Incineration Bottom Ash Research Articles

A sustainable temperature-swing process for CO2 capture and mineralization at below 100 °C using a recyclable chelating agent and bottom ash

Industrial waste utilization for carbon dioxide (CO2) mineralization offers a highly promising approach to significantly reduce CO2 emissions; however, it faces the challenge of consumption of huge amounts of chemicals without their recovery. This study proposes an improved CO2 mineralization process that employs a highly recyclable solution of environmentally friendly chelating agent, N,N-Dicarboxymethyl glutamic acid (GLDA) enriched with NaHCO3 and involves the temperature swing-facilitated dissolution and carbonation of Ca-bearing industrial wastes under ambient pressure and low temperature (<100 °C). Using bottom ash collected from plastic incineration as a representative solid waste, this study emphasizes the significance of temperature control during the Ca extraction and carbonation processes. Ambient temperatures prove favorable for efficient Ca extraction from incinerator bottom ash, while a relatively higher temperature (95 °C) is recommended for subsequent Ca carbonation; the carbonation process was then self-promoted due to the pH increase from carbonation. Subsequently, the solution was efficiently regenerated after use for CO2 capture. Across five CO2 mineralization cycles using the same solution, a comparable CaCO3 generation efficiency was demonstrated, suggesting the high recyclability of the solvent and sustainability of this approach. Although heavy metal accumulation was observed in the extraction solution during cycling, it did not negatively affect the Ca extraction and heavy metal-free CaCO3 was successfully produced. Overall, the proposed CO2 mineralization process utilizing the recyclable GLDA solution has significant potential as a green technology crucial for the global pursuit of CO2 mitigation.

Analysis of pore structure characteristics of MSWI bottom ash micro powder concrete

Municipal solid waste incineration (MSWI) bottom ash is a type of bulk waste. Its potential activity can be better harnessed after it is ground into a fine powder, leading to reduced carbon emissions. This paper investigates the pore structure of MSWI bottom ash micro powder concrete and its impact on mechanical properties. Standard tests were conducted to evaluate the mechanical properties of MSWI bottom ash micro powder concrete with four blending ratios under three water-binder ratios. Subsequently, a mercury intrusion test was performed to determine its internal pore structure characteristic parameters. Remaining specimens from the macroscopic test were sampled, and concrete specimens were observed using a high-power electronic environmental scanning microscope to analyze morphological characteristics at various multiples and curing ages. The results indicate that the pore structure of MSWI bottom ash micro powder concrete is uniformly distributed, displaying good fractal characteristics conducive to subsequent secondary hydration reactions. The inclusion of MSWI bottom ash micro powder increases concrete porosity, leading to a decrease in compressive strength. However, as the curing age increases, the value tends to approach that of ordinary concrete, suggesting that MSWI bottom ash micro powder exhibits potential hydraulicity, albeit with a slow hydration reaction. The observed pattern of MSWI bottom ash micro powder concrete aligns with that of ordinary concrete, wherein higher porosity corresponds to lower compressive strength. The addition of MSWI bottom ash micro powder increases concrete porosity, resulting in reduced compressive strength.

Recycling of municipal solid waste incineration bottom ash (MSWIBA) particles into natural fine sands for sustainable engineering cementitious composites

The manufacture of engineered cementitious composites (ECCs) consumes large amounts of natural fine aggregate. In this study, replacement of the natural fine aggregates in ECCs with municipal solid waste incineration bottom ash (MSWIBA) was found to reduce the consumption of natural river sand and the negative environmental impact of MSWIBA disposal. Previously, scholars have shown the potential of using MSWIBA particles as fine aggregates in concrete, but few scholars have evaluated ECCs with high percentages of MSWIBA powder in place of the natural fine aggregates. This study was conducted to design green ECCs by incorporating MSWIBA (BA–ECCs) to completely replace the natural silica sand with various fibers (PVA, PP and PE) and different fiber volume blends (0%, 0.5%, 1%, 1.5% and 2%) and to evaluate the BA–ECCs based on the fluidities, mechanical properties, microscopic morphologies, pore size distributions and heavy metal leaching capacities. The results showed that the addition of MSWIBA increased the porosities of the BA–ECCs. Compared with those of the control group, the maximum flexural strength of the BA–ECCs with 1.5% fiber doping were approximately 27.75% higher. There were relationships between the compressive strength and flexural strength and between the fiber volume content and strength. Moreover, microstructural observations revealed that the MSWIBA powder interacted strongly with both the matrix and the fibers, and the performance of the MSWIBA powder in the matrix was similar to that of a lightweight aggregate during internal curing. Additionally, fiber agglomeration (winding) at a 2% fiber content reduced the compressive and flexural strengths. The BA-ECCs showed lower heavy metal leaching contents than the MSWIBA, and the concentrations of various heavy metals were below the Chinese standards. Overall, this study could support research on the use of MSWIBA particles to prepare sustainable ECCs and recycle MSWIBA particles.

