Supporting the investigation of health outcomes due to airborne emission by different approaches: current evidence for the waste incineration sector.

Life cycle assessment (LCA) along with a survey on epidemiologic and oxidative potential studies was used for analysing the current evidence of the impact of airborne emissions from municipal solid waste incineration (MSWI) on human health. The correspondence among investigated health outcomes and pollutants was discussed based on the Chemical Abstract Service (CAS) and the International Agency for Research on Cancer (IARC). LCA indicated the ability of MSWI in avoiding human health impact, about - 2 × 10-4 DALY/tonne together with avoided emissions of particulate matter (PM) and resource depletion, about - 2.5 × 10-3 kg Sbeq/tonne and about - 0.11 kg PM2.5 eq/tonne, respectively. Positive emissions were detected for greenhouses (about 900 kg CO2eq/tonne) and ecotoxicity (about 15,000 CTUe/tonne). Epidemiologic studies performed on population exposed to MSWI reported quite contrasting results. In some of these, hazard ratio (HR) ranging from about 0.7 to 2.2 was reported concerning the incidence of stomach, liver, breast and bladder cancer. Larger agreement was detected concerning the incidence of larynx and lung cancer with HR ranging from about 1 to about 2.6. Direct causal nexuses were not definitively identified. Oxidative potential of PM was characterized by a high Pearson correlation > 0.8 to the presence of CrVI, Cu and Zn. These heavy metals were also identified by both CAS and IARC as toxic (i.e. Cu and Zn) and cancerous (i.e. CrVI) substances affecting the organs of both respiratory and digestive apparatus. In general, even if more research is necessary, LCA, oxidative potential and the epidemiologic survey results showed a high level of accordance. This suggests their integrated exploitation for supporting the investigation of both direct and indirect consequences on environment and health related to waste incineration for both retrospective and predictive studies.

Utilization of Municipal Solid Waste Incineration (MSWIFA) in Geopolymer Concrete: A Study on Compressive Strength and Leaching Characteristics.

This study explores the utilization of municipal solid waste incineration fly ash (MSWIFA) in geopolymer concrete, focusing on compressive strength and heavy metal leachability. MSWIFA was sourced from a Shenzhen waste incineration plant and pretreated by washing to remove soluble salts. Geopolymer concrete was prepared incorporate with washed or unwashed MSWIFA and tested under different pH conditions (2.88, 4.20, and 10.0). Optimal compressive strength was achieved with a Si/Al ratio of 1.5, water/Na ratio of 10, and sand-binder ratio of 0.6. The washing pretreatment significantly enhanced compressive strength, particularly under alkaline conditions, with GP-WFA (washed MSWIFA) exhibiting a 49.6% increase in compressive strength, compared to a 21.3% increase in GP-FA (unwashed MSWIFA). Additionally, GP-WFA's compressive strength reached 41.7 MPa, comparable to that of the control (GP-control) at 43.7 MPa. Leaching tests showed that acidic conditions (pH 2.88) promoted heavy metal leaching, which increased over the leaching time, while an alkaline environment significantly reduced the leachability of heavy metals. These findings highlight the potential of using washed MSWIFA in geopolymer concrete, promoting sustainable construction practices, particularly in alkaline conditions.

Removal and recovery of nitrogen from anaerobically treated leachate based on a neglected HNAD nitrogen removal pathway: NH3 stripping.

The heterotrophic nitrification aerobic denitrification (HNAD) process can withstand the environment with high NH4+-N concentration and complex components, and has the potential to be an effective scheme for nitrogen removal of anaerobically treated leachate from municipal solid waste incineration plant. But its mechanism is still unclear and the NH3 stripping process has received little attention. At the same time, the high concentration of NH4+-N in the anaerobically treated leachate also has great recycling potential. In this study, typical HNAD microorganisms were enriched and used for nitrogen removal from anaerobically treated leachate. A one-step system with a total nitrogen removal ratio of more than 98 % was constructed. Isotopic labeling experiments showed that nitrogen was not the main product. The important role of NH3 stripping in the HNAD system was defined, and 46.63 % nitrogen was recovered on this basis.

Evaluating the strength characteristics of mixtures of municipal solid waste incineration bottom ash and reddish laterite clay for sustainable construction.

