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Tiltaksorientert overvåking av Årdalsfjorden i 2023. Overvåking for Hydro Aluminium Årdal
Get PDFProsjektleder: Sigurd ØxnevadNIVA har utført tiltaksorientert overvåking av Årdalsfjorden i 2023 på oppdrag for Hydro Aluminium Årdal. I overvåkingen er det gjort analyser av polysykliske aromatiske hydrokarboner (PAH-forbindelser), fluorid og tungmetaller (arsen, bly, kadmium, kobber, krom, kvikksølv, nikkel og sink) i prøver av blåskjell fra fire stasjoner. Det var høye konsentrasjoner av PAH-forbindelser i blåskjellene fra Hundshammar. Dette er stasjonen som ligger nærmest utslippspunktene innerst i fjorden. Det var overskridelse av miljøkvalitetsstandardene (EQS) for benzo(a)pyren og fluoranten i blåskjellene fra Hundshammar. Kjemisk tilstand for stasjonen Hundshammar klassifiseres derfor som «ikke god». De andre stasjonene var i «god» kjemisk tilstand. Konsentrasjoner av benzo(a)pyren og fluoranten over grenseverdiene innebærer at det er en risiko for sekundær forgiftning i dyr som spiser blåskjell. Selv om det var forhøyede konsentrasjoner av benzo(a)pyren og fluoranten i blåskjellene fra Hundshammar, så er det likevel en god utvikling med nedadgående konsentrasjon av disse prioriterte stoffene siden 2017.Hydro Aluminium ÅrdalpublishedVersio
Tiltaksorientert overvåking av sjøområdet utenfor Elkem Carbon i Kristiansand i 2023
Get PDFProsjektleder Sigurd ØxnevadNIVA har gjennomført tiltaksorientert overvåking av sjøområdet utenfor Elkem Carbon og REC Solar i Kristiansand i 2023. I overvåkingen er det gjort analyser av polysykliske aromatiske hydrokarboner (PAH-forbindelser), tungmetaller (arsen, bly, kadmium, kobber, krom, kvikksølv, nikkel og sink) i prøver av blåskjell fra fem stasjoner. Det var høyest konsentrasjoner av PAH-forbindelser i blåskjellene fra Lumber, og lavere konsentrasjoner med økende avstand fra Elkembukta. Blåskjellene fra Lumber og Fiskå hadde konsentrasjoner av benzo(a)pyren og fluoranten som oversteg miljøkvalitetsstandardene for disse prioriterte stoffene. Kjemisk tilstand for disse stasjonene klassifiseres derfor til «ikke god». Det var ikke forhøyede konsentrasjoner av prioriterte stoffer i blåskjellene fra de tre andre stasjonene. Stasjonene Svensholmen, Timlingen og Flekkerøygapet klassifiseres til «god» kjemisk tilstand.Elkem Carbon i KristiansandpublishedVersio
Technical note: Preventing CO2 overestimation from mercuric or copper(II) chloride preservation of dissolved greenhouse gases in freshwater samples
Get PDFThe determination of dissolved gases (O2, CO2, CH4, N2O, N2) in surface waters allows the estimation of biological processes and greenhouse gas fluxes in aquatic ecosystems. Mercuric chloride (HgCl2) has been widely used to preserve water samples prior to gas analysis. However, alternates are needed because of the environmental impacts and prohibition of mercury. HgCl2 is a weak acid and interferes with dissolved organic carbon (DOC). Hence, we tested the effect of HgCl2 and two substitutes (copper(II) chloride – CuCl2 – and silver nitrate – AgNO3), as well as storage time (24 h to 3 months) on the determination of dissolved gases in low-ionic-strength and high-DOC water from a typical boreal lake. Furthermore, we investigated and predicted the effect of HgCl2 on CO2 concentrations in periodic samples from another lake experiencing pH variations (5.4–7.3) related to in situ photosynthesis. Samples fixed with inhibitors generally showed negligible O2 consumption. However, effective preservation of dissolved CO2, CH4 and N2O for up to 3 months prior to dissolved gas analysis was only achieved with AgNO3. In contrast, HgCl2 and CuCl2 caused an initial increase in CO2 and N2O from 24 h to 3 weeks followed by a decrease from 3 weeks to 3 months. The CO2 overestimation, caused by HgCl2 acidification and a shift in the carbonate equilibrium, can be calculated from predictions of chemical speciation. Errors due to CO2 overestimation in HgCl2-preserved water, sampled from low-ionic-strength and high-DOC freshwater, which is common in the Northern Hemisphere, could lead to an overestimation of the CO2 diffusion efflux by a factor of > 20 over a month or a factor of 2 over the ice-free season. The use of HgCl2 and CuCl2 for freshwater preservation should therefore be discontinued. Further testing of AgNO3 preservation should be performed under a large range of freshwater chemical conditions.publishedVersio
Utslepp av kjølevatn til Idsefjorden frå planlagt datasenter på Jørpeland. Konsekvensvurdering for marint miljø
