Materials and Equipment
Three identical plastic bowls were labelled A, B, and C and they were filled with the wastewater samples collected
from a textile, a metallurgical and a pharmaceutical industry respectively. All the bowls were filled to a height of
16cm and kept outside in the open air.
Analyses of the samples were done in the Environmental/Analytical Laboratory of the Department of Chemistry,
University of Lagos, using the following equipment: pH meter; spectrophotometer; DO meter; and atomic
absorption spectrometer and other ancillary equipment. Standard analytical procedures were followed.