The nitrate reduction reaction (NO3- RR) offers an eco-friendly pathway for sustainable ammonia production, this research presents a novel NO3 -to NH3 conversion mechanisms by elucidating the structure-activity relationship between different [MnO6] octahedral connection modes and catalytic performance. The alpha-MnO2-160 catalyst rich in corner-positioned oxygen vacancies ([Mn3+] - VO- [Mn3+]) demonstrated the best performance, achieving a Faraday efficiency (FE) of 91.48% at -1.0 V vs. RHE and an NH3 production rate of 1540.9 mu mol h- 1 cm- 2 at -1.2 V vs. RHE, while maintaining stability during 15 h of continuous operation. The [Mn3+] - VO[Mn3+] structure, serving as a bimetallic active center, significantly enhances the NO3 -adsorption energy (-2.39 eV) and promotes N - O bond dissociation, while effectively reducing the energy barriers (-3.30 eV, -1.84 eV) of the *NOH -> *N -> *NH pathway and suppressing the conventional *NOH -> *NHOH pathway (-1.25 eV). This corner oxygen vacancy-induced electron rearrangement mechanism achieves precise regulation of the adsorption strength of reaction intermediates, providing a theoretical basis for designing high-performance Mnbased NO3- RR catalysts and demonstrating its potential in efficient catalysis as well as the development of energy and chemical industries.

Viruses are primarily introduced into municipal solid waste (MSW) through human excreta and discarded materials contaminated with human secretions, making MSW an important reservoir for virus dissemination during MSW collection and treatment processes. Workers and residents in and around various waste facilities are particularly susceptible. However, the profiles of viruses from MSW treatment systems have yet to be systematically understood. This paper summarizes the key waste facilities and potential transmission routes within MSW collection and treatment processes, reviews viral prevalence across various media, and discusses both conventional and emerging techniques for virus concentration and detection. The potential of slightly acidic electrolyzed water as a novel disinfectant for mitigating microbial contamination in waste facilities is also explored. Leachate is generated throughout waste storage, transfer, and treatment processes. Bioaerosols are primarily generated during waste handling operations and transportation activities. These environmental matrices represent the major reservoirs and transmission routes for viruses in MSW treatment systems. Viruses detected in leachate and bioaerosols throughout MSW collection and treatment processes are primarily enteric viruses and Severe Acute Respiratory Syndrome Coronavirus 2. Emerging methods like digital polymerase chain reaction and viromic sequencing demonstrate promise in detection sensitivity and analytical convenience. By systematically reviewing previous research, this review offers insights into the potential risks and implications of viral presence in MSW treatment systems. It further emphasizes the necessity of strengthening virus research and control strategies, and outlines future directions, including standardized concentration and detection methods, machine learning prediction techniques, and comprehensive risk assessments of viruses.

Agricultural production generates large quantities of tobacco waste (TW) and discarded plastic mulching film (DPMF), whose sustainable co-management remains challenging. Herein, the co-pyrolysis behavior, kinetics, and synergistic mechanisms of TW and DPMF were systematically investigated using TG-DTG, TG-FTIR, and Py-GC/ MS analyses. Thermogravimetric results reveal a four-stage co-pyrolysis process, in which synergistic interactions reduce char yield by 2.9% compared with individual pyrolysis. TG-FTIR and Py-GC/MS analyses demonstrate enhanced formation of light hydrocarbons and esters, accompanied by suppressed cyclic compounds, indicating improved volatile quality. Isoconversional kinetic analysis (FWO, KAS, and Starink methods) shows that the average apparent activation energy of the TW-DPMF mixture is 56.15 kJ & sdot;mol- 1, which is substantially lower than the weighted average of the individual components (approximately 70.5 kJ/mol), confirming a synergistic reduction in the energy barrier. Model-fitting results further indicate a mechanistic transition from chemicalreaction control to nucleation-driven behavior at elevated temperatures. Based on the observed product distributions and kinetic trends, a dual hydrogen-transfer mechanism is proposed as a plausible explanation for the observed synergistic. This study provides quantitative kinetic and mechanistic insights into the valorization of agricultural residues and plastics through co-pyrolysis.

