Transforming dissolved organic matter (DOM) is a crucial approach to alleviating the formation of disinfection byproducts (DBPs) in water treatment. Although catalytic ozonation effectively transforms DOM, increases in DBP formation potential are often observed due to the accumulation of aldehydes, ketones, and nitro compound intermediates during DOM transformation. In this study, we propose a novel strategy for the sequential oxidation of DOM, effectively reducing the levels of accumulation of these intermediates. This is achieved through the development of a catalyst with a tailored surface and nanoconfined active sites for catalytic ozonation. The catalyst features a unique confinement structure, wherein Mn-N4 moieties are uniformly anchored on the catalyst surface and within nanopores (5-20 Å). This design enables the degradation of the large molecular weight fraction of DOM on the catalyst surface, while the transformed smaller molecular weight fraction enters the nanopores and undergoes rapid degradation due to the confinement effect. The generation of *Oad as the dominant reactive species is essential for effectively reducing these ozone refractory intermediates. This resulted in over 70% removal of carbonaceous and nitrogenous DBP precursors as well as brominated DBP precursors. This study highlights the importance of the nanoscale sequential reactor design and provides new insights into eliminating DBP precursors by the catalytic ozonation process.
在水处理过程中,转化溶解有机物(DOM)是减少消毒副产物(DBP)形成的重要方法。虽然催化臭氧可以有效转化 DOM,但由于 DOM 转化过程中醛、酮和硝基化合物中间产物的积累,DBP 的形成潜力往往会增加。在本研究中,我们提出了一种新型 DOM 顺序氧化策略,可有效降低这些中间产物的累积水平。这是通过开发一种具有定制表面和纳米封闭活性位点的催化臭氧催化剂来实现的。该催化剂具有独特的封闭结构,其中 Mn-N4 分子均匀地固定在催化剂表面和纳米孔(5-20 Å)内。这种设计使催化剂表面的大分子量 DOM 得到降解,而转化后的小分子量 DOM 则进入纳米孔,并在封闭效应的作用下迅速降解。要有效减少这些臭氧难降解中间产物,就必须生成作为主要反应物的*Oad。这使得碳质和氮质 DBP 前体以及溴化 DBP 前体的去除率超过 70%。这项研究强调了纳米级顺序反应器设计的重要性,并为通过催化臭氧过程消除 DBP 前体提供了新的见解。
{"title":"Nanoscale Sequential Reactor Design Achieves Effective Removal of Disinfection Byproduct Precursors in Catalytic Ozonation.","authors":"Zilong Song, Jiaguang Xu, Jingmeng Guan, Peng Wang, Junlang Qiu, Yu Lei, Xinran Zhang, Qingqing Kong, Yangjian Zhou, Xin Yang","doi":"10.1021/acs.est.3c09295","DOIUrl":"https://doi.org/10.1021/acs.est.3c09295","url":null,"abstract":"<p><p>Transforming dissolved organic matter (DOM) is a crucial approach to alleviating the formation of disinfection byproducts (DBPs) in water treatment. Although catalytic ozonation effectively transforms DOM, increases in DBP formation potential are often observed due to the accumulation of aldehydes, ketones, and nitro compound intermediates during DOM transformation. In this study, we propose a novel strategy for the sequential oxidation of DOM, effectively reducing the levels of accumulation of these intermediates. This is achieved through the development of a catalyst with a tailored surface and nanoconfined active sites for catalytic ozonation. The catalyst features a unique confinement structure, wherein Mn-N<sub>4</sub> moieties are uniformly anchored on the catalyst surface and within nanopores (5-20 Å). This design enables the degradation of the large molecular weight fraction of DOM on the catalyst surface, while the transformed smaller molecular weight fraction enters the nanopores and undergoes rapid degradation due to the confinement effect. The generation of *O<sub>ad</sub> as the dominant reactive species is essential for effectively reducing these ozone refractory intermediates. This resulted in over 70% removal of carbonaceous and nitrogenous DBP precursors as well as brominated DBP precursors. This study highlights the importance of the nanoscale sequential reactor design and provides new insights into eliminating DBP precursors by the catalytic ozonation process.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Feilong Dong, Jiani Zhu, Jinxiu Lou, Zefang Chen, Zhiqiao He, Shuang Song, Lizhong Zhu, John C. Crittenden
Investigating the fate of persistent organic pollutants in water distribution systems (WDSs) is of great significance for preventing human health risks. The role of iron corrosion scales in the migration and transformation of organics in such systems remains unclear. Herein, we determined that hydroxyl (•OH), chlorine, and chlorine oxide radicals are generated by Fenton-like reactions due to the coexistence of oxygen vacancy-related Fe(II) on goethite (a major constituent of iron corrosion scales) and hypochlorous acid (HClO, the main reactive chlorine species of residual chlorine at pH ∼ 7.0). •OH contributed mostly to the decomposition of atrazine (ATZ, model compound) more than other radicals, producing a series of relatively low-toxicity small molecular intermediates. A simplified kinetic model consisting of mass transfer of ATZ and HClO, •OH generation, and ATZ oxidation by •OH on the goethite surface was developed to simulate iron corrosion scale-triggered residual chlorine oxidation of organic compounds in a WDS. The model was validated by comparing the fitting results to the experimental data. Moreover, the model was comprehensively applicable to cases in which various inorganic ions (Ca2+, Na+, HCO3–, and SO42–) and natural organic matter were present. With further optimization, the model may be employed to predict the migration and accumulation of persistent organic pollutants under real environmental conditions in the WDSs.
