The investigation of dissolved and suspended-particulate trace metal fractionation in the Black Sea

摘要: Abstract A sequential filtration-ion-exchange column scheme has been developed for the investigation of dissolved trace metal fractionation. The method is designed to separate water metals rapidly into particulate and colloidal-sized species, anionic metal-organic and/or metal-sulfide complexes, ‘free’ (hydrated) cations labile major ion complexes. suspended-particulate matter (0.4 μm filterable material) further subjected a leaching procedure weak-acid leachable, strong-acid refractory fractions. These methods are evaluated with respect laboratory experiments field results. have applied study chemical fractionation in Black Sea, world's largest anoxic basin. We present here results Co, Ni, Cu, Zn, Cd, Pb. Co distribution best explained terms scavenging-regeneration cycle Mn-oxyhydroxides across sulfide interface coprecipitation Fe-sulfides deep waters. Nickel displays nearly constant concentrations depth apparently unaffected by redox processes. Class B (Cu, Pb) high surface waters then decrease low concentrations, consistent precipitation below interface. was generally dominated oxic zone shifting probably suspended soluble forms throughout most column. For leachable forms, phases, important form relatively reactive (weak-acid leachable) precipitates just