To address the issues of high carbon source consumption and high operating costs in traditional biological denitrification processes caused by the low carbon-to-nitrogen (COD/NH3-N) ratio in municipal solid waste leachate from aging landfills. This study focused on the Shanghai Laogang Leachate Treatment Plant, it systematically investigated the thermodynamic equilibrium of free ammonia, mass transfer separation mechanisms, process optimization pathways, and environmental and economic benefits of the steam stripping ammonia removal pretreatment technology. Statistical analysis of continuous operational data over seven months revealed a significant positive correlation (P < 0.05) between daily steam consumption and deamination efficiency. Multiple linear regression analysis further indicated that daily influent flow rate is the primary factor influencing steam consumption (standardized coefficient Beta = 0.863). Based on the established energy consumption model, a specific process optimization scheme was proposed: reducing the bottom pressure of the deamination tower by an average of 0.013 MPa while increasing the bottom pressure of the stripping tower by an average of 0.016 MPa, which corresponds to raising the vacuum pump frequency by 3.804 Hz. This is expected to reduce steam consumption by approximately 10%. Operating cost analysis indicated that the steam ammonia stripping pretreatment saved approximately 11.82 yuan per cubic meter of leachate in carbon source costs. Life cycle assessment (LCA) results show that the new process reduces system-wide carbon emissions by 15.7% and electricity consumption by approximately 60%. This study provides a data-driven theoretical basis and optimization pathway for energy conservation, consumption reduction, and stable operation of large-scale thermal steam ammonia stripping processes for leachate.

Landfill mining offers a sustainable solution for aged waste, but resource utilization of its main landfill-mined soil-like fractions (LMSF) fraction remains constrained by complex impurities and heavy metal contamination. Current treatment methods fail to simultaneously achieve deep purification, detoxification, and recovery of key resources. Herein, a novel cascade process was developed, integrating water-medium selective separation, chelation-based leaching, and a synchronous enrichment mechanism for rare earth elements and humic acid. Results indicated that under optimal conditions (solid-liquid ratio of 1:5, 4 circulation cycles, stirring speed of 600 rpm), the physical separation removed over 80% of inorganic inert impurities. The subsequent leaching using 0.04 mol/L EDTA achieved high elution efficiencies for Cd (95.7%), Cu (88.8%), Zn (77.4%), and Pb (71.0%), effectively mitigating ecological risks. Furthermore, the pH 4.8 NaAc-HAc buffer system recovered 81.88% of rare earth elements (344.35 mg/kg) while synergistically increasing humic acid purity by 1.6 times (to 26.71 g/kg) via the ash-reducing effect. This study provides a viable and environmentally sound technical pathway for converting contaminated aged waste into valuable resources.

The synergistic conversion of CO2 and solid waste into energy is becoming increasingly important for mitigating environmental impacts and advancing the circular economy.This study investigated the co-gasification of tobacco waste (TW) and plastic mulching film (PMF) using a Ni-modified red mud catalyst (Ni-CRM600) in a CO2 atmosphere to produce syngas. The pyrolysis behavior of the raw material was investigated under N2 and CO2 atmospheres, revealing a significant increase in mass loss under CO2 conditions. Subsequently, the Ni-CRM600 catalyst system was used to optimize the effects of CO2 concentration, reaction temperature, and the ratio of TW to PMF on syngas yield. Under optimized reaction conditions, a maximum synthesis gas yield of 1195 mL/g was achieved (H2: 623 mL/g, CO: 572 mL/g). Furthermore, experimental results indicate that both catalyst stability and gas yield decrease with increasing CO2 concentration. CO2 not only serves as the gasification medium for the reaction but also influences product distribution and catalyst stability through the Boudouard reaction, while enhancing the catalyst's resistance to carbon deposition. This study provides important insights into utilizing CO2 auxiliary gasification technology to convert PMF and TW into syngas.

Anaerobic fermentation (AF) for volatile fatty acids (VFAs) is a promising resource recovery approach for food waste (FW). In this study, magnetite-phase steel slag activating peroxymonosulfate (MSSAP) system was developed to enhance the production of VFAs from AF of FW. Results demonstrated that the cumulative VFAs yields were enhanced by 30.7% with MSSAP (from 6918.7 mg COD/L to 9045.30 mg COD/L) by improving solubilization, hydrolysis and acidification. Mechanism analysis revealed that MSSAP was capable to disintegrate FW to improve the overall organics release and enhance the electron transfer capability (representing a 40% increase) and activities of key enzymes (protease, acetate kinase and butyrate kinase). Further investigation suggested that hydrolytic-acidogenic microorganisms (e.g., Bacillota and Chloroflexota) in the MSSAP reactors were obviously enriched. Notably, metagenome analysis indicated that the relative abundances of metabolic pathways related to substrate metabolism and VFAs biosynthesis (e.g., Glycolysis/Gluconeogenesis and Butanoate metabolism), as well as functional genes, were markedly increased by MSSAP. This research provided a novel perspective and theoretical foundation for the integrated resource utilization of FW and steel slag (SS), holding significant implications for engineering applications in practice.