Use of municipal solid waste incineration (MSWI) bottom ash as a permeable subgrade material: An experimental and mechanism study

ABSTRACT As a traditional method of waste treatment, municipal solid waste incineration (MSWI) has become one of the main methods of urban waste treatment. However, as a byproduct of MSWI, a large amount of MSWI bottom ash is not reused in current practice. This study innovatively posits MSWI bottom ash as an eco-friendly adsorbent rather than a pollutant, exploring its potential application as a permeable subgrade material. The results reveal that MSWI bottom ash exhibits promising properties to serve as a permeable subgrade material to achieve the permeability and improve the sustainability for subgrade. Due to the arrangement of its particles, it shows excellent performance in shear strength and permeability, which are comparable to or surpass those of sandy soils. The average pore width of 14.200 nm allows heavy metal substances to be encapsulated within the matrix, significantly reducing their leachability, thereby aligning with environmental friendliness standards. Its adsorption capacity is about 6.60 mg/g, and the adsorption capacity per volume is 3.66 times and 2.04 times that of fly ash and clay, respectively. The mechanism analysis shows that the adsorption process is monolayer heterogeneous adsorption. This paper presents a novel perspective on reusing MSWI bottom ash and provides evidence supporting its effective utilization as a permeable subgrade material, offering substantial environmental benefits through enhanced adsorption ability. Implications: Municipal solid waste incineration (MSWI) is a common method for municipal solid waste treatment, while the MSWI bottom ash is often not reused. This paper explored the explores the feasibility of using MSWI bottom ash as a permeable road base material. The results show that the particle arrangement enables excellent shear strength and permeability, comparable to sandy soil. It meets safety requirements for the leaching of heavy metals and acts as an adsorbent for pollutants leaching from permeable pavements. Furthermore, the mechanisms underlying these behaviors of MSWI were confirmed by microstructural and mineralogical analyses. These indicate that MSWI bottom ash has great potential as a permeable road base material. This paper provides a clear understanding of the physical, mechanical and environmental properties of MSWI bottom ash, which can promote its reuse in practice.

Preparation of Ni-based catalyst from incineration bottom ash for steam reforming of toluene as a model tar compound

Ni-based catalysts are anticipated to emerge as the promising candidates for the reforming of biomass tar, owing to their commendable combination of high activity and low cost. However, waste-derived Ni-based catalysts exhibit inadequate stability in high-temperature reactions due to the sintering of catalyst. In this work, therefore, CaO was extracted from municipal solid waste (MSW) incineration bottom ash (IBA) as the support and the slag was prepared by melting the residues (molten slag, MS) as an inert stabilizer to enhanced the stability of catalysts. Toluene was chosen as the model compound for biomass tar to evaluate the performance of IBA-derived Ni-based catalyst in the steam reforming process. The toluene conversion of catalysts exhibited a volcano-type variation as the MS addition increased from 5 % to 20 %. Ni/MS15Ca85 exhibited excellent activity (83.87 %) at 850 °C, steam-to-carbon ratio (S/C) of 3, and gas hourly space velocity (GHSV) of 23040 h−1, and displayed no significant deactivation after 24 h (GHSV of 45700 h−1). The introduction of MS promoted the reduction of NiO, which improved the catalyst activity by forming the Ni-rich Ni-Fe alloy. Meanwhile, MS promoted the increase of lattice oxygen species (OL) content to enhance the oxidation of carbon. Furthermore, Ca2SiO4 and Ca12Al14O33 formed by the reaction of SiO2 and Al2O3 in MS with CaO contributed to mitigating the aggregation of CaO particles and maintaining the porous structure of catalysts. This work provides a novel approach to improve the catalytic performance of IBA-derived Ni-based catalyst for steam reforming of toluene (SRT) by realizing the precise regulation of each component in IBA and elimination of secondary residue disposal that was rarely considered in previous studies.

