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.
2018
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Tingvoll Fisk AS og Tingvollost holder til Torjulvågen i Tingvoll kommune på Nordmøre. Tingvoll Fisk AS driver med landbasert oppdrett av rognkjeks (Cyclopterus lumpus) med planer om å utvide til havbasert påvekst etter hvert. Tingvollost produserer prisbelønt ost med melk fra egen gård og har lenge vurdert å bygge et biogassanlegg for behandling av husdyrgjødsel. Dette prosjektet undersøkte gjennom igjennomgang av litteratur og labforsøk aktuelle løsninger for oppsamling og separasjon av marint slam fra fiskeoppdrett og biogasspotensialet til sambehandling av marint slam fra rognkjeks, storfegjødsel fra melkekyr og okser og myse fra osteproduksjon. Litteraturstudien, gjennomførte av Tingvoll Fisk AS, konkulderte med at kombinasjonen semi-lukkede merder med en trakt laget av duk under til oppsamling av fiskeslam fra merdene; en såkalt Radial Flow Separator (RFS) for å sedimentere slammet; og geobags for å rense utspyllinga etter RFS er den mest kostnadseffektive og praktiske løsningen for oppsamling og separasjon av marint slam. NIBIO gjennomførte en biometanepotensiale (BMP) test og et reaktorforsøk med ulike blandinger av disse substratene for å vurdere biogasspotensialet og prosess stabilitet. BMP-testen viser at rent fiskeslam gir mest biogassog metanutbytte, men fra tidligere erfaring vet vi at rent fiskeslam kan være utfordrende på grunn av opphoping av flyktige fettsyrer (VFA) over tid. En blanding av 60% storfegjødsel og myse + 40% fiskeslam ga høyeste biogass- og metanutbytta av substratblandinger. I reaktorforsøket var det blandingen med 50% storfegjødsel og myse + 50% fiskeslam som hadde høyeste biogass- og metanutbytte, men viste tegn på prosessforstyrrelse (økende innhold av flyktige fettsyrer) etter kun to uker. Blandingen med 80% storfegjødsel og myse + 20% fiskeslam hadde mindre utbytte og fettsyrenivåene forble lavt i hele forsøksperioden selv om organisk belastningen lignet den andre blandingen. Husdyrgjødsel har en bufferevne som bidrar til å opprettholde prosess stabilitet. Metangassutbytte var tilsvarende BMP-testen til å begynne med, så avtok det etter 15 uker i alle fire reaktorer, spesielt de med 50% fiskeslam. Det er to mulige forklaringer: For det første, fiskeslam inneholder mye fett og protein, substrater som brytes ned til forholdsvis VFA og ammoniakk (ved høyere pH). Begge kan føre til inhibering i for store konsentrasjoner. I de to andre reaktorene med kun 20% fiskeslam kan det være på grunn av sulfat-innholdet i saltvannet. Sulfat-reduserende bakterier (SRB) både konkurrerer med metanogener for molekylær hydrogen og produserer svovlgass, som begge hindrer metanutbyttet. Biogasskulturen som ble brukt til å pode reaktorene er verken tilpasset et marint miljø eller høy fett og protein-innhold. Dette har også mye å si om ytelse og stabilitet. Konklusjonen er at sambehandling av husdyrgjødsel, myse og marint fiskeslam kan gi lønnsomt metanutbytte men at prosessen og mikrobene må tilpasses for å kunne håndtere sulfat fra sjøvannet og protein fra fiskeslammet hvis det skal være stabilt over tid.
