ACS ES&T engineering最新文献

{"title":"Molecular-Level Explanation of AOM Removal by a Composite Coagulant Based on the Subdivision of Organic Components","authors":"Siyu Zhang,&nbsp;Kangying Guo,&nbsp;Beibei Liu,&nbsp;Yue Gao,&nbsp;Qinyan Yue and Baoyu Gao*,&nbsp;","doi":"10.1021/acsestengg.4c0055910.1021/acsestengg.4c00559","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00559https://doi.org/10.1021/acsestengg.4c00559","url":null,"abstract":"<p >Algal organic matter (AOM), comprising intracellular organic matter (IOM) and extracellular organic matter (EOM), poses a significant challenge to drinking water safety. Coagulation serves as an effective method for removing algae, and investigating the binding sites of coagulant hydrolyzates is crucial for comprehending the coagulation mechanism. In this study, a novel polyferric titanium sulfate (PFTS) composite coagulant was prepared and used to remove AOM. Characterization techniques, including Fourier infrared (FTIR), X-ray photoelectron spectroscopy (XPS), hydrolysis polymerization curves, and chemical species analysis were utilized to identify the hydrolyzates of PFTS. The results revealed the formation of Fe–Ti copolymers through the interaction between Fe hydroxyl and Ti hydroxyl, facilitated by a Fe–O–Ti bond. Under optimal coagulation conditions (50 mg/L dosage at neutral pH), PFTS demonstrated superior performance in treating EOM and IOM compared to PFS and PTS, achieving significant DOC removal efficiencies of 46.69% and 56.8%, respectively. Furthermore, the removal characteristics of organics were investigated at the molecular level using Fourier transformation cyclotron resonance mass spectrometry (FT-ICR MS). It was found that organic compounds with unsaturated (H/C &lt; 1.0) and oxidized (O/C &gt; 0.5) substances containing carboxyl groups in AOM could be preferentially removed by PFTS for the carboxyl group demonstrate a higher affinity to Fe and Ti hydroxyl formed in PFTS coagulation. XPS and water contact angle analysis were conducted to gain deeper insights into the interaction between the hydrolyzates of PFTS and AOM. The findings demonstrated that Fe–Ti hydrolyzates could bind with EOM and IOM by forming coordination bonds and H–O···O and H–O···N hydrogen bonds with its −COOH, −NH₂, and −OH groups through bonding reactions. This study highlights the potential of composite coagulants as alternatives to conventional coagulants for the purification of algae-laden water.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 2","pages":"456–467 456–467"},"PeriodicalIF":7.4,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402171","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":"Enhanced Medium-Chain Fatty Acids Production by Electro-fermentation: Insights into the Effect of Biocathode and Ethanol Supply","authors":"Xiaoyan Sun,&nbsp;Yanan Yin*,&nbsp;Hui Chen,&nbsp;Lei Zhao,&nbsp;Cheng Wang and Jianlong Wang,&nbsp;","doi":"10.1021/acsestengg.4c0048810.1021/acsestengg.4c00488","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00488https://doi.org/10.1021/acsestengg.4c00488","url":null,"abstract":"<p >This study explored the enhanced medium-chain fatty acids (MCFA) production by introducing a biocathode as a coelectron donor (ED) in the presence of different ethanol/acetate ratios (<i>R</i>_E/A). Results showed that the introduction of a biocathode effectively promoted MCFA production by 165%–749%. The highest promotion rate was achieved at <i>R</i>_E/A = 0:3, and the highest MCFA concentration of 305.1 mmol C/L was obtained at <i>R</i>_E/A = 2:1. Besides, the introduction of a biocathode also triggered the formation of longer-chain MCFA (i.e., caprylate), and caprylate production was increased with the increase of <i>R</i>_E/A. Electrochemical analyses exhibited a positive correlation between the electrochemical activity and <i>R</i>_E/A. Microbiological analyses showed that the introduction of a biocathode promoted MCFA production by enriching chain elongation functional microorganisms (<i>unclassified_f_Neisseriaceae</i> sp. and <i>Clostridium_sensu_stricto_12</i> sp.) and electrochemically active bacteria (<i>Alcaligenes</i> sp.). Enzyme analyses indicated that promoted MCFA production was achieved by strengthening the acetyl Co-A formation and fatty acid biosynthesis pathway.