Ions Salt added Concentration (ppm) Recovery (%)       Mn Cr Ni Pb Co K+ KCl 1000 95 103 84 95 92 Cl- KCl 1000 90 100 101 101 93 Al3+ Al2(SO4)3 250 88 113 83 110 86 Fe3+ FeCl3 250 82 98 91 102 91 Zn2+ ZnSO4 1000 87 106 88 96 97

Values of recovery are average of triplicate analysis

Table 1: The effect of interference ion on heavy metal recovery