Sammendrag
Four lab scale biogas reactors fed with a substrate composition of ensiled fish waste and manure fixed at 13 and 87 vol %, respectively, were operated with HRTs of 20, 25, 30 and 40 days. Biogas process performance and stability were evaluated with regard to CH4 yields, NH4+ accumulation and abundance of NH4+-tolerant microorganisms. Process performance in the reactors operated at different HRTs were compared to process performance in reactors operated with constant HRT, fed with increased ratios of fish waste. The process performance and microbial dynamics were stable in reactors operated at constant amount of fish waste in the feed and with different HRTs. In the reactors added elevated ratios of fish waste, the concentration of NH4+ and abundance of NH4+-tolerant acetate oxidizing bacteria increased. The biogas process failed in these reactors simultaneously with an observed shift in microbial composition. In particular, the bacterium Tepidanaerobacter Acetatoxydans seemed to affect the biogas process stability. The hydrogenotrophic Methanomicrobiales increased in abundance in response to higher fish waste loading and NH4+ concentrations. This study showed that at a loading of 13% fish waste, it is possible to decrease the HRT from 30 to 20 days without markedly inhibiting the process stability.
Sammendrag
Purpose: Due to environmental concerns, efforts are made to replace the use of peat in horticultural growth media by organic wastes. Four growth media were prepared with the purpose of achieving adequate physical and chemical properties for plant production. Materials and methods: Growth media prepared from mixtures of coir (C) and paper sludge (P), respectively, with two biogas digestates from food waste (D1 and D2), were tested. These mixtures, 20% D1 or D2 + 80% C or P (v/v), were evaluated as growth media for tomato (Solanum lycopersicum L.) and lettuce (Lactuca sativa L.). Results and conclusion: The growth media were all physically stable during the growing period, provided all the macronutrients and most of the micronutrients necessary for plant growth, adequate pH conditions, as well as an adequate electrical conductivity. The mixture of D2 and P produced the highest biomass compared to a mineral fertilised peat (control), with a biomass production of 76% of the control for lettuce and 54% for tomato. Causes for the biomass reduction relative to the control may be related to ammonium toxicity effects, and/or limited plant-available water. The digestates, particularly D1, seemed also to have a phytotoxic effect on the germination.
Forfattere
Merethe Kleiven Lisa Magdalena Rossbach Julian Alberto Gallego-Urrea Dag Anders Brede Deborah H Oughton Claire CoutrisSammendrag
Using Caenorhabditis elegans as a model organism, this study addresses the potential linkage between toxicity of NM300K Ag nanoparticles (AgNPs), their particle size distribution and the presence of dissolved Ag in the test media. Of the three endpoints assessed (growth, fertility and reproduction), reproduction was the most sensitive, with 50% effect concentration (EC50) ranging from 0.26-0.84 mg Ag L-1 and 0.08-0.11 mg Ag L-1 for NM300K and AgNO3, respectively. Silver uptake by C. elegans was similar for both forms of Ag, while bioaccumulation was higher in AgNO3 exposure. The observed differences in toxicity between NM300K and AgNO3 did not correlate to bioaccumulated Ag, which suggests the toxicity to be a function of the type of exposing agent (AgNPs vs AgNO3) and their mode of action. Before addition of the food source, E. coli, size fractionation revealed that dissolved Ag comprised 13-90 % and 4-8 % of total Ag in the AgNO3 and NM300K treatments, respectively. No dissolved Ag was detectable in the actual test media, due to immediate Ag adsorption to bacteria. Results from the current study highlight that information on behavior and characterization of exposure conditions is essential for nanotoxicity studies.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Anastasia Georgantzopoulou Christian Vogelsang Claire Coutris Kuria Ndungu Patricia Almeida Carvalho Andy Booth Kevin V Thomas Ailbhe MackenSammendrag