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 1","pages":"179–190 179–190"},"PeriodicalIF":7.4,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091721","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":"Single-Atom Copper-Bearing Cerium Oxide Electrocatalysts Embedded in an Integrated System Enable Sustainable Nitrogen Recycling from Natural Water Bodies","authors":"Guangming Jiang*,&nbsp;Zixun Liu,&nbsp;Shuxian He,&nbsp;Yinan Liu,&nbsp;Xiangyi Tang,&nbsp;Xiaoshu Lv,&nbsp;Fan Dong and Hong Liu*,&nbsp;","doi":"10.1021/acsestengg.4c0029910.1021/acsestengg.4c00299","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00299https://doi.org/10.1021/acsestengg.4c00299","url":null,"abstract":"<p >Electrocatalytic reduction of nitrate (NO₃^–) to ammonia (NH₃) (NO₃RR) coupled with NH₃ separation represents a sustainable approach to mitigate nitrate pollution and recycle nitrogen from contaminated water. Nevertheless, this process is deemed impractical for contaminated natural water bodies owing to the limited presence of NO₃^––N (&lt;50 mg L^–1) and electrolytes and the relative abundance of scaling ions (Mg²⁺ and Ca²⁺). Furthermore, copper (Cu), as the primary NO₃RR catalyst, generally suffers from NO₂^– accumulation and a prevalence of side hydrogen evolution. Herein, we develop an integrated system comprising sections of NO₃^– enrichment and NO₃RR and NH₃ collection, alongside a single-atom Cu-bearing CeO₂ catalyst (Cu₁/CeO₂) for NO₃RR. With this system, diluted NO₃^– is extracted from contaminated water using anion-exchange resins and then released into a concentrated NaCl aqueous solution, providing a solution with ample NO₃^––N (∼822 mg L^–1) and electrolytes (∼1.7 M NaCl) while being free of scaling ions. Within this solution, the Cu₁/CeO₂ demonstrates an exceptional high and steady NH₃–N production rate of 7.8 g_NH₃–N g_Cu^–1 h^–1, an NH₃–N selectivity of 90.1%, and a Faradaic efficiency of 91.3%, outperforming the Cu nanoparticles (1.8 g_NH₃–N g_Cu^–1 h^–1, 46.3%, and 53.0%). In situ experiments and theoretical computations reveal a dual-site NO₃RR mechanism involving the electron-deficient Cu₁ site and adjacent oxygen vacancies, which collaborate to promote NO₃^– adsorption and lower conversion barrier while inhibiting hydrogen evolution. Finally, we implemented the integrated system along the Yangtze River, achieving nitrate elimination and nitrogen recycling with a competitive energy consumption of 1.36–1.54 kW h mol_N^–1.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"4 12","pages":"2912–2922 2912–2922"},"PeriodicalIF":7.4,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142851178","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":"Semi-solid State PVA-Sodium Silicate Gel Membrane Cell for Electrochemical Oxidation of Gaseous Acetaldehyde at Cobalt Immobilized Graphitic Carbon Nitride Electrode","authors":"Muthuraman Govindan,&nbsp;Elangovan Erusappan,&nbsp;Youngyu Choi and Daekeun Kim*,&nbsp;","doi":"10.1021/acsestengg.4c0050510.1021/acsestengg.4c00505","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00505https://doi.org/10.1021/acsestengg.4c00505","url":null,"abstract":"<p >The removal of gas environmental pollutants from their gaseous state using electrochemical methods is a futuristic technology. The effective migration of ions to the electrode without liquid electrolyte plays a key role in facilitating the removal from the gaseous state. In this study, a poly(vinyl alcohol)-sodium silicate gel membrane and a cobalt-modified graphitic carbon nitride (Co-GCN) electrode were developed for the mineralization of a common air pollutant, acetaldehyde (AA). Confocal laser microscopy, electrochemical impedance spectroscopy, and SEM-EDS analysis demonstrated that the as-prepared gel membrane stably conducts ions with lower resistance. The analysis of Co-GCN using XRD, FTIR, and cyclic voltammetry show a possible coordination of cobalt ions with GCN. At a given applied potential of 0.8 V, 82% removal of AA (80 ppm in 1 h) was achieved. The electron transfer kinetics follow pseudo-first-order kinetics, as the variation in the removal rate is less over a wide range of AA feed concentrations. For applied potentials above 1 V, the complete formation of CO₂ was equivalent to AA removal, with a formation capacity of 1.37 g cm^–2 h^–1. The seed of this first attempt at gaseous AA mineralization may open a new way to remove environmental gaseous pollutants.