{"title":"Unveiling the Mechanism and Kinetics of Pollutant Attenuation by Free Radicals Triggered from Goethite in Water Distribution Systems","authors":"Feilong Dong, Jiani Zhu, Jinxiu Lou, Zefang Chen, Zhiqiao He, Shuang Song, Lizhong Zhu, John C. Crittenden","doi":"10.1021/acs.est.4c04022","DOIUrl":"https://doi.org/10.1021/acs.est.4c04022","url":null,"abstract":"Investigating the fate of persistent organic pollutants in water distribution systems (WDSs) is of great significance for preventing human health risks. The role of iron corrosion scales in the migration and transformation of organics in such systems remains unclear. Herein, we determined that hydroxyl (<sup>•</sup>OH), chlorine, and chlorine oxide radicals are generated by Fenton-like reactions due to the coexistence of oxygen vacancy-related Fe(II) on goethite (a major constituent of iron corrosion scales) and hypochlorous acid (HClO, the main reactive chlorine species of residual chlorine at pH ∼ 7.0). <sup>•</sup>OH contributed mostly to the decomposition of atrazine (ATZ, model compound) more than other radicals, producing a series of relatively low-toxicity small molecular intermediates. A simplified kinetic model consisting of mass transfer of ATZ and HClO, <sup>•</sup>OH generation, and ATZ oxidation by <sup>•</sup>OH on the goethite surface was developed to simulate iron corrosion scale-triggered residual chlorine oxidation of organic compounds in a WDS. The model was validated by comparing the fitting results to the experimental data. Moreover, the model was comprehensively applicable to cases in which various inorganic ions (Ca<sup>2+</sup>, Na<sup>+</sup>, HCO<sub>3</sub><sup>–</sup>, and SO<sub>4</sub><sup>2–</sup>) and natural organic matter were present. With further optimization, the model may be employed to predict the migration and accumulation of persistent organic pollutants under real environmental conditions in the WDSs.","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":9.028,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chirag Manchanda, Robert A Harley, Julian D Marshall, Alexander J Turner, Joshua S Apte
Urban air pollution can vary sharply in space and time. However, few monitoring strategies can concurrently resolve spatial and temporal variation at fine scales. Here, we present a new measurement-driven spatiotemporal modeling approach that transcends the individual limitations of two complementary sampling paradigms: mobile monitoring and fixed-site sensor networks. We develop, validate, and apply this model to predict black carbon (BC) using data from an intensive, 100-day field study in West Oakland, CA. Our spatiotemporal model exploits coherent spatial patterns derived from a multipollutant mobile monitoring campaign to fill spatial gaps in time-complete BC data from a low-cost sensor network. Our model performs well in reconstructing patterns at fine spatial and temporal resolution (30 m, 15 min), demonstrating strong out-of-sample correlations for both mobile (Pearson's R ∼ 0.77) and fixed-site measurements (R ∼ 0.95) while revealing features that are not effectively captured by a single monitoring approach in isolation. The model reveals sharp concentration gradients near major emission sources while capturing their temporal variability, offering valuable insights into pollution sources and dynamics.
