EFFECTS OF ALUM-TREATED WASTE-WATER SLUDGE ON BARLEY GROWTH

Citation
Fh. Wang et al., EFFECTS OF ALUM-TREATED WASTE-WATER SLUDGE ON BARLEY GROWTH, Water, air and soil pollution, 108(1-2), 1998, pp. 33-49
Citations number
52
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environmental Sciences","Water Resources","Metereology & Atmospheric Sciences
ISSN journal
0049-6979
Volume
108
Issue
1-2
Year of publication
1998
Pages
33 - 49
Database
ISI
SICI code
0049-6979(1998)108:1-2<33:EOAWSO>2.0.ZU;2-H
Abstract
Alum sludge derived from a municipal wastewater plant was used as a so il amendment in a greenhouse study with barley (Hordeum vulgare) as th e test crop. Treatment variables included the soil pH (4.5, 5.1 and 6. 5), the amount of Al in the sludge (control = 30 mg Al-T/g; alum sludg es = 38 and 52 mg Al-T/g), and the sludge application rate (100 and 27 0 kg N-T/ha). Soil amendment with the two alum sludges reduced soil pH , increased Al3+ activity in the soil solution, and reduced barley gro wth over the 6-week experiment. Barley growth decreased as the Al3+ ac tivity in the sludged soil solution increased, but for a given (Al3+) the phytotoxicity of Al was markedly pH dependent. For example, at a p H of 5.0 +/- 0.1 an Al3+ activity of 0.5 mu M was sufficient to inhibi t plant growth by about 50%; this IC50 value increased five-fold to ab out 2.5 mu M when the soil pH was 4.5 +/- 0.1. This decrease in the to xicity of Al3+ with acidification was explained in terms of a competit ive interaction between the H+-ion and Al3+ at the root surface. Stepw ise multiple regression allowed the prediction of aerial leaf biomass from soil pH and sludge application rate.