Characteristics of pollutant generation from 3D-printed photocured waste combustion.

With the rapid advancement of photopolymerization-based 3D printing technology, the volume of PCW has experienced a sharp increase. The potential environmental ramifications of PCW disposal demand careful consideration, especially given its current practice of being incineration alongside MSW. In this study, the TG-MS/FTIR system was carried out to probe the thermogravimetric characteristics and volatile byproducts during combustion. Various product compositions resulting from different mixing ratios of PCW incineration with MSW were investigated. It was observed that fluorene (C13H10) and triphenylene (C18H12) produced by PCW combustion 0.52 mg/g and 0.43 mg/g respectively, which are twice as abundant as those generated from normal plastic. When PCW incineration along with MSW, compounds such as naphthalene (C10H8), cyclohexane (C6H12), and heptane (C7H16) were generated in concentrations of 1.25 mg/g, 1.05 mg/g, and 0.95 mg/g respectively, which are at least twice as much as with MSW incineration alone. The incineration of PCW with rubber and textiles resulted in the production of 2.34 mg/g to 3.76 mg/g more PAHs compared to PCW combustion alone. The incineration of PCW with paper resulted in the production of 3.12 mg/g to 5.15 mg/g more heptane, nonane, cyclohexane, pyrene, and anthracene than PCW combustion alone. Incineration of PCW with wood proved to be the cleanest method, with product contents primarily below 0.10 mg/g. When incinerated with food residues or normal plastic, most of the product content remained below 0.05 mg/g. Considering the environmental pollution resulting from PCW combustion, the disposal of PCW warrants careful consideration and management.

Intelligent technologies powering clean incineration of municipal solid waste: A system review.

Cleanliness has been paramount for municipal solid waste incineration (MSWI) systems. In recent years, the rapid advancement of intelligent technologies has fostered unprecedented opportunities for enhancing the cleanliness of MSWI systems. This paper offers a review and analysis of cutting-edge intelligent technologies in MSWI, which include process monitoring, intelligent algorithms, combustion control, flue gas treatment, and particulate control. The objective is to summarize current applications of these techniques and to forecast future directions. Regarding process monitoring, intelligent image analysis has facilitated real-time tracking of combustion conditions. For intelligent algorithms, machine learning models have shown advantages in accurately forecasting key process parameters and pollutant concentrations. In terms of combustion control, intelligent systems have achieved consistent prediction and regulation of temperature, oxygen content, and other parameters. Intelligent monitoring and forecasting of carbon monoxide and dioxins for flue gas treatment have exhibited satisfactory performance. Concerning particulate control, multi-objective optimization facilitates the sustainable utilization of fly ash. Despite remarkable progress, challenges remain in improving process stability and monitoring instrumentation of intelligent MSWI technologies. By systematically summarizing current applications, this timely review offers valuable insights into the future upgrade of intelligent MSWI systems.

Enhancement of methane production from anaerobic digestion of Erigeron canadensis via O2-nanobubble water supplementation.

Malignant invasive Erigeron canadensis, as a typical lignocellulosic biomass, is a formidable challenge for sustainable and efficient resource utilization, however nanobubble water (NBW) coupled with anaerobic digestion furnishes a prospective strategy with superior environmental and economic effectiveness. In this study, influence mechanism of various O2-NBW addition times on methanogenic performance of E. canadensis during anaerobic digestion were performed to achieve the optimal pollution-free energy conversion. Results showed that supplementation of O2-NBW in digestion system could significantly enhance the methane production by 10.70-16.17%, while the maximum cumulative methane production reached 343.18 mL g-1 VS in the case of one-time O2-NBW addition on day 0. Furthermore, addition of O2-NBW was conducive to an increase of 2-90% in the activities of dehydrogenase, α-glucosidase and coenzyme F420. Simultaneously, both facultative bacteria and methanogenic archaea were enriched as well, further indicating that O2-NBW might be responsible for facilitating hydrolytic acidification and methanogenesis. Based on Kyoto Encyclopedia of Genes and Genomes (KEGG) cluster analysis, provision of O2-NBW enhanced the metabolism of carbohydrate and amino acid, translation as well as membrane transport of bacteria and archaea. This study might offer the theoretical guidance and novel insights for efficient recovery of energy from lignocellulosic biomass on account of O2-NBW adhibition in anaerobic digestion system, progressing tenor of carbon-neutral vision.