This study examines effects of mixing municipal solid waste incineration bottom ash (MSWI-BA) with reddish laterite clay (RLC), evaluating factors such as vertical stress, mixing ratio, curing period, and the addition of lime. A total of 153 direct shear tests were conducted to thoroughly assess the mixture's strength characteristics. Vertical stress levels of 85.5 kPa, 172.4 kPa, and 259.3 kPa were used to simulate varying stress conditions, while mixing ratios of 40 %, 80 %, 100 %, and 120 % were applied to explore potential applications of recycled MSWI-BA with clayey soils. A fast-curing approach was employed, with curing periods of 24, 48, and 72 h, to investigate the time-dependent strength development under controlled conditions. A three-way ANOVA analysis confirmed that mixing ratio, curing period, and vertical stress significantly impacted both peak and residual shear strength. The 100 % MSWI-BA mixture, with or without 1 % lime, exhibited optimal performance, providing the pronounced shear strengths and dilative behavior. The study found that MSWI-BA significantly improved shear strength ratios compared to the RLC, with improvement ratios ranging from 1.439 to 2.460 across stress levels. Additionally, upper and lower bound equations for peak and residual strength ratios were developed, providing predictive tools for mixture design. Cohesion values in the range of 8.3-128.9 kPa and friction angles from 40.6° to 44.1° were achieved, surpassing or matching those reported in similar research. The study employed Bolton's (1986) dilatancy model, finding α values between 0.61 and 0.71, comparable to those in studies of granular materials. These results highlight the effectiveness of adding MSWI-BA and lime in enhancing reddish laterite soil stabilization through both chemical and mechanical means, making it a sustainable and cost-effective approach for civil engineering projects by improving material strength, reusing local soils, recycling waste, and reducing carbon footprints.

Occurrence and mass flow rate of PFAS in a Waste-to-Energy water treatment process.

This study investigated the fate of per- and polyfluoroalkyl substances (PFAS) in the in-house process-water treatment (PWT) of a 65 MW Waste-to-Energy (WtE) plant. PFAS are used in a wide variety of applications, but are persistent and will end up in waste streams when products reach the end of their lives. The study aimed to identify the pathway of PFAS from flue-gas treatment to the PWT, and to assess the efficiency of the PWT in removing PFAS. Sampling was conducted over five days at five different locations in the PWT. Nine of the eleven target PFAS were detected in at least one sample. The total concentration of PFAS exhibited day-to-day variations, likely caused by fluctuations in the composition of the waste fuel. The highest average PFAS concentration was observed in foam, and was around 130 times that found in the treated water. However, the mass flow of PFAS in the foam was substantially lower, on average 20 times, than that in the treated water. It was found that the condensate scrubber acts as a PFAS transfer step, carrying over certain PFAS from the flue gases into the condensate and PWT. The mass flow rate of PFAS in the PWT after the addition of condensate was six times that before the addition. The study concludes that, while there are some key changes that could be made to enhance the PFAS removal capacity of the in-house PWT, in its current configuration the PWT is not able to efficiently remove PFAS from process-water.

Unveiling dioxin dynamics: A whole-process simulation study of municipal solid waste incineration.

Theoretical research has explained the process of dioxin (DXN) formation in the municipal solid waste incineration (MSWI). This process includes the generation, adsorption, and emission of DXN. Actual DXN concentrations often significantly deviate from theoretical models. This discrepancy is influenced by several key factors: the type of integrated municipal solid waste (MSW) treatment process, the characteristics of the waste, and the operational controls. The progression of DXN generation, adsorption, and emission concentrations within the MSWI process remains unclear. This lack of clarity is especially pronounced when examining the accounting for the specific components of the MSW. To unravel the evolution of DXN, this article proposes a comprehensive numerical simulation model for the entire process of DXN concentration in an MSWI plant. The model is designed based on existing knowledge of MSW combustion and DXN mechanisms, leveraging FLIC and ASPEN simulation software. It incorporates six key stages to facilitate the DXN simulation: precipitation and formation, high-temperature pyrolysis, high-temperature gas-phase synthesis, low-temperature catalytic synthesis, adsorption on activated carbon, and emission to the atmosphere. Under both benchmark and multiple operating conditions, the simulated experiments confirm the effective representation of the evolution of DXN concentrations throughout the process. Consequently, this study presents a model designed to enhance the development of strategies aimed at reducing DXN emissions and to foster innovation in intelligent control technologies.

