Jingyi Zhu, Yuanxi Huang, Lingjun Bu, Yangtao Wu, Shiqing Zhou
{"title":"Graph Neural Network Integrating Self-Supervised Pretraining for Precise and Interpretable Prediction of Micropollutant Treatability by HO•-Based Advanced Oxidation Processes","authors":"Jingyi Zhu, Yuanxi Huang, Lingjun Bu, Yangtao Wu, Shiqing Zhou","doi":"10.1021/acsestengg.4c00389","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00389","url":null,"abstract":"Machine learning (ML) has become a crucial tool to accelerate research in advanced oxidation processes via predicting reaction parameters to evaluate the treatability of micropollutants (MPs). However, insufficient data sets and an incomplete prediction mechanism remain obstacles toward the precise prediction of MP treatability by a hydroxyl radical (HO<sup>•</sup>), especially when <i>k</i> values approach the diffusion-controlled limit. Herein, we propose a novel graph neural network (GNN) model integrating self-supervised pretraining on a large unlabeled data set (∼10 million) to predict the <i>k</i><sub>HO</sub> values on MPs. Our model outperforms the common-seen and literature-established ML models on both whole data sets and diffusion-controlled limit data sets. Benefiting from the pretraining process, we demonstrate that <i>k</i>-value-related chemistry wisdom contained in the pretrained data set is fully exploited, and the learned knowledge can be transferred among data sets. In comparison with molecular fingerprints, we identify that molecular graphs (MGs) cover more structural information beyond substituents, facilitating a <i>k</i>-value prediction near the diffusion-controlled limit. In particular, we observe that mechanistic pathways of HO<sup>•</sup>-initiated reactions could be automatically classified and mapped out on the penultimate layer of our model. The phenomenon shows that the GNN model can be trained to excavate mechanistic knowledge by analyzing the kinetic parameters. These findings not only well interpret the robust model performance but also extrapolate the <i>k</i>-value prediction model to mechanistic elucidation, leading to better decision making in water treatment.","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"18 1","pages":""},"PeriodicalIF":7.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142256046","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 : 2024-09-18DOI: 10.1021/acsestengg.4c0038410.1021/acsestengg.4c00384
Jiasi Sun, Xi Zhang, Jianjun Guan and Zhen He*,
{"title":"Volatile Fatty Acid Production through Arresting Methanogenesis by Electro-Synthesized Hydrogen Peroxide in Anaerobic Digestion and Subsequent Recovery by Electrodialysis","authors":"Jiasi Sun, Xi Zhang, Jianjun Guan and Zhen He*, ","doi":"10.1021/acsestengg.4c0038410.1021/acsestengg.4c00384","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00384https://doi.org/10.1021/acsestengg.4c00384","url":null,"abstract":"<p >Producing volatile fatty acids (VFAs) in anaerobic digestion (AD) is of strong interest because of VFAs’ potential values in biomanufacturing. Despite some success of VFA production via pretreatment, in situ inhibition of methanogens for VFA accumulation has yet to be explored. Herein, a system consisting of hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) production, application of H<sub>2</sub>O<sub>2</sub> for inhibiting methanogens in AD, and VFA separation was investigated. A polytetrafluoroethylene-based electrospinning electrode was synthesized and capable of generating ∼4.2 g L<sup>–1</sup> H<sub>2</sub>O<sub>2</sub>. When the generated H<sub>2</sub>O<sub>2</sub> was applied to the AD, methanogens were inhibited, and VFA accumulation occurred. With the addition of 80 mg L<sup>–1</sup> H<sub>2</sub>O<sub>2</sub>, an average VFA concentration of 10.6 g COD L<sup>–1</sup> was obtained. The long-term H<sub>2</sub>O<sub>2</sub> inhibition effect on methanogenesis was examined for nearly 100 days. A 2.3- to 3.3-fold increase in malondialdehyde levels, which indicated increased cell damage, along with a significant decrease in methane production and an increase in VFA concentration, might suggest that H<sub>2</sub>O<sub>2</sub> could potentially inhibit methanogens while allowing acidogenic bacteria to remain functional. The accumulated VFAs were separated and then recovered using an electrodialysis unit, with a maximum VFA concentration of 26.7 g COD L<sup>–1</sup>. The results of this study will encourage further exploration of the proposed system for VFA production by addressing several challenges, including a better understanding of the inhibition mechanism and a further increase in VFA yields.