Heavy Metal Removal from Sewage Sludge Ash with Physical Separation

Key Points

• The aim is to reduce concentrations of heavy metals, particularly arsenic and cadmium, in sewage sludge ash for fertilizer use.
• Conducted elemental analysis on ash samples from a domestic fluidized bed incineration facility.
• Employed air classification technology utilizing the Coanda effect to segregate particles into fine, medium, and coarse groups.
• Focused on achieving selective concentration of heavy metals in smaller particle fractions.
• Successfully reduced heavy metal concentrations in medium and coarse particle groups to half of regulatory limits.
• Demonstrated significant concentration of arsenic and cadmium in fine particle groups.
• Confirmed that air classification is an effective, low-cost, and energy-efficient method for heavy metal removal.