Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2020
Sammendrag
There is an increasing interest in plastics, both as a resource and as a pollutant. In Europe, 25.8 million tons of plastic waste are generated each year, and their effects on climate, economy, human and environmental health are major challenges that society needs to address. Although a lot of emphasis is placed on recycling, the use of recycled plastics is still low in the EU. In this context, climate change and environmental concerns have boosted the development of various types of biodegradable plastics. The use of biodegradable plastics spans from disposable containers for food/drink, serviceware and wipes, via waste bags for organic waste collected for biogas production, to agricultural films used to cover soil during vegetable production. However, biodegradable plastics are rarely degraded so quickly and completely that the products disappear in nature, and the label may encourage people think otherwise, enhancing littering. The aim of our study was to describe the fate of biodegradable materials and products during waste treatment, and more specifically during composting. How long does it take these materials to degrade? What are the conditions for degradation, and ultimately, for obtaining plastic-free compost products? To answer these questions, we selected relevant materials, including compostable serviceware, biodegradable plastic bags used for organic waste collection, and biodegradable agricultural mulch films. Composting experiments were performed both at lab-scale (1.5 L containers with externally applied heating) and larger scale (in 140 L insulated compost tumblers, with natural heating from the composting processes, continuously monitored). The endpoints studied were recovery, mass loss, changes in morphology and composition, and microbial analysis of the various composts. In addition, we assessed the applicability of chemical digestion methods used for sample pretreatment of environmental samples containing conventional plastics to biodegradable plastics. Biodegradable plastics is an umbrella term covering materials with diverse polymeric compositions and thus material properties. This was well demonstrated by our selected materials, which displayed distinct degradation behaviors under similar controlled conditions. The time-course of degradation during composting will be presented for all selected materials, together with the main parameters influencing their degradation rates. In addition, some methodological challenges in this research field will be discussed. Finally, experience from a municipal composting facility receiving biodegradable plastic waste will also be presented to put our laboratory-based results into perspective.
Sammendrag
Organic industrial and household waste is increasingly used in biogas plants to produce bioenergy, generating at the same time extensive amounts of organic residues, called biogas digestates. While agricultural soils can benefit from the organic matter and nutrients, in particular nitrogen and phosphorus, contained in biogas digestates, we need to assess the environmental and health risks associated to the undesirable substances that may come along. Among those, only a few are covered by actual regulations. For instance, the quantity of plastic materials below 4 mm in biogas digestate is currently not limited to any threshold, despite its likely occurrence in organic waste (waste bag remains and wrong waste sorting) and persistence in the environment. The aim of our study was identify and quantify plastic materials in digestates from Norwegian biogas plants, that are using various types of organic waste sources (e.g. sewage sludge, food waste, animal manure). In addition, a lab-scale experiment was set up to assess the physical and chemical transformations undergone during biogas processes by plastic materials commonly found in digestates. The methods used in our study included simultaneous thermal analysis coupled to Fourier transform-Infrared spectroscopy (for analysis of polymer composition), scanning electron microscopy (for assessment of physical transformations), and a range of physical and chemical extractions for recovering plastic materials from biogas digestates. While all digestates complied with current regulations, plastic particles with a size of 0.2-3 mm made up to 1% (on dry mass basis) of the samples analyzed. Analysis of the polymeric composition of the recovered plastic fragments confirmed that they originated both from the waste bags themselves (shredded during the first steps of waste handling) and from wrong waste sorting. In addition, the lab-scale biogas treatment was shown to considerably change the structure of the studied plastic materials, illustrating a pathway for the formation of secondary microplastics. Some analytical challenges linked to the size and aging of the plastic materials, as well as the complex composition of the digestates, will be discussed. From a broader perspective, a few options will be presented to address the presence of plastic materials in biogas digestates, and thereby minimize the risk associated to their use as soil amendment.