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"4 12","pages":"2964–2973 2964–2973"},"PeriodicalIF":7.4,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142844099","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":"Volatile Fatty Acid Production through Arresting Methanogenesis by Electro-Synthesized Hydrogen Peroxide in Anaerobic Digestion and Subsequent Recovery by Electrodialysis","authors":"Jiasi Sun, Xi Zhang, Jianjun Guan, Zhen He","doi":"10.1021/acsestengg.4c00384","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00384","url":null,"abstract":"Producing volatile fatty acids (VFAs) in anaerobic digestion (AD) is of strong interest because of VFAs’ potential values in biomanufacturing. Despite some success of VFA production via pretreatment, in situ inhibition of methanogens for VFA accumulation has yet to be explored. Herein, a system consisting of hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) production, application of H<sub>2</sub>O<sub>2</sub> for inhibiting methanogens in AD, and VFA separation was investigated. A polytetrafluoroethylene-based electrospinning electrode was synthesized and capable of generating ∼4.2 g L<sup>–1</sup> H<sub>2</sub>O<sub>2</sub>. When the generated H<sub>2</sub>O<sub>2</sub> was applied to the AD, methanogens were inhibited, and VFA accumulation occurred. With the addition of 80 mg L<sup>–1</sup> H<sub>2</sub>O<sub>2</sub>, an average VFA concentration of 10.6 g COD L<sup>–1</sup> was obtained. The long-term H<sub>2</sub>O<sub>2</sub> inhibition effect on methanogenesis was examined for nearly 100 days. A 2.3- to 3.3-fold increase in malondialdehyde levels, which indicated increased cell damage, along with a significant decrease in methane production and an increase in VFA concentration, might suggest that H<sub>2</sub>O<sub>2</sub> could potentially inhibit methanogens while allowing acidogenic bacteria to remain functional. The accumulated VFAs were separated and then recovered using an electrodialysis unit, with a maximum VFA concentration of 26.7 g COD L<sup>–1</sup>. The results of this study will encourage further exploration of the proposed system for VFA production by addressing several challenges, including a better understanding of the inhibition mechanism and a further increase in VFA yields.","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"18 1","pages":""},"PeriodicalIF":7.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142256102","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}
Puranjan Mishra, Ifunanya R. Akaniro, Ruilong Zhang, Peixin Wang, Yiqi Geng, Dongyi Li, Qiuxiang Xu, Jonathan W. C. Wong, Jun Zhao
{"title":"Unlocking the Potential of Ni/Fe2O3 Bimetallic Nanoparticles for Fermentative Biohydrogen Production","authors":"Puranjan Mishra, Ifunanya R. Akaniro, Ruilong Zhang, Peixin Wang, Yiqi Geng, Dongyi Li, Qiuxiang Xu, Jonathan W. C. Wong, Jun Zhao","doi":"10.1021/acsestengg.4c00269","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00269","url":null,"abstract":"The coordinated system of inorganic nanoparticle-intact living cells has shown great potential in fermentative hydrogen (H<sub>2</sub>) production. Meanwhile, sluggish electron transfer and energy loss during transmembrane diffusion restrict the production of biohydrogen (BioH<sub>2</sub>). Herein, iron oxide, nickel oxide, and Ni/Fe<sub>2</sub>O<sub>3</sub> bimetallic nanocomposites were prepared through the coprecipitation method to investigate their potential effect on the dark fermentative hydrogen production (DFHP) system. The results showed that BioH<sub>2</sub> production could be enhanced by using nickel and iron oxide composites in DFHP, surpassing the performance of individual iron oxide or nickel oxide and their physical mixture. Specifically, Ni/Fe<sub>2</sub>O<sub>3</sub>-5% added to the feed at 150 mg/L increased the BioH<sub>2</sub> yields by 51.24% compared to that in its controlled experiment. The microbial community analysis confirmed a significant change in compositional proportions of the microbiome structure of DFHP in response to Ni/Fe<sub>2</sub>O<sub>3</sub>-5 wt %. The Enterobacter species proportions increased from 32.0% to 39.0%, along with some unclassified genera of microbial communities, from 34.0% to 42.0%, by supplementation of the nanomaterials. Enterobacter species are versatile facultative hydrogen producers and can use various organic wastes as the sole carbon source. The results suggested that the supplemented Ni/Fe<sub>2</sub>O<sub>3</sub>-5% induced the glycolytic efficacy and Fe and Ni availability, thereby increasing the hydrogenase activities. This study provided novel insights into integrating Ni/Fe<sub>2</sub>O<sub>3</sub> into the DFHP system and depicted its potential as an excellent catalyst to increase BioH<sub>2</sub> production. The distinctive microbial communities, unidentified hydrogen-producing bacteria, and increased BioH<sub>2</sub> yield due to the presence of Ni/Fe<sub>2</sub>O<sub>3</sub> in the DFHP system suggest unique and substantial advantages for the sustainable use of bimetallic nanomaterials in fermentation technology.","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"40 1","pages":""},"PeriodicalIF":7.