{"title":"Integrating Mobile and Fixed-Site Black Carbon Measurements to Bridge Spatiotemporal Gaps in Urban Air Quality.","authors":"Chirag Manchanda, Robert A Harley, Julian D Marshall, Alexander J Turner, Joshua S Apte","doi":"10.1021/acs.est.3c10829","DOIUrl":"https://doi.org/10.1021/acs.est.3c10829","url":null,"abstract":"<p><p>Urban air pollution can vary sharply in space and time. However, few monitoring strategies can concurrently resolve spatial and temporal variation at fine scales. Here, we present a new measurement-driven spatiotemporal modeling approach that transcends the individual limitations of two complementary sampling paradigms: mobile monitoring and fixed-site sensor networks. We develop, validate, and apply this model to predict black carbon (BC) using data from an intensive, 100-day field study in West Oakland, CA. Our spatiotemporal model exploits coherent spatial patterns derived from a multipollutant mobile monitoring campaign to fill spatial gaps in time-complete BC data from a low-cost sensor network. Our model performs well in reconstructing patterns at fine spatial and temporal resolution (30 m, 15 min), demonstrating strong out-of-sample correlations for both mobile (Pearson's <i>R</i> ∼ 0.77) and fixed-site measurements (<i>R</i> ∼ 0.95) while revealing features that are not effectively captured by a single monitoring approach in isolation. The model reveals sharp concentration gradients near major emission sources while capturing their temporal variability, offering valuable insights into pollution sources and dynamics.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141475384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kamal J Maji, Zongrun Li, Ambarish Vaidyanathan, Yongtao Hu, Jennifer D Stowell, Chad Milando, Gregory Wellenius, Patrick L Kinney, Armistead G Russell, M Talat Odman
Smoke from wildfires poses a substantial threat to health in communities near and far. To mitigate the extent and potential damage of wildfires, prescribed burning techniques are commonly employed as land management tools; however, they introduce their own smoke-related risks. This study investigates the impact of prescribed fires on daily average PM2.5 and maximum daily 8-h averaged O3 (MDA8-O3) concentrations and estimates premature deaths associated with short-term exposure to prescribed fire PM2.5 and MDA8-O3 in Georgia and surrounding areas of the Southeastern US from 2015 to 2020. Our findings indicate that over the study domain, prescribed fire contributes to average daily PM2.5 by 0.94 ± 1.45 μg/m3 (mean ± standard deviation), accounting for 14.0% of year-round ambient PM2.5. Higher average daily contributions were predicted during the extensive burning season (January-April): 1.43 ± 1.97 μg/m3 (20.0% of ambient PM2.5). Additionally, prescribed burning is also responsible for an annual average increase of 0.36 ± 0.61 ppb in MDA8-O3 (approximately 0.8% of ambient MDA8-O3) and 1.3% (0.62 ± 0.88 ppb) during the extensive burning season. We estimate that short-term exposure to prescribed fire PM2.5 and MDA8-O3 could have caused 2665 (95% confidence interval (CI): 2249-3080) and 233 (95% CI: 148-317) excess deaths, respectively. These results suggest that smoke from prescribed burns increases the mortality. However, refraining from such burns may escalate the risk of wildfires; therefore, the trade-offs between the health impacts of wildfires and prescribed fires, including morbidity, need to be taken into consideration in future studies.
{"title":"Estimated Impacts of Prescribed Fires on Air Quality and Premature Deaths in Georgia and Surrounding Areas in the US, 2015-2020.","authors":"Kamal J Maji, Zongrun Li, Ambarish Vaidyanathan, Yongtao Hu, Jennifer D Stowell, Chad Milando, Gregory Wellenius, Patrick L Kinney, Armistead G Russell, M Talat Odman","doi":"10.1021/acs.est.4c00890","DOIUrl":"https://doi.org/10.1021/acs.est.4c00890","url":null,"abstract":"<p><p>Smoke from wildfires poses a substantial threat to health in communities near and far. To mitigate the extent and potential damage of wildfires, prescribed burning techniques are commonly employed as land management tools; however, they introduce their own smoke-related risks. This study investigates the impact of prescribed fires on daily average PM<sub>2.5</sub> and maximum daily 8-h averaged O<sub>3</sub> (MDA8-O<sub>3</sub>) concentrations and estimates premature deaths associated with short-term exposure to prescribed fire PM<sub>2.5</sub> and MDA8-O<sub>3</sub> in Georgia and surrounding areas of the Southeastern US from 2015 to 2020. Our findings indicate that over the study domain, prescribed fire contributes to average daily PM<sub>2.5</sub> by 0.94 ± 1.45 μg/m<sup>3</sup> (mean ± standard deviation), accounting for 14.0% of year-round ambient PM<sub>2.5</sub>. Higher average daily contributions were predicted during the extensive burning season (January-April): 1.43 ± 1.97 μg/m<sup>3</sup> (20.0% of ambient PM<sub>2.5</sub>). Additionally, prescribed burning is also responsible for an annual average increase of 0.36 ± 0.61 ppb in MDA8-O<sub>3</sub> (approximately 0.8% of ambient MDA8-O<sub>3</sub>) and 1.3% (0.62 ± 0.88 ppb) during the extensive burning season. We estimate that short-term exposure to prescribed fire PM<sub>2.5</sub> and MDA8-O<sub>3</sub> could have caused 2665 (95% confidence interval (CI): 2249-3080) and 233 (95% CI: 148-317) excess deaths, respectively. These results suggest that smoke from prescribed burns increases the mortality. However, refraining from such burns may escalate the risk of wildfires; therefore, the trade-offs between the health impacts of wildfires and prescribed fires, including morbidity, need to be taken into consideration in future studies.