Biomedical subjects

T Winiarski

Publications and source records attributed to T Winiarski.

14 recordsLinked to original sources

PubMed2005

Can geotextiles modify the transfer of heavy metals transported by stormwater in infiltration basins?

Geotextiles are fibrous materials increasingly employed for the design of infiltration basins. However, their influence on the transfer of contaminants carried by stormwater has not been fully investigated. This study, based on column leaching experiments, aims at showing the effect of geotextiles on the transfer of three heavy metals (Zn, Pb and Cd) in a reactive soil (simulating an infiltration basin at laboratory scale). This effect depends on several factors, such as type of geotextile, hydric conditions (geotextile water content), hydraulic conditions (flow-rates) and the number of geotextiles installed. In all cases, geotextiles influence heavy metal retention by modifying flow and thus regulating contact between these metals and the reactive soil.

Cadmium↗

PubMed2004

Retention of three heavy metals (Zn, Pb, and Cd) in a calcareous soil controlled by the modification of flow with geotextiles.

Although geotextiles are increasingly employed in stormwater infiltration basins, their influence on the flow and transfer of contaminants, such as heavy metals, has not been fully investigated. Leaching column experiments were conducted to characterize the flow and transfer of three heavy metals (zinc, lead, and cadmium) in a calcareous soil with and without geotextiles under steady-state flow and close to saturation forthe soil. The influence of geotextiles was characterized for two types of geotextiles (needlepunched and thermosealed) and for two different initial saturation degrees for the needlepunched geotextile. The main results showed that, when placed wet, the needlepunched geotextile had no influence. When placed dry, it homogenized the flow in its surroundings and thus allowed better contact between heavy metals and the reactive soil, resulting in an increase of their retention. The thermosealed geotextile, placed dry, homogenized the flow and increased retention over a larger area, resulting in optimal global retention. In conclusion, geotextiles could be used in infiltration basins, provided that their effect on both flow and heavy metal retention is optimized by appropriate design--choice of geotextiles--and appropriate monitoring--control of hydric conditions.

Adsorption↗

PubMed2004

A 300 year history of lead contamination in northern French Alps reconstructed from distant lake sediment records.

Lead concentrations and isotopic ratios were measured along two well-dated sediment cores from two distant lakes: Anterne (2100 m a.s.l.) and Le Bourget (270 m a.s.l.), submitted to low and high direct human impact and covering the last 250 and 600 years, respectively. The measurement of lead in old sediment samples (>3000 BP) permits, in using mixing-models, the determination of lead concentration, flux and isotopic composition of purely anthropogenic origin. We thus show that since ca. 1800 AD the regional increase in lead contamination was mostly driven by coal consumption ((206)Pb/(207)Pb approximately 1.17-1.19; (206)Pb/(204)Pb approximately 18.3-18.6), which peaks around 1915 AD. The increasing usage of leaded gasoline, introduced in the 1920s, was recorded in both lakes by increasing Pb concentrations and decreasing Pb isotope ratios. A peak around 1970 ((206)Pb/(207)Pb approximately 1.13-1.16; (206)Pb/(204)Pb approximately 17.6-18.0) corresponds to the worldwide recorded leaded gasoline maximum of consumption. The 1973 oil crisis is characterised by a drastic drop of lead fluxes in both lakes (from approximately 35 to <20 mg cm(-2) yr(-1)). In the late 1980s, environmental policies made the Lake Anterne flux drop to pre-1900 values (<10 mg cm(-2) yr(-1)) while Lake Le Bourget is always submitted to an important flux (approximately 25 mg cm(-2) yr(-1)). The good match of our distant records, together and with a previously established series in an ice core from Mont Blanc, provides confidence in the use of sediments as archives of lead contamination. The integration of the Mont Blanc ice core results from Rosman et al. with our data highlights, from 1990 onward, a decoupling in lead sources between the high elevation sites (Lake Anterne and Mont Blanc ice core), submitted to a mixture of long-distance and regional contamination and the low elevation site (Lake Le Bourget), where regional contamination is predominant.

Altitude↗

PubMed2002

Implementation of a monitoring system to measure impact of stormwater runoff infiltration.

Stormwater infiltration is a drainage mode, which is more and more used in urban areas in France. Given the characteristics of urban surfaces, and especially the loads of various pollutants contained in stormwater, it is important to assess the impact of stormwater infiltration systems on soil and groundwater by carrying out field experiments. The main difficulty is due to the complexity of the system observed and the need of multidisciplinary approaches. Another difficulty is that measurements are carried out in situ, in an uncontrolled environment submitted to quantitatively and qualitatively highly variable interferences. Very long term monitoring is needed to get representative results. In order to contribute to solve these problems, the OTHU project has recently been launched in Lyon (France). One of its key action concerns a long-term (10 years) experiment on an infiltration basin specifically rehabilitated for measurements and operational drainage issues. This paper presents the experimental site, the objectives of the project and the way the monitoring process has been built according to the various disciplines involved (biology, ecology, hydrology, chemistry and soil sciences) and to the will of assessing all the uncertainties in the measurement process.

Cities↗

PubMed1983