CaO-based adsorbents derived from municipal solid waste incineration bottom ash for CO2 capture

The utilization of waste-derived adsorbents for CO2 capture presents a promising strategy for the reduction of adsorbent cost and waste volume. In this study, CaO-based adsorbent was prepared from Ca-rich municipal solid waste (MSW) incineration bottom ash (BA) as raw material. The effects of acid patterns, carbonization/calcination temperature, triblock copolymer (P123) and Mn loadings, as well as the steam contents in the flue gas on the cyclic CO2 capture capacity of the adsorbents were studied. The results showed that CaO-based adsorbents obtained by nitric- and acetic-acid extraction showed more stable adsorption capacity, due to more active CaO and less impurity content. When the Ca/Mn molar ratio was 100:1 and the concentration of P123 solution was 2 g/L, the prepared adsorbent showed the adsorption capacity of 0.321 g/g after 20 cycles, which was 175% of the unmodified CaO-based adsorbent (0.183 g/g). The addition of Mn and P123 increased the surface area and pore volume of the adsorbents, resulting in a dense distribution of pore size. Additionally, Mn could also inhibit the particle growth and mitigate sintering of the adsorbents. The electron transfer between Mn3+ and Mn4+ played a crucial role in generating labile oxygen vacancies, which improved the adsorption capacity of the adsorbents.

Correction: Bandarra et al. A Study on the Classification of a Mirror Entry in the European List of Waste: Incineration Bottom Ash from Municipal Solid Waste. Sustainability 2022, 14, 10352

The authors would like to make the following corrections to the published paper [...]

Preparation and characterization of polyvinyl alcohol (PVA)-glycerol composite films incorporating nanosilica from municipal solid waste incinerator bottom ash

This study investigates the fabrication of a composite film composed of polyvinyl alcohol (PVA) and glycerol, incorporating nanosilica derived from municipal solid waste incinerator bottom ash (BA). The nanosilica is blended with a PVA film-forming solution containing glycerol as a plasticizer. The composite films are characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Additionally, thermogravimetric analysis (TGA) is conducted to evaluate the thermal properties, while the mechanical properties are assessed in terms of tensile strength (TS) and elongation at break (EAB). The results indicate that the presence of silica nanoparticles reduces transparency and increases film thickness in the presence of glycerol. Notably, the film containing 1% silica demonstrates a significant enhancement in tensile strength, exhibiting a 50% increase compared to the film without silica. However, higher silica loadings lead to a deterioration in mechanical properties due to silica agglomeration within the polymer matrix. As expected, the presence of silica in the films slightly elevates the degradation temperature.

Environmental and mechanical analysis of low‐carbon concrete with vitrified MSW incineration bottom ash as cement replacement

AbstractThe building sector is responsible for about 37% of the global carbon dioxide emissions, 6% of which result from concrete (and particularly cement) production. Using recycled and supplementary cementitious materials and adopting a whole building life cycle approach can be seen as multi‐beneficial strategies for materials' design. In this framework, this study aims to formulate a green concrete, by replacing 10, 15 and 20% of cement with a secondary raw material constituted of vitrified bottom ash derived from municipal solid waste incineration. The basic physical and mechanical properties were measured up to 365 days, so to evaluate the effects of the cement replacement both on short and long‐term behavior. Life Cycle Assessment was used as a tool to evaluate the environmental performance of the developed green concrete. An Eco‐Mechanical Analysis was also performed to match the environmental impacts with the mechanical behavior, allowing to assess that the concrete produced by replacing 20% of cement with vitrified municipal solid waste incineration bottom ash (if classified as hazardous waste) is the one that leads to optimize the overall sustainability. The approach proposed in this work, which can be easily generalized, contributes to the definition of a route for the implementation of innovative green construction building materials by using waste.

