A Practical Methodology for Waste-to-Energy Facilities to Screen Toxic Combustible Wastes and Priority Metals

Abstract: Waste-to-energy technology is an alternative way to reduce fossil fuels and to secure energy resources. This technology can be readily applied to our real society because non-recyclable but combustible wastes are generated every day and the technology is already available and mature as shown in many facilities for waste incineration. However, this technology incurs environmental and human health concerns due to toxic metals in wastes, which have not been effectively managed because metal- and waste-related risk assessment is too time- and resource-consuming for field facilities. Thus, this study suggests a practical methodology to effectively screen toxic combustible wastes and to identify priority metals to be targeted for pollution prevention; and carries out a case study to demonstrate the methodology. The methodology is based on the assessment of toxicity potentials (for instance, cancer, non-cancer, and eco-toxicity potentials) from metals in combustible wastes on a per-energy basis. The toxicity potential is quantified by using (i) the metal contents and lower heating value (LHV) of a combustible waste and (ii) the characterization factors accounting for the fate, exposure, and effect of metals. A case study is performed by applying the methodology to waste cable coating, waste engine oil, waste paint, refuse-derived fuel (RDF), refuse plastic fuel (RPF), waste medium-density fiberboard (MDF), and wastewater sludge. The case study results showed that the cable coating, engine oil, brown paint, RDF, and wastewater sludge had relatively high toxicity potentials, and their priority metals were lead (Pb), zinc, and copper. This study can be used for waste-to-energy facilities to practically screen toxic waste fuels and to determine post-treatment processes that can effectively remove priority metals. Graphic Abstract: [Figure not available: see fulltext.]