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 1","pages":"239–249 239–249"},"PeriodicalIF":7.4,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091696","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":"Spirulina-Based Multispecies Phototrophic Biofilm Anodic Biocatalyst Endures a Prolonged Dark Phase within Light–Dark Cycle Operations and Enhances Anodic Performance in Biophotovoltaic Cells","authors":"Mohd Golam Abdul Quadir,&nbsp;Nabajyoti Kalita and Pranab Goswami*,&nbsp;","doi":"10.1021/acsestengg.4c0044710.1021/acsestengg.4c00447","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00447https://doi.org/10.1021/acsestengg.4c00447","url":null,"abstract":"<p >Phototrophs with heterotrophic bacterial consortium as an electrode biocatalyst are an emerging concept for developing naturally sustained biophotovoltaic systems. Herein, <i>Spirulina subsalsa</i>-based mixed heterotrophic bacterial community as an anodic catalyst in a microbial fuel cell (MFC) setup with ferricyanide catholyte in 78 days light–dark (16–8 h) cycle-based operation was investigated. The biofilm developed with <i>Spirulina</i> inducted a recalcitrant bacterial community comprising <i>Halomonas</i>, <i>Alcanivorax</i>, <i>Pelagibacterium</i>, and <i>Rhizobiales</i> as the major genera. In an extended dark phase (9 days) within the cyclic operation, a sequential shift of the metabolism from photosynthesis to fermentative states and an increased heterotrophic population were observed. Under direct contact with the graphite anode, the biofilm initiated oscillating open-circuit potentials in the MFC in response to the light–dark circadian trend. The MFC delivered maxima of 587 μW m^–2 and 418 μW m^–2 (at 10 kΩ) under the corresponding circadian and extended dark phases, respectively. The anodic potential shifted to a more negative value, reaching −415.5 mV in the dark starvation period. Analyses of electrode reaction rates (extracted from Tafel plots), corrosion potential, corrosion current, polarization resistance, and residual redox charges (extracted from cyclic voltammograms) were performed to understand the redox processes. Two redox peaks corresponding to 0.6 V (irreversible, extracellular) and 0.26 V (reversible, cell-surface attached) were attributed to redox mediation in this process. Additionally, catholyte-diffused ferricyanide interacts with the biofilm, getting trapped in the matrix polymeric structures, thus preventing the sudden cytotoxic elimination of cells and promoting oxidative charge accumulation over its surface, improving the anodic potential. Rapid respiratory oxygen consumption, the biofilm’s structural reorganization, and ferricyanide’s chemical speciation inside the biofilm were the primary factors that govern the anodic performance of the biofuel cell during the prolonged dark phase operations. The critical findings unveiled through this study advance our understanding of the resilience of phototroph-based multispecies anodic catalysts for developing biophotovoltaic devices for long-term operations.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 1","pages":"60–76 60–76"},"PeriodicalIF":7.4,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091748","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":"Developing Surrogate Indicator for Prompt Adjusting of Ozonation Operation: Insight from Pilot-Scale Treatment Using China’s South-to-North Water Diversion Project Feedwater","authors":"Mei Han,&nbsp;Fang Zou,&nbsp;Yumeng Zhao*,&nbsp;Jinkuo Li,&nbsp;Hongdi Guo,&nbsp;Runzhi Wang,&nbsp;Dezhen Kong,&nbsp;Ruowei Xie and Jun Ma,&nbsp;","doi":"10.1021/acsestengg.4c0060410.1021/acsestengg.4c00604","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00604https://doi.org/10.1021/acsestengg.4c00604","url":null,"abstract":"<p >Energy-intensive ozonation processes could potentially evolve to flexible ozone (O₃) dosing strategies that depend on variations of feedwater quality. Herein, we demonstrate a surrogate indicator using UV absorbance for timely indicating O₃ performance on controlling disinfection byproduct (DBP) formation tendency, which could enable prompt adjustment of O₃ operation in practical drinking water treatment plants (DWTPs). We specifically focused on treating the water sourced from the central route of China’s South-to-North Water Diversion (SNWD) Project at periods of high algae activity. We found that ozonation, positioned between the sand filter and carbon filter in a pilot-scale DWTP process, showed limited removal of typical DBP chloroform (CHCl₃) formed during prechlorination. However, it notably enhanced the elimination of CHCl₃ precursors and subsequently lowered the water’s susceptibility to secondary chlorination. Further, combining parallel factor analysis, Pearson correlation analysis, and two-dimensional correlation spectroscopy, we identified differential UV absorbance at 300 nm (Δ<i>A</i>₃₀₀) as a rapid detection proxy for assessing ozonation efficacy in controlling the DBP formation tendency in DWTP. The formation of CHCl₃ is highly dependent upon precursors of tryptophan and humic/fulvic acid II, which can be effectively indicated by Δ<i>A</i>₃₀₀. Additionally, the secondary chlorination induces a positive relationship between the CHCl₃ formation tendency and Δ<i>A</i>₃₀₀ at the primary reaction stage. As reaction time extends, this correlation becomes negative, which warrants careful consideration in practical use. Meanwhile, the influence of the ozone dosage and NaClO dosage is negligible on the Δ<i>A</i>₃₀₀ predictivity. Overall, this study advances the understanding of a surrogate indicator framework for prompt and real-time monitoring of ozonation performance.