The majority of nanomaterials (NMs) used in industrial and commercial applications are likely to enter the wastewater stream and reach wastewater treatment plants (WWTPs). In Oslo, Norway, the WWTPs receive both municipal and industrial wastewater. The treated effluents are discharged to aquatic recipients and the stabilised sludges are applied on agricultural land, however, the transformation of the particles and the potential hazard they pose in these compartments are poorly understood. The overall goal of this study was to elucidate the behavior of Ag and TiO2 NPs during biological wastewater treatment, and investigate the subsequent effects of transformed particles present in the effluent and sludge relative to their pristine counterparts. A laboratory-scale wastewater treatment system was established and combined with a battery of ecotoxicological assays and characterization techniques. The system was based on activated sludge treatment with a pre-denitrification system and fed with synthetic wastewater spiked daily with 10 µg Ag NPs/L (PVP coated, 25 nm, nanoComposix) and 100 µg TiO2 NPs/L (5 nm, NM-101, JRC) over a period of 5 weeks. Samples from all reactors, including the effluent, were collected weekly and analyzed by sequential filtration and inductively coupled plasma mass spectrometry (ICP-MS) to determine the NP fractionation and partitioning. Transmission electron microscopy and single particle ICP-MS were performed on selected samples. The effects of transformed particles present in the effluents were assessed using a battery of bioassays including freshwater and marine algae (growth inhibition, reactive oxygen species -ROS- formation), crustaceans and in vitro models of relevance for NP toxicity assessment (RTgill-W1 cell line, metabolic activity, epithelial integrity, ROS formation, gene expression). The effects of the aged particles through biosolids application were evaluated using coelomocytes, primary cells involved in immune defense mechanisms, isolated from the exposed earthworms Eisenia fetida. The observed effects were organism-dependent, with bottom feeding organisms and algae being more sensitive. The in vitro models offered a useful tool for the assessment of environmental samples. Through a relevant exposure scenario, this study adds useful pieces to our still fragmentary understanding of the environmental fate of weathered NPs.
Forfattere
Anastasia Georgantzopoulou Christian Vogelsang Claire Coutris Fabio Polesel Benedek Plosz Kuria Ndungu Patricia Almeida Carvalho Ailbhe MackenSammendrag
The increase in production and use of Ag and TiO2 nanomaterials has led to their release in wastewater streams and subsequently in the environment. Nanoparticles (NPs) can undergo transformations in environmental media such as wastewaters leading to an alteration in behavior, bioavailability and toxicity that may differ from their pristine counterparts and make predictions challenging. In this context, the overall goal of the study was to elucidate (i) the behavior and transformation of Ag and TiO2 NPs in realistic matrices such as wastewater effluents and activated sludge and (ii) the subsequent effects of transformed particles in comparison to their pristine counterparts. In this study, a laboratory-scale wastewater treatment system was established and combined with a battery of ecotoxicological assays and characterization techniques. The system contained activated sludge and was operated as a pre-denitrification system fed with synthetic wastewater spiked daily with 10 µg Ag NPs/L (PVP coated, 25 nm, nanoComposix) and 100 µg TiO2 NPs/L (nominal primary size of 5 nm, NM-101, JRC) over a period of 5 weeks. During that period the effluents were collected weekly and the excess sludge was stored for the evaluation of terrestrial toxicity. Samples from all reactors and effluents were collected weekly and analyzed by sequential filtration and ICP-MS to determine the partitioning of NPs and their transformation products. Transmission electron microscopy and sp-ICP-MS were performed on selected samples. The effects of aged particles were assessed using a battery of bioassays including freshwater and marine algae (growth inhibition and reactive oxygen species -ROS- formation), crustaceans, as well as in vitro models of relevance for NP toxicity assessement (RTgill-W1 cell line, effects on metabolic activity, epithelial integrity, ROS formation, gene expression). The extent of the observed effects was dependent on the organism exposed, with bottom feeding organisms and algae being more sensitive, while the in vitro model was a good tool for environmental samples. Furthermore, the biosolids generated from the lab-scale continuous system were used in terrestrial microcosm experiments, giving insight into the fate and potential accumulation in a model terrestrial system. Experimental data generated from the continuous-flow operation of the activated sludge system and the targeted batch experiments will be used to model the fate and the removal of NPs.
Forfattere
Anastasia Georgantzopoulou Claire Coutris Kuria Ndungu Patricia Almeida Carvalho Ana Catarina Almeida Ailbhe MackenSammendrag
Det er ikke registrert sammendrag