Erik J. Joner
Head of Department/Head of Research
Biography
Abstract
Heavy metals in soil pose a constant risk for animals and humans when entering their food chains, and limited means are available to reduce plant accumulation from more or less polluted soils. Biochar, which is made by pyrolysis of organic residues and sees increasing use as a soil amendment to mitigate anthropogenic C emissions and improve agronomic soil properties, has also been shown to reduce plant availability of heavy metals in soils. The cause for the reduction of metal uptake in plants when grown in soils enriched with biochar has generally been researched in terms of increased pH and alkalinity, while other potential mechanisms have been less studied. We conducted a pot experiment with barley using three soils differing in metal content and amended or not with 2% biochar made from Miscanthus x giganteus, and assessed plant contents and changes in bioavailability in bulk and rhizosphere soil by measuring extractability in acetic acid or ammonium nitrate. In spite of negligible pH changes upon biochar amendment, the results showed that biochar reduced extractability of Cu, Pb and Zn, but not of Cd. Rhizosphere soil contained more easily extractable Cu, Pb and Zn than bulk soil, while for Cd it did not. Generally, reduced plant uptake due to biochar was reflected in the amounts of metals extractable with ammonium nitrate, but not acetic acid.
Abstract
We investigated dissipation, earthworm and plant accumulation of organic contaminants in soil amended with three types of sewage sludge in the presence and absence of plants. After 3 months, soil, plants and earthworms were analyzed for their content of organic contaminants. The results showed that the presence of plant roots did not affect dissipation rates, except for galaxolide. Transfer of galaxolide and triclosan to earthworms was significant, with transfer factors of 10–60 for galaxolide and 140–620 for triclosan in the presence of plants. In the absence of plants, transfer factors were 2–9 times higher. The reduced transfer to worms in the presence of plants was most likely due to roots serving as an alternative food source. Nonylphenol monoethoxylate rapidly dissipated in soil, but initial exposure resulted in uptake in worms, which was detected even 3 months after sewage sludge application. These values were higher than the soil concentration at the start of the exposure period. This indicates that a chemical's short half-life in soil is no guarantee that it poses a minimal environmental risk, as even short-term exposure may cause bioaccumulation and risks for chronic or even transgenerational effects.
Authors
Nanna B. Svenningsen Stephanie J Watts-Williams Erik J. Joner Fabio Battini Aikaterini Efthymiou Carla Cruz-Paredes Ole Nybroe Iver JakobsenAbstract
Arbuscular mycorrhizal fungi (AMF) colonise roots of most plants; their extra-radical mycelium (ERM) extends into the soil and acquires nutrients for the plant. The ERM coexists with soil microbial communities and it is unresolved whether these communities stimulate or suppress the ERM activity. This work studied the prevalence of suppressed ERM activity and identified main components behind the suppression. ERM activity was determined by quantifying ERM-mediated P uptake from radioisotope-labelled unsterile soil into plants, and compared to soil physicochemical characteristics and soil microbiome composition. ERM activity varied considerably and was greatly suppressed in 4 of 21 soils. Suppression was mitigated by soil pasteurisation and had a dominating biotic component. AMF-suppressive soils had high abundances of Acidobacteria, and other bacterial taxa being putative fungal antagonists. Suppression was also associated with low soil pH, but this effect was likely indirect, as the relative abundance of, e.g., Acidobacteria decreased after liming. Suppression could not be transferred by adding small amounts of suppressive soil to conducive soil, and thus appeared to involve the common action of several taxa. The presence of AMF antagonists resembles the phenomenon of disease-suppressive soils and implies that ecosystem services of AMF will depend strongly on the specific soil microbiome.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Daniel Rasse Simon Weldon Erik J. Joner Stephen Joseph Claudia I. Kammann Xiaoyu Liu Adam O'Toole Genxing Pan Nazli Pelin Kocatürk SchumacherAbstract
Background Biochar-based fertilizer products (BCF) have been reported to increase both crop yield and N-use efficiency. Such positive effects are often assumed to result from the slow-release of N adsorbed on BCF structures. However, a careful review of the literature suggests that actual mechanisms remain uncertain, which hampers the development of efficient BCF products. Scope Here, we aim at reviewing BCF mechanisms responsible for enhanced N uptake by plants, and evaluate the potential for further improvement. We review the capacity of biochar structures to adsorb and release N forms, the biochar properties supporting this effect, and the methods that have been proposed to enhance this effect. Conclusions Current biochar products show insufficient sorption capacity for the retention of N forms to support the production of slow-release BCFs of high enough N concentration. Substantial slow-release effects appear to require conventional coating technology. Sorption capacity can be improved through activation and additives, but currently not to the extent needed for concentrated BCFs. Positive effects of commercial BCFs containing small amount of biochar appear to result from pyrolysis-derived biostimulants. Our review highlights three prospects for improving N retention: 1) sorption of NH3 gas on specifically activated biochar, 2) synergies between biochar and clay porosities, which might provide economical sorption enhancement, and 3) physical loading of solid N forms within biochar. Beyond proof of concept, quantitative nutrient studies are needed to ascertain that potential future BCFs deliver expected effects on both slow-release and N use efficiency.
Authors
Claire Coutris Erik J. Joner Cecilie Singdahl-Larsen Ana Catarina Almeida Muhammad Umar Sissel Brit Ranneklev Cecilia AskhamAbstract
Microplastics ending up in nature as a result of end-of-life processes for plastic packaging is a serious environmental concern, and was addressed in the Packnoplast project through sampling at three sites: one biogas facility in Norway and two thermoplastic recycling plants, one in Norway and one in The Netherlands. The amounts of microplastics ending up in soil from biogas digestate was estimated to represent 0.4-2 mg/kg soil per year if 6 t/daa of biogas digestate is used as fertilizer. Food packaging is estimated to represent 75% of this. The amounts of microplastics measured are significant, but too small to affect soil properties even on a time-scale of decades. The risk of adverse effects on soil quality, plant growth or soil organisms seem very low at the current predicted rates of plastic inputs to soil. Since plastics are virtually non-degradable, they are still prone to accumulate in soil, and waste streams recycled to soil need to address and prevent plastic contamination even better than today. Thermoplastic recycling plants are handling large amounts of plastic, and during processes in the plant, microplastics are generated. Concentrations of microplastic particles varied from 7 to 51 particles per lite rin the effluent water from the two plants. Discharges of effluent water are often through the sewer system and/or into a water body. Today regulations regarding discharges of microplastics are missing. Sand filter treatment of the effluent water was a promising treatment technique to remove the microplastics. Background concentrations of microplastics, comparable to pristine areas, were found in blue mussels sampled outside the thermoplastic recycling plant in Norway. Knowledge about the risk imposed by microplastics to the aquatic environment is today not known.