AI-based tree modeling for multi-point dioxin concentrations in municipal solid waste incineration.

Numerous investigations have shown that the municipal solid waste incineration (MSWI) has become one of the major sources of dioxin (DXN) emissions. Currently, the primary issue that needs to be addressed for DXN emission reduction control is the online measurement of DXN. Data-driven AI algorithms enable real-time DXN concentration measurement, facilitating its control. However, researchers mainly focus on building models for DXN emissions at the stack. This approach does not allow for the construction of models that online measurement of DXN generation and absorption throughout the whole process. To achieve optimal pollution control, models that encompass the whole process are necessary, not just models focused on the stack. Therefore, this article focuses on modeling the whole process of DXN concentrations, including generation, adsorption, and emission. It uses machine learning techniques based on advanced tree-based data-driven deep and broad learning algorithms. The determination of data characteristics at different phases is grounded in the understanding of the DXN mechanism, offering a novel framework for DXN modeling. State-of-the-art tree-based models, including adaptive deep forest regression algorithm based on cross layer full connection, tree broad learning system, fuzzy forest regression, and aid modeling technologies, are applied to handle diverse data characteristics. These characteristics encompass high-dimensional small samples, low-dimensional ultra-small size samples, and medium-dimensional small samples across different phases related to DXN. The most interesting is the robust validation where the proposed a whole process tree-based model for DXN is validated using nearly one year of authentic data on DXN generation, adsorption, and emission phases in an MSWI plant of Beijing. The proposed modeling framework can be used to explore the mechanism characterization and support the pollution reduction optimal control.

Priority Organic Pollutant Monitoring Inventory and Relative Risk Reduction Potential for Solid Waste Incineration.

Incineration is a promising sustainable treatment method for solid waste. However, the ongoing revelation of new toxic pollutants in this process has become a controversial issue impeding its development. Thus, identifying and regulating high-risk pollutants emerge as pivotal strides toward reconciling this debate. In this study, we proposed a workflow aimed at establishing priority monitoring inventories for organic compounds emitted by industries involving full-component structural recognition, environmental behavior prediction, and emission risk assessment, specifically focusing on solid waste incineration (SWI). A total of 174 stack gas samples from 29 incinerators were first collected. Nontarget full organic recognition technology was then deployed to analyze these samples, and 646 organic compounds were identified. The characteristics, i.e., toxicity effects, toxicity concentrations, persistence, and bioaccumulation potential, of these compounds were assessed and ranked based on the TOXCAST database from the US Environmental Protection Agency and structural effect models. Combined with consideration of changes in seasons and waste types, a priority control inventory consisting of 28 organic pollutants was finally proposed. The risks associated with SWI across different regions in China and various countries were assessed, and results pinpointed that by controlling the priority pollutants, the average global emission risk attributed to SWI was anticipated to be reduced by 71.4%. These findings offer significant guidance for decision-making in industrial pollutant management, emphasizing the importance of targeted regulation and monitoring to enhance the sustainability and safety of incineration processes.

Optimization of municipal solid waste incineration for low-NOx emissions through numerical simulation.

With urbanization, municipal solid waste (MSW) generation is increasing. Traditional landfill methods face land shortages and environmental pollution. Waste incineration, which reduces waste and recovers resources, has become a key management method. However, nitrogen oxides (NOx) produced during incineration severely impact the environment, requiring improved control technologies. This study optimized three denitrification technologies-air staging, flue gas recirculation (FGR), and selective non-catalytic reduction (SNCR)-using numerical simulations. The research provides support for improving waste incinerator efficiency and stability while reducing NOx emissions, aiding the sustainable development of waste incineration technology. By optimizing the primary and secondary air distribution ratios, the initial NOx generation was reduced by 8.39%. When 20% of the recirculated flue gas was introduced as secondary air, NOx generation was reduced by 23.54%, and boiler efficiency increased to 83.78%. The study examined the impact of different sludge mixing ratios on the temperature and NOx emissions within the context of municipal solid waste (MSW) incineration. Initially, the study aimed to address the environmental concerns of NOx emissions during the incineration process by exploring how the introduction of sludge at various mixing ratios would affect combustion parameters. The results showed that a sludge mixing ratio between 3 and 13% optimized the combustion process with 7% being the most effective in balancing temperature control and NOx emissions. Specifically, the best value of the sludge mixing ratio refers to achieving an optimal reduction in NOx emissions while maintaining stable incinerator operation. The chemical compositions of the sludge included key elements such as carbon (C), hydrogen (H), nitrogen (N), sulfur (S), and oxygen (O), with approximate proportions of C: 31.2%, H: 4.7%, N: 2.5%, S: 0.6%, and O: 31.8%.