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141464314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yu-Lin Han, Zhen-Chuan Wu, Bruce E Rittmann, He-Ping Zhao
While partial nitrification (PN) has the potential to reduce energy for aeration, it has proven to be unstable when treating low-strength wastewater. This study introduces an innovative combined strategy incorporating a low rate of oxygen supply, pH control, and sulfide addition to selectively inhibit nitrite-oxidizing bacteria (NOB). This strategy led to a stable PN in a laboratory-scale membrane aerated biofilm reactor (MABR). Over a period of 260 days, the nitrite accumulation ratio exceeded 60% when treating synthetic sewage containing 50 mg NH4+-N/L. Through in situ activity testing and high-throughput sequencing, the combined strategy led to low levels of nitrite-oxidation activity (<5.5 mg N/m2 h), Nitrospira species (relative abundance <1%), and transcription of nitrite-oxidation genes (undetectable). The addition of sulfide led to simultaneous PN and autotrophic denitrification in the single-stage MABR, resulting in over 60% total inorganic nitrogen removal. Sulfur-based autotrophic denitrification consumed nitrite and inhibited NOB conversion of nitrite to nitrate. The combined strategy has potential to be applied in large-scale sewage treatment and deserves further exploration.
{"title":"Achieving Long-Term Stability of Partial Nitrification and Autotrophic Denitrification in an MABR <i>via</i> Sulfide Dosing.","authors":"Yu-Lin Han, Zhen-Chuan Wu, Bruce E Rittmann, He-Ping Zhao","doi":"10.1021/acs.est.4c04007","DOIUrl":"https://doi.org/10.1021/acs.est.4c04007","url":null,"abstract":"<p><p>While partial nitrification (PN) has the potential to reduce energy for aeration, it has proven to be unstable when treating low-strength wastewater. This study introduces an innovative combined strategy incorporating a low rate of oxygen supply, pH control, and sulfide addition to selectively inhibit nitrite-oxidizing bacteria (NOB). This strategy led to a stable PN in a laboratory-scale membrane aerated biofilm reactor (MABR). Over a period of 260 days, the nitrite accumulation ratio exceeded 60% when treating synthetic sewage containing 50 mg NH<sub>4</sub><sup>+</sup>-N/L. Through <i>in situ</i> activity testing and high-throughput sequencing, the combined strategy led to low levels of nitrite-oxidation activity (<5.5 mg N/m<sup>2</sup> h), <i>Nitrospira</i> species (relative abundance <1%), and transcription of nitrite-oxidation genes (undetectable). The addition of sulfide led to simultaneous PN and autotrophic denitrification in the single-stage MABR, resulting in over 60% total inorganic nitrogen removal. Sulfur-based autotrophic denitrification consumed nitrite and inhibited NOB conversion of nitrite to nitrate. The combined strategy has potential to be applied in large-scale sewage treatment and deserves further exploration.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141464312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Although the impacts of exotic wetland plant invasions on native biodiversity, landscape features, and carbon-nitrogen cycles are well appreciated, biogeochemical consequences posed by ecological competition, such as the heterogeneity of dissolved organic matter (DOM) from plant detritus and its impact on the formation of reactive oxygen species, are poorly understood. Thus, this study delves into O2•- photogeneration potential of DOM derived from three different parts (stem, leaf, and panicle) of invasive Spartina alterniflora (SA) and native Phragmites australis (PA). It is found that DOM from the leaves of SA and the panicles of PA has a superior ability to produce O2•-. With more stable aromatic structures and a higher proportion of sulfur-containing organic compounds, SA-derived DOM generally yields more O2•- than that derived from PA. UVA exposure enhances the leaching of diverse DOM molecules from plant detritus. Based on the reported monitoring data and our findings, the invasion of SA is estimated to approximately double the concentration of O2•- in the surrounding water bodies. This study can help to predict the underlying biogeochemical impacts from the perspective of aquatic photochemistry in future scenarios of plant invasion, seawater intrusion, wetland degradation, and elevated solar UV radiation.