Pyrolytic homogeneity enhancement of municipal solid waste using a clustering-based sorting strategy.

Heterogeneity of pyrolytic parameters in municipal solid waste (MSW) significantly hinders its waste-to-energy efficiency. So far, hardly any light has been shed on current pyrolytic heterogeneity conditions or feasible pyrolytic homogeneity enhancement approaches of MSW. Accordingly, pyrolytic properties (Ea and logA) of 130 MSW samples in 6 categories were collected from literature. A kinetic parameters clustering-based sorting strategy for MSW was proposed. A so-called C index was established to compare their sorting performance for Ea and logA against two traditional sorting strategies (substance categorization and density clustering). Results showed that the proposed sorting strategies outperformed the traditional ones in pyrolytic homogeneity enhancement, where the optimal C_Ea and C_logA reached 1578.30 kJ/mol and 93.11 -log min. Among investigated clustering methods, k-means clustering outperformed hierarchical clustering, which could be attributed to its adaptability to the sample structure. Future perspectives involving data set expansion, model framework development, and downstream technologies matching were also discussed. The index C established in this study can be used to evaluate other clustering models.

Pyrolysis of exhausted biochar sorbent: Fates of cadmium and generation of products.

Biochar is a promising sorbent for Cd removal from water, while the disposal of the exhausted Cd-enriched biochar remains a challenge. In this study, pyrolysis was employed to treat the exhausted biochar under N2 and CO2 atmospheres at 600-900 °C, and the fate of Cd during pyrolysis and characteristics of high-valued products were determined. The results indicated that higher temperature and CO2 atmosphere favored the volatilization of Cd. Based on the toxicity characteristic leaching procedure (TCLP) results, the pyrolysis treatment under both atmospheres enhanced the stability of Cd, and the leached Cd concentration of regenerated biochar obtained at high temperatures (>800 °C) was lower than 1 mg/L. Compared with the pristine biochar, the regenerated biochar demonstrated higher carbon content and pH, whereas the contents of oxygen and hydrogen declined, and exhibited promising sorption properties (35.79 mg/g). The atmosphere played an important role in modifying biochar properties and syngas composition. The N2 atmosphere facilitated CH4 production, whereas the CO2 atmosphere increased the proportion of CO. These results implied that pyrolysis can be a valuable and environmental-friendly strategy for the treatment and reuse of exhausted biochar sorbent.

A novel extraction-free dual HiFi-LAMP assay for detection of methicillin-sensitive and methicillin-resistant Staphylococcus aureus.

Staphylococcus aureus (S. aureus) is a leading cause of bacteremia and blood stream infections. Methicillin-resistant S. aureus (MRSA) that first appeared in 1961 often caused hospital-acquired infections (HAIs) and community-acquired infections (CAIs) and was associated with high mortality rate. Accurate and rapid point-of-care testing (POCT) of MRSA is crucial for clinical management and treatment of MRSA infections, as well as the prevention and control of HAIs and CAIs. Here, we reported a novel extraction-free dual HiFi-LAMP assay for discriminative detection of methicillin-susceptible S. aureus and MRSA. The dual HiFi-LAMP assay can detect 30 copies/reaction of nuc and mecA genes with detection limits of 147 and 158 copies per 25 µL reaction, respectively. A retrospective clinical evaluation with 107 clinical S. aureus isolates showed both sensitivity and specificity of 100%. A prospective clinical evaluation with 35 clinical samples revealed a specificity of 100% and a sensitivity of 92.3%. The dual HiFi-LAMP assay can detect almost all S. aureus samples (141/142; 99.3%) within 20 min, implying that the entire HiFi-LAMP assay (including sample process) can be completed within 40 min, extremely significantly shorter than 3-5 days by the traditional clinical microbial culture and antibiotic susceptibility testing. The novel extraction-free dual HiFi-LAMP assay can be used as a robust POCT tool to promote precise diagnosis and treatment of MRSA infections in hospitals and to facilitate surveillance of MRSA at hospital and community settings.IMPORTANCEMethicillin-resistant Staphylococcus aureus (MRSA) was associated with high mortality rate and listed as a "priority pathogen" by the World Health Organization. Accurate and rapid point-of-care testing (POCT) of MRSA is critically required for clinical management and treatment of MRSA infections. Some previous LAMP-based POCT assays for MRSA might be questionable due to their low specificity and the lack of appropriate evaluation directly using clinical samples. Furthermore, they are relatively tedious and time-consuming because they require DNA extraction and lack multiplex detection capacity. Here, we reported a novel extraction-free dual HiFi-LAMP assay for discriminative detection of MRSA and methicillin-susceptible S. aureus. The assay has high specificity and sensitivity and can be completed within 40 min. Clinical evaluation with real clinical samples and clinical isolates showed excellent performance with 100% specificity and 92.3%-100% sensitivity. The novel extraction-free assay may be a robust POCT tool to promote precise diagnosis of MRSA infections and facilitate surveillance of MRSA at hospital and community settings.