Production of Cement mortars from glass powder and municipal incinerated bottom ash

The objective of this research is to find the optimal ratio of glass power (GP) and municipal incinerated bottom ash (MIBA) for producing environmentally friendly interlocking paving blocks. To achieve this, 15 different ratios of mortar samples, sized 5 × 5 × 5 cm, were produced using a 1:3 cement-to-aggregate ratio and a 0.5 water-to-cement ratio. GP was used to substitute cement at 0, 10, and 20% by weight, while MIBA was used to substitute aggregate at 0, 10, 20, 30, and 40% by volume. The samples were divided into two groups and cured with water for 28 and 90 days. Physical testing was performed on the mortar samples after curing. The results show that at 28 days of curing, BA10 and BA20 had compressive strengths of 42.28 and 40.92 MPa respectively, which is higher than the standard for interlocking concrete block (40 MPa) according to TIS 827-2531. At 90 days of curing, GP10BA10, BA10, GP10, GP10BA20, GP20, BA20, and BA30 had compressive strengths of 47.62, 43.63, 43.51, 43.48, 42.73, 42.40, and 40.40 MPa respectively, which also meets the TIS standards.

Utilization of municipal solid waste incinerator bottom ash (MSWIBA) in concrete as partial replacement of fine aggregate

Enhancing sustainable economic development while maintaining environmental integrity is of paramount importance. In this context, the effective utilization of municipal solid waste incinerator bottom ash (MSWIBA) presents a significant opportunity. This study investigated an approach for harnessing the potential of MSWIBA by incorporating it as a partial replacement for fine aggregate in concrete mixtures. Twelve concrete samples were prepared with varying proportions of MSWIBA. The mechanical and microstructural properties of the samples were comprehensively investigated. Moreover, the environmental and economic advantages of these concrete formulations were assessed. The results revealed that the water absorption of the concrete samples without MSWIBA was higher than that of the concrete samples with MSWIBA, suggesting that the added MSWIBA could fill the internal pores of concretes. The water absorption rate curve could be divided into three stages, i.e., rapid decline, slow decline, and stable. The optimal replacement ratio of fine aggregate with MSWIBA was between 24.8% and 57.8%. Notably, when the replacement ratio surpassed 24.8%, MSWIBA positively influenced the development of compressive strength, but it still lower than that of composite Portland cement-based concrete (OPC). Furthermore, pore structure analysis indicated that the efficacy of pore refinement was achieved within a certain replacement threshold. However, the efficacy of pore structure refinement diminished beyond that threshold. The substitution of fine aggregate with MSWIBA aligns with the technical specifications and building material standards, thereby complying with the principles of effective utilization, sustainability, and environmental consideration pertinent to MSWIBA management.

Impacts of wet treatment on leaching toxicity of municipal solid waste incineration bottom ash

Impacts of wet treatment on leaching toxicity of municipal solid waste incineration bottom ash

Tensile and puncture behaviour of a woven geotextile submitted to laboratory mechanical damage tests with incinerator bottom ash

Incinerator bottom ash can be used as recycled aggregate in some engineering applications, where it may be in contact with geotextiles. In this work, a woven geotextile (made of high-density polyethylene filaments) was submitted to mechanical damage under repeated loading tests with different aggregates, namely: incinerator bottom ash, two aggregates of natural origin (tout-venant and gravel 4/8) and a synthetic aggregate (corundum). The damage suffered by the geotextile was assessed by monitoring changes on its tensile and puncture behaviour. The mechanical damage under repeated loading tests induced some reductions in the tensile and puncture properties of the geotextile. The impact of IBA was not exaggeratedly pronounced, and did not differ greatly from that of tout-venant, which was the least damaging aggregate. Gravel 4/8 had a slightly higher impact than incinerator bottom ash, with corundum being the aggregate that induced the most pronounced reductions in the tensile and puncture properties of the geotextile. The use of incinerator bottom ash as recycled aggregate in contact with geotextiles may be a viable option, promoting its valorisation and contributing to more sustainable geotechnical engineering.

