Abstract
Before incinerator bottom ash waste (IBAW) is used as a construction material, its environmental impacts should be thoroughly investigated. IBAW encompasses ferrous and nonferrous constituents that, in the presence of water, might be released into the groundwater and soil. The aim of this study was to find a treatment technique to improve the quality of IBAW and to reduce, to below regulatory limits, its potential to leach metals and salts. IBAW was mixed with limestone to achieve an environmentally and functionally acceptable blend to be used as a road foundation layer. The research studied the leaching characteristics of some constituents—including sulfate, chloride, sodium, copper, zinc, and lead—in IBAW blends under different conditions, such as initial pH value and the use of novel and traditional treatment agents. The experimental program was designed to recreate a realistic environment; a lysimeter was used as a large-scale leaching tool and a laboratory protocol was developed that simulated road foundation field conditions to evaluate the long-term release of heavy metals and salts from IBAW. In the lysimeter experiments, the concentrations of the leached elements were monitored through a sand substrate underneath the IBAW layer to study the potential element migration and sorption process. Mathematical modeling was then used to simulate the release of the aforementioned constituents from the IBAW on the basis of the initial measurement of intrinsic material properties and the sorption process concept. The experimental results showed that the additive treatment had a varied impact on the IBAW blends’ leaching properties, as element release was reduced by a wide margin, ranging from 5% to 96%.
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