尽管外来湿地植物入侵对本地生物多样性、景观特征和碳氮循环的影响已得到充分认识,但人们对生态竞争带来的生物地球化学后果,如植物残体中溶解有机物(DOM)的异质性及其对活性氧形成的影响,却知之甚少。因此,本研究深入探讨了入侵植物 Spartina alterniflora(SA)和原生植物 Phragmites australis(PA)三个不同部位(茎、叶和圆锥花序)产生的 DOM 的氧气光生成潜力。研究发现,SA 的叶片和 PA 的圆锥花序产生的 DOM 具有更强的 O2 生成能力。SA 衍生的 DOM 具有更稳定的芳香结构和更高比例的含硫有机化合物,通常比 PA 衍生的 DOM 产生更多的 O2--。紫外线照射会增强植物残体中各种 DOM 分子的沥滤作用。根据报告的监测数据和我们的研究结果,SA 的入侵估计会使周围水体中的 O2--浓度增加约一倍。这项研究有助于从水生光化学的角度预测在未来植物入侵、海水入侵、湿地退化和太阳紫外线辐射升高的情况下潜在的生物地球化学影响。
{"title":"Superoxide Photoproduction from Wetland Plant-Derived Dissolved Organic Matter: Implications for Biogeochemical Impacts of Plant Invasion.","authors":"Yu Fu, Chunxiao Xu, Xiaojing Liu, Yanna Xue, Lingli Wang, Qingchao Li, Yuqi Xia, Zhen Zhang, Jialin Chen, Jinhui Cao, Sifan Qiu, Zhaohui Wang","doi":"10.1021/acs.est.4c04927","DOIUrl":"https://doi.org/10.1021/acs.est.4c04927","url":null,"abstract":"<p><p>Although the impacts of exotic wetland plant invasions on native biodiversity, landscape features, and carbon-nitrogen cycles are well appreciated, biogeochemical consequences posed by ecological competition, such as the heterogeneity of dissolved organic matter (DOM) from plant detritus and its impact on the formation of reactive oxygen species, are poorly understood. Thus, this study delves into O<sub>2</sub><sup>•-</sup> photogeneration potential of DOM derived from three different parts (stem, leaf, and panicle) of invasive <i>Spartina alterniflora</i> (SA) and native <i>Phragmites australis</i> (PA). It is found that DOM from the leaves of SA and the panicles of PA has a superior ability to produce O<sub>2</sub><sup>•-</sup>. With more stable aromatic structures and a higher proportion of sulfur-containing organic compounds, SA-derived DOM generally yields more O<sub>2</sub><sup>•-</sup> than that derived from PA. UVA exposure enhances the leaching of diverse DOM molecules from plant detritus. Based on the reported monitoring data and our findings, the invasion of SA is estimated to approximately double the concentration of O<sub>2</sub><sup>•-</sup> in the surrounding water bodies. This study can help to predict the underlying biogeochemical impacts from the perspective of aquatic photochemistry in future scenarios of plant invasion, seawater intrusion, wetland degradation, and elevated solar UV radiation.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141464245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Long Tian, Peng Zhou, Zhaoyang Su, Nigel Graham, Wenzheng Yu
Significant progress has been made previously in the research and development of graphene oxide (GO) membranes for water purification, but their biofouling behavior remains poorly understood. In this study, we investigated the biofilm formation and biofouling of GO membranes with different surface microstructures in the context of filtering natural surface water and for an extended operation period (110 days). The results showed that the relatively hydrophilic and smooth Fe(OH)3/GO membrane shaped a thin and spatially heterogeneous biofilm with high stable flux. However, the ability to simultaneously mitigate biofilm formation and reduce biofouling was not observed in the weakly hydrophilic and wrinkled Fe/GO and H-Fe(OH)3/GO membranes. Microbial analyses revealed that the hydrophilicity and roughness distinguished the bacterial communities and metabolic functions. The organic matter-degrading and predatory bacteria were more adapted to hydrophilic and smooth GO surfaces. These functional taxa were involved in the degradation of extracellular polymeric substances (EPS), and improved biofilm heterogeneity. In contrast, the weakly hydrophilic and wrinkled GO surfaces had reduced biodiversity, while unexpectedly boosting the proliferation of EPS-secreting bacteria, resulting in increased biofilm formation and aggravated biofouling. Moreover, all GO membranes achieved sustainable water purification during the entire operating period.
