Waste Incineration Research Articles

Understanding residents’ risk information seeking, processing and sharing regarding waste incineration power projects

Waste incineration power projects (WIPP) may face suspicion and resistance due to potential environmental and health risks. Information behavior has become a crucial way for residents to manage the risks. By integrating the risk information seeking and processing (RISP) model with the protective action decision model (PADM), the study develops a four-stage model that incorporates information acquisition and perceived benefits to understand the determinants of residents’ information behaviors regarding WIPP. A total of 1726 respondents were interviewed. The results indicate that 77.5 % respondents frequently use social media. Of the twenty-five hypothesized paths, twenty-one were found to be significant. Information acquisition from social media plays a larger predictive role than that from official media. Perceived risks, benefits, and knowledge positively predict information sharing, systematic processing, and information seeking, respectively. Perceived knowledge has the strongest direct influence on information insufficiency (β = 0.24, p < 0.001) with the explained variance of systematic processing being the highest (R2 = 0.51). Interesting, the relationship between information insufficiency and information sharing, as well as between relevant channel beliefs and information sharing, are negative. Theoretical insights into extending the PADM and the RISP model are provided, as well as managerial implications for risk communication about WIPP.

Solidification and leaching behaviours of heavy metal Pb in MSW incineration fly ash and its thermal stability at various thermal treatment temperatures

The fly ash generated by municipal solid waste (MSW) incineration contains heavy metals, which pose a significant environmental threat. Thermal treatment emerges as a potential technique for reducing and detoxifying MSW incineration fly ash, but the optimal thermal treatment temperature remains unclear. This study explores the thermal stability of MSW incineration fly ash under various thermal treatment temperatures (1000 °C − 1500 °C). Additionally, the solidification and leaching behaviors of heavy metal Pb were investigated. The results revealed distinctive trends: the mass residual rate showed the fastest decline between 1200 °C and 1273 °C, while the volume residual rate showed the fastest decline between 1100 °C and 1200 °C. The solidification rate of heavy metal Pb decreased as the treatment temperature increased. With the decrease of specific surface area, the leaching rate of heavy metal Pb exhibited a gradual decline, but it sharply surged at the fluid temperature. This was because the encapsulation effect of Pb by calcium silicate iron manganese complex was weakened and an increase in kinds of Pb oxides(Pb2O3, Pb3O4) that can react with glacial acetic acid in the leachate. Thus, it was not advisable to treat the MSW incineration fly ash around the fluid temperature. The optimal thermal treatment temperature was suggested to be 1200 °C, as it achieves goals such as volume reduction, detoxification and low energy consumption. These provide useful theoretical guidelines for the thermal treatment of MSW incineration fly ash.

Atomic-Scale Insights into the Effects of the Foaming Degree on the Glass-Ceramic Matrix Derived from Waste Glass and Incineration Bottom Ash.

Precise management of the inverse correlation between the total porosity and compressive strength is crucial for the progress of foaming glass-ceramics (FGCs). To deeply understand this relationship, we investigated the atomic-level transformations of five CO2-foaming FGC samples using molecular dynamics simulation. The short-range and intermediate-range structures of the FGCs with varying total porosities (36.68%, 66.28%, 66.96%, 72.21%, and 79.88%) in the system were elucidated. Na cations were observed to exhibit a strong interaction with CO2, accumulating at the surface of the pore wall and influencing the oxygen species. Therefore, the change in the atomic structure of the matrix was accompanied by an increase in the total porosity with an increasing CO2 content. Specifically, as the total porosity increased, the bridging oxygen content within the FGCs rose accordingly. However, once the total porosity exceeded 66.96%, the bridging oxygen content began to decline. This observation was significant considering the role of the bridging oxygen content in forming a continuous cross-linked network of chemical bonds, which contributed to the enhanced mechanical strength. Consequently, the influence of the total porosity on the oxygen species resulted in a two-stage reduction in the compressive strength. This study offers valuable insights for the development of high-strength lightweight FGCs.

