Table 2 Average heavy metal concentration in sewage effluent.

Cadmium (Cd)

0.019 µg/ml

0.01 µg/ml

^10,11

Lead (Pb)

3.149 µg/ml

5.00 µg/ml

Nickel (Ni)

0.031 µg/ml

0.20 µg/ml

Chromium (Cr)

0.079 µg/ml

0.10 µg/ml

Manganese (Mn)

0.255 µg/ml

0.20 µg/ml