此前,用于水净化的氧化石墨烯(GO)膜的研究和开发取得了重大进展,但对其生物污损行为的了解仍然很少。在本研究中,我们以过滤天然地表水为背景,研究了不同表面微结构的 GO 膜在长时间(110 天)运行下的生物膜形成和生物污损情况。结果表明,相对亲水且光滑的 Fe(OH)3/GO 膜形成了一层薄且空间异构的生物膜,具有较高的稳定通量。然而,在亲水性弱、起皱的 Fe/GO 膜和 H-Fe(OH)3/GO 膜上,却观察不到同时缓解生物膜形成和减少生物污染的能力。微生物分析表明,亲水性和粗糙度可区分细菌群落和代谢功能。有机物降解细菌和捕食细菌更适应亲水性和光滑的 GO 表面。这些功能类群参与了胞外聚合物质(EPS)的降解,并改善了生物膜的异质性。相反,亲水性弱和起皱的 GO 表面生物多样性减少,却意外地促进了分泌 EPS 的细菌的增殖,导致生物膜形成增加,生物污染加剧。此外,在整个运行期间,所有 GO 膜都实现了可持续的水净化。
{"title":"Surface Microstructure Drives Biofilm Formation and Biofouling of Graphene Oxide Membranes in Practical Water Treatment.","authors":"Long Tian, Peng Zhou, Zhaoyang Su, Nigel Graham, Wenzheng Yu","doi":"10.1021/acs.est.4c03363","DOIUrl":"https://doi.org/10.1021/acs.est.4c03363","url":null,"abstract":"<p><p>Significant progress has been made previously in the research and development of graphene oxide (GO) membranes for water purification, but their biofouling behavior remains poorly understood. In this study, we investigated the biofilm formation and biofouling of GO membranes with different surface microstructures in the context of filtering natural surface water and for an extended operation period (110 days). The results showed that the relatively hydrophilic and smooth Fe(OH)<sub>3</sub>/GO membrane shaped a thin and spatially heterogeneous biofilm with high stable flux. However, the ability to simultaneously mitigate biofilm formation and reduce biofouling was not observed in the weakly hydrophilic and wrinkled Fe/GO and H-Fe(OH)<sub>3</sub>/GO membranes. Microbial analyses revealed that the hydrophilicity and roughness distinguished the bacterial communities and metabolic functions. The organic matter-degrading and predatory bacteria were more adapted to hydrophilic and smooth GO surfaces. These functional taxa were involved in the degradation of extracellular polymeric substances (EPS), and improved biofilm heterogeneity. In contrast, the weakly hydrophilic and wrinkled GO surfaces had reduced biodiversity, while unexpectedly boosting the proliferation of EPS-secreting bacteria, resulting in increased biofilm formation and aggravated biofouling. Moreover, all GO membranes achieved sustainable water purification during the entire operating period.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141464246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Developing efficient technologies to eliminate or degrade contaminants is paramount for environmental protection. Biocatalytic decontamination offers distinct advantages in terms of selectivity and efficiency; however, it still remains challenging when applied in complex environmental matrices. The main challenge originates from the instability and difficult-to-separate attributes of fragile enzymes, which also results in issues of compromised activity, poor reusability, low cost-effectiveness, etc. One viable solution to harness biocatalysis in complex environments is known as enzyme immobilization, where a flexible enzyme is tightly fixed in a solid carrier. In the case where a reticular crystal is utilized as the support, it is feasible to engineer next-generation biohybrid catalysts functional in complicated environmental media. This can be interpreted by three aspects: (1) the highly crystalline skeleton can shield the immobilized enzyme against external stressors. (2) The porous network ensures the high accessibility of the interior enzyme for catalytic decontamination. And (3) the adjustable and unambiguous structure of the reticular framework favors in-depth understanding of the interfacial interaction between the framework and enzyme, which can in turn guide us in designing highly active biocomposites. This Review aims to introduce this emerging biocatalysis technology for environmental decontamination involving pollutant degradation and greenhouse gas (carbon dioxide) conversion, with emphasis on the enzyme immobilization protocols and diverse catalysis principles including single enzyme catalysis, catalysis involving enzyme cascades, and photoenzyme-coupled catalysis. Additionally, the remaining challenges and forward-looking directions in this field are discussed. We believe that this Review may offer a useful biocatalytic technology to contribute to environmental decontamination in a green and sustainable manner and will inspire more researchers at the intersection of the environment science, biochemistry, and materials science communities to co-solve environmental problems.
