Reduction of PCDDs/PCDFs in MSWI fly ash using microwave peroxide oxidation in H2SO4/HNO3 solution

Chemosphere. 2013 May;91(6):864-8. doi: 10.1016/j.chemosphere.2013.01.053. Epub 2013 Feb 27.

Abstract

Microwave peroxide oxidation (MPO) is an energy-efficient and low GHG emission technology to destroy the hazardous organic compounds in solid waste. The objective of this paper is to explore the reduction feasibility of PCDDs/Fs in MSWI fly ash using the MPO in H2SO4/HNO3 solution. Nearly all PCDDs/Fs, 99% in the original fly ash, can be reduced in 120min at the temperature of 150°C using the MPO treatment. It was also found that a change occurred in the content distribution profiles of 17 major PCDD/F congeners before and after MPO treatment. This provides the potential to reduce the actual PCDDs/Fs content more than I-TEQ contents of PCDDs/Fs. The percentile distribution profile has a tendency of higher chlorinated PCDDs/Fs moving to the lower ones. It concludes that a significant reduction efficiency of I-TEQ toxicity was achieved and showed sufficient reduction of toxic level to lower than 1.0ngI-TEQ(gdw)(-1). The treatment temperature would be a critical factor facilitating the dissolution because higher temperature leads more inorganic salt (parts of fly ash) dissolution. Some problems caused by the MPO method are also delineated in this paper.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzofurans / chemistry*
  • Benzofurans / isolation & purification
  • Cities
  • Coal Ash / chemistry*
  • Dibenzofurans, Polychlorinated
  • Environmental Pollutants / chemistry
  • Environmental Pollutants / isolation & purification
  • Feasibility Studies
  • Microwaves
  • Nitric Acid / chemistry*
  • Oxidation-Reduction
  • Peroxides / chemistry*
  • Polychlorinated Dibenzodioxins / analogs & derivatives*
  • Polychlorinated Dibenzodioxins / chemistry
  • Polychlorinated Dibenzodioxins / isolation & purification
  • Refuse Disposal / methods*
  • Solutions
  • Sulfuric Acids / chemistry*

Substances

  • Benzofurans
  • Coal Ash
  • Dibenzofurans, Polychlorinated
  • Environmental Pollutants
  • Peroxides
  • Polychlorinated Dibenzodioxins
  • Solutions
  • Sulfuric Acids
  • Nitric Acid
  • sulfuric acid