Work

Surface catalysed PCDD/F formation from precursors - high PCDF yield does not indicate de novo mechanism!

Year: 2017

Type: article

Abstract: We report results on PCDD/F formation over iron (III) oxides catalysts for a mixture of 2-monochlorophenol (2-MCP) and 1,2-dichlorobenzene (1,2-DCBz) for both oxidation and pyrolysis. Competitive adsorption between chlorinated benzenes and chlorinated phenols affects the transformation of these precursors and plays a crucial role in the PCDD/F formation in mixed MCP/1,2-DCBz-feed streams. Comparing the integrated PCDD and PCDF yields, it becomes apparent that with decreasing 2-MCP content in the feed stream the PCDF yield first rises and then levels off, at ~0.4% for pyrolytic and at ~0.6% for oxidative conditions. Present results further confirm that the PCDD/PCDF-ratio cannot be used to validate the de novo pathway nor can it be used as an indicator of de novo synthesis in incinerators. In fact, the PCDD/PCDF-ratio is strongly dependent on the relative concentration of these two precursors in the reacting stream, i.e., chlorinated benzenes vs. chlorinated phenols.

Source: International Journal of Environment and Pollution

DOI: 10.1504/ijep.2017.087761

Authors: Shadrack Nganai, Slawo Lomnicki

Institutions: South Louisiana Community College, Louisiana State University

Language: English

Topic: Toxic Organic Pollutants Impact

Subfield: Health, Toxicology and Mutagenesis

Field: Environmental Science

Domain: Physical Sciences

Open Access status: green

Funder: National Institute of Environmental Health Sciences

Award: G377101333