title: Removal potential of toxic 2378-substituted PCDD/F from incinerator flue gases by waste-derived activated carbons.
abstract: The application of activated carbons has become a commonly used emission control protocol for the removal or adsorption of persistent organic pollutants from the flue gas streams of waste incinerators. In this study, the 2378-substituted PCDD/F removal efficiency of three types of activated carbons derived from the pyrolysis of refuse derived fuel, textile waste and scrap tyre was investigated and compared with that of a commercial carbon. Experiments were carried out in a laboratory scale fixed-bed reactor under a simulated flue gas at 275°C with a reaction period of four days. The PCDD/F in the solid matrices and exhaust gas, were analyzed using gas chromatography coupled with a triple quadrupole mass spectrometer. In the absence of activated carbon adsorbent, there was a significant increase in the concentration of toxic PCDD/F produced in the reacted flyash, reaching up to 6.6 times higher than in the raw flyash. In addition, there was a substantial release of PCDD/F into the gas phase, which was found in the flue gas trapping system. By application of the different commercial, refuse derived fuel, textile and tyre activated carbons the total PCDD/F toxic equivalent removal efficiencies in the exhaust gas stream were 58%, 57%, 64% and 52%, respectively. In general, the removal of the PCDDs was much higher with an average of 85% compared to PCDFs at 41%. Analysis of the reacted activated carbons showed that there was some formation of PCDD/F, for instance, a total of 60.6 μg I-TEQ kg(-1) toxic PCDD/F was formed in the refuse derived fuel activated carbon compared to 34 μg I-TEQ kg(-1) in the commercial activated carbon. The activated carbons derived from the pyrolysis of waste, therefore, showed good potential as a control material for PCDD/F emissions in waste incinerator flue gases.
authors.affiliation: Energy and Resources Research Institute, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: Yaghoub
authors.initials: Y
authors.lastname: Hajizadeh
authors.forename: Jude A
authors.initials: JA
authors.lastname: Onwudili
authors.forename: Paul T
authors.initials: PT
authors.lastname: Williams
mesh_terms: D000397:Air Pollution / Q000517:prevention & control*; D002606:Charcoal / Q000737:chemistry*; D004147:Dioxins / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D005740:Gases / Q000032:analysis*; D017745:Incineration; D012037:Refuse Disposal / Q000295:instrumentation / Q000379:methods*
chemical_list: D004147:Dioxins; D005740:Gases; D002606:Charcoal