Talks
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Send to friend- Oral communication at the 8th IWA Leading-Edge Conference on Water and Wastewater Technologies held in Amsterdam (The Netherlands), 6 - 10 June 2011:
Integration of CO2 Sequestration in Two-stage Biological Wastewater Treatment Plants.
S.S.S. Salek*[1], R. Kleerebezem*, H.M. Jonkers**, M.C.M. van Loosdrecht*
*Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628BC Delft, The Netherlands, **Department of Geotechnology, Faculty of Civil Engineering and Geosciences, Delft University of Technology, Stevinweg 1, 2628CN Delft, The Netherlands
[1] Corresponding author. E-mail address: S.S.ShayeganSalek@tudelft.nl
Tel.: +31 15 278 1551; fax: +31 15 278 2355.
- Oral communication at the Goldschmidt Conference, Knoxville, Tennessee, June 13-18 2010:
Survival Strategies during Bacterial Biomineralisation: Evidence from Cyanobacterial Precipitation of Hydrozincite in Sardinia, Italy.
B.T. NGWENYA (1)*, M. MAGENNIS (1) AND F. PODDA (2).
1 School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh. EH9 3JW (*correspondence: bryne.ngwenya@ed.ac.uk)
2 Department of Earth Sciences, University of Cagliari, Via Trentino 51, I-09127, Cagliari, Italy (fpodda@unica.it)
In spring of 2006, we collected water samples and bio-precipitates from the Rio Naracauli which drains Pb-Zn mine waste piles in SW Sardinia, Italy. The objective is to study downstream trends in hydrogeochemistry, mineralisation textures and trace metal partitioning between water and hydrozincite. Microscopic studies of the bio-precipitates reveal a characteristic botryoidal morphology with a porous texture consisting of microscopic and nanoscopic plates. While the association with photosynthetic organisms suggests that bio-precipitation is a passive process [1], laboratory experiments suggest that the presence of organic molecules is critical to produce this morphology. We hypothesize that the texture arises via agglomeration of nanoscopic and microscopic crystals by extracellular polymeric substances [2], or nucleation of plates within organic globules produced by metabolising cells [3]. The bacterial surface therefore plays a critical role in determining the texture of the bio-precipitate, such that the porous structure facilitates nutrient/metabolite exchange in the face of mineral precipitation.
[1] Podda et al. [2000]. Appl. Environ. Microbiol. 66, 5092–5098. [2] Braisaant et al. (2003) J. Sed. Res. 73, 485–490. [3] Aloisi et al. (2006) Geology 24, 1017–1020.