Get PDFProsjektleder: Lars G. GolmenPå Jørpeland i Ryfylke er det planer om å etablere eit datasenter. Senteret får behov for 2 m3/s kjølevatn frå Idsefjorden, henta frå 80-100 m djup og sleppt ut på grunnare vatn. Idsefjorden sin økologiske tilstand er god. Der et visse spørsmål knytt til kjemisk tilstand i sedimenta og tilstanden til strandsonefloraen. Vasskvaliteten er tilfredsstillande til bruk som kjølevatn, og vassutskiftinga i resipienten vil i stort ikkje bli nemnande påverka av kjølevatnet. Utslepp av varmt kjølevatn må gå til 40m eller djupare for å unngå negativ påverknad i overflatelaget.COWIpublishedVersio
Application of low-density polyethylene (LDPE) passive samplers for monitoring PAHs in groundwater
Get PDFEquilibrium passive sampling continues to find increasing use for performing in situ assessments and monitoring of hydrophobic organic compounds (HOCs). Although this method has been successfully used in several field studies including open surface waters and sediments, comparatively, their use in groundwater has been very limited. In this study, low-density polyethylene (LDPE) passive samplers were deployed for 80 days in three groundwater wells contaminated with polycyclic aromatic hydrocarbons (PAHs). Prior to deployment, LDPE was loaded with performance reference compounds (PRCs) consisting of deuterated PAHs and their release used to ascertain system equilibrium. Within the 80-day deployment period, LDPE-groundwater equilibrium was confirmed for PAHs with molecular weights (MWs) in the range of 178 to 228 (i.e. anthracene, chrysene). Measured freely dissolved concentrations (Cw) were between one to three orders of magnitude lower than the total filtered concentrations (Ctotal) in the studied wells. The sum of PAHs (ΣPAHs) measured based on Cw and Ctotal were 2.05, 0.07 and 29.2 μg L−1 and 197, 59.7 and 1010 μg L−1, at wells 1, 2 and 3, respectively. A separate dataset, comprising long-term (2010 to 2022) concentrations of PAHs in total (i.e., unfiltered) groundwater, is also presented to provide insight into PAH contamination levels at the assessed groundwater wells based on conventional measurement. Estimated in situ LDPE daily clearance volumes (2.34 to 27.56 Ld−1) for the target analytes were far less than the daily turnover of ground water (144 to 348 Ld−1) encountered in the wells eliminating the possibility of depletive sampling of the groundwater by the passive samplers. These results represent the first published study on the practical application of equilibrium passive sampling using LDPE for monitoring and quantitatively assessing PAHs in groundwater. Also, this work demonstrates that LDPEs are a useful tool for measuring the Cw of PAHs in groundwater, a critical contaminant in many ecological and human health risk assessments.publishedVersio
Beyond the food on your plate: Investigating sources of microplastic contamination in home kitchens
Get PDFGiven that a substantial amount of time is spent in kitchens preparing food, the kitchen equipment used may be relevant in determining the composition and amount of microplastics ending up on our dinner plate. While previous research has predominantly focused on foodstuffs as a source of microplastics, we emphasise that micro- and nanoplastics are ubiquitous and likely originate from diverse sources. To address the existing knowledge gap regarding additional sources contributing to microplastics on our dinner plates, this review investigates various kitchen processes, utensils and equipment (excluding single-use items and foodstuffs) to get a better understanding of potential microplastic sources within a home kitchen. Conducting a narrative literature review using terms related to kitchenware and kitchen-affiliated equipment and processes, this study underscores that the selection of preparation tools, storage, serving, cooking, and cleaning procedures in our kitchens may have a significant impact on microplastic exposure. Mechanical, physical, and chemical processes occurring during food preparation contribute to the release of microplastic particles, challenging the assumption that exposure to microplastics in food is solely tied to food products or packaging. This review highlights diverse sources of microplastics in home kitchens, posing concerns for food safety and human health.publishedVersio
Effects of wave exposure and habitat fragmentation on growth and grazing of rocky shore seaweeds: a mesocosm experiment