The stabilization assessment of landfilled refuse is crucial for its subsequent mining and resource utilisation, however landfill age is often difficult to determine accurately. This study investigates the relationship between landfill age and the humus composition and fluorescence characteristics of refuse derived. Samples were collected from seven landfill units with ages ranging from 7 to 30 years. Analysis of humus components revealed that the content and transformation of humic substances effectively reflect the degradation and humification processes of organic matter over time. Fluorescence excitation-emission matrix spectroscopy combined with parallel factor analysis identified three fluorescent components in the extracted humic acid: C1 (fulvic acid-like), C2 (terrestrial humus-like), and C3 (protein-like), with average relative contents of 40.90%, 38.21%, and 20.89%, respectively. The fluorescence intensities of these components initially increased, peaked around 18 years, and subsequently decreased with increasing landfill age. Based on the variation patterns of humification index (HIX) and biological index (BIX), a unit fluorescence index (Fu) was defined. Using 18 years as a demarcation point, piecewise fitting was performed between Fu and landfill age. For landfill age <= 18 years, Fu = 1325e(0.0996Y), R-2= 0.9822, for >= 18 years, Fu = 60350e(-0.106Y), R-2= 0.9316. Pearson correlation analysis revealed significant positive (R = 0.96, p < 0.05) and negative (R =-0.97, p < 0.05) correlations for the two phases, respectively, confirming a good fit. The model effectively quantifies the relationship between humus soil properties and landfill age, providing a scientific basis for assessing waste stabilization.

The efficient management of food waste (FW) has emerged as a pivotal bottleneck impeding the sustainable development of the urban circular economy. This work employs a thermally activated persulfate (PDS) system to investigate abiotic carbon source production pathways of FW, aiming to achieve efficient resource utilization through biorefinery. The physicochemical properties, structure-activity relationship, and carbon source products analysis of FW during the conversion process revealed that the introduction of PDS significantly enhanced the hydrolysis and the dissolution of organic matter. Under the optimal conditions of PDS dosage of 0.2 mmol/g VS, 70 °C, and 1 h, the system achieved the highest carbon source production efficiency, with SCOD and TOC reaching 13726.0 ± 325.6 mg/L and 3862.0 ± 95.2 mg/L, respectively, representing increases of 35.2% and 26.6% relative to the control. The resulting FW-derived carbon source exhibited significantly elevated concentrations of volatile fatty acids, reducing sugars, and soluble sugars, indicating that complex particulate organic matter was effectively transformed into highly bioavailable low-molecular-weight compounds. EPR analysis elucidated that the ∙OH and ∙SO4- were the key reactive species driving the cleavage, depolymerization, and solubilization of macromolecular organic matter. Simultaneously, dissolved organic matter evolved from protein-like and microbially derived components toward humic-like substances, revealing the synergistic parallel characteristic of carbon source production and humification. In the batch nitrate utilization tests, the FW-derived carbon source achieved a denitrification rate of 70.56 mg/(g MLVSS·d), indicating its feasibility as an alternative external carbon source. As a technology for rapid carbon source production of FW, this approach is anticipated to enhance the utilization efficiency of low-grade resources, while facilitating waste resource utilization and offering feasible and important support for circular economy and sustainable urban development.

The electrochemical hydrogenation of 5-hydroxymethylfurfural (HMF) to 2,5-bis(hydroxymethyl)furan (BHMF) presents a sustainable strategy for biomass valorization, yet selectively upgrading HMF to BHMF with high conversion rate remains challenging. To address this issue, we introduced a computer-assisted framework integrating large language model (LLM), machine learning (ML) and Bayesian optimization to recommend optimal experimental conditions for the HMF-BHMF electrochemical system. We first utilized the multi-modal capacity of GPT-4o to automatically extract literature data via prompt engineering, forming a high-quality dataset comprising 248 experimental entries from 378 publications related to the HMF-BHMF conversion. This LLM-curated dataset was leveraged to train a deep neural network for predicting both conversion and selectivity in a multi-task learning setting. The trained model demonstrated strong predictive performance, achieving R2 scores of 0.870 for conversion rate and 0.920 for selectivity. SHAP analysis revealed that electrochemical kinetics and electrode identity were the most influential factors governing conversion and selectivity respectively. Utilizing the machine learning model, Bayesian optimization identified optimized reaction conditions for balancing the trade-off between selectivity and conversion rate. Experimental validation of one such condition yielded 81.70 % conversion and 52.08 % selectivity, significantly outperforming experimental designs in literature. Our study offers a promising human-machine collaborative approach to accelerating experimental optimization, paving the way for more sustainable electrosynthetic pathways in biomass valorization.

