ACS ES&T engineering最新文献

{"title":"Pt-Nanoparticle-Loaded Porous SnO2 for Optimizing H2S-Sensing Performance at Room Temperature","authors":"Peijin Zou,&nbsp;Zhuangzhuang Ma,&nbsp;Zihuan Tang,&nbsp;Xiaotong Gao,&nbsp;Xiaoxiong Hou and Lichao Jia*,&nbsp;","doi":"10.1021/acsestengg.4c0052210.1021/acsestengg.4c00522","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00522https://doi.org/10.1021/acsestengg.4c00522","url":null,"abstract":"<p >Achieving the real-time detection of hydrogen sulfide (H₂S) based on metal oxide semiconductor (MOS) gas sensors is of great significance for rapid disease diagnosis. However, the high-power consumption and poor selectivity severely limit its practice application. In this study, a platinum nanoparticle (Pt NPs)-loaded porous metal–organic framework (MOF)-derived SnO₂ material was successfully synthesized to optimize the H₂S-sensing performance at room temperature. The optimized Pt-loaded porous SnO₂-based gas sensor exhibited remarkably high sensitivity (712–10 ppm), fast response (21 s), good selectivity, and extremely low detection limit for H₂S (10 ppb) at room temperature. The in-depth analysis demonstrated that the porous structure of Sn-MOF can provide adequate active reaction sites for gas molecules. Moreover, the uniform distribution of surface-loaded Pt NPs can initiate electron and chemical sensitization effects, thereby improving the sensing performance. The successful application of Pt NPs provides a novel approach to improve the room-temperature (RT) sensing performance of metal-oxide-semiconductor-based gas sensors.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 1","pages":"260–270 260–270"},"PeriodicalIF":7.4,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing Food Waste Anaerobic Digestion Efficiency with Biochar as a Sustainable Technology in Decentralized Real-World Systems","authors":"Yong Wei Tiong,&nbsp;Hailin Tian,&nbsp;Pooja Sharma,&nbsp;Miao Yan,&nbsp;Heng Thong Lam,&nbsp;Jonathan Tian En Lee,&nbsp;Jingxin Zhang and Yen Wah Tong*,&nbsp;","doi":"10.1021/acsestengg.4c0057510.1021/acsestengg.4c00575","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00575https://doi.org/10.1021/acsestengg.4c00575","url":null,"abstract":"<p >Long-term anaerobic digestion (AD) of food waste often faces challenges, with volatile fatty acid inhibition being a common issue that hinders optimal performance. This research explores the effect of biochar supplementation on long-term AD of food waste characterized by volatile fatty acid inhibition. The findings demonstrate that adding a modest amount of biochar (0.055 g/L) effectively enhances AD under ambient conditions at 29 °C. This biochar supplementation reduced volatile fatty acids to a safe level of 1195 mg/L after 36 days, well within the generally accepted safe threshold of 1500 mg/L. This safe threshold is supported by other studies, which indicate that maintaining VFA concentrations below 1500 mg/L minimizes the risk of process inhibition and ensures stable AD operation. Additionally, the normalized specific biogas yield averaged 1.33 ± 0.45 m³/kg VS, representing a 47.4% improvement over the control AD conducted under identical conditions. After stabilization, the study assessed whether AD could maintain functionality and stability under mesophilic conditions (35 °C) without further biochar supplementation, simulating a real-world scenario to test long-term efficacy in industrial-like conditions. This mesophilic postbiochar AD resulted in an additional 31.8% increase in the normalized average specific biogas yield, reaching 1.95 ± 0.25 m³/kg VS. Biochar increased <i>Methanosaeta</i> methanogens by 30%, enhancing direct interspecies electron transfer and strengthening syntrophic interactions. This shift made aceticlastic methanogens 9 times more prominent, improving acetate oxidation, biogas yield, and overall AD stability. These findings highlight biochar’s potential to enhance decentralized biogas facilities, promote sustainable food waste management, and advance the bioeconomy by providing a replicable model for closing the food waste loop.