Understanding the total life cycle cost implications of reusing structural steel

Reuse of structural steel could be an environmentally superior alternative to the current practice, which is to recycle the majority (88%) of scrap steel. In spite of the potential benefits, and in a time when “sustainability” and “climate change” are critical societal issues, the question arises: why are greater rates of structural steel reuse not being observed? One of the major factors in the rate of structural steel reuse is how decision-makers understand the life cycle implications of their choice to recycle steel rather than reuse it. This paper contributes towards our understanding of these implications, particularly the cost implications, of reuse as an alternative to recycling by presenting a streamlined life cycle analysis and identifying the major contributors to each process. The results of a case study indicate that a significant reduction in some life cycle impact metrics (greenhouse gas emissions, water use) can result from reusing structural steel rather than recycling it. The largest contributors to the life cycle impact of recycling were the shredding, melting, and forming sub-processes. The largest contributor to reuse was the deconstruction sub-process. A total life cycle cost analysis is performed to understand the cost of damages to the environment and human health in combination with the cost of construction activities. Sensitivity and uncertainty analyses are also conducted to quantify variability in the results and determine economic conditions where the two processes have an equal cost.     

The adoption of green energy technologies: The role of policies in Austria,Germany, and Switzerland

We contribute to the existing research about policy-induced technology adoption in several ways. First, we suggest a new survey design to measure the energy-related policy environment. Second, we simultaneously estimate the policy effects for the adoption propensity and the adoption intensity simultaneously and, third, we compare the policy effects in the three countries, Austria, Germany, and Switzerland. Based on a representative sample of firms for all three countries we find that policies essentially promote the adoption of technologies and they are practically ineffective for the intensity, which poses a great challenge to future policy designs. Voluntary agreements or demand-related factors are among the most important drivers for the adoption propensity of green energy technologies. Given the current institutional framework in the surveyed countries, subsidies are more effective in Austria, taxes are more effective in Germany, and demand-related factors are relatively more effective in Switzerland.     

Biochar and hydrochar effects on greenhouse gas (carbon dioxide, nitrous oxide, and methane) fluxes from soils

With a growing world population and global warming, we are challenged to increase food production while reducing greenhouse gas (GHG) emissions. We studied the effects of biochar (BC) and hydrochar (HC) produced via pyrolysis or hydrothermal carbonization, respectively, on GHG fluxes in three laboratory incubation studies. In the first experiment, ryegrass was grown in sandy loam mixed with equal amounts of a nitrogen-rich peanut hull BC, compost, BC+compost, double compost, or no addition (control); wetting-drying cycles and N fertilization were applied. Biochar with or without compost significantly reduced NO emissions and did not change the CH uptake, whereas ryegrass yield was significantly increased. In the second experiment, 0% (control) or 8% (w/w) of BC (peanut hull, maize, wood chip, or charcoal) or 8% HC (beet chips or bark) was mixed into a soil and incubated at 65% water-holding capacity (WHC) for 140 d. Treatments included simulated plowing and N fertilization. All BCs reduced NO emissions by ～60%. Hydrochars reduced NO emissions only initially but significantly increased them after N fertilization to 302% (HC-beet) and 155% (HC-bark) of the control emissions, respectively. Large HC-associated CO emissions suggested that microbial activity was stimulated and that HC was less stable than BC. In the third experiment, nutrient-rich peanut hull BC addition and incubation over 1.5 yr at high WHCs did not promote NO emissions. However, NO emissions were significantly increased with BC after NHNO addition. In conclusion, BC reduced NO emissions and improved the GHG-to-yield ratio under field-relevant conditions. However, the risk of increased NO emissions with HC addition must be carefully evaluated.     

Impact of Climate Change on Ecological Quality Indicators and Biogeochemical Fluxes in the Baltic Sea: A Multi-Model Ensemble Study

Multi-model ensemble simulations using three coupled physical-biogeochemical models were performed to calculate the combined impact of projected future climate change and plausible nutrient load changes on biogeochemical cycles in the Baltic Sea. Climate projections for 1961-2099 were combined with four nutrient load scenarios ranging from a pessimistic business-as-usual to a more optimistic case following the Helsinki Commission's (HELCOM) Baltic Sea Action Plan (BSAP). The model results suggest that in a future climate, water quality, characterized by ecological quality indicators like winter nutrient, summer bottom oxygen, and annual mean phytoplankton concentrations as well as annual mean Secchi depth (water transparency), will be deteriorated compared to present conditions. In case of nutrient load reductions required by the BSAP, water quality is only slightly improved. Based on the analysis of biogeochemical fluxes, we find that in warmer and more anoxic waters, internal feedbacks could be reinforced. Increased phosphorus fluxes out of the sediments, reduced denitrification efficiency and increased nitrogen fixation may partly counteract nutrient load abatement strategies.     

