Nuclear Techniques ›› 2014, Vol. 37 ›› Issue (06): 60102-060102.doi: 10.11889/j.0253-3219.2014.hjs.37.060102


Characteristics of fly ash and bottom ash from the municipal solid waste incineration plant in Shanghai

CAO Lingling1,2,4 LIU Ke1,2,4 ZENG Jianrong1 LONG Shilei1,2,4 BAO Liangman1,4 MA Chenyan2,3 LI Yan1,4   

  1. 1(Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Jiading Campus, Shanghai 201800, China) 2(University of Chinese Academy of Sciences, Beijing 100049, China) 3(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China) 4(Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Chinese Academy of Sciences, Shanghai 201800, China)
  • Received:2013-11-29 Revised:2014-03-03 Online:2014-06-10 Published:2014-06-04

Abstract: Background: Incineration is an attractive method of energy production and waste reduction for the treatment of municipal solid waste (MSW). However, the secondary pollutants followed such as fly ash (FA), bottom ash (BA) from the waste incineration are always a concern. Yet few articles provide detailed information about the physical and chemical characteristics of trace elements in ash at the molecular level. Purpose: The elemental concentrations and microstructure characteristics of ash were investigated to understand the distribution and migration of the elements in MSW incineration process. Methods: The study of the characteristics of FA and BA from Shanghai MSW incineration plant was based on the concentrations of elements, water-soluble salts, microstructure, section-distribution of the elements in single particle, isotope ratio and chemical species of Pb, which were studied respectively by using synchrotron radiation X-ray fluorescence (SR-XRF), Ion Chromatography (IC), Scanning electron microscopy (SEM), X-ray energy dispersive microanalysis (EDX), Synchrotron radiation micro-beam X-ray fluorescence (μ-XRF), Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and X-ray absorption near-edge structure (XANES) spectra. Results: Mass concentrations of most metal elements in FA were higher than those in BA, especially Pb and Cd, which had been obviously enriched. FA particles were of relatively smaller size and rougher surface than those of BA, which brought easier adsorption of heavy metals in FA. The large enrichment factors of Pb, Cd, Cu and Zn indicated these elements were in extreme pollution state. Water-soluble salts in FA and BA mainly existed as chloride and sulfate of Ca, Na and K. The ion concentrations in FA were generally higher than those in BA. Results of μ-XRF suggested that Pb, Zn, Cu, Cr, Fe and Mn had nonuniform distributions and highly localized to some small regions in FA and BA. Isotope ratio of Pb in FA and BA was similar. Chemical species of Pb were also similar and existed mainly as PbCl2, PbS and PbO. Conclusion: The distribution and migration of the elements in MSW incineration process were related to elements characteristics and incineration environment. As hazardous wastes, FA from MSW must conduct a stabilizing treatment before landfill and BA should require pretreatments before utilization.

Key words: Municipal solid waste (MSW), Synchrotron radiation, Elements composition, Microstructure