Trace metals partitioning among different sedimentary mineral phases and the deposit-feeding polychaete Armandia brevis.
Sci Total Environ
; 543(Pt A): 248-266, 2016 Feb 01.
Article
em En
| MEDLINE
| ID: mdl-26595396
Trace metals (Cd, Co, Cu, Fe, Mn, Ni, Pb, Zn) were determined in two operationally defined fractions (HCl and pyrite) in sediments from Ensenada and El Sauzal harbors (Mexico). The HCl fraction had significantly higher metal concentrations relative to the pyrite fraction in both harbors, underlining the weak tendency of most trace metals to associate with pyrite. Exceptionally, Cu was highly pyritized, with degrees of trace metal pyritization (DTMP) >80% in both harbors. Dissolved Fe flux measurements combined with solid phase Fe sulfide data indicated that 98 mt of Fe are precipitated as iron sulfides every year in Ensenada Harbor. These Fe sulfides (and associated trace metals) will remain preserved in the sediments, unless they are perturbed by dredging or sediment resuspension. Calculations indicate that dredging activities could export to the open ocean 0.20±0.13 to (0.30±0.56)×10(3) mt of Cd and Cu, respectively, creating a potential threat to marine benthic organisms. Degrees of pyritization (DOP) values in Ensenada and El Sauzal harbors were relatively low (<25%) while degrees of sulfidization (DOS) were high (~50%) because of the contribution of acid volatile sulfide. DOP values correlated with DTMP values (p≤0.001), indicating that metals are gradually incorporated into pyrite as this mineral is formed. Significant correlations were also found between DTMP values and -log(Ksp(MeS)/Ksp(pyr)) for both harbors, indicating that incorporation of trace metals into the pyrite phase is a function of the solubility product of the corresponding metal sulfide. The order in which elements were pyritized in both harbors was Zn≈Mn
AssuntosPalavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Poliquetos
/
Poluentes Químicos da Água
/
Monitoramento Ambiental
/
Sedimentos Geológicos
/
Metais Pesados
Limite:
Animals
País/Região como assunto:
Mexico
Idioma:
En
Revista:
Sci Total Environ
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Espanha
País de publicação:
Holanda
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Poliquetos
/
Poluentes Químicos da Água
/
Monitoramento Ambiental
/
Sedimentos Geológicos
/
Metais Pesados
Limite:
Animals
País/Região como assunto:
Mexico
Idioma:
En
Revista:
Sci Total Environ
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Espanha
País de publicação:
Holanda