Performance analysis of a new compressed air energy storage system coupled with the municipal solid waste power generation systems

In order to improve the performance of the compressed air energy storage (CAES) system, a novel design is proposed: the CAES system is combined with the municipal solid waste power generation systems, including a waste incineration power generation system and a biogas power generation system. During the charging process, the feedwater and the condensate from the waste incineration power generation system are used to cool the compressed air. During the discharge process, the released compressed air is heated by the flue gas from the waste incineration power generation system, and the high-temperature compressed air works in the expander. Finally, the expanded air from the expander is fed into the combustor of the biogas power generation system, thus replacing the compressor of the gas cycle. Through the system integration, the efficiency of the CAES system is improved, and some equipment of the original CAES system is reduced. Based on the systems simulation, energy analysis, exergy analysis, economic analysis, and sensitivity analysis are performed. As a result, for the CAES subsystem, the round-trip efficiency, the energy storage density, and the exergy efficiency can reach 75.32 %, 14.10 MJ/m3, and 74.31 %. Besides, the dynamic payback period can reach 6.82 years.

A study of the stabilization and solidification of heavy metals in co-vitrification of medical waste incineration ash and coal fly ash

Medical waste incineration ash (MWIA) has significant concentrations of heavy metals, dioxins, and chlorine that, if handled incorrectly, might cause permanent damage to the environment and humans. The low content of calcium (Ca), silicon (Si), and aluminum (Al) is a brand-new challenge for the melting technique of MWIA. This work added coal fly ash (CFA) to explore the effect of melting on the detoxication treatment of MWIA. It was found that the produced vitrification product has a high vitreous content (98.61%) and a low potential ecological risk, with an initial ash solidification rate of 67.38%. By quantitatively assessing the morphological distribution features of heavy metals in ashes before melting and molten products, the stabilization and solidification rules of heavy metals during the melting process were investigated. This work ascertained the feasibility of co-vitrification of MWIA and CFA. In addition, the high-temperature melting and vitrification accelerated the detoxification of MWIA and the solidification of heavy metals.

Modular stochastic configuration network prediction interval for furnace temperature in municipal solid waste incineration

The high dimensionality of characteristic variables and the presence of numerous uncertain factors affecting furnace temperature during municipal solid waste incineration can lead to poor accuracy and generalization ability for furnace temperature prediction. This paper adopts the modular neural network modeling approach and incorporates Gaussian process regression analysis into stochastic configuration networks to propose a method for establishing a furnace temperature prediction interval model. First, a Gaussian mixture model is used to decompose the complex task into several subtasks. Then, considering the differences among the subtasks, Gaussian process regression with different kernel functions is combined with a stochastic configuration network to form corresponding base models, which are trained and learned. The prediction interval results are obtained through blending ensemble methods. Finally, the effectiveness of the proposed method is tested using historical data obtained from the municipal solid waste incineration process. The results indicate that the furnace temperature prediction model demonstrates advantages in terms of accuracy and generalization ability, making it applicable to the field of process parameter modeling.

Source apportionment of PM2.5 using DN-PMF in three megacities in South Korea

AbstractPM2.5 pollution is problematic in megacities on the western coast in South Korea (Seoul, Incheon, and Gwangju). As these megacities are located downwind of China, their air quality is easily affected by local and long-range transport sources. PM2.5 samples collected in Seoul (n = 222), Incheon (n = 221), and Gwangju (n = 224) from September 2020 to March 2022, were chemically characterized. Dispersion normalized positive matrix factorization was applied to these PM2.5 speciated data to provide source apportionments. Nine common sources (including secondary nitrate, secondary sulfate, biomass burning, mobile, and waste incinerator) were identified at all sites. The conditional bivariate probability function helped to identify each site’s local sources. Joint potential source contribution function analysis identified northeast China and Inner Mongolia as potential source areas of long-range transport pollutants affecting all sites. Forced lifestyle changes due to the pandemic such as limited gatherings while increased recreational activities may have caused different patterns on the biomass burning source. The constraints on old vehicles during the policy implementation periods likely reduced the mobile source contributions in cities that adopted the policy. Secondary nitrate accounted for 40% of the PM2.5 mass at all sites, implying a significant impact from NOX sources. While the current policy focuses primarily on controlling primary emission sources, it should include secondary sources as well which may include precursor emissions control. Healthier air quality would be achieved if the policy effects are not limited to local, but also to foreign sources in regions upwind of Korea by intergovernmental collaboration.