Application of waste derived magnetic acid-base bifunctional CoFe/biochar/CaO as an efficient catalyst for biodiesel production from waste cooking oil.

The loss of active components, weak acid resistance, and low recover efficiency of common Ca-based catalysts limited its further development and application. In this study, to effectively produce biodiesel from waste cooking oil (WCO), a green and recyclable magnetic acid-base bifunctional CoFe/biochar/CaO catalyst was prepared from sargassum and river snail shell waste via hydrothermal method. The catalysts' structure and properties were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), CO2/NH3 temperature programmed desorption (CO2/NH3 TPD), etc., The prepared catalyst mainly consisted of the carbon skeleton, CoFe alloy, and CaO. CoFe alloy provided catalyst's ferromagnetism for magnetic separation as well as acid sites for transesterification of WCO. Ca and other metal species with nanoscale (∼5.64 nm) were dispersively anchored on sargassum biochar surface, thereby leading to good catalytic activity (99.21% biodiesel yield) and stability (91.70% biodiesel yield after the 5th cycle). In addition, response surface methodology-Box-Behnken design (RSM-BBD) revealed the optimal operational conditions were 16:1 methanol/oil molar ratio, 3 wt% catalyst dosage, 73 °C for 157 min. The maximum biodiesel yield predicted value was 98.29% and the experimental value was 99.21%, indicating good satisfaction of the established model. Moreover, the quality of WCO biodiesel met the ASTM D6751 standards. This study benefits magnetic waste-derived acid-base bifunctional catalysts for the disposal of WCO towards sustainable biodiesel production.

Integrated serum pharmacochemistry and investigation of the anti-influenza A virus pneumonia effect of Qingjin Huatan decoction.

ETHNOPHARMACOLOGICAL RELEVANCE: Qingjin Huatan Decoction (QJHTT) consists of 11 herbal medicines: Scutellaria baicalensis Georgi, Gardenia jasminoides J. Ellis, Platycodon grandiflorus (Jacq.) A. DC., Ophiopogon japonicus (Thunb.) Ker Gawl., Morus alba L., Fritillaria thunbergii Miq., Anemarrhena asphodeloides Bunge, Trichosanthes kirilowii Maxim., Citrus reticulata Blanco, Poria cocos (Schw.) Wolf, and Glycyrrhiza uralensis Fisch. As a traditional Chinese medicinal formula, QJHTT has been used for more than 400 years in China. It has shown promising results in treating influenza A virus (IAV) pneumonia. AIM OF THE STUDY: To elusive the specific pharmacological constituents and mechanisms underlying its anti-IAV pneumonia effects. MATERIALS AND METHODS: The components in QJHTT were analyzed through the use of a serum pharmacology-based ultra high-performance liquid chromatography Q- Exactive Orbitrap mass spectrometry (UHPLC-Q Exactive Orbitrap-MS) method. Simultaneously, the dynamic changes in IAV-infected mouse lung viral load, lung index, and expression of lung inflammation factors were monitored by qRT-PCR. RESULTS: We successfully identified 152 chemical components within QJHTT, along with 59 absorbed chemical prototype constituents found in the serum of mice treated with QJHTT. 43.45% of these chemical components and 43.10% of the prototype constituents were derived from the monarch drugs, namely Huangqin and Zhizi, aligning perfectly with traditional Chinese medicine theory. Notably, our analysis led to the discovery of 14 compounds within QJHTT for the first time, three of which were absorbed into the bloodstream. Simultaneously, we observed that QJHTT not only reduced the viral load but also modulated the expression of inflammation factors in the lung tissue including TNF-α, IL-1ß, IL-4, IL-6, IFN-γ, and IL17A. A time-effect analysis further revealed that QJHTT intervention effectively suppressed the peak of inflammatory responses, demonstrating a robust anti-IAV pneumonia effect. CONCLUSIONS: We comprehensively analyzed the pharmacological material basis of QJHTT by a highly sensitive and high-resolution UHPLC-Q Exactive Orbitrap-MS method, and demonstrated its efficacy in combating IAV pneumonia by reducing lung viral load and inflammatory factors. This study has significant importance for elucidating the pharmacological basis and pharmacological mechanism of QJHTT in combating IAV pneumonia.

