3.2. Cadmium
Cd concentrations (0.19–0.62 mg/L) in wastewater samples collected from in-let to cell-5, exceeded the permissible limit (0.1 mg/L) set for industrial and sewage wastewater (Pak-EPA, 2000), while its concentrations (0.05–0.09 mg/L) in the samples from cells 6 and 7 and out-let met the permissible limit (Table 3).
Furthermore, Cd concentrations in the out-let wastewater samples were significantly lower (P < 0.01) than in-let of the CW, indicating that the CW has effectively removed the Cd from the wastewater. In