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 3","pages":"631–641 631–641"},"PeriodicalIF":7.4,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143608834","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":"Understanding Zerovalent Iron Exposure on Biological Nitrogen Removal: From Impacts to Potential Mechanisms","authors":"Wenbin Liu,&nbsp;Jianzheng Li,&nbsp;Tao Liu,&nbsp;Jiuling Li and Jia Meng*,&nbsp;","doi":"10.1021/acsestengg.4c0042610.1021/acsestengg.4c00426","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00426https://doi.org/10.1021/acsestengg.4c00426","url":null,"abstract":"<p >Microorganism-dominated nitrogen conversion in wastewater treatment is of great significance to the nitrogen cycle. Until now, Fe⁰ has been widely used in sludge dewaterability, sulfide control, and bioenergy recovery. However, there is limited information about the comprehensive assessment of Fe⁰ on multiple biological nitrogen removal processes. Here, the impact of Fe⁰ dosage on the activity of ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, anammox bacteria, and denitrifiers was evaluated. The results revealed that anammox has a more sensitive response to iron dosages (5.34 mM), and improved intracellular iron (216%) is the key to stimulating microbial metabolism by accelerating electron transfer, enzymatic activity, and ATP biosynthesis. Moreover, the long-term operation confirmed that additional Fe⁰ increased the relative abundance of ammonia-oxidizing bacteria, anammox bacteria, and denitrifiers, and the enriched nitrogen removal pathways further improved the nitrogen removal to 93.3% from 79.2% in an oxygen-limited system. This study helps us deeply understand the underlying mechanism of microbial activity stimulated by iron.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 1","pages":"50–59 50–59"},"PeriodicalIF":7.4,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091735","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":"Highly Efficient Recovery of Phosphate from Water Using Cerium Carbonate Hydroxide-Decorated Magnetic Biochar: A Slow-Release Phosphate Fertilizer for Agricultural Reuse","authors":"Jianhua Qu,&nbsp;Siqi Wang,&nbsp;Ziwei Li,&nbsp;Shuqi Wei,&nbsp;Fuxuan Bi,&nbsp;Shaojuan Yan,&nbsp;Hui Yu,&nbsp;Lei Wang and Ying Zhang*,&nbsp;","doi":"10.1021/acsestengg.4c0040710.1021/acsestengg.4c00407","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00407https://doi.org/10.1021/acsestengg.4c00407","url":null,"abstract":"<p >Phosphate removal plays a pivotal role in alleviating eutrophication and maintaining water quality. Cerium (Ce) demonstrates considerable promise in phosphate removal, attributed to its strong affinity for phosphate ions. This study provides a dual utilization strategy for synthesizing Fe₂O₃- and CeCO₃OH-decorated hydrophilic porous biochar (Fe/Ce@HPBC), designed for phosphate recovery from eutrophic waters and followed by its application as a slow-release phosphate fertilizer. Fe/Ce@HPBC possessed excellent phosphate adsorption quantity, achieving a maximum uptake of 203.88 mg/g in accordance with the Sips model. Furthermore, the slow-release experiment demonstrated that Fe/Ce@HPBC used as a fertilizer after phosphate recovery could sustainably release 39.8% of its phosphate content within 28 days. Fe/Ce@HPBC-P could also significantly increase the effective phosphorus content of soil by 65.51% and promote the phosphorus uptake of maize seedlings by 70.36%. Mechanistic investigation revealed that the outstanding phosphate adsorption by Fe/Ce@HPBC was attributed to the formation of inner-sphere complexation through ligand exchange between phosphate and Ce(HCO₃)²⁺/Ce–OH, in addition to electrostatic attraction caused by enhanced surface protonation. Overall, this study contributes to the advancement of phosphate recovery techniques and promotes the development of sustainable agriculture by presenting an effective strategy for mitigating eutrophication.