Effect of landfilling time on physico-chemical properties of combustible fractions in excavated waste.

Excavated waste is a byproduct of microbial decomposition and fermentation following landfill disposal. The effective management and utilization of excavated waste offer broad prospects for environmental and resource protection, as well as economic growth. While current research predominantly focuses on plastics in landfills, the physico-chemical properties of excavated waste over extended landfilling time remain unclear. This study aimed to address this gap by excavating waste from a landfill in Tianjin, China, with a maximum landfilling time of 18 years. The findings revealed that, compared to municipal solid waste (MSW), the excavated waste exhibited increased calorific value, ash content, and fixed carbon content after screening the landfill-mined-soil-like-fine fraction. The average calorific value of the excavated waste could reach 57.8 MJ/kg. Additionally, the oxygen content in the excavated combustible waste exceeded that of MSW, increasing from 25.59 % to 34.22 %. This phenomenon is potentially linked to the oxidation of attached soil impurities and waste. The study identified polyethylene (PE), polypropylene (PP), expanded polystyrene (EPS), polyethylene terephthalate (PET), and wood as the primary combustible components. Notably, the excavated waste exhibited a significant decrease in surface gloss, adopting a rough texture with apparent holes, potentially attributed to the acidification and corrosion of organic matter during fermentation. Nevertheless, the breaking of molecular bonds could also contribute to waste fragmentation. Furthermore, an increase in landfilling time resulted in a more pronounced decrease in mechanical properties. For instance, the failure load of PE decreased from 15.61 N to 6.46 N, and PET reduced from 884.83 N to 186.56 N. The chemical composition of excavated waste has changed, with -OH and CO observed in PE with an 18-year landfilling time. In conclusion, these results provide a theoretical foundation for the recycling of excavated waste and contribute to the advancement of waste management and recycling technologies.

Effect of heterogeneous fenton-like pretreatment on semi-permeable membrane-covered co-composting: Humification and microbial community succession.

This study focused on the impacts of heterogeneous Fenton-like pretreatment on the humification and bacterial community during co-composting of wheat straw with cattle dung covered with a semi-permeable membrane. In this study, FeOCl and low concentration of H2O2 were used for pretreatment and composting, which lasted for 39 days. The results showed that the pretreatment promoted the humification process, with degree of polymerization and percentage of humic acid increasing by 53.2 % and 7.3 %, respectively. Furthermore, the diversity and structure of bacterial communities were altered by pretreatment. During the thermophilic phase, pretreatment considerably promoted the metabolism of carbohydrate. According to redundancy analysis, C/N, moisture and organic matter were the key environmental factors that dominated the microbial community. In summary, heterogeneous Fenton-like pretreatment provided a novel idea for improving the humic acid content and maturity of the compost pile.

Electron-Sponge Nature of Polyoxometalates for Next-Generation Electrocatalytic Water Splitting and Nonvolatile Neuromorphic Devices.

