The effect of sewage sludge application on the growth and absorption rates of Pb and As in water spinach

Abstract

This paper investigated the effect of the application of sewage sludge on the growth rates and absorption rates of Pb and As in potted water spinach. Our results indicated that application of sewage sludge promoted vegetable growth, and the dry weight of water spinach reached a maximal value (4.38 ± 0.82 g) upon 8% sludge application. We also found that the dry weights of water spinach after treatment were all greater than those of the control systems (CK). Treatment with sludge promoted the absorption of Pb and As in water spinach, with a significant (p < 0.05) increase of absorbed Pb following treatment concentrations above 10%, and a peak absorption of As at 8%. Finally, we found that concentrations of Pb and As were higher in rhizosphere-attached soil than in free pot.