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"4 12","pages":"3045–3056 3045–3056"},"PeriodicalIF":7.4,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142844151","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":"Novel Insights into the Long-Term Thiosulfate Pretreatment for Enhanced Short-Chain Fatty Acids Production from Sludge Anaerobic Fermentation: Organics Transformation, Electron Transfer, and Microbial Cooperation","authors":"Boyi Cheng,&nbsp;Da Zhang,&nbsp;Jinqi Jiang,&nbsp;Tianwei Hao*,&nbsp;Samir Kumar Khanal,&nbsp;Weijun Zhang,&nbsp;Zongping Wang,&nbsp;Guanghao Chen and Gang Guo*,&nbsp;","doi":"10.1021/acsestengg.4c0051010.1021/acsestengg.4c00510","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00510https://doi.org/10.1021/acsestengg.4c00510","url":null,"abstract":"<p >Thiosulfate-assisted anaerobic fermentation (AF) effectively converts waste activated sludge into high-value products (e.g., short-chain fatty acids (SCFAs)). However, the roles of thiosulfate in organics transformation, electron transfer, and microbial interactions within AF systems are not fully understood, especially under long-term operations. In this study, an 88 day long-term experiment was conducted to address this knowledge gap. The results indicated an average SCFA yield of 3625.1 mg COD/L and an acetate proportion of 49.4% with a thiosulfate dosage of 600 mg S/L. Model organic degradation tests revealed that thiosulfate functioned as an electron acceptor, facilitating NAD⁺/NADH transformation, stimulating the expression of protein complexes like cytochrome <i>c</i> to enhance electron transport, and lowering thermodynamic barriers of propionate and butyrate to acetate (Δ<i>G</i>1_propionate = −335.0 kJ/mol; Δ<i>G</i>2_butyrate = −113.8 kJ/mol). Molecular ecological networks analysis showed that thiosulfate strengthened cooperative relationships among biomarkers of hydrolytic bacteria (i.e., <i>Proteiniphilum</i>, <i>UBA5851</i>), acidogenic bacteria (i.e., <i>UBA4179</i>), and sulfur reducers (i.e., <i>JAEUSI01</i>). Functional gene analysis using random forest confirmed that thiosulfate upregulated the expression of key genes (e.g., 2-oxoacid ferredoxin oxidoreductase) associated with electron transfer and acidogenic metabolism. This study deepens our understanding of thiosulfate, facilitating electron transfer and strengthening microbial cooperation within AF systems.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 1","pages":"226–238 226–238"},"PeriodicalIF":7.4,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091854","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":"Trace MnFe2O4 Boosts Polyphenol-Maillard Reaction and Humification Process for Value-Added Composting: Integrated Effect of Chemical and Enzymatic Catalysis","authors":"Yujiao Long,&nbsp;Hongmei Jin*,&nbsp;Haiyan Li,&nbsp;Ning Zhu,&nbsp;Enhui Sun,&nbsp;Chao Shan,&nbsp;Hongchao Li and Yun Cao,&nbsp;","doi":"10.1021/acsestengg.4c0041510.1021/acsestengg.4c00415","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00415https://doi.org/10.1021/acsestengg.4c00415","url":null,"abstract":"<p >Promoting humification during composting is of pivotal significance for converting organic waste to value-added fertilizer. Traditional composting additives for enhanced humification commonly suffer from low efficiency and a large dosage. Herein, we presented a novel and effective technique with great application potential to promote humification during composting via simple addition of trace MnFe₂O₄, behind which the essential mechanism was interpreted from both chemical and biological perspectives. Results indicated that with an economical dosage of MnFe₂O₄ (0.02 wt %), the content of humic acid (HA) and humification index (HI) were increased by 15.2 and 18.7% in comparison with the control group, respectively. The chemical mechanism steering such enhanced humification was revealed through analysis of precursor substances evolution and HA structural characterization. Specifically, MnFe₂O₄ addition catalyzed the polyphenol-Maillard reaction, leading to rapid oxidation and subsequent polymerization of the precursor substances. Meanwhile, analysis of diversity and evolution of microbial communities as well as activities of laccase and peroxidase demonstrated that MnFe₂O₄ addition increased the relative abundance of laccase/peroxidase-producing bacteria and thus elevated the enzymatic activities of laccase/peroxidase, which played crucial roles in catalyzing polyphenol-Maillard reaction and humification. This study demonstrates that MnFe₂O₄ could serve as a promising composting additive to promote humification and thereby produce value-added composts.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"4 12","pages":"3067–3079 3067–3079"},"PeriodicalIF":7.4,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142844150","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}