{"title":"Enzyme-Immobilized Porous Crystals for Environmental Applications.","authors":"Hao Wang, Xiaoxue Kou, Rui Gao, Siming Huang, Guosheng Chen, Gangfeng Ouyang","doi":"10.1021/acs.est.4c01273","DOIUrl":"https://doi.org/10.1021/acs.est.4c01273","url":null,"abstract":"<p><p>Developing efficient technologies to eliminate or degrade contaminants is paramount for environmental protection. Biocatalytic decontamination offers distinct advantages in terms of selectivity and efficiency; however, it still remains challenging when applied in complex environmental matrices. The main challenge originates from the instability and difficult-to-separate attributes of fragile enzymes, which also results in issues of compromised activity, poor reusability, low cost-effectiveness, etc. One viable solution to harness biocatalysis in complex environments is known as enzyme immobilization, where a flexible enzyme is tightly fixed in a solid carrier. In the case where a reticular crystal is utilized as the support, it is feasible to engineer next-generation biohybrid catalysts functional in complicated environmental media. This can be interpreted by three aspects: (1) the highly crystalline skeleton can shield the immobilized enzyme against external stressors. (2) The porous network ensures the high accessibility of the interior enzyme for catalytic decontamination. And (3) the adjustable and unambiguous structure of the reticular framework favors in-depth understanding of the interfacial interaction between the framework and enzyme, which can in turn guide us in designing highly active biocomposites. This Review aims to introduce this emerging biocatalysis technology for environmental decontamination involving pollutant degradation and greenhouse gas (carbon dioxide) conversion, with emphasis on the enzyme immobilization protocols and diverse catalysis principles including single enzyme catalysis, catalysis involving enzyme cascades, and photoenzyme-coupled catalysis. Additionally, the remaining challenges and forward-looking directions in this field are discussed. We believe that this Review may offer a useful biocatalytic technology to contribute to environmental decontamination in a green and sustainable manner and will inspire more researchers at the intersection of the environment science, biochemistry, and materials science communities to co-solve environmental problems.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141464313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xin Wang, Shengyan Pu, Jiaqi Ding, Jing Chen, Peng Liao, Delai Zhong, Daniel C W Tsang, John C Crittenden, Linling Wang
Clay minerals are ubiquitous in subsurface environments and have long been recognized as having a limited or negligible impact on the fate of arsenic (As) due to their negatively charged surfaces. Here, we demonstrate the significant role of kaolinite (Kln), a pervasive clay mineral, in enhancing As(V) immobilization during ferrous iron (Fe(II)) oxidation at near-neutral pH. Our results showed that Fe(II) oxidation alone was not capable of immobilizing As(V) at relatively low Fe/As molar ratios (≤2) due to the generation of Fe(III)-As(V) nanocolloids that could still migrate easily as truly dissolved As did. In the presence of kaolinite, dissolved As(V) was significantly immobilized on the kaolinite surfaces via forming Kln-Fe(III)-As(V) ternary precipitates, which had large sizes (at micrometer levels) to reduce the As mobility. The kaolinite-induced heterogeneous pathways for As(V) immobilization involved Fe(II) adsorption, heterogeneous oxidation of adsorbed Fe(II), and finally heterogeneous nucleation/precipitation of Fe(III)-As(V) phases on the edge surfaces of kaolinite. The surface precipitates were mixtures of amorphous basic Fe(III)-arsenate and As-rich hydrous ferric oxide. Our findings provide new insights into the role of clay minerals in As transformation, which is significant for the fate of As in natural and engineered systems.
粘土矿物在地下环境中无处不在,由于其表面带负电荷,长期以来一直被认为对砷(As)的归宿影响有限或可以忽略不计。在这里,我们证明了高岭石(Kln)这种普遍存在的粘土矿物在接近中性 pH 值的亚铁(Fe(II))氧化过程中对增强砷(V)固定的重要作用。我们的研究结果表明,在铁/砷摩尔比(≤2)相对较低的情况下,由于生成了铁(III)-砷(V)纳米胶体,单独的铁(II)氧化作用无法固定砷(V),而这些纳米胶体仍然可以像真正溶解的砷那样容易迁移。在高岭石存在的情况下,溶解的 As(V)通过形成 Kln-Fe(III)-As(V)三元沉淀物被显著固定在高岭石表面,这些沉淀物具有较大的尺寸(微米级),从而降低了 As 的迁移率。高岭石诱导的砷(V)固定化异质途径包括铁(II)吸附、吸附的铁(II)异质氧化,最后在高岭石边缘表面形成铁(III)-砷(V)相的异质成核/沉淀。表面沉淀物是无定形碱性砷酸铁(III)和富含砷的水合氧化铁的混合物。我们的研究结果为了解粘土矿物在砷转化过程中的作用提供了新的视角,这对于研究砷在自然和工程系统中的归宿具有重要意义。