This study investigated a hybrid energy system for the co-firing coupling power generation of municipal multisource organic solid waste sludge. Under the condition of a sludge treatment capacity of 300 t/d, project experimental study on coupled power generation by co-firing sludge with moisture contents of 40, 60, and 80% was conducted. Based on the on-site analytical data, an energy balance model for the sludge integrated treatment system and coal-fired boiler system was established, and the energy consumption of the hybrid energy system was calculated. Five types of unit loads 300, 360, 450, 480, and 540 MW were selected for a comprehensive comparative analysis in terms of thermal economy, carbon emissions, exhaust emissions, and profitability. The results demonstrate that, the maximum fluctuation range of the energy consumption loss was 41.49%, the maximum fluctuation range of the heat consumption of power generation was 7.32%, with a variation of 564.30 kJ/kW & sdot;h, and the maximum fluctuation range of the net standard coal consumption rate was 7.58%, with a variation of 22.80 g/kW & sdot;h. The maximum fluctuation range of carbon emissions resulting from electricity consumption was 17.93%, and the maximum fluctuation range of carbon emissions resulting from energy consumption was 70.21%. This study can provide a reference for the energy conservation and carbon reduction optimization design of municipal multi-source organic solid waste co-firing coupled with a power generation hybrid energy system.

Municipal solid waste incineration fly ash (MSWI-FA) contains carcinogenic PCDD/Fs, leachable heavy metals, and soluble chlorides. Although mechanochemical (MC) treatment is a promising method for FA detoxification, pilot-scale validation and simultaneous multi-pollutant removal are lacking. This study reports the construction and operation of a 5 t/d pilot-scale MC plant designed to co-remove PCDD/Fs, heavy metals, and chlorides from MSWI-FA. Key results demonstrate PCDD/Fs degradation efficiencies of 94.3% for low-contamination FA1 (from 4050.8ng/kg to 229.4ng/kg) and 91.0% for high-contamination FA2 (from 33458.9ng/kg to 2999ng/kg). This degradation is attributed to charge-transfer-induced cleavage of C-Cl bonds via O2- release from activated CaO-additive systems. MC treatment effectively immobilized heavy metals (Hg, Cu, Zn, Ba, As, Cr) in FA to levels compliant with the GB 8978 standard by converting soluble compounds into stable crystalline phases, although Pb leaching remained elevated (3-4mg/L). Dechlorination efficiency reached 60%, achieved through the release of encapsulated chlorides via lattice distortion and the subsequent physical separation of volatile species by the pilot plant airflow classification system. Finally, a combined washing-mechanochemical process is proposed for FA treatment, enabling the production of building materials from the treated FA and salt recovery from washing residues. This study validates the scalability of MC technology for MSWI-FA processing and management, providing a technical foundation for industrial applications.

The escalating generation of municipal solid waste incineration fly ash (MSWI-FA), a hazardous byproduct enriched with heavy metals and dioxins, poses severe environmental and disposal challenges. Municipal solid waste incineration fly ash -based geopolymers (MSWI-FA-GPs) emerge as a transformative waste valorization technology, capable of simultaneously immobilizing heavy metals (>99% for Pb, Cd) and upcycling waste into valuable materials. This review highlights that FA-GPs exhibit superior mechanical strength (up to 149.89MPa), exceptional thermal stability (91.3% retention at 1000 ℃), and a 49.7% lower carbon footprint compared to ordinary Portland cement. Furthermore, by integrating industrial solid wastes (e.g., slag, red mud), FA-GPs can be functionalized for advanced environmental applications, demonstrating high efficiency in CO2 capture and dye adsorption, and are promising as potential catalytic materials. Notably, their scalable application is constrained by the cost of alkali activators and the heterogeneity of raw materials. This work aims to provide a roadmap for advancing MSWI-FA-GPs from laboratory innovation to industrial implementation, thereby supporting the circular economy and carbon neutrality goals.