Title of article :
Microbial controls on metal mobility under the low nutrient
fluxes found throughout the subsurface
Author/Authors :
Stephen Boult، نويسنده , , Victoria L. Hand، نويسنده , , David J. Vaughan، نويسنده ,
Issue Information :
هفته نامه با شماره پیاپی سال 2006
Abstract :
Laboratory simulations and field studies of the shallow subsurface have shown that microbes and their extracellular products can
influence the mobility of toxic metals from waste disposal sites. Modelling the transport of contaminants in groundwater may,
therefore, require the input of microbial ecology data in addition to geochemical data, thus increasing the costs and the uncertainty of
predictions. However, whether microbial effects on contaminant mobility occur extensively in the natural subsurface is unknown
because the conditions under which they have been observed hitherto are generally unrepresentative of the average subsurface
environment. Here, we show that microbial activity affects the mobility of a toxic trace metal (Cu) under the relatively low nutrient
fluxes that dominate subsurface systems. More particularly, we show that under these low nutrient conditions, microbes and microbial
products can immobilize metal but may themselves be subject to subsequent mobilization, thus complicating the pattern of metal
storage and release. Our results show that the capability of microbes in the subsurface to change both the capacity of porous media to
store metal, and the behaviour of metal that is released, is not restricted to the well researched environments close to sites of waste
disposal. We anticipate our simulations will be a starting point for generating input data for transport models, and specifying the
mechanism of metal remobilisation in environments more representative of the subsurface generally.
Keywords :
Extracellular-polysaccharide (EPS) , Subsurface , Metal mobility , Low nutrient , SEC , SEC-ICP-MS
Journal title :
Science of the Total Environment
Journal title :
Science of the Total Environment