N. Calace et al., Changes in copper, lead and zinc concentrations in plants from paper mill sludge-treated soils, ANN CHIM, 90(11-12), 2000, pp. 655-663
Effects of paper mill sludge addition on the availability of metals were st
udied on different soils both laboratory and naturally polluted; copper, le
ad and zinc concentrations were determined in Hordeum Distichum plants grow
n on the untreated and on sludge-treated soils. In some case a decrease of
metal concentration is observed on sludge-treated soils; these results are
consistent with the reduction of metal mobile forms in the soil, before pla
nt growth. The decrease of metal availability in sludge-treated soils may b
e related with the pH value of the soil after sludge addition.