Designing next-generation molecular devices typically necessitates plentiful oxygen-bearing sites to facilitate multiple-electron transfers. However, the theoretical limits of existing materials for energy conversion and information storage devices make it inevitable to hunt for new competitors. Polyoxometalates (POMs), a unique class of metal-oxide clusters, have been investigated exponentially due to their structural diversity and tunable redox properties. POMs behave as electron-sponges owing to their intrinsic ability of reversible uptake-release of multiple electrons. In this review, numerous POM-frameworks together with desired features of a contender material and inherited properties of POMs are systematically discussed to demonstrate how and why the electron-sponge-like nature of POMs is beneficial to design next-generation water oxidation/reduction electrocatalysts, and neuromorphic nonvolatile resistance-switching random-access memory devices. The aim is to converge the attention of scientists who are working separately on electrocatalysts and memory devices, on a point that, although the application types are different, they all hunt for a material that could exhibit electron-sponge-like feature to realize boosted performances and thus, encouraging the scientists of two completely different fields to explore POMs as imperious contenders to design next-generation nanodevices. Finally, challenges and promising prospects in this research field are also highlighted.

Glutamate-pantothenate pathway promotes antibiotic resistance of Edwardsiella tarda.

Although cellular metabolic states have been shown to modulate bacterial susceptibility to antibiotics, the interaction between glutamate (Glu) and chloramphenicol (CAP) resistance remains unclear because of the specificity of antibiotics and bacteria. We found that the level of Glu was upregulated in the CAP-resistant strain of Edwardsiella tarda according to a comparative metabolomics approach based on LC-MS/MS. Furthermore, we verified that exogenous metabolites related to Glu, the tricarboxylic acid (TCA) cycle, and glutathione (GSH) metabolism could promote CAP resistance in survival assays. If GSH metabolism or the TCA cycle is inhibited by L-buthionine sulfoximine or propanedioic acid, the promotion of CAP resistance by Glu in the corresponding pathway disappears. According to metabolomic analysis, exogenous Glu could change pantothenate metabolism, affecting GSH biosynthesis and the TCA cycle. These results showed that the glutamate-pantothenate pathway could promote CAP resistance by being involved in the synthesis of GSH, entering the TCA cycle by direct deamination, or indirectly affecting the metabolism of the two pathways by pantothenate. These results extend our knowledge of the effect of Glu on antibiotic resistance and suggest that the potential effect, which may aggravate antibiotic resistance, should be considered before Glu and GSH administration in the clinic.

From cellulose to tar: Analysis of tar formation pathway with distinguishing the primary and secondary reactions.

Tar problem seriously hinders the development of biomass gasification. The tar formation of biomass is greatly influenced by cellulose. In this work, PY-GC/MS was employed for providing a precise insight into the formation of primary and secondary products, and a tar contribution index was introduced to evaluate the potential of tar formation from different origins. Combined with statistical analysis and corroboration by DFT analysis, key intermediates for tar formation are recognized, and corresponding influence is confirmed. A new framework from cellulose to tar was built. The secondary reaction acts a more important role for tar formation. The aromatic precursors and high-activity small-molecular gases are two key compounds responding to tar formation, and the existence of high-activity small-molecular gases could significantly reduce the energy barrier during tar formation. For furans, the energy barrier can be reduced from 100.2 kcal/mol to 74.2 kcal/mol in the presence of ethylene.

Continuous renal replacement therapy with oXiris® in patients with hematologically malignant septic shock: A retrospective study.

BACKGROUND: The mortality rate from septic shock in patients with hematological malignancies (HMs) remains significantly higher than that in patients without HMs. A longer resuscitation time would definitely be harmful because of the irreversibly immunocompromised status of the patients. Shortening the resuscitation time through continuous renal replacement therapy (CRRT) with oXiris® would be an attractive strategy in managing such patients. AIM: To explore the effects of CRRT and oXiris® in shortening the resuscitation time and modifying the host response by reducing inflammation mediator levels. METHODS: Forty-five patients with HM were diagnosed with septic shock and underwent CRRT between 2018 and 2022. Patients were divided into two groups based on the hemofilter used for CRRT (oXiris® group, n = 26; M150 group, n = 19). We compared the number of days of negative and total fluid balance after 7 d of CRRT between the groups. The heart rate, norepinephrine dose, Sequential Organ Failure Assessment (SOFA) score, and blood lactic acid levels at different time points in the two groups were also compared. Blood levels of inflammatory mediators in the 26 patients in the oXiris® group were measured to further infer the possible mechanism. RESULTS: The average total fluid balance after 7 d of CRRT in the oXiris® group was significantly lower than that of patients in the M150 hemofilter group. The SOFA scores of patients after CRRT with oXiris® therapy were significantly lower than those before treatment on day 1 (d1), d3 and d7 after CRRT; these parameters were also significantly lower than those of the control group on d7. The lac level after oXiris® therapy was significantly lower than that before treatment on d3 and d7 after CRRT. There were no significant differences in the above parameters between the two groups at the other time points. In the oXiris® group, procalcitonin levels decreased on d7, whereas interleukin-6 and tumor necrosis factor levels decreased significantly on d3 and d7 after treatment. CONCLUSION: CRRT with oXiris® hemofilter may improve hemodynamics by reducing inflammatory mediators and playing a role in shortening the resuscitation period and decreasing total fluid balance in the resuscitation phases.

