8 



7 6 5 



-log (Cu)-p 



+ 



o 



Figure 4-8. Variations in metal activities (M) of manganese, 

 zinc and iron with total copper concentration. 



Note: A) Aquil medium, IQ-^-^m EDTA; B) Aquil with lO'^-^M EDTA, 

 lO-^MTris. 



54 