Very high correlations between fresh weight and lipid-adjusted PCB-153 serum concentrations: irrespective of fasting status, age, body mass index, gender, or exposure distributions

Background and aim

Persistent organochlorine pollutants (POPs) have in epidemiological studies been associated with health hazards. The exposure window might be crucial and it is, accordingly, important to analyze exposure concentrations in samples collected at the window of interest. This makes the use of stored blood samples extremely interesting. However, small blood volumes from stored samples in biobanks means that the researchers in epidemiological studies most often have to select a limited number of biomarkers representing the POP exposure and abstain from analyses of lipid concentrations. This raises the question of the necessity of lipid adjustment. The aim of the present study was to evaluate the correlation between fresh weight and lipid adjusted concentrations.

Methods

We included data from studies were we have used the PCB congener 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB-153) as a biomarker for POP exposure and where fresh weight as well as lipid adjusted PCB-153 concentrations are known (n = 1628). The variety of the cohort members in the different studies gave us the possibility to better understand how well these measures correlate.

Results

When all individuals were included in the analyses a correlation coefficient of 0.95 between fresh weight and lipid adjusted serum concentrations was obtained. Restricting the analyses to specific subgroups (based on gender, fasting status, age and BMI) gave correlation coefficients between 0.85 and 0.97.

Conclusions

This study does strongly support the use of samples from biobanks in epidemiological studies for analyzing PCBs, at least regarding PCB-153, even though it is not possible to lipid adjust the results.     

How researchers frame scientific contributions to sustainable development: a typology based on grounded theory

Given that research on sustainable development usually relates to real-world challenges, it requires researchers to align scientific knowledge production with concrete societal problem situations. To empirically explore how researchers frame scientific contributions when designing and planning projects, we conducted a qualitative study on land use–related projects based on the methodology of grounded theory. We identified major influence factors and various types of research design. Among the factors that influence project framing, scientific considerations were found to be more important than expected. Core characteristics of project framings concerned (a) type of scientific contributions envisaged; (b) real-world sustainability challenges addressed, and (c) researchers’ conceptions of how knowledge would reach its addressees. Three different types of project framing were found, suggesting that framing strongly depends on (the researchers’ perception of) how well a real-world problem situation is understood scientifically and how strongly are societal actors aware of the problem and act upon it. The spectrum of how researchers planned that knowledge would reach its addressees comprised communicating results to interactive conceptions allowing for mutual learning throughout the research process. The typology reveals a variety of useful and promising project framings for sustainable development research. The typology may serve to reconcile conceptual ideals and expectations with researchers’ realities.     

Echoes from the Past: A Healthy Baltic Sea Requires More Effort

Integrated sediment multiproxy studies and modeling were used to reconstruct past changes in the Baltic Sea ecosystem. Results of natural changes over the past 6000 years in the Baltic Sea ecosystem suggest that forecasted climate warming might enhance environmental problems of the Baltic Sea. Integrated modeling and sediment proxy studies reveal increased sea surface temperatures and expanded seafloor anoxia (in deep basins) during earlier natural warm climate phases, such as the Medieval Climate Anomaly. Under future IPCC scenarios of global warming, there is likely no improvement of bottom water conditions in the Baltic Sea. Thus, the measures already designed to produce a healthier Baltic Sea are insufficient in the long term. The interactions between climate change and anthropogenic impacts on the Baltic Sea should be considered in management, implementation of policy strategies in the Baltic Sea environmental issues, and adaptation to future climate change.     

A new device for formaldehyde and total aldehydes real-time monitoring

A new sensitive technique for the quantification of formaldehyde (HCHO) and total aldehydes has been developed in order to monitor these compounds, which are known to be involved in air quality issues and to have health impacts. Our approach is based on a colorimetric method where aldehydes are initially stripped from the air into a scrubbing solution by means of a turning coil sampler tube and then derivatised with 3-methylbenzothiazolinone-2-hydrazone in acid media (pH?=??0.5). Hence, colourless aldehydes are transformed into blue dyes that are detected by UV–visible spectroscopy at 630 nm. Liquid core waveguide LCW Teflon® AF-2400 tube was used as innovative optical cells providing a HCHO detection limit of 4 pptv for 100 cm optical path with a time resolution of 15 min. This instrument showed good correlation with commonly used techniques for aldehydes analysis such as DNPH derivatisation chromatographic techniques with off-line and on-line samplers, and DOAS techniques (with deviation below 6 %) for both indoor and outdoor conditions. This instrument is associated with simplicity and low cost, which is a prerequisite for indoor monitoring.