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 2","pages":"500–514 500–514"},"PeriodicalIF":7.4,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phenomenological Interpretations of Membrane Properties Following Repeated Chemical Cleaning of an End-of-Life Potable Reuse Reverse Osmosis Element Dominated by Inorganic Fouling","authors":"Bilal Abada,&nbsp;Jana Safarik,&nbsp;Kenneth P. Ishida and Shankararaman Chellam*,&nbsp;","doi":"10.1021/acsestengg.4c0048610.1021/acsestengg.4c00486","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00486https://doi.org/10.1021/acsestengg.4c00486","url":null,"abstract":"<p >A tail end-of-life reverse osmosis (RO) element from the third stage of a three-stage train extensively fouled by silicon was investigated for the effects of repeated alkaline cleaning and their consequences on foulant reversal and membrane integrity. Detailed surface characterization revealed that after four years of operation in the world’s largest potable reuse facility, it was severely fouled by inorganic substances with lesser contributions from bioorganic materials that together had reduced its water permeance and salt rejection to only ∼20 and ∼80% of their initial values, respectively. Swatches of the heavily fouled membrane were exposed repeatedly (but separately) to two high-pH cleaning agents (NaOH or TPP/DBS, a mixture of sodium tripolyphosphate and sodium dodecylbenzesulfonate) simulating repetitive cleaning-in-place (CIP) protocols typical of real-world operations. Although five-to-ten cleaning cycles fully recovered the fouled membrane’s water permeance, salt rejection always remained below 90% confirming its end-of-life. X-ray photoelectron (XPS), energy-dispersive X-ray (EDS), and Fourier transform infrared (FTIR) spectroscopy of fouled membranes implicated silicon as the dominant foulant, which was only partially removed even after ten cleaning cycles, although water permeance was completely restored. Importantly, exposing a virgin membrane to identical “cleaning” regimens as the end-of-life membrane artificially increased water permeance without changing its salt rejection. FTIR and XPS scans of the virgin membrane following repetitive exposure to NaOH or TPP/DBS revealed no damage/degradation of its polyamide layer as demonstrated by the relatively constant amide I/amide II absorbance ratios and consistent oxygen/nitrogen atomic ratios, both symptomatic of maintaining membrane integrity. Hence, we phenomenologically invoked swelling and/or surface property modifications to mechanistically explain the quantitative increase of water permeance after repeatedly exposing the virgin membrane to CIP agents (while maintaining the active polyamide layer’s integrity). Similarly, we attributed a portion of the restored permeance of the fouled membrane upon progressive chemical cleaning to swelling and/or surface property modification that could be indirectly inferred. Therefore, it is paramount to comparatively characterize virgin and fouled membranes prior to and after exposure to CIP chemicals to distinguish foulant removal from other mechanisms potentially contributing to recovering water permeance.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 1","pages":"167–178 167–178"},"PeriodicalIF":7.4,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestengg.4c00486","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"d-Phenylalanine Alleviates the Corrosion by Desulfovibrio vulgaris in Saline Water","authors":"Hongyi Li,&nbsp;Zhengyan Kang,&nbsp;Chengcheng Ding,&nbsp;Xinxin Zhao,&nbsp;Yiqi Cao,&nbsp;Baiyu Zhang,&nbsp;Chao Song* and Shuguang Wang*,&nbsp;","doi":"10.1021/acsestengg.4c0036210.1021/acsestengg.4c00362","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00362https://doi.org/10.1021/acsestengg.4c00362","url":null,"abstract":"<p >A biofilm is a major contributor to microbiologically influenced corrosion (MIC) in cooling water systems, resulting in severe economical and environmental impacts. <span>d</span>-Amino acids offer a potential alternative for preventing biofilm formation in these systems, where salinity levels vary due to diverse water sources, such as freshwater and diluted seawater. However, the impact of <span>d</span>-amino acids on corrosion inhibition under saline conditions remains unexplored. In this study, we evaluated the effect of <span>d</span>-phenylalanine (<span>d</span>-Phe) on corrosion by <i>Desulfovibrio vulgaris</i> at three salinity levels. <span>d</span>-Phe (10 mg/L) played little role in corrosion inhibition at low salinity (5 g/L) but obviously decreased the corrosion by 40.6% and 59.6% at moderate salinity (15 g/L) and high salinity (20 g/L), respectively. It was attributed