Concentration of Copper, Zinc, Lead, Cadmium, and Nickel in the Incinerator Bottom Ash in Five County Hospitals in Kenya

Concentration of Copper, Zinc, Lead, Cadmium, and Nickel in the Incinerator Bottom Ash in Five County Hospitals in Kenya

A comprehensive assessment of green concrete incorporated with municipal solid waste incineration bottom: Experiments and life cycle assessment (LCA)

To reduce the high carbon emissions in the concrete field and facilitate the sustainable development of concrete, in this study, we repurposed high-volume municipal solid waste incineration bottom ash (MSWIBA) as a supplementary cementitious materials (SCMs) for the production of concrete at different percentages (0%, 10%, 20%, 30%, 40%, 50% and 60%). The influence of MSWIBA on the compressive strength, hydration, microstructure and heavy metal leaching behaviour of concrete was investigated. The results showed that a high volume of MSWIBA will reduce the compressive strength (from 56.81 MPa to 12.65 MPa) because aluminium produces hydrogen in an alkaline environment and excessive incorporation of MSWIBA leads to insufficient active substances. The content of ettringites and calcium silicate hydrate (C-S-H) initially increases (from 0.286 ％ to 0.405 ％ and from 0.635 ％ to 0.893 ％) and subsequently decreases (from 0.405 ％ to 0.275 ％ and from 0.893 ％ to 0.500 ％) as the proportion of MSWIBA in the mixture gradually increases due to the aluminium salt content reacting with the sulfate and pozzolanic reactivity of MSWIBA. In addition, compared with those in MSWIBA, the amounts of leachable hazardous ions (Cu, Pb, Cr, As and Hg) in concrete were effectively reduced by 87.1%, 83.3%, 70.0%, 90.3%, and 89.3%, respectively. Additionally, the measured heavy metal leaching met Chinese specification requirements. Life cycle assessment (LCA) was employed to evaluate environmental impacts (EIs), and it was found that using MSWIBA as a SCM can reduce the EI by 7.5 ％− 44.1 ％ (from 2.58E-11 to 1.56E-11) when the replacement cement ratio of MSWIBA is from 10 ％ to 60 ％. By normalizing the EI indices, it was found that the global warming potential (GWP) and eutrophication potential (EP) were the main contributors to the EI. Finally, a model was established to assess the comprehensive performance, including the environmental impact, compressive strength, porosity, apparent density, and ecology-strength efficiency, of the different MSWIBA formulations, and the comprehensive performance improved when the MSWIBA percentage was 30%.

Development of green cement from solid wastes

In this study, a green cement (GC) was prepared primarily using incineration bottom ash (IBA) and recycled concrete fine (RCF) at a low clinkering temperature of 1200ºC. This clinker mainly consisted of belite (C2S) and rankinite (C3S2) and demonstrated the versatility of strong carbonation reactivity and latent hydraulicity. Compared to the commercial benchmark - ordinary Portland cement - after being subjected to carbonation curing, GC exhibited superior macro- and micro-mechanical performance due to the densified microstructure. In addition to rapid strength gain at an early age, the carbonated GC also exhibited a substantial increase in strength at later ages and eventually recorded a high strength of 86.4 MPa. Furthermore, the leaching behaviour assessment on commonly regulated heavy metals validated the environmental stability of this waste-derived binder. The development of this sustainable cement has good potential to divert solid wastes otherwise destined for landfill sites to high-value-added construction products.

Production and Characterization of Bricks from Bottom Ash and Textile Sludge Using Plastic Waste as Binding Agent

The production of traditional clay bricks consumes a large amount of energy and resources and can lead to the depletion of natural resources like clay. On the contrary, the improper disposal of waste materials such as bottom ash, textile sludge, and plastic waste can lead to environmental pollution and health hazards. Bricks and concrete blocks have been widely used in construction, but the continuous exploitation of raw materials can negatively impact the environment. This study aimed to produce bricks made from municipal solid waste, incinerated bottom ash, and textile sludge, using plastic waste as a binder. It assessed the potential use of these bricks as an alternative material for brick block production. The physical and chemical characteristics of the raw materials were determined using standard test methods. The crushed plastic waste was melted and mixed with dried textile sludge and bottom ash in various ratios, including 1 : 1 : 1, 2 : 1 : 1, 1 : 2 : 1, 1 : 1 : 2, and 1 : 2 : 2 for plastic, municipal incinerated bottom ash, and textile sludge, respectively. The mixed sample was then placed into molds until it dried, and the resulting bricks were tested for compressive strength, water absorption, efflorescence, and leachability. The results indicated that the bricks had suitable physical and chemical properties, with compressive strength ranging from 8.527 to 16.4 MPa and water absorption percentages ranging from 1.3 to 3.4%. Slight efflorescence was observed for the 1 : 2 : 2 ratios. The production of traditional clay bricks consumes a large amount of energy and resources and can lead to the depletion of natural resources like clay. On the other hand, the improper disposal of waste materials such as bottom ash, textile sludge, and plastic waste can lead to environmental pollution and health hazards.

