Table 3: Synergism parameter ( ).

HE (mL) Zn2+  
25 (ppm) ( )
HE-Zn2+  
Zn2+  
50 (ppm) ( )
HE-Zn2+  

20.280.160.411.02500.470.64 1.06
40.350.160.471.03010.470.761.4354
60.470.160.711.53510.470.882.3408
80.650.160.944.90.470.821.0305
100.470.160.641.23660.470.751.1236