Initial pH

q(mg/g)

Pb(II)

Cd(II)

Zn(II)

2 2.5 3

3.5 4

4.5 5 5.5

0.965 0.984 0.9964 0.9962 0.9905 0.993 0.971 0.968

0.998 0.998 0.997 0.999 0.9988 1.000 0.9978 0.9974

2.794 17.146 12.750 17.842 27.580 14.537 10.999 6.9750