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SEGH Member participated in the Antarctic Circumpolar Expedition

02 July 2017
Francois De Vleeschouwer, researcher at EcoLab, (CNRS, Toulouse France) and SEGH secretary, had the opportunity to embark onboard the RV Akademik Treshnikov to participate in the ACE Expedition


François De Vleeschouwer, researcher at EcoLab, (CNRS, Toulouse France) and SEGH secretary, had the opportunity to embark onboard the RV Akademik Treshnikov to participate in the ACE Expedition. From December 2016 to March 2017, scientific teams from all over the world joined into an unprecedented expedition around Antarctica. From biology to climatology to oceanography, researchers from 22 selected projects worked on a number of interrelated fields revolving around Antarctica.

 

François De Vleeschouwer is involved in a British Antarctic Survey-supervised project dealing with « Measuring the changes in the ocean’s capacity to absorb CO2 ». Concentrations of CO2 in the atmosphere have increased since 1750 AD as a result of human activity. This is linked to warming of the atmosphere and oceans, changes in climate, recession of ice sheets and sea level rise. More than one quarter of this CO2 is absorbed by the oceans; the Southern Ocean accounting for 43%. The capacity of the Southern Ocean to absorb CO2 has recently been limited (according to some models) by an increase in the strength of the Southern Hemisphere Westerly Winds (SHW), which draw CO2 saturated waters back to the surface. This will potentially drive up atmospheric greenhouse gases and accelerate rates of global warming.Reconstructing past changes in the SHW and their impact on the oceanic CO2 sink is therefore a major priority for palaeoclimate science.

 

François De Vleeschouwer participated to the leg 2 of the ACE navigation from Hobart, Tasmania to Punta Arenas, Chile. After an unfortunate storm that obliged the expedition to cancel the sampling at Macquarie Island, the boat navigated throuhgh Antarctic waters to then cross the Drake’s Passage. F. De Vleeschouwer sampled soils, mosses and peatlands on various islands from the Antarctic (Scott, Maher, Lauft, Siple) and sub-Antarctic (Diego Ramirez Archipelago).

 

The main objective of this project is to determine the Holocene (last 12000 yrs) changes in the strength of the SHW over the Southern Ocean by generating records of wind-driven aerosols and other proxies in sediment records from lakes and bogs on the west coasts of sub-Antarctic islands and, These data will be further used in global climate models to test if past changes in the SHW explain past variations in atmospheric CO2.

Further information can be found on : http://spi-ace-expedition.ch/

 

Francois de Vleeschouwer, CNRS, Toulouse, France

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  • Lead sorption characteristics of various chicken bone part-derived chars 2018-01-18

    Abstract

    Recycling food waste for beneficial use is becoming increasingly important in resource-limited economy. In this study, waste chicken bones of different parts from restaurant industry were pyrolyzed at 600 °C and evaluated for char physicochemical properties and Pb sorption characteristics. Lead adsorption isotherms by different chicken bone chars were carried out with initial Pb concentration range of 1–1000 mg L−1 at pH 5. The Pb adsorption data were better described by the Langmuir model (R2 = 0.9289–0.9937; ARE = 22.7–29.3%) than the Freundlich model (R2 = 0.8684–0.9544; ARE = 35.4–72.0%). Among the chars derived from different chicken bone parts, the tibia bone char exhibited the highest maximum Pb adsorption capacity of 263 mg g−1 followed by the pelvis (222 mg g−1), ribs (208 mg g−1), clavicle (179 mg g−1), vertebrae (159 mg g−1), and humerus (135 mg g−1). The Pb adsorption capacities were significantly and positively correlated with the surface area, phosphate release amount, and total phosphorus content of chicken bone chars (r ≥ 0.9711). On the other hand, approximately 75–88% of the adsorbed Pb on the chicken bone chars was desorbable with 0.1 M HCl, indicating their recyclability for reuse. Results demonstrated that chicken bone char could be used as an effective adsorbent for Pb removal in wastewater.

  • Occurrence of pharmaceuticals and personal care products, and their associated environmental risks in a large shallow lake in north China 2018-01-13

    Abstract

    Eighteen selected pharmaceuticals and personal care products (PPCPs), consisting of five non-antibiotic pharmaceuticals (N-APs), four sulfonamides (SAs), four tetracyclines (TCs), four macrolides (MCs), and one quinolone (QN) were detected in water, pore water, and sediment samples from Baiyangdian Lake, China. A total of 31 water samples and 29 sediment samples were collected in March 2017. Caffeine was detected with 100% frequency in surface water, pore water, and sediment samples. Carbamazepine was detected with 100% frequency in surface water and sediment samples. Five N-APs were prominent, with mean concentrations of 4.90–266.24 ng/l in surface water and 5.07–14.73 μg/kg in sediment samples. Four MCs were prominent, with mean concentrations of 0.97–29.92 ng/l in pore water samples. The total concentrations of the different classes of PPCPs followed the order: N-APs (53.26%) > MCs (25.39) > SAs (10.06%) > TCs (7.64%) > QNs (3.64%) in surface water; N-APs (42.70%) > MCs (25.43%) > TCs (14.69%) > SAs (13.90%) > QNs (3.24%) in sediment samples, and MCs (42.12%) > N-APs (34.80%) > SAs (11.71%) > TCs (7.48%) > QNs (3.88%) in pore water samples. The geographical differences of PPCP concentrations were largely due to anthropogenic activities. Sewage discharged from Baoding City and human activities around Baiyangdian Lake were the main sources of PPCPs in the lake. An environmental risk assessment for the upper quartile concentration was undertaken using calculated risk quotients and indicated a low or medium-high risk from 18 PPCPs in Baiyangdian Lake and its five upstream rivers.

  • Association of soil potassium and sodium concentrations with spatial disparities of prevalence and mortality rates of hypertensive diseases in the USA 2018-01-12

    Abstract

    Crop available soil potassium is generally low and on the decline in the southeastern states of the USA because of the increasing crop and runoff removal and decreasing application of potassium fertilizer. Hypertension-related mortality rates are also high in the southeastern states and are on the rise. Among 41 elements analyzed from 4856 sites across all 48 states, potassium is identified as the only independent element whose soil concentration has significant association with spatial disparities of essential hypertension and hypertension-related mortality rates in the 48 states between 1999 and 2014. Essential hypertension and hypertension-related mortality rates of the 6 states with the lowest soil potassium concentration are about 50–26% higher than that of the 6 states with the highest soil potassium concentration in the 48 states (RR: 1.50, 1.26, low CI 95% 1.47, 1.25 and upper CI 95% 1.53, 1.27, respectively). Though sodium was not identified as an independent factor, an apparent significant inverse correlation exists between hypertension prevalence rates and soil sodium concentration in the 48 states (r = − 0.66, p = 0.00). There likely has been a decline of potassium in USA produces per unit weight over time and a likely association between this decline and increasing hypertension rate, particularly in the southeastern states. Hence, results of this study suggest the need of increasing potassium intakes for reducing hypertension-related mortality rates in the southeastern states. Results of this study also support further examination of potential benefits of sodium from mixture of non-chloride salts in natural produces.