Nanoadsorbents for Pollutants Cleanup: Balancing Efficiency and Environmental Sustainability

Efficient and scalable nano-adsorbents have emerged as promising solutions for vast anthropogenic environmental contamination, demonstrating high capacities in removing heavy metal cations and oxy-anions. However, their widespread adoption raises critical questions about the safe disposal and long-term environmental impact. We delved into the fate of contaminant-sorbed nano-adsorbents in soil and landfill conditions, addressing concerns such as desorption, dissolution, and the release of toxic constituents. Our research explores various nanocomposites for their toxic ions sorption capacities, and redox-transformation/degradation capabilities along with distinct contaminant removal mechanisms. Furthermore, we have tried to investigate their soil fractionation and leaching behaviors through a sequential leaching approach in simulated landfill conditions to comment on long-term fate and process sustainability.

Results suggest that to assess the environmental applicability of nanocomposites, it's crucial to consider the long-term fate of adsorbent wastes post-contaminant removal. Understanding soil fractionation and leaching in landfills informs disposal strategies, minimizing environmental risks. Redox-active nanoparticles limit recyclability due to strong binding, favoring safe disposal. Conversely, weak binders like layered double hydroxides allow for contaminant recovery and potential reuse.