Greenhouse Gas Emissions and Mitigation Strategies across the Life Cycle of Municipal Solid Waste Incineration Plants in China

Greenhouse Gas Emissions and Mitigation Strategies across the Life Cycle of Municipal Solid Waste Incineration Plants in China

Atmospheric emissions of hexachlorobutadiene in fine particulate matter from industrial sources

Hexachlorobutadiene (HCBD) is a concerning chemical that is included in the United States Toxic Substances Control Act, and the Stockholm Convention. Knowledge of the sources of HCBD is insufficient and is pivotal for accurate inventory and implementing global action. In this study, unintentional HCBD release and source emission factors of 121 full-scale industrial plants from 12 industries are investigated. Secondary copper smelting, electric arc furnace steelmaking, and hazardous waste incineration show potential for large emission reductions, which are found of high HCBD emission concentrations of > 20 ng/g in fine particulate matter in this study. The highest HCBD emission concentration is observed for the secondary copper smelting industry (average: 1380 ng/g). Source emission factors of HCBD for the 12 industries range from 0.008 kg/t for coal fire power plants to 0.680 kg/t for secondary lead smelting, from which an estimation of approximately 8452.8 g HCBD emissions annually worldwide achieved. The carcinogenic risks caused by HCBD emissions from countries and regions with intensive 12 industrial sources are 1.0-80 times higher than that without these industries. These results will be useful for formulating effective strategies of HCBD control.

Formulation and durability of slag/metakaolin-based geopolymers with 70 % municipal solid waste incineration fly ash (MSWI FA)

In this study, municipal solid waste incineration fly ash (MSWI FA) was used as an alternative to geopolymers for resource recovery. The 70 % MSWI FA mixing and durability of slag-metakaolin based geopolymer was assessed. The optimum formulation was determined based on MSWI FA mixing, silica-aluminum ratio (A), sodium-silica ratio (B), water-solid ratio, and slag content, and the solidification effect was analyzed in terms of compressive strength and heavy metal leaching concentration. The solidified products were tested by acid rain leaching, acid and alkali immersion, high-temperature calcination, and freeze-thaw cycles. The crystalline phases and structures of the solidified products were analyzed for stability using X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR) Spectroscopy , and Scanning Electron Microscopy (SEM). The experimental results revealed that when the mixing amount of MSWI FA was as high as 70 %, the compressive strength of the solidified products under the optimal formulation was 11.97 Mpa, and the solidification rate of heavy metals was greater than 92 %. The solidified products also exhibit good durability properties such as acid and alkali resistance, high-temperature resistance, and freeze-thaw resistance. Based on this study, the geopolymer possesses strong MSWI FA treatment capability.

Đánh giá mức độ phát thải của các chất polyclodibenzo-p-dioxin và polyclodibenzofuran phát sinh không chủ định từ lò đốt rác chất thải sinh hoạt và rác thải công nghiệp ở Việt Nam

Polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) are the most toxic substances among the group of unintentional persistent organic pollutants (U - POP) generated from many sources, in which domestic and industrial waste incinerators are the highest emission risk. Assessment of pollution potential and dioxin/furan emissions from incinerators in developing countries, including Vietnam, is still limited; especially in-depth studies on the content and characteristics of PCDD/PCDF emitted into the atmosphere. Therefore, the research team evaluated the emission potential and characteristics of 07 PCDD and 10 PCDF, those are considered to be the most toxic isomers and congeners, from stack gas samples collected from incinerators at 33 facilities in 11 provinces in Vietnam. The total concentration of PCDD/PCDF in the industrial incinerators’ emission ranged from 37.3 to 3348.6 pg TEQs/m3 and domestic waste incinerators had lower total concentrations and fluctuated within about 37.3-1323.8 pg TEQs/m3. The characteristic of incinerator emissions is that the proportion of 2,3,7,8- TCDD accounts for 2.9 to 9.04%. The highest contributing concentrations were congeners 1,2,3,7,8-PeCDD, with its contributing percentage from 22.95-32.42%. The second largest contributor is congeners 2,3,4,7,8- PeCDF, accounting for 20.94- 21.50% of the total toxic congeners of PCDD/PCDF in both types of incinerators. However, in terms of toxic equivalency (TEQ), the concentration of industrial waste incinerators is much higher than that of domestic waste incinerators. The results of stack gas samples showed that the PCDD/PCDF content for domestic waste incinerators has 5/17 establishments that exceeded the permissible standard threshold: 0.6 ng/Nm3, according to QCVN 61-MT:2016/BTNMT. Industrial waste incinerators have 5/16 establishments that exceeded the permissible standard threshold: 0.6ng/Nm3 for furnaces with a capacity of 300kg/hour according to QCVN 30:2012/BTNMT.

Mitigating CO2 emissions through an industrial symbiosis approach: Leveraging cork ash carbonation

This study explores for the first time the potential use of carbonation as a method for managing cork ash, a byproduct of biomass waste incineration. Additionally, the cork ash was combined with fly ash from municipal solid waste incineration to leverage the carbonation reaction's ability to stabilize heavy metals. The findings suggest that subjecting biomass ash to carbonation can lead to the formation of mineral carbonates, effectively capturing CO2 and reducing its release into the atmosphere. The combination of various alkaline wastes and the stabilization of leachable heavy metals through carbonation reactions also opens opportunities for synergies between different industrial sectors. Finally, the study proposes a route for the obtained materials valorisation via ‘end of waste’: the reuse of the resulting materials as substitutes for natural resources, particularly in applications like building materials and polymer composites, can further enhance carbon dioxide savings.

Experimental investigation on the high-temperature corrosion of 12Cr1MoVG boiler steel in waste-to-energy plants: Effects of superheater operating temperature and moisture

Waste-to-energy (WTE) technology via municipal solid waste incineration (MSWI) have developed very rapidly with the advantages of achievement on waste disposal and energy conversion. This technology is developing towards higher capacity and efficiency. Therefore, the operation parameters of WTE boilers must be improved. However, higher steam parameters means higher surface temperature of exchange tube in superheaters and reheaters in WTE boilers, resulting higher risk of engineering failure due to high-temperature corrosion. Additionally, the incineration of MSW releases flue gas with a high content of corrosive species and water vapor, which can cause severe high-temperature corrosion. This experimental investigation details the effect of surface temperature and water vapor concentration on the high-temperature corrosion behavior of 12Cr1MoVG boiler steel under an atmosphere mimicking MSWI. The corrosion test environment consists of high temperature, ash deposit and simulated flue gas of waste incineration according to a real WTE boiler. The experiment was conducted using a two-zone bench-scale tube furnace with a gas temperature of 600℃ and the sample temperatures of 380℃, 430℃, and 480℃. For the investigation of water vapor concentration effect, 18 % vol and 23 % vol were set up in this study. After 240 hours of exposure, the corrosion weight curves illustrated that the corrosion kinetics was highly dependent on the surface temperature of corrosion samples. Furthermore, an increase in water vapor concentration exacerbated the high-temperature corrosion. XRD analysis identified the corrosion products as metal chlorides and metal oxides. Cross-sectional SEM images and EDS analysis revealed that an increase in water vapor accelerated the corrosion rate of the steel samples due to chromium dilution behavior.

Comparative life cycle assessment of landfill sludge treatment technologies in China.

