[Complexation Between Copper(Ⅱ) and Colored Dissolved Organic Matter from Municipal Solid Waste Landfill]

Area of Science:

• Environmental Chemistry
• Geochemistry
• Spectroscopy

Context:

• Landfill leachate contains complex mixtures of organic matter and heavy metals.
• Understanding metal-organic interactions is crucial for assessing environmental risks.
• Colored dissolved organic matter (CDOM) plays a significant role in metal speciation.

Purpose:

• To investigate the complexation mechanisms between copper (Cu(II)) and CDOM in landfills of varying ages.
• To quantify the changes in CDOM composition and metal-binding characteristics over time.
• To elucidate the evolution of heavy metal species within landfill environments.

Summary:

• Three-dimensional excitation-emission matrix fluorescence spectroscopy (3DEEM), fluorescence quenching titration, and parallel factor analysis (PARAFAC) were used to study Cu(II)-CDOM complexation.
• Landfilled CDOM composition shifts, with decreasing protein-like matter and increasing humic-like and fulvic-like matter.
• Conditional stability constants and fluorophore participation varied among CDOM fractions, indicating altered Cu(II) binding with landfill age.

Impact:

• Provides insights into the biogeochemical processes governing heavy metal behavior in landfills.
• Highlights the dynamic nature of metal-organic complexation and its implications for contaminant mobility.
• Informs strategies for landfill management and remediation of contaminated sites.