.M. Valente Jose L. Safanelli Eduardo L. Bottega Ricardo S.D. Dalmolin Csilla Farkas Alexander Steiger Taciara Z. Horst Leonardo Ramirez-Lopez Thomas Scholten Felix Stumpf Pablo Rosso Marcelo M. Costa Rodrigo S. Zandonadi Johanna Wetterlind Martin AtzmuellerSammendrag
Digital soil mapping (DSM) relies on a broad pool of statistical methods, yet determining the optimal method for a given context remains challenging and contentious. Benchmarking studies on multiple datasets are needed to reveal strengths and limitations of commonly used methods. Existing DSM studies usually rely on a single dataset with restricted access, leading to incomplete and potentially misleading conclusions. To address these issues, we introduce an open-access dataset collection called Precision Liming Soil Datasets (LimeSoDa). LimeSoDa consists of 31 field- and farm-scale datasets from various countries. Each dataset has three target soil properties: (1) soil organic matter or soil organic carbon, (2) clay content and (3) pH, alongside a set of features. Features are dataset-specific and were obtained by optical spectroscopy, proximal- and remote soil sensing. All datasets were aligned to a tabular format and are ready-to-use for modeling. We demonstrated the use of LimeSoDa for benchmarking by comparing the predictive performance of four learning algorithms across all datasets. This comparison included multiple linear regression (MLR), support vector regression (SVR), categorical boosting (CatBoost) and random forest (RF). The results showed that although no single algorithm was universally superior, certain algorithms performed better in specific contexts. MLR and SVR performed better on high-dimensional spectral datasets, likely due to better compatibility with principal components. In contrast, CatBoost and RF exhibited considerably better performances when applied to datasets with a moderate number (<20) of features. These benchmarking results illustrate that the performance of statistical methods can be highly context-dependent. LimeSoDa therefore provides an important resource for improving the development and evaluation of statistical methods in DSM.
Forfattere
Belchior Oliveira Trigueiro da Silva Ademir De Oliveira Ferreira Rattan Lal Thiago Inagaki Telmo Jorge Carneiro Amado João Carlos De Moraes Sá Edivan Rodrigues de Souza Aline Roma Tomaz William Ramos da Silva Felipe José Cury FracettoSammendrag
Frequent and intensive tillage in conventional agriculture disrupts soil aggregates, engendering significant depletion of soil organic carbon (SOC) stocks. Long-term studies are essential for assessing the impact of sustainable practices on aggregate dynamics and carbon sequestration in sugarcane monocropping in tropical ecosystems. The following hypothesis was first, conventional sugarcane management would degrade soil, thereby reducing C stocks and breaking down aggregates. Second, conservation management that involves reduced disturbance could restore C storage, reaching levels similar to those observed in native vegetation (NV) over time. Third, macroaggregation could be a key mechanism for C storage under conservation management. This study evaluated the distribution of SOC among distinct aggregate classes under conventional (CC) and minimum (MC) cultivation in a 60-year-old sugarcane system, comparing results with undisturbed NV. The monitored properties included aggregate mass, SOC content and stock, weighted average diameter (WAD), aggregate and C stability indexes (ASI and CSI), soil C–CO2 emissions, and C preservation capacity (CPC). The long-term CC had a significant impact on aggregate dynamics, manifesting in a reduction in macroaggregate mass and SOC content, an increase in CO2 emissions, and a decrease in CPC. While the total SOC stock remained comparable in NV and MC (76 Mg C ha−1), CC led to a 20% SOC loss. Although CC led to an increase in microaggregate C, it failed to counterbalance the loss of macroaggregate C. The ASI, with a reliability of approximately 99% in NV, exhibited a decline of 1% at 10 cm and 2% at 20 cm under MC and CC conditions. Concurrently, WAD reduced by 16% at 10 cm. CSI exhibited higher levels in NV and MC compared to CC at 10 cm depth. CPC in large macroaggregates was highest in NV (21 g kg−1), decreasing by 50% in CC (7 g kg−1) and by 33% in MC (14 g kg−1). At a depth of 20 cm, large macroaggregate mass was 28% lower in CC and 14% lower in MC compared to NV, resulting in a 29% and 21% reduction in macroaggregate C stock, respectively. In summary, the application of MC resulted in the preservation of SOC stocks at levels comparable to those observed in NV, thereby underscoring its capacity to maintain crop sustainability and augment carbon sequestration in tropical sugarcane systems.
Forfattere
Valentina Sierra-Jimenez Robert J. Macias Jonathan P. Mathews Vincent Carre Sébastien Leclerc Alice Budai Farid Chejne Jimena Castro-Gutierrez Alain Celzard Vanessa Fierro Manuel Garcia-PerezSammendrag
This study investigates optimal carbonization conditions for biochar production, focusing on pressure and acid pretreatments to maximize carbon yield and enhance biochar functionality. Over thirty combinations of pressure and acid type were tested, including organic acids (CH3COOH and HCOOH) and inorganic acids (H3PO4 and H2SO4), using hybrid poplar wood as feedstock. The results show that carbon conversion efficiencies up to 72 wt % were achieved with organic acids under pressures ≥ 20 bar. Inorganic acids produced biochar doped with phosphorus (P) and sulfur (S), demonstrating the potential for customizing biochar properties to specific applications. To understand biochar transformations at the molecular level, we employed a range of advanced characterization techniques, such as solid-state 13C NMR, ICP-OES, XPS, BPCA, LDI FT-ICRMS, and ESR, as well as 3D atomistic modeling of up to 13,000 atoms. These methods revealed how pressure and acid pretreatments influence the chemical composition, porosity, and atomistic structure of the resulting biochar. The study provides valuable insights into the relationship between processing conditions and biochar properties, demonstrating that optimized carbonization processes can improve production efficiency and reduce biomass requirements. This scalable approach offers significant potential for reducing carbon emissions and makes biochar a promising material for carbon storage, soil amendment, and other environmental applications.
Forfattere
Alice BudaiSammendrag
Det er ikke registrert sammendrag
Forfattere
Karen Ane Frøyland Skjennum Thomas Hartnik Gijs D. Breedveld Erlend Grenager Sørmo Jan MulderSammendrag
Per- and polyfluoroalkyl substances (PFAS) pose significant environmental and human hazards due to their resistance towards natural degradation. Anthropogenic activities have resulted in worldwide spreading of PFAS, and soil remediation of PFAS is challenging due to its persistent and mobile nature. Amendment with commercial activated carbon (AC) of fossil origin is one of the preferred immobilization strategies for contaminated soil. However, waste-based sorbents may represent a greener alternative to AC. Here, we review the status and potential for the use of waste-based materials as PFAS sorbents in soil remediation. Key properties in the search of candidate materials are discussed, followed by an overview of potential sorbents. The materials reviewed are bark, protein-rich waste, chitosan, amine-modified waste, compost, biosolids, biochar produced from waste-based substrates, and a selection of industrial waste, notably bottom- and fly ash, char and slag. Performance and sorption behavior of these materials are compared for long- and short-chain PFAS, and their applicability is further discussed. Besides great sorption capacity and affinity, promising amendments combine high abundance, low cost, a potential for modification and low risk. Biochar emerges as the most mature and promising candidate of the materials reviewed. Other waste-based materials also show great PFAS sorption capacities, but their performances in soil have not been properly assessed. Besides sorption studies in environmentally relevant matrices, upscaling and long-term studies are needed to further examine the potential use of waste-based sorbents in remediation of PFAS contaminated soil.
Sammendrag
Det er ikke registrert sammendrag