L1 /
13
CH3041
HEAVY METALS
• If a metal is
present in aqueous soln it
may travel long distances.
may travel long distances.
• Complexation with humic
matter often increases metal solubility.
eg. most Cun+(aq) is present as Cun+-FA(aq)
eg. most Cun+(aq) is present as Cun+-FA(aq)
• All free TM ions precipitate
at high pH.
• The precipitated metals may concentrate
by density and may also cause other metals
to coprecipitate in the same place.
by density and may also cause other metals
to coprecipitate in the same place.
• The ‘heavy metals’ Pb & Hg bioaccumulate readily, often as a result of bioconversion into organometallic cmpds which are lipophilic. eg. Cd BCF
2.26E6 in shellfish