Variables related to bronchopulmonary dysplasia severity: a Six-Year retrospective study.

OBJECTIVES: This was a retrospective observational study conducted in a tertiary neonatal intensive care unit, in order to investigate factors which influenced the severity of bronchopulmonary dysplasia under NICHD new classification. METHODS: Six years of clinical data with different grades of bronchopulmonary dysplasia patients were collected and analyzed, bivariate ordinal logistic regression model and multivariable ordinal logistic regression model were used with sensitivity analyses. RESULTS: We identified seven variables were associated with the severity of BPD via a bivariate ordinal logistic regression model, including the level of referral hospital (OR 0.273；95% CI 0.117, 0.636), method of caffeine administration (OR 00.418；95% CI 0.177, 0.991), more than two occurrences of reintubation (OR 4.925；95% CI 1.878, 12.915), CPAP reapplication (OR 2.255；95% CI 1.059, 4.802), presence of positive sputum cultures (OR 2.574；95% CI 1.200, 5.519), the cumulative duration of invasive ventilation (OR 1.047；95% CI 1.017, 1.078), and postmenstrual age at the discontinuation of oxygen supplementation (OR 1.190；95% CI 1.027, 1.38). These seven variables were further analyzed via all multivariable ordinal logistic regression models, and we found that tertiary hospital birth and early administration of caffeine could reduce the severity of BPD by approximately 70% (OR 0.263；95% CI 0.090, 0.770) and 60% (OR 0.371；95% CI 0.138, 0.995), respectively. In contrast, multiple reintubations were related to higher BPD severity with an OR of 3.358 (95% CI 1.002, 11.252). CONCLUSION: Improving perinatal care in level II hospitals, standardized caffeine administration, and optimized extubation strategy could potentially decrease the severity of BPD.

Enhanced mechanism of copper doping in magnetic biochar for peroxymonosulfate activation and sulfamethoxazole degradation.

Magnetic biochar is excellent for separation and peroxymonosulfate (PMS) activation. Copper doping could improve the catalytic capability of magnetic biochar significantly. In this study, cow dung biochar is applied to investigate the effects of copper doping on the magnetic biochar, focusing on the specific influence on the consumption of active sites, the production of oxidative species and the toxicity of degradation intermediates. The results showed that copper doping promoted the uniform distribution of iron sites on the biochar surface and reduced iron aggregation. At the same time, copper doping interpreted the biochar with larger specific surface area, which was beneficial to the adsorption and degradation of sulfamethoxazole (SMX). The SMX degradation kinetic constant with copper-doped magnetic biochar was 0.0403 min-1, which was 1.45 times than that of magnetic biochar. Besides, copper doping might accelerate the consumption of CO, Fe0, Fe2+ sites and hinder the activation of PMS at copper-related sites. Furthermore, copper doping promoted the PMS activation by magnetic biochar through accelerated electron transfer. For the oxidative species, copper doping accelerated the production of hydroxyl radicals, singlet oxygen, and superoxide radicals in solution and inhibited the generation of sulfate radicals. In addition, SMX could be directly decomposed into less toxic intermediates in the copper-doped magnetic biochar/PMS system. In conclusion, this paper provides insight and analysis of the advantages of copper doping on the magnetic biochar, which helps to facilitate the design and practical application of bimetallic biochar.

H2O2 activation and contaminants removal in heterogeneous Fenton-like systems.