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142256044","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}
Weimin Cheng, Ke Shi, Duc-Viet Nguyen, Jianliang Xue, Qing Jiang, Di Wu, Yanlu Qiao, An Liu
{"title":"Enhancing Sulfate Reduction Efficiency in Microbial Electrolysis Cells: The Impact of Mixing Conditions and Heavy-Metal Concentrations on Functional Genes, Cell Activity, and Community Structure in Sulfate-Laden Wastewater Treatment","authors":"Weimin Cheng, Ke Shi, Duc-Viet Nguyen, Jianliang Xue, Qing Jiang, Di Wu, Yanlu Qiao, An Liu","doi":"10.1021/acsestengg.4c00421","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00421","url":null,"abstract":"Microbial electrolysis cells (MECs) are promising for the treatment of sulfate-laden wastewater. The performance of the MEC cathode biofilms is influenced not only by the wastewater quality but also by the hydrodynamic mixing condition. Yet, the combined effects of these combined conditions have seldom been explored. This study examines the effectiveness and operational patterns of MECs in treating sulfate-laden wastewater under varying heavy-metal (Cu<sup>2+</sup> as representative) concentrations (0–80 mg L<sup>–1</sup>) and different hydrodynamic conditions (complete-mixing (CM) and nonmixing (NM, as control)). Results showed that CM-MECs achieved higher sulfate reduction efficiency (51 to 76%) compared to NM-MECs (with 46–69% of sulfate reduction) across the range of Cu<sup>2+</sup> concentrations. Kinetic analysis revealed that CM-MECs reduced sulfate faster due to increased expression of genes involved in sulfate reduction and electron transport. Furthermore, CM-MECs maintained intact cell structures, enhanced electron transfer, and increased the relative abundance of <i>Desulfobulbus</i> when treating wastewater with low Cu<sup>2+</sup> concentrations (<40 mg L<sup>–1</sup>). Microbial defense mechanisms against Cu<sup>2+</sup> also contributed to the enhanced sulfate reduction efficiency in the CM-MECs. These findings offer new insights into the design MECs with flowing conditions and pave the way for their future application in the treatment of heavy metal and sulfate-laden wastewater.","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"12 1","pages":""},"PeriodicalIF":7.1,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255865","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 : 2024-09-17DOI: 10.1021/acsestengg.4c0042110.1021/acsestengg.4c00421
Weimin Cheng, Ke Shi, Duc-Viet Nguyen, Jianliang Xue*, Qing Jiang, Di Wu*, Yanlu Qiao and An Liu,
{"title":"Enhancing Sulfate Reduction Efficiency in Microbial Electrolysis Cells: The Impact of Mixing Conditions and Heavy-Metal Concentrations on Functional Genes, Cell Activity, and Community Structure in Sulfate-Laden Wastewater Treatment","authors":"Weimin Cheng, Ke Shi, Duc-Viet Nguyen, Jianliang Xue*, Qing Jiang, Di Wu*, Yanlu Qiao and An Liu, ","doi":"10.1021/acsestengg.4c0042110.1021/acsestengg.4c00421","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00421https://doi.org/10.1021/acsestengg.4c00421","url":null,"abstract":"<p >Microbial electrolysis cells (MECs) are promising for the treatment of sulfate-laden wastewater. The performance of the MEC cathode biofilms is influenced not only by the wastewater quality but also by the hydrodynamic mixing condition. Yet, the combined effects of these combined conditions have seldom been explored. This study examines the effectiveness and operational patterns of MECs in treating sulfate-laden wastewater under varying heavy-metal (Cu<sup>2+</sup> as representative) concentrations (0–80 mg L<sup>–1</sup>) and different hydrodynamic conditions (complete-mixing (CM) and nonmixing (NM, as control)). Results showed that CM-MECs achieved higher sulfate reduction efficiency (51 to 76%) compared to NM-MECs (with 46–69% of sulfate reduction) across the range of Cu<sup>2+</sup> concentrations. Kinetic