Comparison of SFE with Soxhlet in the analyses of PCDD/PCDFs and PCBs in sediment

The efficiency of supercritical fluid extraction (SFE) for the isolation of polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) from sediments was investigated by comparing SFE with Soxhlet. Five sediments obtained from an international interlaboratory study were used as a test material. SFE was performed with an automatic system where extracted analytes were collected by solid-phase trapping using carbon mixed with Celite as an adsorbent. For the first time, SFE of the most toxic PCBs, coplanar PCBs, was studied with real sediment samples. The majority of PCBs investigated, a total of 38 congeners from tri- to decachlorinated, were quantitatively extracted from sediment by SFE with pure CO2 at pressure 400 atm and temperature 100 degrees C. Under these conditions a successful extraction was obtained also for PCDD/PCDFs except for hepta- and octachlorinated congeners. Copper powder added to the sediment efficiently prevented the transfer of sulfur from the sample during SFE. The TEQs of both PCDD/PCDFs and PCBs obtained by SFE corresponded well with those obtained by the Soxhlet-based method. The reproducibility of SFE was high for both groups.     

Community energy initiatives to alleviate fuel poverty: the material politics of Energy Cafés

Community action has an increasingly prominent role in the debates surrounding transitions to sustainability. Initiatives such as community energy projects, community gardens, local food networks and car sharing clubs provide new spaces for sustainable consumption, and combinations of technological and social innovations. These initiatives, which are often driven by social good rather than by pure monetary motives, have been conceptualised as grassroots innovations. Previous research in grassroots innovations has largely focused on conceptualising such initiatives and analysing their potential for replication and diffusion; there has been less research in the politics involved in these initiatives. We examine grassroots innovations as forms of political engagement that is different from the 1970s’ alternative technology movements. Through an analysis of community-run Energy Cafés in the United Kingdom, we argue that while present-day grassroots innovations appear less explicitly political than their predecessors, they can still represent a form of political participation. Through the analytical lens of material politics, we investigate how Energy Cafés engage in diverse – explicit and implicit, more or less conscious – forms of political engagement. In particular, their work to “demystify” clients’ energy bills can unravel into various forms of advocacy and engagement with energy technologies and practices in the home. Some Energy Café practices also make space for a needs-driven approach that acknowledges the embeddedness of energy in the household and wider society.     

Distribution of total mercury, methyl mercury and selenium in pod of killer whales (Orcinus Orca) stranded in the northern area of Japan: comparison of mature females with calves

Total mercury (T-Hg) and selenium (Se) concentrations in liver, kidney and muscle from a pod of killer whales including five mature females and three calves stranded in the northern area of Japan were analyzed. In the mature female, contamination level of T-Hg in the liver sample (62.2+/-21.9 microg/wet g) was markedly higher than that in kidney sample and muscle sample. The molar ratio of T-Hg to Se in the liver sample was approximately 1, and those in the kidney and muscle samples were markedly lower than 1. These results suggest that the formation of HgSe compound increases the hepatic accumulation of mercury (Hg). In contrast, contamination level of T-Hg in the calf organs was much lower than that in the mature female organs. These results suggest that the transfer of Hg from the mother to the fetus via placenta and/or to calf via milk is trace.     

Effective antibacterial and antioxidant properties of methanolic extract of Laurus nobilis seed oil

This study was carried out to determine the in vitro antimicrobial and antioxidant activities of the essential oil, seed oil, and methanolic extract of seed oil obtained from Laurus nobilis L. (Lauraceae). The methanolic extract of seed oil exhibited more effective antibacterial activity comparing to essential oil and seed oil, GC-MS analyses of the essential oil resulted in the identification of 25 compounds. 1.8-Cineol (44.72%), a-Terpinyl acetate (12.95%), Sabinene (12.82%) were the main components. The fatty acid composition was characterized with the high content of linoleic acid (40.79%) and lauric acid (38.08%). The 50% (IC50) inhibition activity of the essential oil on the free radical DPPH was determined as 94.655 mg ml(-1), whereas IC50 value of methanolic extract of seed oil was found unstable. In the case of the linoleic acid system, oxidation of linoleic acid was inhibited by essential oil and methanolic extract of seed oil, which showed 64.28 and 88.76% inhibition, respectively. The inhibition value of the methanolic extract of seed oil was quite close to the synthetic antioxidant BHT, 92.46% inhibition.     

The influence of sweating on the heat transmission properties of cold protective clothing studied with a sweating thermal manikin.

One of the objectives of the European SUBZERO project was to study the influence of sweat evaporation and condensation on the heat transmission properties of cold protective clothing. With the sweating thermal manikin Coppelius, water vapour transfer through and water condensation in the clothing can be determined simultaneously with the thermal insulation. In this study, 4 cold protective ensembles, intended for use temperatures between 0 and -50 degrees C, were measured with the dry manikin and at 2 different sweating rates. In addition, the ensembles were measured with non-sweating thermal manikins and in wear trials.     

Volatile organic compounds in indoor environment and photocatalytic oxidation: state of the art

Volatile organic compounds (VOCs) are the major pollutants in indoor air, which significantly impact indoor air quality and thus influencing human health. A long-term exposure to VOCs will be detrimental to human health causing sick building syndrome (SBS). Photocatalytic oxidation of VOCs is a cost-effective technology for VOCs removal compared with adsorption, biofiltration, or thermal catalysis. In this paper, we review the current exposure level of VOCs in various indoor environment and state of the art technology for photocatalytic oxidation of VOCs from indoor air. The concentrations and emission rates of commonly occurring VOCs in indoor air are presented. The effective catalyst systems, under UV and visible light, are discussed and the kinetics of photocatalytic oxidation is also presented.     

Electricity production using food waste: a review

Environmental Chemistry Letters - Conventional treatments of food waste such as incineration, landfilling, and composting require large land areas and induce contamination in air, soil,...     

Soft copy photogrammetry to measure shore platform erosion on decadal timescales

Shore platform erosion is considered a driving mechanism for cliff recession on many rocky coasts and, in the vicinity of sea defence structures, a threat to their stability, yet the spatial pattern of platform erosion, as well as the rate of lowering, is poorly documented. Measurements based on techniques such as the micro-erosion metre or laser scanner, though highly accurate for short time scales and specific locations, are difficult to extrapolate in space and time. They also fail to record mesoscale changes such as block removal. This paper describes a technique to quantify spatial and temporal changes and presents first results.