Contact time (min)
q(mg/g)
Pb(II)
Cd(II)
Zn(II)
15 30 45 60 75 90
0.910 0.964 0.976 0.988 0.996 1.000
0.735 0.768 0.808 0.821 0.895 0.903
0.184 0.836 2.140 3.450 4.751 5.403