analysis revealed that CM-MECs reduced sulfate faster due to increased expression of genes involved in sulfate reduction and electron transport. Furthermore, CM-MECs maintained intact cell structures, enhanced electron transfer, and increased the relative abundance of <i>Desulfobulbus</i> when treating wastewater with low Cu<sup>2+</sup> concentrations (<40 mg L<sup>–1</sup>). Microbial defense mechanisms against Cu<sup>2+</sup> also contributed to the enhanced sulfate reduction efficiency in the CM-MECs. These findings offer new insights into the design MECs with flowing conditions and pave the way for their future application in the treatment of heavy metal and sulfate-laden wastewater.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"5 1","pages":"1–11 1–11"},"PeriodicalIF":7.4,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091795","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":"Oxygen Functionalization of Carbon Nanotubes Shifted the Formation Pathway of Hydroxyl Radicals in Catalytic Ozonation: The Overlooked Role of Hydrogen Peroxide","authors":"Yanye Tian, Yingtong Li, Guang-Guo Ying, Deli Wu, Kaimin Shih, Yong Feng","doi":"10.1021/acsestengg.4c00403","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00403","url":null,"abstract":"The oxygen functionalization of multiwalled carbon nanotubes (CNTs) could enhance their reactivity in catalytic ozonation for hydroxyl radical (<sup>•</sup>OH) formation. However, the detailed pathway for the transformation of ozone to <sup>•</sup>OH and the mechanism for the decreased treatment performance at acidic pH values remain unclear. In this study, surface oxygen-functionalized CNTs (O-CNTs) were prepared and used in catalytic ozonation to reveal the pathway for <sup>•</sup>OH formation. The efficiencies of ozone utilization and its conversion to <sup>•</sup>OH were increased by 2.7 and 554.8 times, respectively, under the catalysis of the O-CNTs. The great reactivity of the O-CNTs was related to their high surface oxygen contents and increased dispersion. Hydrogen peroxide was generated as a significant intermediate during the catalytic ozonation of the O-CNTs. The exposure of this substance linearly correlated with <sup>•</sup>OH exposure and pollutant degradation constants, with correlation coefficients of 0.991 and 0.911, respectively. The formation of hydrogen peroxide was relatively slower at acidic pH values, which explains the low performance of catalytic ozonation. A mechanism was proposed that involved the generation of hydrogen peroxide to trigger the peroxone process for free <sup>•</sup>OH formation. These findings deepen our understanding of oxygen functionalization and offer insights into the catalytic ozonation of surface oxygen-rich carbonaceous materials.","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"31 1","pages":""},"PeriodicalIF":7.1,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142256048","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 : 2024-09-16DOI: 10.1021/acsestengg.4c0040310.1021/acsestengg.4c00403
Yanye Tian, Yingtong Li, Guang-Guo Ying, Deli Wu, Kaimin Shih and Yong Feng*,
{"title":"Oxygen Functionalization of Carbon Nanotubes Shifted the Formation Pathway of Hydroxyl Radicals in Catalytic Ozonation: The Overlooked Role of Hydrogen Peroxide","authors":"Yanye Tian, Yingtong Li, Guang-Guo Ying, Deli Wu, Kaimin Shih and Yong Feng*, ","doi":"10.1021/acsestengg.4c0040310.1021/acsestengg.4c00403","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00403https://doi.org/10.1021/acsestengg.4c00403","url":null,"abstract":"<p >The oxygen functionalization of multiwalled carbon nanotubes (CNTs) could enhance their reactivity in catalytic ozonation for hydroxyl radical (<sup>•</sup>OH) formation. However, the detailed pathway for the transformation of ozone to <sup>•</sup>OH and the mechanism for the decreased treatment performance at acidic pH values remain unclear. In this study, surface oxygen-functionalized CNTs (O-CNTs) were prepared and used in catalytic ozonation to reveal the pathway for <sup>•</sup>OH formation. The efficiencies of ozone utilization and its conversion to <sup>•</sup>OH were increased by 2.7 and 554.8 times, respectively, under the catalysis of the O-CNTs. The great reactivity of the O-CNTs was related to their high surface oxygen contents and increased dispersion. Hydrogen peroxide was generated as a significant intermediate during the catalytic ozonation of the O-CNTs. The exposure of this substance linearly correlated with <sup>•</sup>OH exposure and pollutant degradation constants, with correlation coefficients of 0.991 and 0.911, respectively. The formation of hydrogen peroxide was relatively slower at acidic pH values, which explains the low performance of catalytic ozonation. A mechanism was proposed that involved the generation of hydrogen peroxide to trigger the peroxone process for free <sup>•</sup>OH formation. These findings deepen our understanding of oxygen functionalization and offer insights into the catalytic ozonation of surface oxygen-rich carbonaceous materials.