Characterization of air pollution control residues produced in a municipal solid waste incinerator in Portugal

Abstract

This study is mainly related with the physical and chemical characterization of a solid waste, produced in a municipal solid waste (MSW) incineration process, which is usually referred as air pollution control (APC) residue. The moisture content, loss on ignition (LOI), particle size distribution, density, porosity, specific surface area and morphology were the physical properties addressed here. At the chemical level, total elemental content (TC), total availability (TA) and the leaching behaviour with compliance tests were determined, as well as the acid neutralization capacity (ANC). The main mineralogical crystalline phases were identified, and the thermal behaviour of the APC residues is also shown. The experimental work involves several techniques such as laser diffraction spectrometry, mercury porosimetry, helium pycnometry, gas adsorption, flame atomic absorption spectrometry (FAAS), ion chromatography, scanning electron microscopy (SEM), X-ray fluorescence (XRF), X-ray diffraction (XRD) and simultaneous thermal analysis (STA). The results point out that the APC residues do not comply with regulations in force at the developed countries, and therefore the waste should be considered hazardous. Among the considered heavy metals, lead, zinc and chromium were identified as the most problematic ones, and their total elemental quantities are similar for several samples colleted in an industrial plant at different times. Moreover, the high amount of soluble salts (NaCl, KCl, calcium compounds) may constitute a major problem and should be taken into account for all management strategies. The solubility in water is very high (more than 24% for a solid/liquid ratio of 10) and thus the possible utilizations of this residue are very limited, creating difficulties also in the ordinary treatments, such as in solidification/stabilization with binders.

Waste incinerator residue treatment: variability implications

“…Quina et al reported BET surface areas between 4.9-6.8m 2 /g for five separate collections of semi-dry APC residues, from a Portuguese EfW incinerator over a two year period (Quina et al 2008b). The variability in the specific surface area of residue collected from a single facility over time was therefore much smaller than that observed for residues collected from different sites.…”

“…(Baciocchi et al 2009;Cappai et al 2012;De Boom and Degrez 2012;Dyer et al 2006;Geysen et al 2004b;Li et al 2007;Quina et al 2008b;Wang et al 2010). Residue properties vary not only between facilities but also over time when collected from a single facility (Environment Agency 2002;Quina et al 2008b).…”

Air Pollution Control in Municipal Solid Waste Incinerators

“…Air pollution control (APC) residues produced in incineration plants are classified as hazardous solid waste mainly due to its high alkaline pH, high content in volatile heavy metals and soluble salts, and trace amounts of very toxic compounds such as dioxins and furans (Quina et al 2008b). The current APC disposal methods in use are very limited, and in the near future they are likely to become unsustainable, due to stringent environmental regulations.…”

“…Thus, according to measurements in diverse European incinerators, the limit of 0.5 mg/Nm 3 is usually complied (BREF, 2006). Lead and chromium are currently the most problematic heavy metals found in APC residues that lead to a classification as hazardous waste (Quina et al, 2008b).…”

Energy Recovery Routes from Municipal Solid Waste: A Case Study of Arusha-Tanzania

“…This method has advantages, such as substantial reduction in volume and mass. In order to apply the method in a large scale, there are fundamental parameters such as fuel behavior in thermal degradation, energy contents and its chemical reactions that should be in place so as to assist designers to come up with an appropriate method of waste energy recovery and disposal system (M.J. Quina et al, 2008).…”