01555378

Component

One of the beneficial utilizations of municipal solid waste incineration (MSWI) bottom ash (BA) can be for road construction material; for example, the partial replacement of fine aggregate and Hot-Mix Asphalt (HMA) and Portland Cement Concrete (PCC). However, the leaching of potential toxic elements (e.g. alkaline elements and heavy metals) from HMA and PCC containing BA can eventually lead to the pollution of surface or ground water. This paper presents and discusses the chemical and leaching characteristics of MSWI BA obtained from a Refused Derived Fuel incineration plant in Florida, when used in HMA and PCC. Chemical analysis of MSWI BA was conducted by using petrographic analyses such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDS). The leaching characteristics of major alkaline and trace elements of HMA and PCC specimens containing varying amounts of the BA from 10 to 40% for HMA and 10 to 50% for PCC were investigated through Synthetic Precipitation Leaching Procedure (SPLP) batch tests. Leaching results reveal that the leaching potential of highly alkaline elements increases with increasing BA contents. However release of trace heavy metals mostly is reduced when MSWI BA is incorporated into HMA and PCC, especially with lower BA contents (10−20%) because of physical and chemical encapsulation of the elements. The release of most elements of interest (except aluminum) meets the criteria of the secondary maximum contamination level standard for the U.S. drinking water. In addition, the leaching concentrations of all of the priority elements (including aluminum) are below the U.S. stormwater runoff discharge limit.

Alternate title: Investigation of Leaching Behavior of Municipal Solid Waste Incineration Bottom Ash Used as Road Construction Materials. This paper was sponsored by TRB committee ADC60 Waste Management and Resource Efficiency in Transportation.

01550057

15-4970

English

21p

2015

Transportation Research Board 94th Annual Meeting

Digital/other

Figures; Photos; References; Tables

Bottom ash; Chemical analysis; Heavy metals; Hot mix asphalt; Leaching; Petrography; Portland cement concrete; Runoff; Water quality

Environment; Highways; Materials; Pavements; I15: Environment; I22: Design of Pavements, Railways and Guideways; I33: Other Materials used in Pavement Layers

Transportation Research Board Annual Meeting 2015 Paper #15-4970

TRIS, TRB, ATRI

Dec 30 2014 1:40PM