</p>","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"4 12","pages":"3021–3031 3021–3031"},"PeriodicalIF":7.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142844033","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}
Jiyun Park, Smruti Ranjan Dash, Seow Wah How, Di Wu, Jeonghwan Kim
{"title":"Anaerobic Fluidized Bed Membrane Bioreactor with Multichanneled Biocarrier for Carbon-Neutral, Decentralized Greywater Treatment","authors":"Jiyun Park, Smruti Ranjan Dash, Seow Wah How, Di Wu, Jeonghwan Kim","doi":"10.1021/acsestengg.4c00186","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00186","url":null,"abstract":"This study investigated the effect of hydraulic retention times (HRTs) on the organic removal efficiency, membrane fouling, and methane production rate from an anaerobic fluidized bed membrane bioreactor (AFMBR) to treat synthetic greywater with a soluble chemical oxygen demand (SCOD) of 300 mg/L. Here, a polyvinylidene fluoride (PVDF)-based biocarrier was applied to control membrane fouling and facilitate attached biofilm growth. At an HRT of 16 h, which corresponds to 3.75 L/m<sup>2</sup> h of permeate flux, transmembrane pressure was maintained as 0.15 bar. As the HRT decreased 12 h, the SCOD removal efficiency dropped 42% quickly while bulk volatile suspended solid (VSS) concentration increased 1300 mg/L. However, when the HRT was further reduced to 8 h, the SCOD removal stabilized at 81% gradually with reducing the bulk VSS to 300 mg/L. During the entire operational period, the biogas produced by AFMBR under the fluidization of multichanneled media consisted of 50% methane. The methane yield was 0.13 L of CH<sub>4</sub>/day at an HRT of 8 h. A 16S ribosomal ribonucleic acid analysis of the microbial community demonstrated that the relative abundance of Methanosaeta grown on the PVDF media increased as the HRT decreased. Spectroscopic observation revealed that a significant portion of biomass was grown inside media channels having higher surface roughness than their outer surfaces.","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"18 1","pages":""},"PeriodicalIF":7.1,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142256047","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":"Predicting Biogas Yield after Microwave Pretreatment Using Artificial Neural Network Models: Performance Evaluation and Method Comparison","authors":"Yuxuan Li, Mahuizi Lu, Luiza C. Campos, Yukun Hu","doi":"10.1021/acsestengg.4c00276","DOIUrl":"https://doi.org/10.1021/acsestengg.4c00276","url":null,"abstract":"In the field of anaerobic digestion (AD) for biogas production, accurately predicting biogas yields following microwave pretreatment (MP) remains a significant challenge. Traditional kinetic models, such as the modified Gompertz (MG) model, are widely utilized but often lack the precision and adaptability needed for optimal process design and operational efficiency. This highlights a crucial gap in the development of more accurate and flexible predictive tools. To address this gap, advanced machine learning techniques, specifically, artificial neural networks (ANN), have been explored. This study developed and evaluated three ANN models: ANN, deep feed forward backpropagation (DFFBP), and deep cascade forward backpropagation network (DCFBP). The DCFBP model demonstrated superior predictive accuracy with a high coefficient of determination (<i>R</i><sup>2</sup> = 0.9946) and a lower mean absolute error (MAE = 0.34). Key input parameters, including the ratios of volatile solids to total solids (VS/TS) and the ratio of soluble chemical oxygen demand to total chemical oxygen demand (SCOD/TCOD), were integrated to enhance the prediction precision. These findings highlight the potential of ANN models to improve biogas yield predictions, offering significant benefits for the optimization and design of AD processes.","PeriodicalId":7008,"journal":{"name":"ACS ES&T engineering","volume":"16 1","pages":""},"PeriodicalIF":7.1,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142256052","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}