Characteristics of Incineration Residues (Fly Ash vs. Bottom Ash), Major Leachable Heavy Metals, Treatment Methods, Leachable Substances

□ Characteristics of Incineration Residues (Bottom Ash vs. Fly Ash), Major Leachable Heavy Metals, Treatment Methods (Summary), Leachable Substances ○ Bottom Ash

• Definition: Initially considered harmless as an incineration residue, but exceeding limits for designated waste, with detected Pb.
• Major Heavy Metals: Pb, Cr, Cu / As, Hg, Cd, Zn
• Leachable Heavy Metals: Pb, Cu, Cr
• Issues with Leachates: Contamination of water sources such as rivers, lakes, etc., leading to food contamination and human health risks.
  • Pb: Accumulates in bones / Causes anemia, nerve paralysis, etc. / Interferes with SH group enzyme action (inhibits hemoglobin synthesis, decreases red blood cells) / Toxic to children
  • Cu: Present in gastric and hepatic juices / Mainly generated from mines, factory effluents
  • Cr: Causes interstitial perforation, skin disorders, etc. / Lesions on mucous membranes
• Treatment Methods:
  1. Recycling: Utilization in road pavement, artificial aggregates, ferrous materials, etc.
  2. Landfill after Stabilization Treatment: Landfilling in regular landfills after reducing leachable heavy metal content.
  3. Landfilling in Designated Waste Landfills: Landfilling without stabilization treatment in designated waste landfills.

○ Fly Ash

• Definition: Incineration residue with fly ash components, with most leachable heavy metal concentrations exceeding regulatory limits, requiring solidification/stabilization intermediate treatment before disposal as designated waste.
• Major Heavy Metals: Pb, Cr, Cu, Zn
• Treatment Methods:
  1. Landfill after Stabilization Treatment: Landfilling in regular landfills after reducing leachable heavy metal content.
  2. Landfilling in Designated Waste Landfills: Landfilling without stabilization treatment in designated waste landfills.