Authors
Erik J. JonerAbstract
No abstract has been registered
Authors
Kaare Magne Nielsen Kyrre Linné Kausrud Gunnar Skov Simonsen Martin Steinbakk Pål Trosvik Astrid Louise Wester Yngvild Wasteson Siamak Pour Yazdankhah Øivind Bergh Ole Martin Eklo Erik J. Joner Elisabeth Henie MadslienAbstract
No abstract has been registered
Abstract
Green roofs are increasingly being used to meet the challenges of extreme rainfall and surface water management in cities and towns. Biochar is a locally sourced and carbon-negative material that can be used as a substrate component for green roofs. Here are some experiences NIBIO has gained in this area through research and testing of various concept.
Authors
Yngvild Wasteson Henning Sørum Bjørn-Arne Lindstedt Adriana Dorota Osinska Arnfinn Sundsfjord Hans Geir Eiken Erik J. Joner Anders Aas Carsten Ulrich Schwermer Pawel Krzeminski Ernst Kristian Rødland Astrid Louise Wester Halfdan Olafssøn Andre Olafssøn Trond Ingebretsen Rune Holmstad Nina DueAbstract
No abstract has been registered
Authors
Yngvild Wasteson Henning Sørum Bjørn-Arne Lindstedt Arnfinn Sundsfjord Hans Geir Eiken Erik J. Joner Anders Aas Carsten Ulrich Schwermer Pawel Krzeminski Ernst Kristian Rødland Astrid Louise Wester Halfdan Olafssøn Andre Olafssøn Trond Ingebretsen Rune Holmstad Nina DueAbstract
No abstract has been registered
Authors
Carla Cruz-Paredes Tomas Diera Marie Louise Davey Maria Monrad Rieckmann Peter Christensen Majbrit Dela Cruz Kristian Holst Laursen Erik J. Joner Jan H. Christensen Ole Nybroe Iver JakobsenAbstract
Arbuscular mycorrhizal fungi (AMF) are important in plant nutrient uptake, but their function is prone to environmental constraints including soil factors that may suppress AMF transfer of phosphorus (P) from the soil to the plant. The objective of this study was to disentangle the biotic and abiotic components of AMF-suppressive soils. Suppression was measured in terms of AMF-mediated plant uptake of 33P mixed into a patch of soil and treatments included soil sterilization, soil mixing, pH manipulation and inoculation with isolated soil fungi. The degree of suppression was compared to volatile organic compound (VOC) production by isolated fungi and to multi-element analysis of soils. For a selected suppressive soil, sterilization and soil mixing experiments confirmed a biotic component of suppression. A Fusarium isolate from that soil suppressed the AMF activity and produced greater amounts than other fungal isolates of the antimicrobial VOC trichodiene (a trichothecene toxin precursor), beta-chamigrene, alpha-cuprenene and p-xylene. These metabolites deserve further attention when unravelling the chemical background behind the suppression of AMF activity by soil microorganisms. For the abiotic component of suppression, soil liming and acidification experiments confirmed that suppression was strongest at low pH. The pH effect might be associated with changed availability of specific suppressive elements. Indeed 33P uptake from the soil patches correlated negatively to Al levels and Al toxicity seems to play a major role in the AMF suppressiveness at pH below 5.0–5.2. However, the documentation of a biotic component of suppression for both low and high pH soils leads to the conclusion that biotic and abiotic components of suppression may act in parallel in some soils. The current insight into the components of soil suppressiveness of the AMF activity aids to develop management practices that allow for optimization of AMF functionality.
Authors
Amy Lusher Rachel Hurley Hans Peter H Arp Andy Booth Inger Lise Nerland Bråte Geir W. Gabrielsen Alessio Gomiero Tania Gomes Bjørn Einar Grøsvik Norman Green Marte Haave Ingeborg G. Hallanger Claudia Halsband Dorte Herzke Erik J. Joner Tanja Kögel Kirsten Rakkestad Sissel B. Ranneklev Martin Wagner Marianne OlsenAbstract
Given the increasing attention on the occurrence of microplastics in the environment, and the potential envi-ronmental threats they pose, there is a need for researchers to move quickly from basic understanding to applied science that supports decision makers in finding feasible mitigation measures and solutions. At the same time, they must provide sufficient, accurate and clear information to the media, public and other relevant groups (e.g., NGOs). Key requirements include systematic and coordinated research efforts to enable evidence-based decision making and to develop efficient policy measures on all scales (national, regional and global). To achieve this, collaboration between key actors is essential and should include researchers from multiple disciplines, policy-makers, authorities, civil and industry organizations, and the public. This further requires clear and informative communication processes, and open and continuous dialogues between all actors. Cross-discipline dialogues between researchers should focus on scientific quality and harmonization, defining and accurately communi-cating the state of knowledge, and prioritization of topics that are critical for both research and policy, with the common goal to establish and update action plans for holistic benefit. In Norway, cross-sectoral collaboration has been fundamental in supporting the national strategy to address plastic pollution. Researchers, stakeholders and the environmental authorities have come together to exchange knowledge, identify knowledge gaps, and set targeted and feasible measures to tackle one of the most challenging aspects of plastic pollution: microplastic. In this article, we present a Norwegian perspective on the state of knowledge on microplastic research efforts. Norway’s involvement in international efforts to combat plastic pollution aims at serving as an example of how key actors can collaborate synergistically to share knowledge, address shortcomings, and outline ways forward to address environmental challenges.
Abstract
The presence of tire crumb rubber particles in soil surrounding three artificial football fields in Asker and Bærum municipalities, Norway, was studied. Concentrations of crumb rubber particles in soil were found to be high.