Get PDFSeaweeds are foundation species on rocky shores that are exposed to a series of stressors. These include wave exposure, desiccation, grazing, and human activities, with habitat fragmentation as a common result. As part of climate and biodiversity changes, we are expecting increased winds and more frequent storm events, warmer climate, and trophic downgrading of ecosystems, causing overgrazing events. Here, we present the results from a two-factorial mesocosm experiment on the relationship between wave exposure, habitat fragmentation and growth (branching and tip elongation) of Fucus vesiculosus in the intertidal and upper subtidal. We found that intertidal seaweeds branched significantly more at low than high wave exposure. There was no effect of habitat fragmentation on branching, and no effects on tip growth from either wave exposure or habitat fragmentation. The experiment suffered greatly from uncontrolled grazing. Gastropod coverage was higher inside seaweed patches than in the seaweed free areas between and outside of the patches. In basins with highly fragmented seaweed patches, we found more gastropods at low than high wave exposure, whereas in basins with low fragmentation we found more gastropods at higher wave exposure. The percent coverage of gastropods in the basins did not seem to impact seaweed growth.publishedVersio
Lactic and propionic acid bacteria starter cultures for improved nutritional properties of pea, faba bean and lentil
Get PDFIncreasing plant-based food consumption as a sustainable and health-oriented alternative to meat is pivotal. Pulses are rich in proteins, minerals, and vitamins; however, they also contain antinutritional compounds, impairing their nutritional value. This study addresses this challenge through the development and application of four distinct microbial consortia in pulse-based fermentations, featuring lactic acid bacteria or a combination of lactic and propionic acid bacteria. Microbial starters significantly reduced galacto-oligosaccharides in all pulse materials, concurrently degrading vicine and convicine in faba beans, while the impact on tannins in faba beans and lentil was moderate. Fermentation with lactic acid and propionic acid bacteria consortia exhibited notable vitamin B12 production, and the effect on the content of phenolic compounds of the studied pulses was also evidenced. Additionally, genomic analyses discerned distinctive profiles among the samples, elucidating the microbial community dynamics shaping fermentation outcomes. The results of this study proved how fermentation can advance the development of pulse-based products with improved nutritional and sustainability attributes.publishedVersio
Exploring BPA alternatives – Environmental levels and toxicity review
Get PDFBisphenol A alternatives are manufactured as potentially less harmful substitutes of bisphenol A (BPA) that offer similar functionality. These alternatives are already in the market, entering the environment and thus raising ecological concerns. However, it can be expected that levels of BPA alternatives will dominate in the future, they are limited information on their environmental safety. The EU PARC project highlights BPA alternatives as priority chemicals and consolidates information on BPA alternatives, with a focus on environmental relevance and on the identification of the research gaps. The review highlighted aspects and future perspectives. In brief, an extension of environmental monitoring is crucial, extending it to cover BPA alternatives to track their levels and facilitate the timely implementation of mitigation measures. The biological activity has been studied for BPA alternatives, but in a non-systematic way and prioritized a limited number of chemicals. For several BPA alternatives, the data has already provided substantial evidence regarding their potential harm to the environment. We stress the importance of conducting more comprehensive assessments that go beyond the traditional reproductive studies and focus on overlooked relevant endpoints. Future research should also consider mixture effects, realistic environmental concentrations, and the long-term consequences on biota and ecosystems.publishedVersio
Driftskontroll av kalkdoseringsanlegg i Vegårvassdraget. År 2023
Get PDFProsjektleder: Øyvind KasteDriftskontroll av kalkdoseringsanlegg er et system som overvåker effektiviteten ved anlegg som doserer kalk i sure vassdrag. På Hauglandsfoss doseringsanlegg i Storelva, Vegårvassdraget, ble det etablert driftskontroll i 2001. Denne rapporten gir en dokumentasjon på driften i 2023 og inneholder samtidig en fortegnelse over hendelser og avvik som kan danne grunnlag for forbedringstiltak knyttet til driftsrutiner, installasjoner eller kalkingsstrategi.Vegårshei kommunepublishedVersio