to that <span>d</span>-Phe reduced the secretion of extracellular protein from 292.5 μg/mg to 245.6 μg/mg and decreased the biofilm thickness from 25.46 μm to 20.87 μm on the coupon surface. Besides, <span>d</span>-Phe decreased the sessile cells from 15.1 × 10⁷ cells/cm² to 12.8 × 10⁷ cells/cm² at high salinity. Furthermore, transcriptome analysis found that indole, the signal molecule negatively regulating the biofilm formation, was increased by adding <span>d</span>-Phe at high salinity. Moreover, peptidoglycan reorganization was strengthened at high osmotic pressure via absorbing additional <span>d</span>-Phe, leading to weak bacterial adhesion. The work provides mechanistic insights into the application of <span>d</span>-Phe for biofilm inhibition and MIC mitigation in industries.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"4 12","pages":"2938–2948 2938–2948"},"PeriodicalIF":7.4,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142850305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanism of Dissolved Organic Matter Constructing Zerovalent Iron Interfacial Mass-Transfer Channel Combined with Shewanella oneidensis MR-1 To Remove Cr(VI)","authors":"Minghui Xiang,&nbsp;Long Chen,&nbsp;Xinlei Ren,&nbsp;Zhiyuan Yang,&nbsp;Shiting Zhu,&nbsp;Ziying Zhang,&nbsp;Mengyu Su,&nbsp;Jin Zhang* and Hui Li*,&nbsp;","doi":"10.1021/acsestengg.4c0050610.1021/acsestengg.4c00506","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00506https://doi.org/10.1021/acsestengg.4c00506","url":null,"abstract":"<p >Nanoscale zerovalent iron (nZVI) is a promising remediation agent for the removal of heavy-metal wastewater. However, nZVI tends to agglomerate and be oxidatively deactivated during the reaction, which limits its application. To address the problem, this study develops a novel modification method to regulate the reaction interface of nZVI by introducing fulvic acid (FA), a naturally occurring environmental component, to the synthesis of nZVI. FA disrupts the circumferential-stress equilibrium of nZVI, enhances the Kirkendall effect, and establishes mass-transfer channels, facilitating the outward transfer of reducible Fe(II) and electrons and the inward transport of surface-adsorbed Cr(VI). The Cr(VI) removal is further enhanced by coupling FA-nZVI with <i>Shewanella oneidensis</i> MR-1, which reduces Fe(III) hydroxides to Fe(II) at the FA-nZVI interface, thereby preventing accumulation of the passivation layer that blocks the mass-transfer channels. The synergistic action of mass-transfer channels with MR-1 enhances the Cr(VI) removal rate by 4.7 times, ensuring a Cr(VI) removal rate of more than 60% under extreme conditions. By exploring the new functions of FA as an organic carbon component, this study provides a fresh perspective on carbon utilization in ecosystems. Leveraging environmental factors for the microstructural modulation of nZVI is an efficient and environmentally friendly approach for remediation of heavy-metal pollution.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 1","pages":"215–225 215–225"},"PeriodicalIF":7.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sodium Dodecylbenzenesulfonate Promotes Fe@Fe2O3 Electron Transfer and Induces Free-Radical Conversion to Enhance Tetrabromobisphenol A Degradation","authors":"Zhiyuan Yang,&nbsp;Yujing Huang,&nbsp;Hui Li,&nbsp;Jin Zhang* and Minghui Xiang*,&nbsp;","doi":"10.1021/acsestengg.4c0042310.1021/acsestengg.4c00423","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00423https://doi.org/10.1021/acsestengg.4c00423","url":null,"abstract":"<p >The solubility of hydrophobic pollutants in the aqueous phase affects the degradation efficiency of the pollutants, and cosolvents are usually used to enhance the solubility of hydrophobic pollutants; however, the effect of cosolvents on the pollutant degradation process is not clear. This study constructed a sodium dodecylbenzenesulfonate (SDBS)/Fe@Fe₂O₃/PMS system for the efficient removal of tetrabromobisphenol A (TBBPA). SDBS increases the adsorption of oxygen species on the surface of Fe@Fe₂O₃, disrupts the dense oxide layer, and promotes the release of iron ions from the core. Kinetic results indicate that the degradation rate constant of TBBPA increases by 87.5 times in the presence of SDBS, and the system is minimally affected by environmental factors, making it broadly applicable. SDBS enhances the dissolved oxygen in the system, promotes the conversion of hydroxyl radicals (^•OH) into superoxide radical (O₂^•–) and singlet oxygen (¹O₂), and facilitates the transformation of TBBPA into TBBPA radical cations through electron transfer, which then undergoes debromination, hydroxylation, and demethylation to form small molecular degradation products. The dual role of SDBS enables the reutilization of aged ZVI, making it a promising technology for pollutant remediation.