ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Lab-scale batch experiments using several 150-L transparent acrylic reactors wereconducted to develop optimum capping materials that can capture phosphorous released frompolluted lake sediments. The sediment used in the experiment was very fine clay (7.7 Φ in mean grainsize), and organic carbon (Corg) content was as high as 2%. Four kinds of batches with differentcapping materials; powdered-gypsum (CaSO4·2H2O), granular-gypsum, sand, composite material(gypsum+sand), and one control batch were operated for 45 days. Phosphorous fluxes released frombottom sediments in the control batch were estimated to be 4.3 mg·m-2·d-1, while 0.9 mg·m-2·d-1, 1.0mg·m-2·d-1, 2.2 mg·m-2·d-1, and 0.5 mg·m-2·d-1 in the batch capped with powdered-gypsum,granular-gypsum, sand, and composite material, respectively. The results obtained from lab-scalebatch experiments show that there were 80% reduction of phosphorous for some materials such aspowdered-gypsum, granular-gypsum, and composite material, whereas sand only about 50%. Increasein apatite-P fraction (48% → 80%) in the gypsum batches, compared to the control batch, indicatesthat abundant Ca2+ and SO42- ions from the gypsum added into oxygen-depleted sediment surfacemight have supplied abundant oxygen by reducing the sulfate ions very actively, resulting in Ca-Pprecipitates
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/15/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.544-545.561.pdf
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