Emerging contaminants can be removed effectively in heterogeneous Fenton-like systems. Currently, catalyst activity and contaminant removal mechanisms have been studied extensively in Fenton-like systems. However, a systematic summary was lacking. This review summarized: 1) The effects of various heterogeneous catalysts on emerging contaminants degradation by activating H2O2; 2) The role of active sites in different catalysts during the activation of H2O2 and their contribution to the generation of active species; 3) The modulation of degradation pathways of emerging contaminants. This paper will help scholars to advance the controlled construction of active sites in heterogeneous Fenton-like systems. Suitable heterogeneous Fenton catalysts can be selected in practical water treatment processes.

Conversion and impact of dissolved organic matters in a heterogeneous catalytic peroxymonosulfate system for pollutant degradation.

Dissolved organic matters (DOM) are widely present in different water sources, causing significant effects on water treatment processes. Herein, the molecular transformation behavior of DOM during peroxymonosulfate (PMS) activation by biochar for organic degradation in a secondary effluent were comprehensively analyzed. Evolution of DOM was identified and inhibition mechanisms to organic degradation were elucidated. DOM underwent oxidative decarbonization (e.g., -C2H2O, -C2H6, -CH2 and -CO2), dehydrogenation (-2H) and dehydration reactions by ·OH and SO4·-. N and S containing compounds witnessed deheteroatomisation (e.g., -NH, -NO2+H, -SO2, -SO3, -SH2), hydration (+H2O) and N/S oxidation reactions. Among DOM, CHO-, CHON-, CHOS-, CHOP- and CHONP-containing molecules showed moderate inhibition while condensed aromatic compounds and aminosugars exhibited strong and moderate inhibition effects on contaminant degradation. The fundamental information could provide references for the rational regulation of ROS composition and DOM conversion process in a PMS system. This in turn offered theoretical guidance to minimize the interference of DOM conversion intermediates on PMS activation and degradation of target pollutants.

Influence and mechanism of water matrices on H2O2-based Fenton-like oxidation processes: A review.

Water matrices often coexist with the target pollutant during H2O2-based Fenton-like processes, which affects H2O2 activation and pollutant removal. Specifically, water matrices include inorganic anions (such as chloride, sulfate, nitrate, bicarbonate, carbonate and phosphate ions) and natural organic matters (such as humic acid (HA) and fulvic acid (FA)). In this review, the roles and mechanisms of water matrices in various Fenton-like systems were analyzed and summarized comprehensively. Carbonate and phosphate ions usually act as inhibitors. In contrast, the effects of other water matrices are usually controversial. Generally, water matrices can inhibit pollutants degradation through scavenging OH, forming low reactive radicals, adsorbing on catalyst sites, and changing solution pH. However, inorganic anions can exhibit a promotion effect, which is attributed to their complexation with copper ions in mixed contaminants as well as with cobalt and copper ions in catalysts. Furthermore, the photo-reactivity of nitrate and the generation of secondary radicals with long lifetime are conducive to the promotion of inorganic anions. Besides, HA (FA) can be activated by external energy or act as electron shuttle, thus displaying a facilitative effect. This review will provide guidance for the practical applications of the Fenton-like process.

Prediction of NH3 and HCN yield from biomass fast pyrolysis: Machine learning modeling and evaluation.

Rapid pyrolysis is a promising technique to convert biomass into fuel oil, where NOX emission remains a substantial environmental risk. NH3 and HCN are top precursors for NOX emission. In order to clarify their migration path and provide appropriate strategies for their controlling, six up-to-date machine learning (ML) models were established to predict the NH3 and HCN yield during rapid pyrolysis of 26 biomass feedstocks. Cross-validation and grid search methods were used to determine the optimal hyperparameters for these ML models. The support vector regression (SVR) model achieved optimal accuracy among them. The optimal root means square error (%), mean absolute error (%), and R2 of test set for NH3/HCN yield were 1.2901/1.1531, 1.0501/0.84712, and 0.98253/0.96152, respectively. In addition, based on the results of Pearson correlation analysis, the input variables with a weak linear correlation with the target product were eliminated, which was found capable of improving the prediction accuracy of almost all ML models except SVR. While after input variables elimination, the SVR model still showed the optimal NH3 and HCN yield prediction accuracy. It reflects SVR's great significance and potential for predicting the yield of NOX precursors during rapid biomass pyrolysis.