Heavy Metal Remediation by Dry Mycelium Membranes: Approaches to Sustainable Lead Remediation in Water

Lead contamination poses significant and lasting health
risks,
particularly in children. This study explores the efficacy of dried
mycelium membranes, distinct from live fungal biomass, for the remediation
of lead (Pb­(II)) in water. Dried mycelium offers unique advantages,
including environmental resilience, ease of handling, biodegradability,
and mechanical reliability. The study explores Pb­(II) removal mechanisms
through sorption and mineralization by dried mycelium hyphae in aqueous
solutions. The sorption isotherm studies reveal a high Pb­(II) removal
efficiency, exceeding 95% for concentrations below 1000 ppm and ∼63%
above 1500 ppm, primarily driven by electrostatic interactions. The
measured infrared peak shifts and the pseudo-second-order kinetics
for sorption suggests a correlation between sorption capacity and
the density of interacting functional groups. The study also explores
novel surface functionalization of the mycelium network with phosphate
to enhance Pb­(II) removal, which enables remediation efficiencies
>95% for concentrations above 1500 ppm. Scanning electron microscopy
images show a pH-dependent formation of Pb-based crystals uniformly
deposited throughout the entire mycelium network. Continuous cross-flow
filtration tests employing a dried mycelium membrane demonstrate its
efficacy as a microporous membrane for Pb­(II) removal, reaching remediation
efficiency of 85–90% at the highest Pb­(II) concentrations.
These findings suggest that dried mycelium membranes can be a viable
alternative to synthetic membranes in heavy metal remediation, with
potential environmental and water treatment applications.