Sorption and bioavailability of arsenic in selected Bangladesh soils.
Environ Geochem Health
; 31 Suppl 1: 61-8, 2009 Apr.
Article
em En
| MEDLINE
| ID: mdl-19116761
ABSTRACT
The bioavailability of arsenic (As) in the soil environment is largely governed by its adsorption-desorption reactions with soil constituents. We have investigated the sorption-desorption behaviour of As in four typical Bangladeshi soils subjected to irrigation with As-contaminated groundwater. The total As content of soils (160 samples) from the Laksham district ranged from <0.03 to approximately 43 mg kg(-1). Despite the low total soil As content, the concentration of As in the pore water of soils freshly irrigated with As-contaminated groundwater ranged from 0.01 to 0.1 mg l(-1). However, when these soils were allowed to dry, the concentration of As released in the pore water decreased to undetectable levels. Remoistening of soils to field moisture over a 10-day period resulted in a significant (up to 0.06 mg l(-1)) release of As in the pore water of soils containing >10 mg As kg(-1) soil, indicating the potential availability of As. In soils containing <5 mg As kg(-1), As was not detected in the pore water. A comparison of Bangladeshi soils with strongly weathered long-term As-contaminated soils from Queensland, Australia showed a much greater release of As in water extracts from the Australian soils. However, this was attributed to the much higher loading of As in these Australian soils. The correlation of pore water As with other inorganic ions (P, S) showed a strongly significant (P < 0.001) relationship with P, although there was no significant relationship between As and other inorganic cations, such as Fe and Mn. Batch sorption studies showed an appreciable capacity for both As(V) and As(III) sorption, with As(V) being retained in much greater concentrations than As(III).
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Arsênio
/
Poluentes do Solo
/
Poluentes Químicos da Água
Limite:
Humans
País/Região como assunto:
Asia
/
Oceania
Idioma:
En
Revista:
Environ Geochem Health
Assunto da revista:
QUIMICA
/
SAUDE AMBIENTAL
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Austrália