Municipal solid waste incineration ashes: origin, composition, and reactivity in cementitious systems

Kumar, Vikram

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https://hdl.handle.net/2142/113261 Copy

Description

Title

Municipal solid waste incineration ashes: origin, composition, and reactivity in cementitious systems

Author(s)

Kumar, Vikram

Issue Date

2021-06-29

Director of Research (if dissertation) or Advisor (if thesis)

Garg, Nishant

Department of Study

Civil & Environmental Eng

Discipline

Civil Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Municipal Solid Waste
• Paper
• Plastic
• Food
• Metal
• Glass
• Yard
• Site-Specific
• Material Flow Analysis
• Environment
• Emissions
• Recycling
• Landfilling
• Incineration
• Waste-to-Energy
• Incineration Fly Ash
• Incineration Bottom Ash
• MSWI Ash
• Cement Hydration
• Cementitious
• Hydration Kinetics
• Acceleration
• Retardation
• Performance Prediction
• Supplementary Cementitious Materials
• Hazardous Materials
• X-ray Fluorescence, X-ray Diffraction, Scanning Electron Microscopy
• Helium Pycnometry
• Wet Laser Diffraction
• Isothermal Conduction Calorimetry
• Morphology

Abstract

Municipal Solid Waste (MSW) management primarily involves recycling, landfilling, and incineration for energy recovery. MSW composition data based on site-specific studies and material flow analysis indicates the presence of plastics in the municipal solid waste stream of U.S. states. Specifically, in an MSW stream solely consisting of paper, food, yard, plastic, metal, and glass material glasses, the plastic fraction ranges between 20 and 25 % in the discarded waste stream of U.S. states. Unfortunately, technological barriers limit the recycling of plastic fractions. In absence of recycling, the non-recyclable plastics and contaminated MSW are landfilled, resulting in environmental emissions. However, given the advancements in air pollution control devices, incineration for energy recovery can be a better alternative to landfilling. Data collected shows that presently incineration capacity of U.S. states is inadequate to process the MSW generated. Further expansion of incineration (waste-to-energy) facilities is unlikely considering the costs associated with the landfilling of incineration residues, i.e., MSWI Ashes. Research investigations had indicated that MSWI ashes can be compositionally comparable to coal fly ash, blast furnace slag, and clay. Thus, the MSWI ashes may find applications as a supplementary cementitious material. Successful utilization of MSWI ashes as supplementary cementitious material can reduce the expenses associated with the landfilling of MSWI ashes and improve the commercial viability of the waste-to-energy (WTE) industry. Despite being compositionally similar to other supplementary cementitious materials, the MSWI ashes are largely unutilized as supplementary cementitious material. This is because the performance of a cementitious system in the presence of MSWI ashes is not well investigated. Thus, in this thesis, the behaviour of cementitious systems containing MSWI ashes was investigated. Specifically, the hydration behaviour of ordinary Portland cement blended with 8 distinct and diverse MSWI ashes was studied. The findings indicate that incorporating these MSWI ashes can either accelerate or retard cement hydration depending upon their composition. Specifically, Cu, Fe, Al, Ti, Si, K, Zn, and Sr from the MSWI ash matrix appear to retard cement hydration, while Pb, Br, S, Ca, and Cl appear to accelerate cement hydration. Based on these results, a performance predicting parameter – Incineration Ash Coefficient (IAC) – was introduced that correlates with the 7-day compressive strength of mortars incorporating MSWI ashes reasonably well (R2=0.79). This new parameter, based on fundamental chemical and physical characteristics of ashes, can aid in the selection and employment of MSWI ashes as supplementary cementitious materials.

Graduation Semester

2021-08

Type of Resource

Thesis

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Copyright 2021 Vikram Kumar

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