{"title":"d-Phenylalanine Alleviates the Corrosion by Desulfovibrio vulgaris in Saline Water","authors":"Hongyi Li, Zhengyan Kang, Chengcheng Ding, Xinxin Zhao, Yiqi Cao, Baiyu Zhang, Chao Song* and Shuguang Wang*, ","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 × 10<sup>7</sup> cells/cm<sup>2</sup> to 12.8 × 10<sup>7</sup> cells/cm<sup>2</sup> 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}
ACS ES&T engineeringPub Date : 2024-11-13DOI: 10.1021/acsestengg.4c0050610.1021/acsestengg.4c00506
Minghui Xiang, Long Chen, Xinlei Ren, Zhiyuan Yang, Shiting Zhu, Ziying Zhang, Mengyu Su, Jin Zhang* and Hui Li*,
{"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, Long Chen, Xinlei Ren, Zhiyuan Yang, Shiting Zhu, Ziying Zhang, Mengyu Su, Jin Zhang* and Hui Li*, ","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}
ACS ES&T engineeringPub Date : 2024-11-12DOI: 10.1021/acsestengg.4c0042310.1021/acsestengg.4c00423
Zhiyuan Yang, Yujing Huang, Hui Li, Jin Zhang* and Minghui Xiang*,
{"title":"Sodium Dodecylbenzenesulfonate Promotes Fe@Fe2O3 Electron Transfer and Induces Free-Radical Conversion to Enhance Tetrabromobisphenol A Degradation","authors":"Zhiyuan Yang, Yujing Huang, Hui Li, Jin Zhang* and Minghui Xiang*, ","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@Fe<sub>2</sub>O<sub>3</sub>/PMS system for the efficient removal of tetrabromobisphenol A (TBBPA). SDBS increases the adsorption of oxygen species on the surface of Fe@Fe<sub>2</sub>O<sub>3</sub>, 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 (<sup>•</sup>OH) into superoxide radical (O<sub>2</sub><sup>•–</sup>) and singlet oxygen (<sup>1</sup>O<sub>2</sub>), 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}
ACS ES&T engineeringPub Date : 2024-11-11DOI: 10.1021/acsestengg.4c0056310.1021/acsestengg.4c00563
Anwar Alsanea, Ayoub Bounaga, Karim Lyamlouli, Youssef Zeroual, Rachid Boulif, Chen Zhou and Bruce Rittmann*,
{"title":"Sulfate Leached from Phosphogypsum Is Transformed in a Hydrogen-Based Membrane Biofilm Reactor","authors":"Anwar Alsanea, Ayoub Bounaga, Karim Lyamlouli, Youssef Zeroual, Rachid Boulif, Chen Zhou and Bruce Rittmann*, ","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 (S<sup>0</sup>). The first step is reducing sulfate to soluble sulfide, which can then be partially oxidized to S<sup>0</sup>. We evaluated sulfate reduction to soluble sulfide using a hydrogen-based membrane biofilm reactor (H<sub>2</sub>-MBfR) from PG leachate (PG water). The H<sub>2</sub>-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 CO<sub>2</sub> increased the H<sub>2</sub> availability and improved flux. Batch operation increased the generation of soluble sulfide, as sulfate was reduced biologically instead of precipitating as CaSO<sub>4</sub> (as verified by X-ray diffraction and solubility calculations). Alkalinity analyses quantified the effects of precipitation, mainly CaSO<sub>4</sub>, on the sulfide reduction performance. While H<sub>2</sub>-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 H<sub>2</sub> delivery must slightly exceed the H<sub>2</sub> 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}
ACS ES&T engineeringPub Date : 2024-11-11DOI: 10.1021/acsestengg.4c0053510.1021/acsestengg.4c00535
Alireza Arhami Dolatabad, Runze Sun, Jiefei Cao, Jiamin Mai, Xuejia Zhang, Zhentian Lei, Katerina Litvanova, Alena Kubatova and Feng Xiao*,
{"title":"Thermal Degradation of Long-Chain Fluorinated Greenhouse Gases: Stability, Byproducts, and Remediation Approaches","authors":"Alireza Arhami Dolatabad, Runze Sun, Jiefei Cao, Jiamin Mai, Xuejia Zhang, Zhentian Lei, Katerina Litvanova, Alena Kubatova and Feng Xiao*, ","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 (C<sub>7</sub>F<sub>14</sub>) and perfluorooct-1-ene (C<sub>8</sub>F<sub>16</sub>) 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}
ACS ES&T engineeringPub Date : 2024-11-11DOI: 10.1021/acsestengg.4c0061710.1021/acsestengg.4c00617
Yvan D. Hernandez-Charpak, Harshal J. Kansara, Thomas A Trabold, Jeffrey S. Lodge, Christopher L. Lewis and Carlos A. Diaz*,