Authors
Kaare Magne Nielsen Yngvild Wasteson Siamak Pour Yazdankhah Øivind Bergh Ole Martin Eklo Erik J. Joner Elisabeth Henie Madslien Pål Trosvik Bjørnar YtrehusAbstract
No abstract has been registered
Authors
Yngvild Wasteson Hege Salvesen Blix Erik J. Joner Elisabeth Henie Madslien Jakob Ottoson Henning Sørum Wolfgang Uhl Siamak Pour Yazdankhah Øivind Bergh Ole Martin Eklo Kaare Magne Nielsen Pål TrosvikAbstract
The request from NFSA and NEA: Antimicrobial agents and microorganisms are introduced to sewage systems by different human activities, from private homes, institutions such as schools and hospitals, office buildings, industrial and commercial activities, i.e., from everywhere where people work and live. The Norwegian Food Safety Authority (NFSA) and Norwegian Environment Agency (NEA) asked the Norwegian Scientific Committee for Food and Environment (Vitenskapskomiteen for mat og miljø, VKM) for an extension of the 2009 VKM report “Risk assessment of contaminants in sewage sludge applied on Norwegian soils” regarding the impact of wastewater (WW)- and sewage sludge treatment methods used in Norway, on the fate and survival of antimicrobial resistant bacteria, fate of antimicrobial resistance genes, and main drivers for resistance (e.g. antibiotics, antifungal agents, heavy metals, disinfectants). The request addressed by VKM: VKM appointed a working group, consisting of three members of the Panel on Microbial Ecology, four external members and VKM staff to prepare a draft Opinion document. The Panel on Microbial Ecology has reviewed and revised the draft prepared by the working group and approved the Opinion document “Assessment of the impact of wastewater and sewage sludge treatment methods on antimicrobial resistance”. The antimicrobial resistance cycle: Exposure to antimicrobial agents is regarded as the most important driver for development and dissemination of AMR in microorganisms. Consequently, an important location for the development of AMR is the gut of humans or animals receiving antimicrobial drug therapy. As ARB, ARG, resistance genes and antimicrobial agents will end up in the WW system, this system could be regarded as a potential hot spot for interactions between different microorganisms, between different antimicrobial agents, and between microorganisms and antimicrobial agents. Hospitals and pharmaceutical companies are regarded as being an important source for antimicrobial drug residues released in WW. At the wastewater treatment plant (WWTP), bacteria and genes end up either in the effluent wastewater fraction or in the sludge fraction. When ARB and ARG are distributed with the WW sludge, they may reach arable land when the sludge is used as soil improver and fertilising product, and thus be recycled into the food-production chain. When following the effluent WW fraction, ARB and ARB will be released into WW recipients, such as lakes, rivers or fjords, and may, from these environments, also be recycled into food production. In each step of these cycles, ARB and ARG will be introduced into new environmental compartments to which they must adapt, and to microbial communities with which they must compete for survival and growth. Depending on the bacterial species, these new environmental compartments will be more or less hostile, but they will also provide opportunities for microbial interactions, like dissemination of ARG due to horizontal gene transfer (HGT) within and between bacterial species. Findings: It is challenging to deliver a general assessment of the nature of as well as the probability for direct discharge of ARB and ARG into effluent WW and applied sludge. This is due to the combined complexity of resistance carriers, traits, various sources of variation, and the WW systems. Moreover, there is currently a lack of harmonized methods and protocols to compare studies from different systems. However, there are no strong indications that there is a significant enrichment of ARB in WWTP operated under European conditions, which, on a general level, also applies to the Norwegian situation. Although some studies indicate a slight increase in the fraction of ARB, the absolute reduction in bacterial load during WW treatment (WWT) is significant; removal of between 99 % to 99.9 % of faecal indicator bacteria is generally achieved by secondary .......
Abstract
Heavy metals in soil pose a constant risk for animals and humans when entering their food chains, and limited means are available to reduce plant accumulation from more or less polluted soils. Biochar, which is made by pyrolysis of organic residues and sees increasing use as a soil amendment to mitigate anthropogenic C emissions and improve agronomic soil properties, has also been shown to reduce plant availability of heavy metals in soils. The cause for the reduction of metal uptake in plants when grown in soils enriched with biochar has generally been researched in terms of increased pH and alkalinity, while other potential mechanisms have been less studied. We conducted a pot experiment with barley using three soils differing in metal content and amended or not with 2% biochar made from Miscanthus x giganteus, and assessed plant contents and changes in bioavailability in bulk and rhizosphere soil by measuring extractability in acetic acid or ammonium nitrate. In spite of negligible pH changes upon biochar amendment, the results showed that biochar reduced extractability of Cu, Pb and Zn, but not of Cd. Rhizosphere soil contained more easily extractable Cu, Pb and Zn than bulk soil, while for Cd it did not. Generally, reduced plant uptake due to biochar was reflected in the amounts of metals extractable with ammonium nitrate, but not acetic acid.
Abstract
Remediation using nanoparticles depends on proper documentation of safety aspects, one of which is their ecotoxicology. Ecotoxicology of nanoparticles has some special features: while traditional ecotoxicology aims at measuring possible negative effects of more or less soluble chemicals or dissolved elements, nanoecotoxicology aims at measuring the toxicity of particles, and its main focus is on effects that are unique to nano-sized particles, as compared to larger particles or solutes. One of the main challenges when testing the ecotoxicity of nanoparticles lies in maintaining stable and reproducible exposure conditions, and adapt these to selected test organisms and endpoints. Another challenge is to use test media that are relevant to the matrices to be treated. Testing of nanoparticles used for remediation, particularly red-ox-active Fe-based nanoparticles, should also make sure to exclude confounding effects of altered red-ox potential which are not nanoparticle-specific. Yet another unique aspect of nanoparticles used for remediation is considerations of ageing of nanoparticles in soil or water, leading to reduced toxicity over field-relevant time scales. This review discusses these and other aspects of how to design and interpret appropriate tests and use these in hazard descriptions for subsequent risk assessments.
Abstract
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.
Abstract
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.