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 1","pages":"12–21 12–21"},"PeriodicalIF":7.4,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sulfate Leached from Phosphogypsum Is Transformed in a Hydrogen-Based Membrane Biofilm Reactor","authors":"Anwar Alsanea,&nbsp;Ayoub Bounaga,&nbsp;Karim Lyamlouli,&nbsp;Youssef Zeroual,&nbsp;Rachid Boulif,&nbsp;Chen Zhou and Bruce Rittmann*,&nbsp;","doi":"10.1021/acsestengg.4c0056310.1021/acsestengg.4c00563","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00563https://doi.org/10.1021/acsestengg.4c00563","url":null,"abstract":"<p >The high level of sulfate in phosphogypsum (PG), a byproduct of phosphoric acid production, offers an option of recovering elemental sulfur (S⁰). The first step is reducing sulfate to soluble sulfide, which can then be partially oxidized to S⁰. We evaluated sulfate reduction to soluble sulfide using a hydrogen-based membrane biofilm reactor (H₂-MBfR) from PG leachate (PG water). The H₂-MBfR was initiated using synthetic sulfate medium prior to switching to PG water, and it achieved sulfate removal of 70–80% and ∼60% of influent S as soluble sulfide. Upon switching to PG water, sulfate removal flux increased due to higher sulfate surface loading, but soluble sulfide kept declining and precipitates began forming. Venting the fibers to release accumulated CO₂ increased the H₂ availability and improved flux. Batch operation increased the generation of soluble sulfide, as sulfate was reduced biologically instead of precipitating as CaSO₄ (as verified by X-ray diffraction and solubility calculations). Alkalinity analyses quantified the effects of precipitation, mainly CaSO₄, on the sulfide reduction performance. While H₂-MBfR demonstrated promise for reducing sulfate to sulfide in PG water, its long-term success will require that calcium be minimized to reduce abiotic sulfate removal, while H₂ delivery must slightly exceed the H₂ demand for biological sulfate reduction to sulfide.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 2","pages":"468–474 468–474"},"PeriodicalIF":7.4,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestengg.4c00563","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal Degradation of Long-Chain Fluorinated Greenhouse Gases: Stability, Byproducts, and Remediation Approaches","authors":"Alireza Arhami Dolatabad,&nbsp;Runze Sun,&nbsp;Jiefei Cao,&nbsp;Jiamin Mai,&nbsp;Xuejia Zhang,&nbsp;Zhentian Lei,&nbsp;Katerina Litvanova,&nbsp;Alena Kubatova and Feng Xiao*,&nbsp;","doi":"10.1021/acsestengg.4c0053510.1021/acsestengg.4c00535","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00535https://doi.org/10.1021/acsestengg.4c00535","url":null,"abstract":"<p >Perfluorocarbons (PFCs) are synthetic industrial chemicals, which, once released into the atmosphere, exhibit strong greenhouse effects. They are also potential products of incomplete degradation of per- and polyfluoroalkyl substances in thermal processes. This study aims to fill a significant gap in the literature regarding the thermal stability of PFCs. Among the PFCs examined, perfluorohept-1-ene (C₇F₁₄) and perfluorooct-1-ene (C₈F₁₆) degraded at temperatures as low as 200 °C, achieving near-complete degradation at approximately 300 °C. The mineralization of these two unsaturated PFCs reached up to ∼40 mol % at temperatures between 300 °C and 500 °C. In contrast, their saturated counterparts required significantly higher temperatures (≥600 °C) for similar levels of degradation and yielded less than 10 mol % fluorine. This disparity is likely due to the hemolytic thermal cleavage of the relatively weak C3–C4 bonds in the unsaturated PFCs, initiating radical-chain reactions that release fluorine. The analysis indicates that the thermal degradation pathways of perfluoroalkenes predominantly involve chain scission and cyclization, leading to the formation of various linear and cyclic byproducts, particularly at temperatures below 500 °C. The addition of granular activated carbon enhanced the thermal mineralization of these PFCs, whereas common commercial catalysts were only moderately effective or ineffective.