{"title":"Application of Differential Scanning Calorimetry to Assess Molecular Weight Degradation of Poly(butylene Adipate-co-terephthalate)-Based Plastics","authors":"Yvan D. Hernandez-Charpak, Harshal J. Kansara, Thomas A Trabold, Jeffrey S. Lodge, Christopher L. Lewis and Carlos A. Diaz*, ","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><sub><i>C</i></sub>, were found in degraded samples using DSC. This increase in <i>T</i><sub><i>C</i></sub> 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><sub><i>C</i></sub> 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}
ACS ES&T engineeringPub Date : 2024-11-10DOI: 10.1021/acsestengg.4c0052110.1021/acsestengg.4c00521
Jingdong Yang, Guang-Guo Ying, Deli Wu, Zhimin Ao, Kaimin Shih and Yong Feng*,
{"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, Guang-Guo Ying, Deli Wu, Zhimin Ao, Kaimin Shih and Yong Feng*, ","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 (Fe<sub>1</sub>@NC, Fe<sub>5</sub>@NC, Fe<sub>10</sub>@NC) were prepared and used as model SACs for catalytic ozonation. It was found that the Fe<sub>5</sub>@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–N<sub>4</sub> moieties. Pretreatment of Fe<sub>5</sub>@NC by ozonation for 3 h did not deactivate the material. Accelerated formation of hydroxyl radicals in Fe SACs–O<sub>3</sub> 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 Fe<sub>5</sub>@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}
ACS ES&T engineeringPub Date : 2024-11-06DOI: 10.1021/acsestengg.4c0059710.1021/acsestengg.4c00597
Sijie Li, Yibin Yu, Jingjing Chang, Zhaozhu Zheng, Gang Li, Xiaoqin Wang* and David L. Kaplan,
{"title":"Enhanced CO2 Capture and Utilization through Chemically and Physically Dual-Modified Amino Cellulose Aerogels Integrated with Microalgae-Immobilized Hydrogels","authors":"Sijie Li, Yibin Yu, Jingjing Chang, Zhaozhu Zheng, Gang Li, Xiaoqin Wang* and David L. Kaplan, ","doi":"10.1021/acsestengg.4c0059710.1021/acsestengg.4c00597","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00597https://doi.org/10.1021/acsestengg.4c00597","url":null,"abstract":"<p >This study introduces a novel method for CO<sub>2</sub> capture and utilization by integrating chemically and physically dual-modified amino cellulose aerogels with microalgae-immobilized silk fibroin/sodium alginate (SF/SA) composite hydrogels. The modified cellulose aerogels, enhanced with 3-(2-aminoethylamino)propyl-dimethoxymethylsilane (AEAPMDS) and fumed silica-polyethyleneimine (SiO<sub>2</sub>@PEI), exhibited significantly improved CO<sub>2</sub> adsorption capacity, mechanical strength, and thermal stability compared to microcrystalline cellulose (MCC) aerogels. This modification addresses the limitations of traditional physical and chemical adsorption methods. The captured CO<sub>2</sub> was effectively utilized by the microalgae embedded in the SF/SA hydrogel, leading to increased growth rates, improved carbon fixation efficiency, and reduced energy consumption during CO<sub>2</sub> capture and storage. Temperature regulation was applied to optimize CO<sub>2</sub> adsorption and desorption, demonstrating the system’s potential for air quality improvement and sustainable bioengineering applications, providing a new strategy to combat climate change.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 2","pages":"551–565 551–565"},"PeriodicalIF":7.4,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402169","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}
ACS ES&T engineeringPub Date : 2024-11-06DOI: 10.1021/acsestengg.4c0045910.1021/acsestengg.4c00459
Sanket Joag, Jonathan Kiesewetter and Shankararaman Chellam*,
{"title":"Electrode Corrosion, pH, and Dissolved Oxygen Dynamics, and Hardness/Silicon Removal during Aluminum Electrocoagulation of Hypersaline Produced Water","authors":"Sanket Joag, Jonathan Kiesewetter and Shankararaman Chellam*, ","doi":"10.1021/acsestengg.4c0045910.1021/acsestengg.4c00459","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00459https://doi.org/10.1021/acsestengg.4c00459","url":null,"abstract":"<p >Hypersaline produced water with >100,000 mg/L total dissolved solid concentration arising from unconventional oil and gas operations in the Permian Basin, Texas, was electrocoagulated with an aluminum anode and cathode. Anodic aluminum dissolution, formation of a (hydr)oxide passivation layer, and morphology and physicochemical properties of electrodes pre- and post-electrocoagulation were thoroughly characterized by microscopy, spectroscopy, and electrochemical techniques over a 10-fold variation in