Calmano, WolfgangWolfgangCalmanoAhlf, WolfgangWolfgangAhlfFörstner, UlrichUlrichFörstner2008-09-152008-09-151983International Conference Heavy Metals in the Environment, Heidelberg, September 1983, Edinburgh 1983, pp. 952-5http://tubdok.tub.tuhh.de/handle/11420/412Treatment of dredged sludge from the Hamburg harbour area with sulfurous acid (6%) shows nearly complete removal of Cd, Zn, and Mn within the first 10 minutes. Within 1 hour more than 50% of Cr, Ni, Pb and Hg are mobilized; dissolution of Cu and Fe reaches about 40%. The capability of certain bacteria (Thiobacillus thiooxidans and Thiobacillus ferrooxidans) to oxidize sulfur and ferrous iron respectively, while decreasing the pH value from 4-5 to about 2 was utilized for enhancing dissolution of metals from dredged sludge. Acidification with sulfurous acid to pH 4 and following bacterial leaching solubilized the following metal percentages from the dredged material: Cd and Co = 98%, Zn = 95%, Mn = 91%, Cu = 84%, Ni = 66%, Cr = 45%, Fe = 27% and Pb = 17 %.enhttp://doku.b.tu-harburg.de/doku/lic_ohne_pod.phpConference Paperurn:nbn:de:gbv:830-tubdok-485010.15480/882.41011420/41210.15480/882.410930768450Other