Leaching of PAHs from rubber modified asphalt pavements

The present study aimed to, for the first time, quantify the total content of 16 priority EPA PAHs in end-of-life tyre derived crumb rubber granulates and various manufactured rubberised asphalt mix designs. After identifying the availability of 16 EPA PAHs, the leaching behaviour of rubberised asphalt specimens, were evaluated using the Dynamic Surface Leaching Test (DSLT) based on CEN/TS 16637-2:2014 standard. This was prior to modelling the release mechanisms of PAHs by utilizing a mathematical diffusion-controlled leaching model. According to the results, the total content of 16 EPA PAHs in crumb rubber granulates ranged between 0.061 and 8.322 μg/g, which were associated with acenaphthene and pyrene, respectively. The total content of PAHs in rubberised asphalt specimens varied between 0.019 and 4.992 μg/g depending on the volume of crumb rubber granulates in the asphalt concrete mix design, and type of binder. Results of the leaching experiments revealed that the highest leached PAHs were benzo[b]fluoranthene, benzo[k]fluoranthene and naphthalene with a 64-days cumulative release per specimen surface area > 1 μg/m2. Acenaphthylene, fluoranthene, fluorene and indeno[1,2,3-c,d]pyrene were released in cumulative concentrations between 0.1 and 1 μg/m2. The PAHs with a cumulative release potential below 0.1 μg/m2 during DSLT were benzo[a]anthracene, benzo[a]pyrene, benzo[g,h,i]perylene and chrysene. The diffusion coefficients, which were calculated by mathematical modelling of DSLT data, revealed that the leaching process of 16 EPA PAHs from surface of rubberised asphalt concrete mix designs fitted all the criteria set by the NEN 7345 standard for diffusion-controlled leaching during all stages of leaching experiments

Combiner la gestion durable des eaux pluviales et l'utilisation de la chaleur du sol ; suivi de la maison écologique Hanson, Watford, UK

Colloque avec actes et comité de lecture. Internationale.International audienc

The Microbiology of Permeable Pavements

SUMMARY Pervious pavement systems (meaning permeable pavements within this context and used interchangeably) are known to retain and degrade hydrocarbons within the structure of the pavement. The key to this decontamination has been shown to be the naturally occurring microbial communities living on the pavement building materials. Research by Formpave and Coventry University has shown that once oil is trapped on a suitable strongly oil-retaining geotextile membrane layer, the oil rapidly becomes a food source for the microbial communities. Oil is metabolised by aerobic bacteria and fungi that convert the oil into sugars such as glucose for growth and reproduction. Over time, a network of microbial growth spreads over the surface of Inbitex forming a biofilm, further improving the filtration and purification properties of the system. The presence of a large food source growing on the oil attracts larger predatory organisms such as protozoa and metazoa to the biofilm. These organisms play an important role in maintaining the free-draining characteristics of the geotextile and also the vigorous growth of the oil degrading organisms. An understanding of the processes underpinning the environmental benefits of permeable pavements is essential in order to optimise the operation of the system

Scoping Potential Routes to UK Civil Unrest via the Food System: Results of a Structured Expert Elicitation

We report the results of a structured expert elicitation to identify the most likely types of potential food system disruption scenarios for the UK, focusing on routes to civil unrest. We take a backcasting approach by defining as an end-point a societal event in which 1 in 2000 people have been injured in the UK, which 40% of experts rated as “Possible (20–50%)”, “More likely than not (50–80%)” or “Very likely (>80%)” over the coming decade. Over a timeframe of 50 years, this increased to 80% of experts. The experts considered two food system scenarios and ranked their plausibility of contributing to the given societal scenario. For a timescale of 10 years, the majority identified a food distribution problem as the most likely. Over a timescale of 50 years, the experts were more evenly split between the two scenarios, but over half thought the most likely route to civil unrest would be a lack of total food in the UK. However, the experts stressed that the various causes of food system disruption are interconnected and can create cascading risks, highlighting the importance of a systems approach. We encourage food system stakeholders to use these results in their risk planning and recommend future work to support prevention, preparedness, response and recovery planning

Scoping potential routes to UK civil unrest via the food system: results of a structured expert elicitation

We report the results of a structured expert elicitation to identify the most likely types of potential food system disruption scenarios for the UK, focusing on routes to civil unrest. We take a backcasting approach by defining as an end-point a Societal Event in which 1 in 2,000 people have been injured in the UK, which 40% of experts rated as “Possible (20–50%)” or “More likely than not (50–80%)” or “Very likely (>80%)” over the coming decade. Over a longer timeframe of 50 years, nearly 80% of experts rated such an event as “Possible (20–50%)” or “More likely than not (50–80%)” or “Very likely (>80%)”. The experts considered two food system scenarios and ranked their plausibility of contributing to the given societal scenario. For a timescale of 10 years the majority identified a food distribution problem as the most likely. Over a timescale of 50 years the experts were more evenly split between the two scenarios, but over half thought the most likely route to civil unrest would be a lack of total food in the UK. Overall, in the next 50 years, 45% of participants said there is a greater than 20% chance of civil unrest due to insufficient food in the UK due to extreme weather or ecological collapse. However, the experts stressed that the various causes are interconnected, can create cascading risks and highlighted the importance of a systems approach. We encourage food system stakeholders to use these results in their risk planning, and recommend future work to support prevention, preparedness, response and recovery planning

A New Ocean State After Nuclear War

Nuclear war would produce dire global consequences for humans and our environment. We simulated climate impacts of US-Russia and India-Pakistan nuclear wars in an Earth System Model, here, we report on the ocean impacts. Like volcanic eruptions and large forest fires, firestorms from nuclear war would transport light-blocking aerosols to the stratosphere, resulting in global cooling. The ocean responds over two timescales: a rapid cooling event and a long recovery, indicating a hysteresis response of the ocean to global cooling. Surface cooling drives sea ice expansion, enhanced meridional overturning, and intensified ocean vertical mixing that is expanded, deeper, and longer lasting. Phytoplankton production and community structure are highly modified by perturbations to light, temperature, and nutrients, resulting in initial decimation of production, especially at high latitudes. A new physical and biogeochemical ocean state results, characterized by shallower pycnoclines, thermoclines, and nutriclines, ventilated deep water masses, and thicker Arctic sea ice. Persistent changes in nutrient limitation drive a shift in phytoplankton community structure, resulting in increased diatom populations, which in turn increase iron scavenging and iron limitation, especially at high latitudes. In the largest US-Russia scenario (150 Tg), ocean recovery is likely on the order of decades at the surface and hundreds of years at depth, while changes to Arctic sea-ice will likely last thousands of years, effectively a “Nuclear Little Ice Age.” Marine ecosystems would be highly disrupted by both the initial perturbation and in the new ocean state, resulting in long-term, global impacts to ecosystem services such as fisheries.publishedVersio