Study on the Combined Effect of Municipal Solid Waste Incineration Bottom Ash and Waste Shingle in Hot Mix Asphalt.

This study investigated the positive effect of the combined use of recycled asphalt shingles (RASs) and municipal solid waste incineration (MSWI) bottom ash (B.A.) in asphalt concrete, which contributes to enhanced sustainability in pavement engineering. In addition, unlike traditional approaches that employ individual recycling material in hot mix asphalt (HMA), the combined use of the two waste materials maximizes the mechanical performance of the asphalt mixture. The addition of RAS (with 30-40% aged binder) as an additive generally enhances the strength/stiffness of the asphalt mixture. The high porosity/absorption of MSWI BA results in an additional amount of liquid asphalt binder in the mixture. As an admixture, RAS could supply the additional asphalt binder in the mixture when MSWI BA is used as an aggregate replacement. This research was conducted in two phases: (1) to examine the effect of MSWI BA alone and its optimal asphalt content (OAC), and (2) to assess the combined effect of B.A. and RAS in HMA. Multiple laboratory testing methods were employed for the mechanical performance investigation, including the Marshall stability test, rutting test, and indirect tensile test. The testing results show that the 20% B.A. replacement exhibits the best performance and that it requires an additional asphalt binder of 1.1%. For the combined use of MSWI BA and RAS, 5% RAS shows the best mechanical performance. All mixtures that contain the B.A. and RAS show greater strength than the control specimen (regular HMA).

Wet shaking table operating parameters optimization for maximizing metal recovery from incineration bottom ash fine fraction

Municipal solid waste incineration bottom ash has emerged as a secondary source of valuable metals, including aluminum and copper. Specifically, the fine fraction, with a particle size less than two millimeters, exhibits average grades of 2.5 g/kg for copper and 10.0 g/kg for elemental aluminum. Gravimetric concentration equipment, such as wet shaking tables, is widely used in the mining and recycling industries to concentrate materials based on density. However, the optimization of these devices typically relies on a trial-and-error approach. This paper presents a statistical model that optimizes the crucial working parameters of the wet shaking table for recovering elemental aluminum in a light product mineral matrix and copper in a high-density product. The statistical analysis highlights that upper values of shaking amplitude are beneficial for both the recovery and grade of copper and aluminum in the obtained products. Conversely, variations in other parameters, such as wash water or desk tilt, yield contrasting effects on grade and recovery. By precisely adjusting the working parameters of the device, the analyses demonstrate that copper enrichment of up to 45 times can be achieved in the product smaller than 500 µm and up to 15 times in the 500–2000 µm product, resulting in the recovery of approximately 65 % of the total copper.

Simplified framework for efficient utilization of municipal solid waste incinerator bottom ash as construction material via systematic classification and characterization

The incinerator bottom ash (IBA) constitutes approximately 80% of the municipal solid waste (MSW) incineration residues. To minimize the end-waste, one of the sustainable solutions is to utilize IBA. IBA is often utilized directly with or without simple pre-treatment after receiving from the incineration plant. However, the significant heterogeneity in the physicochemical composition of the IBA has hindered its widespread utilization. The given study proposes a simplified framework to improve the utilization efficiency of IBA via a systematic classification and characterization approach. The IBA was classified into ten classes (classified IBA) according to the four particle size ranges and three mineralogical categories. A comprehensive characterization of chemical/mineralogical compositions of classified IBA using state-of-the-art techniques was then conducted to understand the properties of each class, which aid in determining the appropriate applications for each category of classified IBA. The leaching behavior of the classified IBA was also studied to evaluate the environmental safety of the classified IBA classes and suggested avoiding categories with high concentrations of leachable toxic elements. The framework developed in this study for efficiently utilizing IBA is demonstrated for IBA collected from a local incineration plant.