Abstract
Plastics in terrestrial ecosystems negatively affect their functioning by altering physical properties and disturbing soil microorganisms. The same could be true for biodegradable plastics entering nature through incomplete degradation in composting plants, and their subsequent application to soil in fertilizer substrate. So far, no standard analysis protocol for biodegradable plastic degradation exist. This Master's thesis has focused on developing methods for the analysis of biodegradable plastic degradation in a compost matrix and lays a foundation which later research can be built upon. Fenton's reagent and hydrogen peroxide were tested as a sample up-concentrating pre-treatment of an organic matter matrix containing biodegradable microplastics. The degradation of four different biodegradable plastics in nylon bags in a compost tumbler and a compost oven incubation were assessed. Samples for pH and phospholipid fatty acids (PLFA) of different treatments were collected to compare their development and interchangeability. Fenton's reagent was the better suited up-concentrating pre-treatment for samples with some uncertainty remaining. Assessing the biodegradable plastic degradation indicated an incomplete process in home composts and (Norwegian) composting plants. pH values coarsely reflected the composting conditions and suggested interchangeability of most treatments. Analysis of pH together with PLFA results would have been optimal, but could not be accomplished as the COVID-19 epidemic hindered the PLFA analysis. While some uncertainties in the developed methods remain, it can be concluded that a basis for establishing biodegradable plastic degradation analysis was created. Subsequent research should continue their development to assess whether biodegradable plastic remains from composting plants contribute to the accumulation of plastics in terrestrial ecosystems.
Abstract
At the Norwegian Institute of Bioeconomy Research (NIBIO, formerly Bioforsk), biochar has been a topic of research since 2009 through both laboratory and field studies. Initial results demonstrated that biochar produced from clean biomass is safe to use on agricultural soils, and that pyrolysis temperatures of ≥370 °C are necessary for producing biochar that is resistant to decomposition on a timescale of 100 years. Further work identified the chemical transformations that are responsible for biochar stability and contributed to finding the best indicator of this stability. Throughout the years, we have had close collaboration with industry and farmers in Norway, where now industrial networks are in action and there is financial support for the implementation of biochar technology. Despite the convincing benefits of biochar as a climate mitigation solution, it has only slowly advanced beyond the research stage, notably because its effect on yield are too modest. There is therefore a need for win-win biochar solutions benefiting both food production and climate mitigation. Such a solution is the development of biochar fertilizers, which capitalizes on the capacity of biochar to capture and release nutrients. As biochar properties largely depend on pyrolysis conditions and feedstock properties, our current work contributes to the selective design of biochars for the purpose of improving nutrient use efficiency.
Authors
Elisabeth Henie Madslien Nana Yaa Ohene Asare Øivind Bergh Erik J. Joner Pål Trosvik Siamak Pour Yazdankhah Ole Martin Eklo Kaare Magne Nielsen Bjørnar Ytrehus Yngvild WastesonAbstract
No abstract has been registered
Lecture – Plastics and microplastics in waste recycled to soil. Sources and challenges
Erik J. Joner
Authors
Erik J. JonerAbstract
No abstract has been registered
Abstract
We investigated dissipation, earthworm and plant accumulation of organic contaminants in soil amended with three types of sewage sludge in the presence and absence of plants. After 3 months, soil, plants and earthworms were analyzed for their content of organic contaminants. The results showed that the presence of plant roots did not affect dissipation rates, except for galaxolide. Transfer of galaxolide and triclosan to earthworms was significant, with transfer factors of 10–60 for galaxolide and 140–620 for triclosan in the presence of plants. In the absence of plants, transfer factors were 2–9 times higher. The reduced transfer to worms in the presence of plants was most likely due to roots serving as an alternative food source. Nonylphenol monoethoxylate rapidly dissipated in soil, but initial exposure resulted in uptake in worms, which was detected even 3 months after sewage sludge application. These values were higher than the soil concentration at the start of the exposure period. This indicates that a chemical's short half-life in soil is no guarantee that it poses a minimal environmental risk, as even short-term exposure may cause bioaccumulation and risks for chronic or even transgenerational effects.
Abstract
Norway is strongly committed to the Paris Climate Agreement with an ambitious goal of 40% reduction in greenhouse gas emission by 2030. The land sector, including agriculture and forestry, must critically contribute to this national target. Beyond emission reduction, the land sector has the unique capacity to actively removing CO2 from the atmosphere through biological carbon storage in biomass and in soils. Soils are the largest reservoir of terrestrial carbon, and relatively small changes in soil carbon content can have an amplified mitigation effect on the Earth’s climate. Therefore, improved management of soils for carbon storage is receiving a lot of attention, for example through international political initiatives such as the “4-permill” initiative. However, in Norway, many mitigation measures targeting soil carbon might negatively impact food production and economic activity. For example, soil carbon storage can be increased by shifting from cereal crop production to grasslands, but Norway already has abundant grassland and a comparatively small area dedicated to cereals. Another such issue is cultivation on drained peatland, where food is produced at the expense of large losses of soil carbon as CO2 to the atmosphere. Therefore, there is a need to look for win-win solutions for soil carbon storage, which benefit both food production and climate mitigation. Large-scale conversion of agricultural and forest waste biomass to biochar is such an option, and is considered the activity with the largest potential for soil carbon sequestration in Norway. Biochar has been demonstrated to have a mean residence time exceeding 100 years in Norwegian field conditions (Rasse et al, 2017), and no negative effects on plant and soils has been observed. However, despite the convincing benefits of biochar as a climate mitigation solution, it has not yet advanced much beyond the research stage, notably because its effect on yield are too modest. Here, we will first present the comparative advantage of biochar technology as compared to traditional agronomy methods for large-scale C storage in Norwegian agricultural soils. We will further discuss the need for developing innovations in pyrolysis and nutrient-rich waste recycling leading to biochar-fertilizer products as win-win solution for carbon storage and food production.
Abstract
The potential impact of silver nanoparticles (Ag NPs) on aquatic organisms is to a large extent determined by theirbioavailability through different routes of exposure. In the present study juvenile Atlantic salmon (Salmo salar) were exposed todifferent sources of radiolabeled Ag (radiolabeled110mAg NPs and110mAgNO3). After 48 h of waterborne exposure to 3mg/Lcitrate stabilized110mAg NPs or110mAgNO3, or a dietary exposure to 0.6mg Ag/kg fish (given as citrate stabilized or uncoated110mAg NPs, or110mAgNO3), Ag had been taken up in fish regardless of route of exposure or source of Ag (Ag NPs or AgNO3).Waterborne exposure led to high Ag concentrations on the gills, and dietary exposure led to high concentrations in thegastrointestinal tract. Silver distribution to the target organs was similar for both dietary and waterborne exposure, with the liveras the main target organ. The accumulation level of Ag was 2 to 3 times higher for AgNO3than for Ag NPs when exposure wasthrough water, whereas no significant differences were seen after dietary exposure. The transfer (Bq/g liver/g food or water)from exposure through water was 4 orders of magnitude higher than from feed using the smallest, citrate-stabilized Ag NPs(4 nm). The smallest NPs had a 5 times higher bioavailability in food compared with the larger and uncoated Ag NPs (20 nm).Despite the relatively low transfer of Ag from diet to fish, the short lifetime of Ag NPs in water and their transfer to sediment,feed, or sediment-dwelling food sources such as larvae and worms could make diet a significant long-term exposure route.
