Attribution of Global Warming Potential impacts in a multifunctional metals industry system using different system expansion and allocation methodologies

PurposeIn order to reach a more circular economy, materials previously classified as waste can be upgraded and turned into valuable co-products, with associated environmental benefits. The generation of co-products raises many questions around the multifunctionality issue from a life cycle perspective. This article explores the attribution of Global Warming Potential (GWP) impacts for an ironmaking process, HIsarna, which additionally produces two co-products: zinc-rich process dust and slag, suitable for the zinc and cement sectors, respectively.MethodsA wide range of LCA allocation methodologies are applied to attribute impacts between the main product, hot metal, and the two co-products. These include system expansion, physical allocation, economic allocation and zero burden allocation. Each method attributes a different GWP to each co-product. Additionally, different perspectives are explored to consider the most suitable methods according to the co-product user and the co-product producer. For instance, it might be in the co-product user’s interest that the co-product GWP was minimised, and lower than other material inputs performing a similar function. Conversely, the co-product producer may be incentivised to lower its primary product’s GWP by attributing the greatest possible burden to the co-products.Results and discussionThe GWP impacts for zinc-rich process dust range from 0 to 3.71 kg CO2 eq. per kg. At the higher end, the GWP of zinc-rich dust would be higher than that of primary zinc concentrate. A similarly wide range is applicable for slag, 0 to 1.27 kg CO2 eq. per kg. This impacts the final GWP applied to HIsarna hot metal, which has an initial GWP of 1.72 kg CO2 eq. per kg but could decrease to 1.17 kg CO2 eq. per kg depending on the allocation methods employed. This would be a substantial reduction of over 30%, larger than many decarbonisation options that are predicted to provide. This scenario would also heavily burden the co-products and could be in conflict with interests of a co-product user seeking to utilise low emissions feedstocks as part of a decarbonisation strategy.ConclusionsThe reduction in GWP impact attributed to hot metal with the different approaches highlights the relevance of harmonizing the allocation methods used for co-products. The appropriateness of each of the approaches for attributing GWP impacts has been explored, offering insights as to how the benefits of such systems could be assessed and attributed in the future as circularity strategies and valuable co-products become more prevalent

Quantitative real-time PCR (qPCR) for Eimeria tenella replication - Implications for experimental refinement and animal welfare

AbstractThe Eimeria species are highly pathogenic parasites of chickens. Research aimed at reducing their impact is hindered by a lack of non-subjective, quantitative, tools to measure parasite replication in the host. The time-consuming, and often time-sensitive, nature of existing approaches precludes their use in large-scale genetic, epidemiological, and evolutionary analyses. We have used quantitative real-time PCR (qPCR) to accurately quantify Eimeria tenella in chicken tissue and shown this to be more efficient and sensitive than traditional methodologies. We tested four chicken-specific reference qPCR assays and found beta-actin (actb) to be optimal for sample normalisation. In an experimental setting, chickens were inoculated with 500, 1500, or 4500 E. tenella oocysts and parasite replication and the impact of infection measured by i) qPCR analysis of DNA extracted from caecal tissues collected at five and eight days post-infection (dpi), ii) faecal oocyst counts (FOCs) on samples taken from six to eight dpi, and iii) lesion scoring on caeca collected post-mortem at five and eight dpi. Quantitative real-time PCR test results indicated a significant dose-dependent increase in parasite numbers among study groups for samples collected five dpi (i.e., prior to gametogony) (R2=0.994) (p<0.002) but not in those from day eight (after most oocyst shedding) (R2=0.006) (p>0.379). A strong dose-dependent increase in parasite replication and severity of infection was also revealed by FOC (R2=0.997) and lesion scoring. Importantly, qPCR offers substantial improvements for animal welfare via improved statistical power and reduced group sizes in experimental studies. The described qPCR method overcomes subjective limitations of coproscopic quantification, allows reproducible medium- to high-throughput examination of tissues, faeces, and oocysts, and is a valuable tool for determining the impact of Eimeria infections in both experimental and field settings

New Directions for Rights-Based Fisheries Management

SpeechKEYWORDS: Ecosystem & Oceans Policy Approaches to Fisheries Management, & Marine Resources for Recreation & Tourism, Fisheries economics, Keynote speake

Heating up the Holocene

With direct meteorological data on the Antarctic Peninsula only dating back to the 1950s, scientists must search elsewhere for climate change records of the distant past. A series of expeditions to analyse ancient moss are poised to provide a longer-term perspective on the region’s warming pattern