Artificial carbonation for controlling the mobility of critical elements in bottom ash

In municipal solid waste incineration (MSWI), bottom ash, generated at a stoker grate type incinerator, the critical elements were identified in terms of EU regulation. The stabilizing effect of moderate carbonation (pH 8.28 ± 0.03) on critical contaminants was studied through availability and diffu...

Full description

Saved in:
Bibliographic Details
Published in:Journal of material cycles and waste management 2006-09, Vol.8 (2), p.145-153
Main Authors: Todorovic, Jelena, Svensson, Malin, Herrmann, Inga, Ecke, Holger
Format: Article
Language:English
Subjects:
Avfallsteknik
By products
Contaminants
Experimental design
Incineration
Incinerators
Leaching
Municipal solid waste
Power plants
Waste Science and Technology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In municipal solid waste incineration (MSWI), bottom ash, generated at a stoker grate type incinerator, the critical elements were identified in terms of EU regulation. The stabilizing effect of moderate carbonation (pH 8.28 ± 0.03) on critical contaminants was studied through availability and diffusion leaching protocols. Data from the performed tests were evaluated with the goal of reusing MSWI bottom ash as secondary construction material. To investigate the mobilizing effect of CO^sub 2^, suspended MSWI bottom ash was severely carbonated (pH 6.40 ± 0.07). The effect of CO^sub 2^ and its interaction with other leaching factors, such as liquid/solid (L/S) ratio, leaching time, pH, ultrasound treatment, and leaching temperature, were examined using a reduced 2^sup 6-1^ experimental design. Contaminants identified as critical were Cr, Cu, Mo, Sb, Cl^sup -^, and SO^sub 4^ ^sup 2-^. Although moderate carbonation decreased the release of Cr, Cu, Mo, and Sb from compacted bottom ash, the main disadvantage remains its inability to demobilize Cl^sup -^ and SO^sub 4^ ^sup 2-^. The hypothesized mobilizing effect of severe carbonation was proven. The treatment enhanced the separation of critical components (α = 0.05) (except for Cl^sup -^), i.e., about fivefold for Sb and about twofold for Cr, Cu, and S. Nevertheless, the prospect is good that severe carbonation could constitute the deciding key parameter to facilitate the technical feasibility of a future washing process for MSWI bottom ash.[PUBLICATION ABSTRACT]
ISSN:1438-4957
1611-8227
1611-8227
DOI:10.1007/s10163-006-0153-x