The removal of heavy
metals from wastewater remains a challenge
due to the limitations of current remediation methods. This study
aims to develop multicomponent composites as inexpensive and environmentally
friendly sorbents with enhanced capture of cadmium (Cd) and lead (Pb).
The composites are based on calcium montmorillonite (CM) and activated
carbon (AC) because of their proven effectiveness as sorbents for
diverse toxins in environmental settings. In this study, we used a
combination of computational and experimental methods to delineate
that β-lactoglobulin enhances CM and AC binding and protection
properties for Cd and Pb. Modeling and molecular dynamics simulations
investigated the formation of material systems formed by CM and AC
in complex with β-lactoglobulin and predicted their capacity
to bind heavy metal ions at neutral pH conditions. Our simulations
suggest that the enhanced binding properties of the material systems
are attributed to the presence of several binding pockets formed by
β-lactoglobulin for the two heavy metal ions. At neutral pH
conditions, divalent Cd and Pb shared comparable binding propensities
in all material systems, with the former being consistently higher
than the latter. To validate the interactions depicted in simulations,
two ecotoxicological models (
L. minor
and
H. vulgaris
) were exposed to
Cd, Pb, and a mixture of the two. The inclusion of CM-lactoglobulin
(β-lactoglobulin amended CM) and AC-lactoglobulin (β-lactoglobulin
amended AC) at 0.05–0.2% efficiently and dose-dependently reduced
the severe toxicity of metals and increased the growth parameters.
This high efficacy of protection shown in the ecotoxicological models
may result from the numerous possible interaction pockets of the β-lactoglobulin-amended
materials depicted in simulations. The ecotoxicological models support
the agreement with computations. This study serves as a proof of concept
on how computations in tandem with experiments can be used in the
design of multicomponent clay- and carbon-based sorbent amended systems
with augmented functionalities for particular toxins.