Authors
Nanna B. Svenningsen Stephanie J Watts-Williams Erik J. Joner Fabio Battini Aikaterini Efthymiou Carla Cruz-Paredes Ole Nybroe Iver JakobsenAbstract
Arbuscular mycorrhizal fungi (AMF) colonise roots of most plants; their extra-radical mycelium (ERM) extends into the soil and acquires nutrients for the plant. The ERM coexists with soil microbial communities and it is unresolved whether these communities stimulate or suppress the ERM activity. This work studied the prevalence of suppressed ERM activity and identified main components behind the suppression. ERM activity was determined by quantifying ERM-mediated P uptake from radioisotope-labelled unsterile soil into plants, and compared to soil physicochemical characteristics and soil microbiome composition. ERM activity varied considerably and was greatly suppressed in 4 of 21 soils. Suppression was mitigated by soil pasteurisation and had a dominating biotic component. AMF-suppressive soils had high abundances of Acidobacteria, and other bacterial taxa being putative fungal antagonists. Suppression was also associated with low soil pH, but this effect was likely indirect, as the relative abundance of, e.g., Acidobacteria decreased after liming. Suppression could not be transferred by adding small amounts of suppressive soil to conducive soil, and thus appeared to involve the common action of several taxa. The presence of AMF antagonists resembles the phenomenon of disease-suppressive soils and implies that ecosystem services of AMF will depend strongly on the specific soil microbiome.
Abstract
Green roofs are used increasingly to alleviate peaks of water discharge into the sewage systems in urban areas. Surface runoff from roofs contain pollutants from dry and wet deposition, and green roofs offer a possibility to reduce the amounts of pollutants in the water discharged from roofs by degradation and filtering. These pollutants would otherwise enter wastewater treatments plants and ultimately end up in sewage sludge that is spread on agricultural soils. The most common substrates used in green roofs have limited capacity for filtration and sorption. Also, more sustainable alternatives are sought, due to the high carbon footprint of these materials. Biochar is a carbon-rich material produced by pyrolysis of biomass, and several types of biochar have been described as good sorbents and filter materials. Biochar is also a light and carbon negative material, which may fulfill other desired criteria for new green roof substrates. We here report on an experiment where two types of biochar, produced from olive husks at 450 °C or from forest waste at 850 ° C were mixed with volcanic rock or peat, and tested for retention capacity of phenanthrene and six heavy metals in a column experiment with unsaturated gravimetric water flow lasting for 3 weeks. The results suggest that biochar as a component in green roof substrates perform better than traditional materials, concerning retention of the tested pollutants, and that different types of biochar have different properties in this respect.
Abstract
No abstract has been registered
Lecture – Capture+ A dawn for biochar in Norway
Erik J. Joner, Adam Thomas O'toole, Alice Budai, ...
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Authors
Rune Hjorth Claire Coutris Nhung H.A. Nguyen Alena Sevcu Juliàn Alberto Gallego-Urrea Anders Baun Erik J. JonerAbstract
No abstract has been registered
Abstract
Matching high performing varieties of legumes with effective symbiotic N-fixing bacteria can potentially enhance production volumes and economic returns when cultivating grain legumes. We investigated whether field inoculation with local or introduced Rhizobia to six different varieties of faba bean improved growth, nitrogen (N) fixation and protein content in a field experiment in Southern Norway. In 2016, a full factorial experiment featuring three inoculation treatments (a mixture of four morphotypes of Rhizobia isolated from locally grown faba bean, a mix of two efficient and well documented Rhizobium strains from Latvia, and a non-inoculated control treatment) and six faba bean (Vicia faba) genotypes (Agua Dulce, Bauska, Jõgeva, Gloria, Julia, Lielplatones) was set up in an experimental field with sandy loam soil with no recent legume culture history (>10 years). At late flowering/early pod formation stage we quantified N fixation of the crop using the N-15 natural abundance method, using weeds from the same plots as reference plants. We also assessed morphological and phenological characters, seed yields and protein levels at plant maturity. Clear differences were observed, and detailed results from this study will be presented at the conference (analyses are still pending). This research is a part of the EU FP7 project Eurolegume.
Authors
Erik J. Joner Eystein Skjerve Leif Sundheim Arne Tronsmo Yngvild Wasteson Karl Fredrich Eckner Georg Kapperud Jørgen Fr Lassen Judith Narvhus Truls Nesbakken Lucy Robertson Jan Thomas Rosnes Taran Skjerdal Line VoldAbstract
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Abstract
Sewage sludge is an important amendment that enriches soils with organic matter and provides plants with nutrients such asnitrogenandphosphorus.However,knowledgeonthe fateandeffectsof organic pollutants presentin the sludge on soilorganisms is limited.In the present study, the uptake of triclosan, galaxolide, and tonalide in the earthworm Dendrobaena veneta was measured 1 wk afteramendment of agricultural soil with sewage sludge, while elimination kinetics were assessed over a 21-d period after transferring worms toclean soil. After 1-wk exposure, earthworms had accumulated 2.6 0.6 mgg1galaxolide, 0.04 0.02 mgg1tonalide, and0.6 0.2 mgg1triclosan. Both synthetic musks were efficiently excreted and below the limit of quantification after 3 and 14 d ofdepuration for tonalide and galaxolide, respectively. Triclosan concentrations, on the other hand, did not decrease significantly over thedepuration period, which may lead to the transfer of triclosan in the food web.
Authors
Lea Piscitelli Pierre-Adrien Rivier Donato Mondelli Teodoro Miano Daniel Rasse Erik J. JonerAbstract
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Two types of nano-scale zero-valent iron (nZVI-B prepared by borohydride reduction and nZVI-T produced by thermal reduction of iron oxide nanoparticles in H2) and amicro-scale ZVI (mZVI) were compared for PCB degradation efficiency in water and soil. In addition, the ecotoxicity of nZVI-B and nZVI-T particles in treated water and soil was evaluated on bacteria, plants, earthworms, and ostracods. All types of nZVI and mZVI were highly efficient in degradation of PCBs in water, but had little degradation effect on PCBs in soil. Although nZVI-B had a significant negative impact on the organisms tested, treatment with nZVI-T showed no negative effect, probably due to surface passivation through controlled oxidation of the nanoparticles.