Sammendrag
No abstract has been registered
Forfattere
Dainis Rungis Matti W. Leino Liga Lepse Smiljana Goreta Ban Erik de Vahl Külli Annamaa Priit Põldma Terhi Suojala-Ahlfors Danguole Juskeviciene Chris Kik Ingunn M. Vågen Helena StavelikovaSammendrag
Potato onions (Allium cepa var aggregatum G. Don) are multiplying or aggregating onions, very similar to shallots and have been historically cultivated throughout Europe. Currently in Northern Europe they are maintained in home gardens and ex situ field collections. Potato onions are primarily vegetatively propagated, however in Estonia, near Lake Peipsi, this species has been propagated by seed since the seventeenth century. There is increasing interest in Northern Europe in utilizing this germplasm in organic and/or sustainable farming systems. The genetic diversity and relationship between and within European potato onion collections is unclear. From historical records it is known that cultivation, exchange and trade of potato onion has occurred throughout Europe for hundreds of years. This study utilised molecular markers to assess genetic diversity, duplication of genotypes and relationships among and between Nordic, Baltic, Czech and Croatian potato onion collections. Of 264 accessions, 80 catalogued as unique had identical genotypes with one or more other accessions, and are putative duplicates. The genetic diversity within two Estonian sexually propagated accessions was comparable to that found in all of the vegetatively propagated accessions. Accessions from the Nordic countries grouped together genetically, as did Latvian and Lithuanian accessions. Croatian accessions were genetically separated. These genetic relationships suggest historical movement of potato onion germplasm in North-Eastern Europe. The results, in conjunction with other passport and characterization data, can assist in the development of potato onion core collections, facilitating the conservation and utilization of valuable potato onion genetic resources.
Forfattere
Belachew Asalf Tadesse Rodrigo B. Onofre David M. Gadoury Natalia A. Peres Arne StensvandSammendrag
No abstract has been registered
Sammendrag
No abstract has been registered
Forfattere
Simo Maduna Kelvin L. Hull Edward D. Farrell Jessica J. Boomer Ana Verissimo Ilaria A. M. Marino Carlotta Mazzoldi Lorenzo Zane Sabine P. Wintner Mikhail V. Chesalin Charlene da Silva Chrysoula Gubili Stefano Mariani Aletta E. Bester-van der MerweSammendrag
Members of the smoothhound shark genus Mustelus display a widespread distribution pattern across ocean basins with a high degree of sub-regional endemism. The patterns and processes that resulted in smoothhound biodiversity and present-day distribution remain largely unknown. We infer the phylogenetic relationships of the genus Mustelus, based on sequence data (3474 bp) from three mitochondrial genes (CR, NADH-2 and 12S-16SrRNA) and a nuclear gene (KBTBD2) from seven species of Mustelus distributed across the eastern Atlantic- and Indo-Pacific oceans. Using the CR and KBTBD2 dataset, we infer the phylogeographic placement of Old World Mustelus, with particular reference to species from southern Africa. Using a near-complete phylogeny of the genus including Old World and New World species of Mustelus and publicly available sequences of the NADH-2 gene, we found supporting evidence indicating a major cladogenic event separating placental and aplacental species. Biogeographical analyses further revealed that the radiation of Mustelus in the southern African region was driven primarily by long-distance dispersal during the upper Miocene to lower Pleistocene. The placement of the placental blackspotted smoothhound Mustelus punctulatus at the base of the placental non-spotted clade suggests the secondary loss of black spots in the genus, and this was also supported by the ancestral state reconstruction. The results furthermore suggest that the Southern Hemisphere species of the genus arose from multiple separate dispersal events from the Northern Hemisphere which is in line with the earliest record of Mustelus in the Northern Hemisphere.
Forfattere
Lise Nistrup Jørgensen Niels Matzen Andrea Ficke Ghita C. Nielsen Marja Jalli Antanas Ronis Björn Andersson Annika DjurleSammendrag
No abstract has been registered
Forfattere
Marja Jalli Janne Kaseva Björn Andersson Andrea Ficke Lise Nistrup-Jørgensen Antanas Ronis Timo Kaukoranta Jens-Erik Ørum Annika DjurleSammendrag
No abstract has been registered
Forfattere
Sherin Jose Joel Abbey Laura Jaakola David PercivalSammendrag
No abstract has been registered