Drivers of change behind the spatial distribution and fate of typical trace organic pollutants in fresh waste leachate across China.

There have been growing concerns regarding the health and environmental impacts of trace organic pollutants (TOPs). However, fresh leachate from municipal solid waste (MSW) has been overlooked as a potential reservoir of TOPs. Therefore, we investigated 90 legacy and emerging TOPs in fresh leachate from 14 provinces and municipalities in China. Additionally, the fate and final discharge impacts of TOPs in 14 leachate treatment systems were analyzed. The results revealed that the detection rate of 90 TOPs was over 50 % in all samples. Notably, polychlorinated biphenyls, banned for 40 years, were frequently detected in fresh leachate. The concentration of pseudo-persistent TOPs (105-107 ng/L) is significantly higher than that of persistent TOPs (102-104 ng/L). Spatial distribution patterns of TOPs in fresh leachate suggest that economy, population, climate, and policies impact TOPs discharge from MSW. For example, economically developed and densely populated areas displayed higher TOPs concentrations, whereas warmer climates facilitate TOPs leaching from MSW. We confirmed that waste classification policies were a key driver of the decline in multiple TOPs in leachate. Mass balance analysis shows that the final effluent and sludge from current dominant leachate treatment systems contain refractory TOPs, especially perfluoroalkyl acids, which must be prioritized for control. This paper was the first comprehensive investigation of multiple TOPs in fresh leachate at a large geographic scale. The factors affecting the occurrence, spatial distribution, and fate of TOPs in fresh leachate were revealed. It provides a valuable reference for the establishment of policies for the management of TOPs in MSW and the associated leachate.

Solidification and utilization of municipal solid waste incineration ashes: Advancements in alkali-activated materials and stabilization techniques, a review.

Researchers are actively investigating methodologies for the detoxification and utilization of Municipal Solid Waste Incineration Bottom Ash (MSWIBA) and Fly Ash (MSWIFA), given their potential as alkali-activated materials (AAMs) with low energy consumption. Recent studies highlight that AAMs from MSWIFA and MSWIBA demonstrate significant durability in both acidic and alkaline environments. This article provides a comprehensive overview of the processes for producing MSWIFA and MSWIBA, evaluating innovative engineering stabilization techniques such as graphene nano-platelets and lightweight artificial cold-bonded aggregates, along with their respective advantages and limitations. Additionally, this review meticulously incorporates relevant reactions. Recommendations are also presented to guide future research endeavors aimed at refining these methodologies.

Geopolymer Materials from Fly Ash-A Sustainable Approach to Hazardous Waste Management.

This study explores the utilisation challenges of fly ash from municipal waste incineration, specifically focusing on ash from a dry desulphurisation plant (DDS), which is categorised as hazardous due to its high heavy metal content. The ash's low silicon and calcium contents restrict its standalone utility. Laboratory investigations initially revealed that geopolymers derived solely from fly ash after flue gas treatment (FGT), in combination with coal combustion fly ash, exhibited low compressive strength (below 0.6 MPa). However, the study demonstrated significant improvements by modifying the FGT ash through water leaching. This process enhanced its performance when mixed with high-silica and -aluminium fly ash, resulting in geopolymers achieving compressive strengths of up to 18 MPa. Comparable strength outcomes were observed when the modified ash was blended with commercial cement. Leachability tests conducted for heavy metals (HMs) such as copper, zinc, lead, cadmium, and nickel indicated that their concentrations fell below the regulatory limits for landfill disposal: 2, 4, 0.5, 0.04, and 0.4 mg/kg, respectively. These results underscore the effectiveness of water-washing FGT ash in conjunction with other materials for producing geopolymers, contributing to sustainable waste management practices.