{"title":"Enhanced Arsenate Immobilization by Kaolinite via Heterogeneous Pathways during Ferrous Iron Oxidation.","authors":"Xin Wang, Shengyan Pu, Jiaqi Ding, Jing Chen, Peng Liao, Delai Zhong, Daniel C W Tsang, John C Crittenden, Linling Wang","doi":"10.1021/acs.est.4c01976","DOIUrl":"https://doi.org/10.1021/acs.est.4c01976","url":null,"abstract":"<p><p>Clay minerals are ubiquitous in subsurface environments and have long been recognized as having a limited or negligible impact on the fate of arsenic (As) due to their negatively charged surfaces. Here, we demonstrate the significant role of kaolinite (Kln), a pervasive clay mineral, in enhancing As(V) immobilization during ferrous iron (Fe(II)) oxidation at near-neutral pH. Our results showed that Fe(II) oxidation alone was not capable of immobilizing As(V) at relatively low Fe/As molar ratios (≤2) due to the generation of Fe(III)-As(V) nanocolloids that could still migrate easily as truly dissolved As did. In the presence of kaolinite, dissolved As(V) was significantly immobilized on the kaolinite surfaces via forming Kln-Fe(III)-As(V) ternary precipitates, which had large sizes (at micrometer levels) to reduce the As mobility. The kaolinite-induced heterogeneous pathways for As(V) immobilization involved Fe(II) adsorption, heterogeneous oxidation of adsorbed Fe(II), and finally heterogeneous nucleation/precipitation of Fe(III)-As(V) phases on the edge surfaces of kaolinite. The surface precipitates were mixtures of amorphous basic Fe(III)-arsenate and As-rich hydrous ferric oxide. Our findings provide new insights into the role of clay minerals in As transformation, which is significant for the fate of As in natural and engineered systems.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141453628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding the bioavailability of per- and polyfluoroalkyl substances (PFAS) in food is essential for accurate human health risk assessment. Given the rising incidence of inflammatory bowel disease (IBD), this study aimed to investigate the impacts of IBD on the bioavailability of PFAS in food using mice models. The relative bioavailability (RBA) of PFAS was the highest in the chronic IBD mice (64.3-144%), followed by the healthy (60.8-133%) and acute IBD mice (41.5-121%), suggesting that chronic IBD enhanced the PFAS exposure risk. In vitro tests showed that the intestinal micelle stability increased as a result of reduced content of short-chain fatty acids, thus promoting the PFAS bioaccessibility in the digestive fluid of chronic IBD. Additionally, increased pathogenic and decreased beneficial bacteria in the gut of IBD groups facilitated the intestinal permeability, thus enhancing PFAS absorption. These together explained the higher RBA of PFAS in the chronic IBD. However, remarkably lower enzymatic activities suggested severely impaired digestive ability in the acute IBD, which facilitated the excretion of PFAS from feces, thus lowering the RBA. Conversely, PFAS exposure might exacerbate IBD by changing the gut microbiota structures. This study hints that individuals with chronic intestinal inflammation might have higher PFAS exposure risk than the healthy population.
{"title":"Insights into the Enhanced Bioavailability of Per- and Polyfluoroalkyl Substances in Food Caused by Chronic Inflammatory Bowel Disease.","authors":"Yumin Zhu, Xin Yang, Xiaohua Song, Yibo Jia, Yanfeng Zhang, Lingyan Zhu","doi":"10.1021/acs.est.4c01511","DOIUrl":"https://doi.org/10.1021/acs.est.4c01511","url":null,"abstract":"<p><p>Understanding the bioavailability of per- and polyfluoroalkyl substances (PFAS) in food is essential for accurate human health risk assessment. Given the rising incidence of inflammatory bowel disease (IBD), this study aimed to investigate the impacts of IBD on the bioavailability of PFAS in food using mice models. The relative bioavailability (RBA) of PFAS was the highest in the chronic IBD mice (64.3-144%), followed by the healthy (60.8-133%) and acute IBD mice (41.5-121%), suggesting that chronic IBD enhanced the PFAS exposure risk. <i>In vitro</i> tests showed that the intestinal micelle stability increased as a result of reduced content of short-chain fatty acids, thus promoting the PFAS bioaccessibility in the digestive fluid of chronic IBD. Additionally, increased pathogenic and decreased beneficial bacteria in the gut of IBD groups facilitated the intestinal permeability, thus enhancing PFAS absorption. These together explained the higher RBA of PFAS in the chronic IBD. However, remarkably lower enzymatic activities suggested severely impaired digestive ability in the acute IBD, which facilitated the excretion of PFAS from feces, thus lowering the RBA. Conversely, PFAS exposure might exacerbate IBD by changing the gut microbiota structures. This study hints that individuals with chronic intestinal inflammation might have higher PFAS exposure risk than the healthy population.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141453653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}