current density (2–20 mA/cm<sup>2</sup>) and a four-fold change in charge loading (CL) (∼270–1080 C/L). In addition to the anticipated oxidative anodic electrodissolution, both electrodes underwent chemical dissolution, leading to super-Faradaic aluminum dosing and lowering the bulk pH, contrary to the oft-cited advantage of electrocoagulation over conventional alum coagulation. The remarkably high concentration of chloride ions (∼68,000 mg/L) significantly influenced anodic dissolution behavior primarily by damaging the passive aluminum oxide layer leading to pitting corrosion. Importantly, organic compounds in the produced water negligibly impacted anodic aluminum (electro)dissolution. Not only the total CL but also the current affected pitting. Passing more current (and higher current densities) increased the chemical dissolution of aluminum, enhancing super-Faradaic behavior, and simultaneously increased the surface area and depth of pits (at constant CL) but had negligible effects on the floc size and morphology. The dependence of pitting and Faradaic efficiency on current constitutes a novel finding and is specific to hypersaline solutions as ohmic overpotentials were insufficient to trigger side reactions. Post-electrocoagulation, electrodes repassivated by consuming dissolved oxygen, resulting in a thicker and more conductive (hydr)oxide layer, characterized as an n-type semiconductor via Mott–Schottky analysis. Electrocoagulation effectively removed silicon (∼90%) by forming aluminosilicate flocs. Calcium and magnesium were removed by cathodic electrodeposition albeit to substantially smaller extents (∼20%) and strontium removal was negligible.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 1","pages":"86–102 86–102"},"PeriodicalIF":7.4,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestengg.4c00459","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091835","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":"Enhanced Reactivity and Electron Efficiency of Zerovalent Iron with Various Methods","authors":"Zhen Li, Jinhua Zhang, Jinxiang Li*, Jinyou Shen and Xiaohong Guan*, ","doi":"10.1021/acsestengg.4c0055610.1021/acsestengg.4c00556","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00556https://doi.org/10.1021/acsestengg.4c00556","url":null,"abstract":"<p >Over the past 30 years, various methods have been developed for enhancing contaminant removal by zerovalent iron (ZVI), thus accumulating a large amount of quantitative data including the reactivity (<i>k</i><sub>obs</sub>) and electron efficiency (EE). However, comparisons and relationships of the data are still lacking, which hinders the selection and development of ZVI enhancement methods for practical applications. In this review, a large number of <i>k</i><sub>obs</sub> and EE results are systematically summarized and classified into three types based on enhancement mechanisms: regulating iron (hydr)oxide films of ZVI (RIF), accelerating ZVI corrosion (AZC), and coupling of iron reactive species with ZVI (CIRs). Then, the comparisons of <i>k</i><sub>obs</sub> and EE by ZVI along with their enhancement multiples (referred to as <i>R</i><sub><i>k</i></sub> and <i>R</i><sub>EE</sub>) were conducted within the context of RIF, AZC, and CIRs. This review identified that in cases where ZVI exhibited low reactivity toward pollutants, it often possessed a high electron efficiency for pollutant reduction and vice versa. Moreover, there existed correlations between lg<i>k</i><sub>obs</sub> (lg<i>R</i><sub><i>k</i></sub>) and lgEE (lg<i>R</i><sub>EE</sub>) by ZVI with enhancement methods. These relationships suggest that when both the <i>k</i><sub>obs</sub> (<i>R</i><sub><i>k</i></sub>) and EE (<i>R</i><sub>EE</sub>) parameters are known, the other parameter can be predicted to some extent. Finally, this review discussed the effects of the solution chemistry and iron-related compounds on the <i>k</i><sub>obs</sub> (<i>R</i><sub><i>k</i></sub>) and EE (<i>R</i><sub>EE</sub>) by ZVI with enhancement methods in detail and outlined their potential research needs in future studies.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"4 12","pages":"2874–2887 2874–2887"},"PeriodicalIF":7.4,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142844189","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}