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.

A comprehensive emission inventory of air pollutants from municipal solid waste incineration in China's megacity, Beijing based on the field measurements.

The rising of municipal solid waste incineration (MSWI), constituting 5 % of NOx emissions in Beijing, poses a significant challenge to improving air quality. This study establishes a comprehensive historical inventory of air pollutants (APs) emitted from MSWI plants between 2004 and 2023. The inventory was developed using both the continuous emissions monitoring systems (CEMS)-based method and the EF (emission factors) -based method, incorporating detailed plant-level activity data and localized EF derived from field measurements. These include data from CEMS and manual monitoring. Analysis of CEMS data reveals high compliance rates with emission limits for MSW in Beijing, with 99.9 %, 99.5 %, 99.8 %, 98.7 %, and 99.5 % of units meeting standards for PM, SO2, NOx, CO and HCl, respectively. This suggests effective implementation of emission standards in Beijing, although further strengthening of policies, particularly for CO emissions, is warranted. Overall, total AP emissions have increased annually largely attributed to measures implemented for DeSOx, DeNOx, and DePM since 1998. Most MSWI facilities are located in suburban areas rather than urban cores. Emissions of SO2, HCl, CO, Hg, Cd + Ti, other metals, dioxins, VOCs, and NH3 exhibit a spatially homogeneous distribution at the district level, while PM and NOx emissions demonstrate heterogeneity. Scenario analysis underscores the importance of continuous improvement and upgrading of advanced air pollution control devices. This study contributes a methodological framework for estimating emissions, reducing uncertainties, and informing policy-making to mitigate APs emissions in megacities. It serves as a valuable reference for similar cities grappling with air quality challenges.

Zinc speciation in fly ash from MSWI using XAS - novel insights and implications.

The chemical forms of zinc in fly ash from municipal solid waste incineration (MSWI) crucially affect ash management, influencing both material recovery options and the risk of unwanted leaching into ecosystems. The zinc speciation was investigated in fly ash samples sourced from full-scale MSWI plants, including four grate fired boilers (GB) and one fluidized bed boiler (FB). We applied X-ray Absorption Spectroscopy (XAS), and the spectra were analyzed against a unique library of over 30 relevant compounds, tailored to the nuances of zinc chemistry of fly ash. Nano-XANES and sequential leaching were employed as complementary analytical methods. Multiple chemical forms of zinc were found in the ash, whereof potassium zinc chloride salts (K2ZnCl4) emerged as the predominant form in GB fly ash representing 41-64 % of the zinc content, while less for FB fly ash (19 %). The mere exposure to humidity in the air during storage resulted in hydroxylation of the alkali zinc chlorides into Zn5(OH)8Cl2·H2O. Other forms of zinc in the ash were Zn4Si2O7(OH)2·H2O, ZnFe2O4, ZnAl2O4, surface adsorbed zinc, and Zn5(CO3)2(OH)6. Notably, the proportion of zinc in spinel forms (ZnFe2O4 and ZnAl2O4) increased threefold in FB ash compared to GB ash, representing ∼60 % and ∼10-20 % of the zinc, respectively.

Impacts of advanced metals recovery on municipal solid waste incineration bottom ash: aggregate characteristics and performance in portland limestone cement concrete.

The optimization of alternative materials in concrete production continues to garner considerable attention in order to meet sustainability goals and supplement natural materials. Portland limestone cement (PLC) and municipal solid waste incineration (MSWI) bottom ash (BA) have been proposed separately as green cement and coarse aggregate supplement in low-strength concrete production, creating sustainable products and alternative disposal scenario for a waste material. This study discusses the impact of advanced ash processing techniques on aggregates and presents the performance of concrete incorporating both of these products with PLC for the first time. Two sources of MSWI BA were investigated, one as-produced (TMR) and one processed with novel advanced metals recovery (AMR). The AMR process reduced total Al content in ash compared to TMR (20,500 vs 17,000 mg/kg), though not aluminum oxide content, as the AMR process targets metallic aluminum. A composition study on both aggregates supports a reduction in ferrous and non-ferrous metals following the AMR process. All control and test mixes met 28-day compressive strength requirements (17 Mpa). Both AMR and TMR MSWI BA-amended concretes yielded compressive strengths below control specimens (no ash) ranging from 17 to 23 MPa, with little to no difference observed dependent on MSWI BA processing. The life-cycle discussion supports benefits deriving from supplementing naturally mined materials and recovering ferrous and nonferrous metals with the AMR process.

