Neutralization of an extremely acidic sludge and stabilization of heavy metals in flyash aggregates

M. Polat, Erkan Guler, Eli Lederman, Haim Cohen

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


An extremely acidic, heavy metal-rich sludge (pH = -1.2) was scrubbed with a Class-F fly ash in order to simultaneously neutralize the acidity and stabilize the heavy metals contained in both wastes. This paper outlines the leaching behavior of the aggregate material generated by scrubbing. For proper fly ash/sludge ratios, the fly ash acted as an outstanding neutralizer for the acidic waste. Leaching of heavy metals from the aggregate samples was below the environmental limits within a pH range between 3 and 9. Subsequent washing of the leached aggregate with acidic CALWET solutions did not result in an additional release of heavy metals. It is proposed that coordinative bonding of the metal cations onto neutral surface sites and electrostatic adsorption led to stabilization of the heavy metals within the aggregate structure below hydrolysis pHs.

Original languageEnglish
Pages (from-to)482-489
Number of pages8
JournalWaste Management
Issue number4
StatePublished - 2007
Externally publishedYes

Bibliographical note

Funding Information:
The authors acknowledge the funds from the ‘Dokuz Eylül University Research Fund’ under the projects coded ‘0908.99.05.02’, ‘0922.99.01.32’ and ‘0908.01.00.02’ and from the Israeli Higher Education Council.


Dive into the research topics of 'Neutralization of an extremely acidic sludge and stabilization of heavy metals in flyash aggregates'. Together they form a unique fingerprint.

Cite this