Experimental and statistical determination of indicator parameters for the evaluation of fly ash and boiler ash PCDD/PCDF concentration from municipal solid waste incinerators

• Published in: Chemosphere (Oxford) Vol. 67; no. 9; pp. S155 - S163
• Main Authors: Streibel, T., Nordsieck, H., Neuer-Etscheidt, K., Schnelle-Kreis, J., Zimmermann, R.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier Ltd 01.04.2007; Elsevier
• Subjects: Air Pollutants - analysis; Air Pollutants - toxicity; Applied sciences; Benzofurans - analysis; Benzofurans - chemistry; Boiler ash; Carbon - chemistry; Coal Ash; Dibenzofurans, Polychlorinated; Exact sciences and technology; Fly ash; Gases - analysis; Gases - chemistry; Incineration; Indicator parameters; Particulate Matter - analysis; Particulate Matter - chemistry; PCDD/PCDF; Phenols - analysis; Phenols - chemistry; Pollution; Polychlorinated Dibenzodioxins - analogs & derivatives; Polychlorinated Dibenzodioxins - analysis; Polychlorinated Dibenzodioxins - chemistry; Principal Component Analysis; Risk Assessment; Solid residues; Waste incineration; Waste Management - methods; Waste Management - statistics & numerical data; Europe; Germany; Bavaria; Germany, Bavaria; Waste incineration; Fly ash; Solid residues; Indicator parameters; Boiler ash; PCDD/PCDF; Parameter estimation; Heat treatment; Urban waste; Combustion; Multivariate analysis; Sulfur dioxide; Hydrochloric acid; Incineration plant; Ash content; Nitrogen oxide; Correlation coefficient; Indicator; Gaseous effluent; Air flow; Incineration; Correlation analysis; Solid waste; Phenols; Air pollution; Principal component analysis
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2006.05.151

On-line detectable indicator parameters in the flue gas of municipal solid waste incinerators (MSWI) such as chlorinated benzenes (PCBz) are well known surrogate compounds for gas-phase PCDD/PCDF concentration. In the here presented work derivation of indicators is broadened to the detection of fly and boiler ash fractions with increased PCDD/PCDF content. Subsequently these fractions could be subject to further treatment such as recirculation in the combustion chamber to destroy their PCDD/PCDF and other organic pollutants’ content. Aim of this work was to detect suitable on-line detectable indicator parameters in the gas phase, which are well correlated to PCDD/PCDF concentration in the solid residues. For this, solid residues and gas-phase samples were taken at three MSWI plants in Bavaria. Analysis of the ash content from different plants yielded a broad variation range of PCDD/PCDF concentrations especially after disturbed combustion conditions. Even during normal operation conditions significantly increased PCDD/PCDF concentrations may occur after unanticipated disturbances. Statistical evaluation of gas phase and ash measurements was carried out by means of principal component analysis, uni- and multivariate correlation analysis. Surprisingly, well known indicators for gas-phase PCDD/PCDF concentration such as polychlorinated benzenes and phenols proved to be insufficiently correlated to PCDD/PCDF content of the solid residues. Moreover, no single parameter alone was found appropriate to describe the PCDD/PCDF content of fly and boiler ashes. On the other hand, multivariate fitting of three or four parameters yielded convenient correlation coefficients of at least r = 0.8 for every investigated case. Thereby, comprehension of plant operation parameters such as temperatures and air flow alongside concentrations of inorganic compounds in the gas phase (HCl, CO, SO 2, NO x ) gave the best results. However, the suitable set of parameters suited best for estimation of PCDD/PCDF concentration in solid residues has to be derived anew for each individual plant and type of ash.