Document Type
Thesis
Date of Award
1-31-1991
Degree Name
Master of Science in Environmental Science - (M.S.)
Department
Chemical Engineering, Chemistry and Environmental Science
First Advisor
Piero M. Armenante
Second Advisor
David Kafkewitz
Third Advisor
Richard B. Trattner
Abstract
In this study, a reliable and inexpensive method for biologically immobilizing toxic heavy metal residues present in very high concentrations in incinerator ash was developed. Desulfovibrzo, a genus of sulfate-reducing bacteria was cultured and treated with combined ash under anaerobic conditions. The carbon source, lactate, and the electron acceptor, sulfate, were provided to the cultures for their normal growth. Since the sulfate reducers utilize organic matter using sulfate as the oxidizing agent, sulfides are the corresponding end products of the reaction. Ash was added to well established cultures of desu f ovibrio. Immobilization of the heavy metals in the ash matrix occured as the metals precipitated as sulfides (PbS, CdS). The culture medium was analysed periodically for sulfate decrease until a steady state value was reached indicating the completion of bacterial activity. Next, the biologically treated ash was subjected to a number of leaching tests. The results showed a high degree of immobilization especially for the ash treated with cultures grown at room temperatures. The treated ash passed all existing and previous EPA leaching tests and met the required standards for Pb, Cd, and Cr, the metals of interest in this project. The proposed approach appears to have significant potential in the treatment of heavy metal contaminated incinerator ash prior to land burial, since it minimizes the problems associated with metal leaching and groundwater contamination.
Recommended Citation
Parasar, Uma, "Anaerobic biological treatment of incinerator ash to immobilize toxic metal residues" (1991). Theses. 2575.
https://digitalcommons.njit.edu/theses/2575
