Environmental sustainability assessment of the management of municipal solid waste incineration residues: a review of the current situation

Abstract

Incineration has become an attractive option for municipal solid waste (MSW) management, due to its several benefits. In fact, it allows volume and mass reduction of waste and energy recovery from MSW combustion. Nevertheless, MSW incineration (MSWI) produces three main types of residues: bottom ash (BA), fly ash (FA) and air pollution control (APC) residues, which require an adequate handling. BA is the most significant by-product from MSWI and is generally considered as nonhazardous waste. Instead, FAs are included as hazardous wastes because are characterised by high content of chlorides, heavy metals and organic compounds. The aim of this paper was to examine the characteristics of MSWI solid residues, the management and reuse of these wastes and their environmental assessment from a life cycle perspective. It was noted that the main components that make up the residues are lead and zinc as well as oxides, mainly CaO, SiO 2 and Al 2 O 3 . Furthermore, it is necessary to take into account the presence of PCDD/F which characterised FA and APC residues, mainly due to chlorine content. Chemical and physical properties of those residues make possible their reuse as construction material, as adsorbent, as well as in geotechnical and agricultural applications. Nevertheless, several studies have demonstrated that a drawback of the reuse of MSWI residues is the existence of heavy metals in elevated concentrations which may affect the environmental quality. In this regard, many studies were aimed to assess the environmental impact related to the introduction of MSWI residues as secondary material in several fields of application.

Recycling of inorganic waste in monolithic and cellular glass‐based materials for structural and functional applications

“…The advantages of vitrification are somewhat compensated by significant drawbacks, such as the high cost of plants and the energy consumption . The overall sustainability of the process is quite disputable, if the economic advantage relies only on avoided disposal costs.…”

“…The high temperatures required by vitrification cause the destruction of many hazardous organic compounds, but gaseous emissions still need attention, especially concerning the presence of chloride salts and volatile heavy metal oxides . Chlorine has a very limited solubility in glasses and may lead, if uncontrolled, to the formation of hazardous species in the cooling step and to the corrosion of equipments.…”

“…44,48 The high temperatures required by vitrification cause the destruction of many hazardous organic compounds, 2,3 but gaseous emissions still need attention, especially concerning the presence of chloride salts and volatile heavy metal oxides. 4 Chlorine has a very limited solubility in glasses 49 and may lead, if uncontrolled, to the formation of hazardous species in the cooling step and to the corrosion of equipments. A preliminary washing treatment may be applied 50 -53 in order to remove all the water soluble salts and some heavy metals, but the aqueous by-product could determine a new disposal problem.…”

Bonus Point System for Refuse Classification and Sustainable Development: A Study in China

“…Landfill and incineration currently make up 98% of China's municipal solid waste treatment [5]. The use of landfills results in the release of large amounts of CH 4 and N 2 O [6], and smoke, fly ash, and slag [7].…”

Stabilization of lead in incineration fly ash by moderate thermal treatment with sodium hydroxide addition

“…S/S methods can be divided into solidification, chemical stabilization, and weathering [11]. Solidification, namely encapsulation, is a process to mix IFA with liquid (water or aqueous solution) firstly and then to solidify the slurry.…”