Reasonable treatment of large amounts of sludge excavated from landfills has gained increasing attention due to the diminishing availability of landfill space in China. In this study, five landfill sludge (LS) treatment technologies using life cycle assessment (LCA) and life cycle cost (LCC) were investigated, i.e., co-incineration in coal-fired power plants (CFPP) and waste incineration power plant (WIPP), co-processing in cement kiln, bricks production, and sintering ceramsite. The LCA results demonstrate that sintering ceramsite outperforms other technologies and LCC results indicate sintering ceramsite also provides the highest economic benefit ($869.94). To further enhance environmental and economic performances of the LS treatment, the substitution of coal with natural gas and biomass can reduce Energy Conservation and Emission Reduction (ECER) index by 74% and 98%, respectively. This substitution can increase economic returns by 24% and 26%, respectively. Furthermore, national-level economic benefit and carbon emission reduction potential of different LS treatment technology alternative scenarios were assessed. Results display that a combination of 50% CFPP, 25% bricks, and 25% ceramsite (biomass) offers the highest economic gain, which is 3.02 times that of 50% CFPP and 50% cement (original case). Conversely, the replacement of 25% brick with 25% cement in the above combination result in the lowest carbon reduction, which is 9.35 times that of the original case.

Toward zero-waste resource recovery from municipal solid waste incineration ash by electrochemical and chemical mining

Toward zero-waste resource recovery from municipal solid waste incineration ash by electrochemical and chemical mining

Co-pyrolysis of fly ash with sewage sludge for PCDD/F removal.

Fly ash generated from municipal waste incineration (MWI) contains various toxic substances, and it has to be properly treated before disposal or reuse. Water washing and thermal pyrolysis can improve the destruction efficiency of PCDD/Fs in fly ash generated from municipal solid waste incinerators. Since sulfur oxides and nitrogen compounds generated by the heating of the sewage sludge poison the catalytic active sites for PCDD/Fs formation on fly ash surface, co-pyrolysis of fly ash with sewage sludge effectively inhibits precursor formation and de novo synthesis reaction, resulting in the great reduction of PCDD/F formation. The results of the pyrolysis at 350 °C show that the PCDD/Fs removal efficiencies based on mass concentration are over 99%. The results at 350 °C of different reaction times show that the reaction time of 10 min is sufficient to reach the European End of Waste criteria (≤ 20 pg TEQ/g) when the ratio of fly ash/sewage sludge is controlled at 1:1.

Feasibility of stabilizing Cd, Pb, and Ni in MSWI fly ash using leachate as an alternative stabilizer

For the synergistic disposal of municipal solid waste incineration (MSWI) fly ash and leachate, MSWI fly ash was stabilized using leachate, sodium sulfide (Na2S), and sodium diethyldithiocarbamate (DDTC) separately or simultaneously. Results show that the leaching concentration of Cd, Ni, and Pb can be reduced when leachate is used alone but exceeds the landfill admission contents. The leaching concentration of heavy metals were lower than the threshold of the pollution control standard of Chinese garbage landfill (GB 16889-2008) after curing for 14d when DDTC was beyond 1.5%, and Na2S more than 10% except for Pb. The results of orthogonal experiment showed that the lowest leaching concentration was got at 5-fold dilution of leachate, 3% Na2S and 0.8% DDTC, and DDTC was the most influential factor. The leachate can be utilized as a partial stabilizer for stabilization of fly ash. After chemical stabilization, the crystal structure of fly ash changed little, and the surface was densified. The analysis of two-dimensional correlation spectroscopy results showed that the different order between the major function groups of fly ash and stabilizers was got, may be related to chelation, chemical reactions, and precipitation.

