HEAVY-METAL DISTRIBUTION IN WASTE-WATER FROM A TREATMENT-PLANT

The results of a study using a multivariate statistical approach to de termine the effects of a treatment process on the distribution of heav y metals in the soluble fraction of a wastewater sample are reported. Treated, partially treated, and untreated wastewater samples from a mu nicipal treatment plant were analyzed to determine the concentrations of Cd, Cr, Cu, Ni, Pb, and Zn. Analyses were performed by atomic absor ption spectrophotometry. The concentration of solids in all samples of wastewater was determined too. Preliminary results show that the prim ary sedimentation affects the distribution of metals in the soluble fr action more than the secondary sedimentation, and the distribution is not related to the dates of sampling. The results of this study using such analysis may help to determine the optimal conditions as well as to understand the heavy metals removal process trend. (C) 1998 Academi c Press.