In:
Materials Science Forum, Trans Tech Publications, Ltd., Vol. 544-545 ( 2007-5), p. 561-564
Abstract:
Lab-scale batch experiments using several 150-L transparent acrylic reactors were
conducted to develop optimum capping materials that can capture phosphorous released from polluted lake sediments. The sediment used in the experiment was very fine clay (7.7 Φ in mean grain
size), and organic carbon (Corg) content was as high as 2%. Four kinds of batches with different capping materials; powdered-gypsum (CaSO4·2H2O), granular-gypsum, sand, composite material
(gypsum+sand), and one control batch were operated for 45 days. Phosphorous fluxes released from bottom sediments in the control batch were estimated to be 4.3 mg·m-2·d-1, while 0.9 mg·m-2·d-1, 1.0
mg·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-scale batch experiments show that there were 80% reduction of phosphorous for some materials such as
powdered-gypsum, granular-gypsum, and composite material, whereas sand only about 50%. Increase in apatite-P fraction (48% → 80%) in the gypsum batches, compared to the control batch, indicates
that abundant Ca2+ and SO4 2- ions from the gypsum added into oxygen-depleted sediment surface
might have supplied abundant oxygen by reducing the sulfate ions very actively, resulting in Ca-P precipitates.
Type of Medium:
Online Resource
ISSN:
1662-9752
DOI:
10.4028/www.scientific.net/MSF.544-545
DOI:
10.4028/www.scientific.net/MSF.544-545.561
Language:
Unknown
Publisher:
Trans Tech Publications, Ltd.
Publication Date:
2007
detail.hit.zdb_id:
2047372-2
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