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Nano-scale zero-valent iron (nZVI) has been conceived for cost-efficient degradation of chlorinated pollutants in soil as an alternative to e.g permeable reactive barriers or excavation. Little is however known about its efficiency in degradation of the ubiquitous environmental pollutant DDT and its secondary effects on organisms. Here, two types of nZVI (type B made using precipitation with borohydride, and type T produced by gas phase reduction of iron oxides under H2) were compared for efficiency in degradation of DDT in water and in a historically (>45 years) contaminated soil (24 mg kg−1 DDT). Further, the ecotoxicity of soil and water was tested on plants (barley and flax), earthworms (Eisenia fetida), ostracods (Heterocypris incongruens), and bacteria (Escherichia coli). Both types of nZVI effectively degraded DDT in water, but showed lower degradation of aged DDT in soil. Both types of nZVI had negative impact on the tested organisms, with nZVI-T giving least adverse effects. Negative effects were mostly due to oxidation of nZVI, resulting in O2 consumption and excess Fe(II) in water and soil.
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Nonylphenols (NP) are a group of alkylphenols, formed upon degradation of nonylphenol ethoxylates such as nonylphenol monoethoxylate (NP1EO) or nonylphenol diethoxylate (NP2EO), which have been broadly used as non-ionic surfactants. Both NP and their ethoxylates are often present in the sewage, despite being banned and substituted by less toxic alcohol ethoxylates in many countries. There is a number of degradation studies of nonylphenol in the soil environment, but there is a lack of understanding on how plants and soil organisms such as earthworms can affect the degradation. In our study, we investigated the degradation of 4-nonylphenol (4-NP) in a mineral field soil in the presence of barley (Hordeum vulgare) and earthworms (Aporrectodea caliginosa). Soil was spiked with 4-NP at a concentration of 12.5 mg kg-1 d.w. soil. Results showed that the degradation of 4-NP in soil was rapid during the 28 days after spiking, with remaining concentration of 0.397 mg kg-1 d.w. soil on day 28. Degradation was much slower between days 28 and 120, with a remaining concentration of 0.214 mg kg-1 d.w. soil on day 120. No significant difference in the degradation of 4-NP in the presence of either plants or worms was observed, but sampling after 28 days of exposure revealed transfer of 4-NP to worms (worm tissue concentration = 0.79 μg g-1), which increased with time (1.66 μg g-1 after 120 d). The calculated transfer factor after 28 (TF28) and 120 days (TF120) was 0.07 and 0.13 respectively. No toxicity or accumulation in plants was observed at the concentration tested herein. Concentration of 4-NP in the rhizosphere was not statistically different from that in the bulk soil.
Authors
Sarah Calvache Gil Tatsiana Espevig Erik J. Joner T.E. Andersen Trond Olav Pettersen Trygve S. AamlidAbstract
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Authors
Sarah Calvache Gil Tatsiana Espevig Tina E. Andersen Erik J. Joner Agnar Kvalbein Trond Olav Pettersen Trygve S. AamlidAbstract
Red fescue (RF, Festuca rubra L.) is used on golf putting greens in the Nordic region due to its high disease resistance and low requirements for nitrogen (N) and water, but low density and growth rate makes RF susceptible to annual bluegrass (AB, Poa annua L.) invasion. Putting greens seeded with RF + bentgrass (Agrostis sp.) may be more competitive with AB but also have different playing characteristics. Our objective was to compare RF, RF + colonial bentgrass (CB, Agrostis capillaris L.), and RF + velvet bentgrass (VB, Agrostis canina L.) putting greens at two mowing heights (4.0 or 5.5 mm), three N rates (5, 10, or 15 g N m−2 yr−1), and three phosphorus (P)–arbuscular mycorrhizal fungi treatments (0 and 1.8 g P m−2yr−1 without inoculation and 0 g P m−2yr−1 with inoculation). The four-factorial experiment was conducted in 2011 and 2012 at Landvik, Norway. Red fescue provided lower visual quality and density and less competition against AB than RF + bentgrass combinations. Increasing the N rate from 5 to 15 g N m−2yr−1 increased the proportion of bentgrass tillers from 53 to 64% in RF + CB and from 86 to 92% in RF + VB. Surface hardness increased in the order RF + VB < RF + CB < RF turfs. Ballroll distance decreased with increasing N rate and was longer with RF and RF + VB than with RF + CB. The main effects of N and mowing height on AB invasion were not significant, but lower mowing increased AB competition in RF. Mycorrhiza colonization of roots was not significantly affected by any practice, and neither P nor arbuscular mycorrhizal fungi influenced the competition against AB.
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Authors
Erik J. JonerAbstract
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Remediation of soil and groundwater has been attempted using various iron based nanoparticles during more than a decade, but the technology has not been adopted as widely as expected. This is partly due to ongoing work on optimization of the nanoparticles used, as well as their coatings, injection parameters and correct choice of particles according to the pollutants to be treated. Another aspect that has hampered large scale adoption or even testing is the lack of knowledge on possible negative effects of what is perceived a large scale spreading of reactive nanoparticles into the environment. This may potentially cause harm to humans and the environment, including organisms living in soil and neighboring streams, rivers and lakes. Two years ago, the EU project NanoRem (Taking Nanotechnological Remediation Processes from Lab Scale to End User Applications for the Restoration of a Clean Environment) started a considerable effort in valorizing nanoremediation, and as part of this testing the potential toxicity of particles used and developed during the project. After two years, seven different types of nanoparticles have been tested with a range of standardized and non-standardized tests adapted to nanotoxicological assessments, and results show that most particles are non-toxic at environmentally relevant concentrations (<100 mg/kg or mg/L). In some cases, however, iron nanoparticles have shown toxicity at far lower concentrations, and these effects have not been caused by competition for electron acceptors, as often observed when highly reductive chemicals are tested for biological effects. An overview of the tests used and results obtained will be presented. Also, our strategy for field testing and early results from polluted fields injected with different nanoparticles will be discussed to make some preliminary conclusions on the overall benefit of this technology in terms of environmental protection and risks.
