In this paper, emission and distribution behavior of six heavy metals (As, Cd, Cr, Ni, Pb, and Hg), particulate matter and mass distribution of mercury within the different streams of a fluidized bed sewage sludge incinerator are presented. At the inlet of air pollution control devices (APCDs); Cd, Cr, Ni and Pb were mainly enriched in coarse particles; comparatively As content was higher in fine particles (&PM2. 5). The concentration of heavy metals in total particulate matter and PM2. 5, at the inlet of APCDs, were in the order of Cr>Ni>Pb>As>Cd. Mercury was almost always distributed in flue gas. Metals, other than mercury, were efficiently removed in APCDs and their concentrations in bottom ash, with fly ash being higher, whereas for that in wastewater, then waste sand was lesser. Overall mercury removal efficiency of APCDs was 98. 6 %. More than 83. 3 % of mercury was speciated into oxidized form at the inlet of APCDs, attributed by higher chlorine content in sludge. Mercury was mainly distributed in wastewater (78. 4 %), wastewater from a spray dry reactor (16. 8 %), fly ash in a hopper (3. 4 %) and flue gas (1. 4 %). This result is one of the first for data to be obtained; more experiments are required to control emission from such sources.
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Acknowledgments This study was supported by the Korea Ministry of Environment under the human resource development project for energy from waste and recycling. This research has also been financially supported by the R&D project of New & Renewable Energy, ‘‘Fluidization Combustion Technology of Sludge and RDF using Mixture of Recirculating Flue-gas and Oxygen,’’ funded by the Korea Institute of Energy Technology Evaluation and Planning (KETEP).
All Science Journal Classification (ASJC) codes
- Waste Management and Disposal
- Mechanics of Materials