Bioavailability and Speciation Analysis of Heavy Metals in Textile Dyeing Sludge

The paper investigates the speciation of heavy metals in textile dyeing sludge samples from Shanghai dyeing plants using Tessier A sequential extraction method. The results show that Cd exists mainly in exchangeable and Fe-Mn oxides fractions, accounting for 47.6% and 23.2% respectively. Therefore the conclusions that Cd is more active than other elements and it has potential impact on environment are draw and more attention should be paid to it. Bioavailability of Pb, Cu, Zn, Ni and Cd was also investigated with textile dyeing sludge samples in a pot scale experiment. Heavy metals in textile dyeing sludge and plants were analyzed after Loliumperenn L. had been grown on the textile dyeing sludge for 60 days. Chemical fractions of textile dyeing sludge were analyzed with a sequential extraction technique. The bioavailability of heavy metals decreased in the order of Cu and Zn>Pb>Ni and Cd.