Fig. 6. Free ionic concentrations of (a) Ca, (b) Zn, and (c) Cd based upon speciation calculations in the column leachates. 
, no additives; 
, 0.3% Ca(OH)2; 
, 0.5% zeolite A; 
, 2.5% zeolite A.
Fig. 6. Free ionic concentrations of (a) Ca, (b) Zn, and (c) Cd based upon speciation calculations in the column leachates. , no additives; , 0.3% Ca(OH)2; , 0.5% zeolite A; , 2.5% zeolite A.