Immobilization of Cu(II) and Zn(II) into hydrocalumite - An X-ray absorption fine structure (XAFS) investigation

The fate of heavy metals is crucial to the reuse of municipal waste incineration ash (MWIA) as construction materials. It is, however, not completely clear how they interact with cementitious phases at the molecular scale. This study investigated the uptake and speciation of Cu(II) and Zn(II) during the generation of Al-hydrocalumite-type high-pH phases through co-precipitation and adsorption experiments. Hydrocalumite (Hc) and minor phases, such as calcite and hydrogarnet, were identified as primary phases using X-ray diffraction (XRD). The characterization of Hc+Cu(II), Hc+Zn(II), and Hc+Cu(II)+Zn(II) via XRD, SEM, and bulk Cu(II)/Zn(II) EXAFS showed that both Cu(II) and Zn(II) exists as the surface/interlayer adsorption on the Hc+Cu(II)/Hc+Zn(II) and Hc+Cu(II)+Zn(II). Thermodynamic calculations support the experimental observations for the bulk phase. This study help understand the interacting mechanism between Cu(II)/Zn(II) and Hc phase, and pave the way of safe utilization of heavy-metal-containing waste as supplementary cementitious materials.

High-efficient stabilization and solidification of municipal solid waste incineration fly ash by synergy of alkali treatment and supersulfated cement

Municipal solid waste incineration fly ash (IFA) designated as hazardous waste poses risks to environment and human health. This study introduces a novel approach for the stabilization and solidification (S/S) of IFA: a combined approach involving alkali treatment and immobilization in low-carbon supersulfated cement (SSC). The impact of varying temperatures of alkali solution on the chemical and mineralogical compositions, as well as the pozzolanic reactivity of IFA, and the removal efficiency of heavy metals and metallic aluminum (Al) were examined. The physical characteristics, hydration kinetics and effectiveness of SSC in immobilizing IFA were also analyzed. Results showed that alkali treatment at 25 °C effectively eliminated heavy metals like manganese (Mn), barium (Ba), nickel (Ni), and chromium (Cr) to safe levels and totally removed the metallic Al, while enhancing the pozzolanic reactivity of IFA. By incorporating the alkali-treated IFA and filtrate, the density, compressive strength and hydration reaction of SSC were improved, resulting in higher hydration degree, finer pore structure, and denser microstructure compared to untreated IFA. The rich presence of calcium-aluminosilicate-hydrate (C-(A)-S-H) and ettringite (AFt) in SSC facilitated the efficient stabilization and solidification of heavy metals, leading to a significant decrease in their leaching potential. The use of SSC for treating Ca(OH)2- and 25°C-treated IFA could achieve high strength and high-efficient immobilization.

Co-incineration of medical waste in municipal solid waste incineration increased emission of chlorine/brominated organic pollutants

Co-incineration of medical waste (MW) in municipal solid waste incinerators (MSWIs) is a crucial disposal method for emergency disposal of MW and the management of MW in small and medium-sized towns. This study aims to analyze and compare the levels and distribution patterns of chlorine/brominated dioxins and their precursors in fly ash from MSWIs and medical waste incinerators (MWIs) while also focusing on identifying the new pollution concerns that may arise from the co-incineration of municipal solid waste (MSW) mixed with MW (MSW/MW). The concentration of chlorobenzene (CBzs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) in fly ash from co-incineration of MSW/MW are 887.4, 134.4 and 27.6 μg/kg, respectively, which are 5.1, 2.0 and 2.9 times higher than that from MSWIs. The levels of polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) are about three orders of magnitude lower than that of PCDD/Fs. For the fly ash from MSWIs, the predominant PCDD/Fs congener is OCDD, which prefers synthesis and adsorption on fine-grained fly ash. For fly ash from MWIs, the major PCDD/Fs congeners are 1, 2, 3, 4, 6,7, 8-HpCDF, and OCDF, which prefer synthesis and adsorption on coarse-grained fly ash. Correlation analysis exhibited that both 1,2,3-TriCBz and 1,2,4-TriCBz in fly ash have a markedly linear correlation with PCDD/Fs and PCBs, but PBDD/Fs shows a poor negative correlation with PCDD/Fs.