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Erik J. JonerAbstract
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Authors
Lisbeth Schnug Torbjørn Ergon Lena Jakob Janeck J Scott-Fordsmand Erik J. Joner Hans Petter LeinaasAbstract
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Authors
Erik J. JonerAbstract
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Nano-sized zero valent iron (nZVI) has been studied for in situ remediation of contaminated soil and ground water. However, little is known about its effects on organisms in soil and aquatic ecosystems. In this study, the effect of nZVI on degradation of DDT and its ecotoxicological effects on collembola (Folsomia candida) and ostracods (Heterocypris incongruens) were investigated. Two soils were used in suspension incubation experiments lasting for 7 and 30 d; a spiked (20 mg DDT kg−1) sandy soil and an aged (>50 years) DDT-polluted soil (24 mg DDT kg−1). These were incubated with 1 or 10 g nZVI kg−1, and residual toxicity in soil and the aqueous phase tested using ecotoxicological tests with collembola or ostracods. Generally, addition of either concentration of nZVI to soil led to about 50% degradation of DDT in spiked soil at the end of 7 and 30 d incubation, while the degradation of DDT was less in aged DDT-polluted soil (24%). Severe negative effects of nZVI were observed on both test organisms after 7 d incubation, but prolonged incubation led to oxidation of nZVI which reduced its toxic effects on the tested organisms. On the other hand, DDT had significant negative effects on collembolan reproduction and ostracod development. We conclude that 1 g nZVI kg−1 was efficient for significant DDT degradation in spiked soil, while a higher concentration was necessary for treating aged pollutants in soil. The adverse effects of nZVI on tested organisms seem temporary and reduced after oxidation.
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Authors
Erik J. JonerAbstract
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Authors
Erik J. JonerAbstract
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Sewage sludge application on soils represents an important potential source of silver nanoparticles (Ag NPs) to terrestrial ecosystems, and it is thus important to understand the fate of Ag NPs once in contact with soil components. Our aim was to compare the behavior of three different forms of silver, namely silver nitrate, citrate stabilized Ag NPs (5 nm) and uncoated Ag NPs (19 nm), in two soils with contrasting organic matter content, and to follow changes in binding strength over time. Soil samples were spiked with silver and left to age for 2 h, 2 days, 5 weeks or 10 weeks before they were submitted to sequential extraction. The ionic silver solution and the two Ag NP types were radiolabeled so that silver could be quantified by gamma spectrometry by measuring the 110mAg tracer in the different sequential extraction fractions. Different patterns of partitioning of silver were observed for the three forms of silver. All types of silver were more mobile in the mineral soil than in the soil rich in organic matter, although the fractionation patterns were very different for the three silver forms in both cases. Over 20% of citrate stabilized Ag NPs was extractible with water in both soils the first two days after spiking (compared to 1–3% for AgNO3 and uncoated Ag NPs), but the fraction decreased to trace levels thereafter. Regarding the 19 nm uncoated Ag NPs, 80% was not extractible at all, but contrary to AgNO3 and citrate stabilized Ag NPs, the bioaccessible fraction increased over time, and by day 70 was between 8 and 9 times greater than that seen in the other two treatments. This new and unexpected finding demonstrates that some Ag NPs can act as a continuous source of bioaccessible Ag, while AgNO3 is rapidly immobilized in soil.
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Authors
Claire Coutris Knut-Erik Tollefsen Mussie Woldehawariat John W Einset Erik J. Joner Deborah Helen Oughton Steven BrooksAbstract
Norway has the world’s largest facility for testing and improving CO2 capture. The aim of carbon capture technology is to minimize greenhouse gas emissions through a reaction between amines and effluents from gas power plants. During the overall process of CO2 capture, amines and their transformation products might escape to the environment through emissions, leakage, and as solid waste. The two main groups of transformation products with the most potential to cause environmental harm have been identified as nitrosamines and nitramines, both of which are considered to be carcinogenic. Recent theoretical modelling as well as laboratory experiments have found nitramine compounds, 2-nitroaminoethanol (CAS: 74386-82-6) and dimethylnitramine (CAS: 4164-28-7) to be present. However, despite the likelihood of these compounds increasing in the environment, no environmental toxicity data for these compounds currently exist. The aim of this project was to provide an environmental risk assessment for the selected nitramine compounds taking into account the key trophic groups within freshwater, marine and terrestrial environments. The toxicity assessment was made using a suite of standardised bioassays for the measure of acute and chronic toxicity. In the soil environment, the most potent compound was 2-nitroaminoethanol, which impaired the reproduction of earthworms and the seedling emergence of sunflower and ryegrass. The opposite was found in the aquatic environment, with freshwater and marine species consistently more affected by dimethylnitramine. All the tested freshwater species were more sensitive to nitramines than marine species. The selected amines were not acutely toxic to aquatic and soil species, with EC50 in the mg/L range. Both nitramines increased the nitrogen and carbon transformation activity of soil microorganisms.
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Erik J. JonerAbstract
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Erik J. JonerAbstract
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Authors
Erik J. JonerAbstract
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Authors
Claire Coutris Mussie Woldehawariat Erik J. Joner John W Einset Deborah Helen Oughton Knut-Erik TollefsenAbstract
No abstract has been registered
Authors
Erik J. JonerAbstract
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Abstract Due to difficulties in tracing engineered nanoparticles (ENPs) in complex media, there are few data on the exposure of soil biota to ENPs. This study used neutron activated cobalt (Co NPs) and silver (Ag NPs) nanoparticles, as well as soluble cobalt and silver salts, to assess the uptake, excretion and biodistribution in the earthworm Eisenia fetida. Concentrations of cobalt in worms after four weeks exposure reached 88% and 69% of the Co ions and Co NPs concentrations in food, respectively, while corresponding values for Ag ions and Ag NPs were 2.3% and 0.4%. Both Ag ions and Ag NPs in earthworms were excreted rapidly, while only 32% of the cobalt accumulated from Co ions and Co NPs were excreted within four months. High accumulation of cobalt was found in blood and in the digestive tract. Metal characterization in the exposure medium was assessed by sequential extraction and ultrafiltration. The Co NPs showed significant dissolution and release of ions, while Ag ions and particularly Ag NPs were more inert.
