| Abstract
| - The utilization of biomass residues as sources for naturalchelates is a new approach to improve the ecological andeconomical balance of leaching techniques for the remediation of metal-polluted soils. Residues, such asmolasses, blood meal, and silage effluents, containingvariousaliphatic carboxylic acids, sugar acids, and amino acidsor their precursor compounds were selected, hydrolyzedand oxidized, if required, and analyzed for their organicconstituents. Soils that were contaminated with metalsviasewage sludge amendment were extracted in batch andcolumn experiments at various pH values. Grass silageeffluent removed ∼75% of Cd and >50% of Cu and Zn atpH4.4. The neutralized effluent was less effectiveexceptfor Cu (69% leached). The neutral blood mealhydrolysateextracted primarily Cu (55−66%) and Ni (38−67%).Metalbonds attacked by this extractant were identified using asequential leaching procedure. Hydrolysatescontainingsugar acids mobilized Cu and Pb under alkalineconditions. The actual results support the conclusionthat biomass residues have a potential to serve asextractantsin remediation techniques.
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