Acid mine drainage
(AMD) is a pervasive source of metal pollution
that severely impacts freshwater ecosystems and has a direct impact
on human health. Conventional active and passive methods work very
well for removing iron in AMD remediation, which is typically the
highest metallic impurity. However, conventional passive remediation
fails to remove all aluminum, which has severe ecological implications.
Removal of aluminum ions using chelation, which traditionally uses
small molecules that bind metals tightly for sequestration, holds
promise. Yet, chelation strategies are limited because once introduced
into surface water, small molecules are difficult to reclaim and often
persist in the environment as pollutants. To address this, we have
designed six unique scaffolds based on functional graphenic materials
(FGMs) to create nonsoluble materials that could be placed at the
end of a passive remediation process to remove persistent aluminum.
When tested for efficacy, all six FGMs successfully demonstrated a
reversible capacity to remove aluminum from acidic water, chelating
up to 21 μg of Al/mg of FGM. Furthermore, when they were exposed
to E. coli as an approximation for environmental
compatibility, viability was unaffected, even at high concentrations,
suggesting these FGMs are nontoxic and viable candidates for passive
chelation-based remediation.