Authors
Emilie Bigorgne Laurent Foucaud Emmanuel Lapied Jérôme Labile Céline Botta Catherine Sirguey Jaïro Falla Jérôme Rose Erik J. Joner Francois Rodius Johanne NahmaniAbstract
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Authors
Emmanuel Lapied Johanne Y. Nahmani Elara Moudilou Perrine Chaurand Jérôme Labille Jérôme Rose Jean-Marie Exbrayat Deborah Helen Oughton Erik J. JonerAbstract
No abstract has been registered
Abstract
Due to sewage sludge application on soils, terrestrial ecosystems are very likely to be exposed to silver nanoparticles (AgNPs) and it is thus important to understand the behavior of Ag NPs once in contact with soil components. The aim of this work was to compare the behavior of silver under three forms, silver nitrate, citrate stabilized AgNPs (C-ANPs) and uncoated AgNPs (P-AgNPs), in two soils with contrasting organic matter content, and over time. The physical and chemical properties of the studied soils as well as the nanoparticles size, shape, crystallographic structure and specific surface area were characterized. Soil samples were spiked with silver nitrate, C-AgNPs or P-AgNPs, and let for ageing 2 hours, 2 days, 5 weeks or 10 weeks before they were submitted to sequential extraction. The ionic silver solution and the two AgNPs types were radiolabeled so that we could detect and quantify silver by gamma spectrometry by measuring the 110mAg tracer in the different sequential extraction fractions. We thereby obtained for each silver form, soil type and time point a distribution of silver in the different fractions. Silver was generally more mobile in the mineral soil, although the fractionation patterns were very different for the three silver types in both cases. Over 20% of the total C-AgNPs concentration were water soluble in both soils (<5% for AgNO3 and P-AgNPs) the first two days after spiking, but the fraction decreased to trace levels thereafter. This was compensated by an increase in the reducible fraction. Regarding P-AgNPs, 80% were not extractable at all, but contrary to AgNO3 and C-AgNPs, the water soluble and ion exchangeable fractions did not decrease over time in the mineral soil, and even increased in the organic soil.
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Authors
Vicki Stone Bernd Nowack Anders Baun Nico van den Brink Frank von der Kammer Maria Dusinska Richard Handy Steven Hankin Martin Hassellöv Erik J. Joner Teresa FernandesAbstract
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Abstract
In terrestrial ecotoxicology there is a serious lack of data for potential hazards posed by engineered nanoparticles (ENPs). This is partly due to complex interactions between ENPs and the soil matrix, but also to the lack of suitable toxicological end points in organisms that are exposed to ENPs in a relevant manner. Earthworms are key organisms in terrestrial ecosystems, but so far only physiological end points of low sensitivity have been used in ecotoxicity studies with ENPs. We exposed the earthworm Lumbricus terrestris to silver nanoparticles and measured their impact on apoptosis in different tissues. Increased apoptotic activity was detected in a range of tissues both at acute and sublethal concentrations (down to 4 mg/kg soil). Comparing exposure in water and soil showed reduced bioavailability in soil reflected in the apoptotic response. Apoptosis appears to be a sensitive end point and potentially a powerful tool for quantifying environmental hazards of ENPs.
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Authors
H. Dupré de Boulois Erik J. Joner C. Leyval I. Jakobsen B.D. Chen P. Roos Y. Thiry G. Rufyikiri B. Delvaux S. DeclerckAbstract
No abstract has been registered
Abstract
Studies regarding the environmental impact of engineered nanoparticles (ENPs) are hampered by the lack of tools to localize and quantify ENPs in water, sediments, soils, and organisms. Neutron activation of mineral ENPs offers the possibility of labeling ENPs in a way that avoids surface modification and permits both localization and quantification within a matrix or an organism. Time-course experiments in vivo also may be conducted with small organisms to study metabolism and exposure, two aspects currently lacking in ecotoxicological knowledge about ENPs. The present report explains some of the prerequisites and advantages of neutron activation as a tool for studying ENPs in environmental samples and ecologically relevant organisms, and it demonstrates the suitability of neutron activation for Ag, Co/Co3O4, and CeO2 nanoparticles. In a preliminary experiment with the earthworm Eisenia fetida, the dietary uptake and excretion of a Co nanopowder (average particle size, 4 nm; surface area, 59 m(2)/g) were studied. Cobalt ENPs were taken up to a high extent during 7 d of exposure (concentration ratios of 0.16-0.20 relative to the ENP concentration in horse manure) and were largely retained within the worms for a period of eight weeks, with less than 20% of absorbed ENPs being excreted. Following dissection of the worms, Co-60 was detected in spermatogenic cells, cocoons, and blood using scintillation counting and autoradiography. The experimental opportunities that neutron activation of ENPs offer are discussed.
Abstract
Considerable knowledge exists about the effect of aluminium (Al) on root vitality, but whether elevated levels of Al affect soil microorganisms is largely unknown. We thus compared soils from Al-treated and control plots of a field experiment with respect to microbial and chemical parameters, as well as root growth and vitality. Soil from a field experiment established in a 50 year old Norway spruce (Picea abies L.) stand where low concentrations of aluminum (0.5 mM AlCl3) had been added weekly or bi-weekly during the growth season for seven years was compared to a control treatment with respect to microbial and chemical parameters, as well as root growth and vitality. Analysis of soil solutions collected using zero tension lysimeters and porous suction cups showed that Al treatment lead to increased concentrations of Al, Ca and Mg and lower pH and [Ca+Mg]/[Al] molar ratio. Corresponding soil analyses showed that soil pH remained unaffected (pH 3.8), that Al increased, while extractable Ca and Mg decreased due to the Al treatment. Root ingrowth into cores placed in the upper 20 cm of the soil during 28 months was not affected by Al additions, neither was the mortality of these roots. The biomass of some taxonomical groups of soil microorganisms in the humus layer, analyzed using specific membrane components (phospholipid fatty acids; PLFAs), was clearly affected by the imposed Al treatment, but less so in the underlying mineral soil. Microbial community structure in the humus layer was also clearly modified by the Al treatment, whereas differences in the mineral horizon were less clear. Shifts in PLFA trans/cis ratios indicative of short term physiological stress were not observed. Yet, aluminium stress was indicated both by changes in community structure and in ratios of single PLFAs for treated/untreated plots. Thus, soil microorganisms were more sensitive indicators of subtle chemical changes in soil than chemical composition and vitality of roots.