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 2","pages":"389–401 389–401"},"PeriodicalIF":7.4,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of Differential Scanning Calorimetry to Assess Molecular Weight Degradation of Poly(butylene Adipate-co-terephthalate)-Based Plastics","authors":"Yvan D. Hernandez-Charpak,&nbsp;Harshal J. Kansara,&nbsp;Thomas A Trabold,&nbsp;Jeffrey S. Lodge,&nbsp;Christopher L. Lewis and Carlos A. Diaz*,&nbsp;","doi":"10.1021/acsestengg.4c0061710.1021/acsestengg.4c00617","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00617https://doi.org/10.1021/acsestengg.4c00617","url":null,"abstract":"<p >The use of biodegradable plastics is increasing as customer expectations toward sustainability are addressed. However, their biodegradation processes, mechanisms, and dynamics in real applications are still not well understood. Commonly available analytical techniques such as differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy can help to better understand the biodegradation kinetics of biodegradable plastics in different environments, e.g., home compost, industrial compost, and soil. Polymer fragmentation, mainly through hydrolysis, is the first stage of biodegradation. Evaluating the evolution of the molecular weight is a challenging measurement in uncontrolled environments, e.g., open soil or ocean, and requires expensive instrumentation and chemical solvents. This work presents how DSC can be used to evidence plastic degradation (e.g., reduction in molecular weight) of biodegradable polybutylene adipate-<i>co</i>-terephthalate-based plastics in home and industrial compost settings. Significant increases in crystallization temperature, <i>T</i>_<i>C</i>, were found in degraded samples using DSC. This increase in <i>T</i>_<i>C</i> was correlated with a loss in reduced viscosity, a metric widely used to infer polymer molecular weight. A positive monotonic relationship was observed, establishing <i>T</i>_<i>C</i> as a possible indicator of polymer degradation.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 3","pages":"642–654 642–654"},"PeriodicalIF":7.4,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143609137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formation of Both Free Hydroxyl Radicals and Surface Oxygen During Catalytic Ozonation by Single-Atom Iron: An Overlooked Pollutant-Dependent Oxidation Mechanism","authors":"Jingdong Yang,&nbsp;Guang-Guo Ying,&nbsp;Deli Wu,&nbsp;Zhimin Ao,&nbsp;Kaimin Shih and Yong Feng*,&nbsp;","doi":"10.1021/acsestengg.4c0052110.1021/acsestengg.4c00521","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00521https://doi.org/10.1021/acsestengg.4c00521","url":null,"abstract":"<p >Single-atom catalysts (SACs) such as iron (Fe) SACs have recently shown great promise for catalytic ozonation, but the major reactive species for pollutant degradation remain unclear. Here, a series of Fe SACs doped in porous nitrogen-doped graphitized carbon (Fe₁@NC, Fe₅@NC, Fe₁₀@NC) were prepared and used as model SACs for catalytic ozonation. It was found that the Fe₅@NC had much greater reactivity for catalytic ozonation than common catalysts, which was ascribed to the abundant catalytic sites including surface oxygen-containing groups and Fe–N₄ moieties. Pretreatment of Fe₅@NC by ozonation for 3 h did not deactivate the material. Accelerated formation of hydroxyl radicals in Fe SACs–O₃ oxidation was verified by electron spin resonance spectroscopy, but quenching tests showed conflicting results. Based on the experimental studies and density functional theory calculations, a pollutant-dependent degradation mechanism involving either free hydroxyl radicals or surface oxygen atoms as oxidizing species was proposed. Surface oxygen atom-dominated oxidation required the pre-adsorption of pollutants onto Fe₅@NC, otherwise, free hydroxyl radical-mediated oxidation occurred. This mechanism is expected to clarify the inconsistency regarding the formation of major reactive species in catalytic ozonation and could deepen our understanding of the catalytic behavior of SACs.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 1","pages":"250–259 250–259"},"PeriodicalIF":7.4,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}