Chlorine-induced Gas-Solid coupled corrosion behaviors of tube materials in high steam parameter MSW incinerator.

The fast development of the waste incineration industry requires deeper insights into heating surface corrosion behavior at higher operating parameters with complex corrosion sources. This research investigates the corrosion behaviors of three types of plates, namely SA210-C, TP310, and 12CrMoV, when subjected to simulated flue gas and fly ash deposition simultaneously at temperatures ranging from 500℃ to 620℃. The results indicate that the weight loss due to coupling corrosion was 2.5 to 84.5 times higher than that of gas-phase corrosion under the same operating conditions. Among the three stainless-steels, TP310 demonstrates superior corrosion resistance. It is worth noting that, under the gas-solid coupling corrosion conditions, we observed a distinct two-layer structure of corrosion products. Despite the fly ash simulants detaching over time, the two-layer structure remained unchanged. Based on the theory of eutectic molten salt formation, we propose that alkali metal chlorides only initiate the formation of the molten layer in the initial stage of corrosion. Furthermore, we offer additional suggestions for the mechanism of sustaining the molten layer in the absence of alkali metal chlorides.

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.

Resource utilization of medical waste incineration fly ash to activate peroxydisulfate for tetracycline degradation: Synergy between adsorption and PDS activation.

Medical waste incineration fly ash (MWI FA) is classified as a hazardous solid waste. Therefore, the development of recycling technologies to convert MWI FA into useful products is necessary and challenging. In this study, we developed a sustainable approach for preparing a catalyst through the pyrolysis of water-washed MWI FA (WW FA-x, where x corresponds to the pyrolysis temperature). Subsequently, it was applied as a potent peroxydisulfate (PDS) activator to remove tetracycline (TC) from water. The results showed that the WW FA-800 exhibited remarkable adsorption performance as well as highly efficient catalytic activation of PDS, with a 115 mg/g maximum TC adsorption capacity and 93.5% (reaction kinetic rate = 315 µmol/g/h) TC removal within 60 min. A synergistic effect was achieved by adsorption and PDS activation. TC degradation was primarily driven by non-radical (1O2 and electron transfer) processes. WW FA-800 possesses multiple active sites, including defects, π-π*, O-CO groups, Fe0, and Cu(I). Three possible pathways for TC decomposition have been proposed, with the majority of intermediates exhibiting less toxicity than TC. Furthermore, the WW FA/PDS system exhibited an excellent anti-interference ability, and universality in the degradation of various organic contaminants. Notably, energy consumption was minimal, approximately 2.80 kWh/(g·TC), and the leachability of heavy metals in the WW FA-800 was within acceptable limits. This study provides a MWI FA recycling route for the development of highly active catalysts.

A robust acid-resistant chelating polymer for enhanced stabilization of lead ions in fly ash.

Fly ash derived from municipal solid waste incinerators (MSWIs) harbors significant quantities of heavy metals with high leaching toxicity, resulting in detrimental environmental effects. Pb2+ in fly ash is the ion most likely to exceed permissible levels. However, chemical stabilization methods demonstrate poor efficacy in stabilizing Pb2+ under acidic conditions. Herein, we have developed a robust acid-resistant chelating polymer (25DTF) for enhanced stabilization of Pb2+ in fly ash. 25DTF was synthesized through the reaction of formaldehyde with 2,5-dithiourea. 25DTF exhibited remarkable chelation efficiency, nearing 100%, for Pb2+ in fly ash. 25DTF demonstrated exceptional chelation efficiency, surpassing 99.9%, when interacting with Pb2+ in fly ash at pH ≤ 7. Even under acidic conditions, 25DTF effectively prevented the secondary dissolution of Pb2+. Additionally, it indicated outstanding Pb2+ chelation efficiency across diverse regions of China. The 25DTF chelating agent shows considerable potential in alleviating metal ion contamination in soil, wastewater, and urban environmental management, thereby fostering advancements in environmental stewardship.