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1.
J Environ Manage ; 370: 122567, 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39303598

RESUMEN

Integrated fixed-film activated sludge (IFAS) system, an improvement of the activated sludge process, combines the advantages of both attached sludge (AS) and suspended sludge (SS). This study aimed to fully decipher the roles of AS and SS in simultaneous N and P removal in an IFAS system through metagenomic analysis. It was found that AS contributed about 84.04%, 97%, and 95.12% to exogenous NO3--N reduction, endogenous NO3--N reduction, and endogenous NO2--N reduction, respectively. Compared with AS, SS exhibited a greater contribution to anaerobic P release (69.06%) and aerobic P uptake (73.48%). Nitrate and nitrite reductase enzymes showed higher activities in AS, while the activities of exopolyphosphatase and alkaline phosphatase D were more active in SS. P content further indicated that in AS, only a small amount of P was stored in EPS, with most presented intracellularly. In SS, the amount of P stored in EPS was found to be higher. Metagenomic analysis revealed genes related to the synthesis and degradation of endogenous carbon were higher in AS, whereas the TCA cycle exhibited higher activity in SS. P removal-related genes (such as ppk2, ppx, and adk) was significantly higher in SS than in AS. The alteration of genes associated with nitrogen metabolism suggested that the microbes in AS had a higher capacity for nitrification and denitrification. In summary, the discrepancy in the roles of AS and SS in N and P removal in IFAS can be attributed to variations in enzyme activity, P storage in EPS, microbial community composition, and functional gene abundance.

2.
Chemistry ; : e202402930, 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39269730

RESUMEN

Sp2-carbon (sp2-c) covalent organic frameworks (COFs), featuring distinctive π-conjugated network structures, facilitate the migration of photo-generated carriers, rendering them exceptionally appealing for applications in photoelectrochemical water splitting. However, owing to the powdery nature of COFs, leaving anchor the sp2-c COFs powder tightly onto a conductive substrate challenging. Here, we propose a method for preparing photoactive substance-conductive substrate integrated photocathodes through copper surface-mediated knoevenagel polycondensation (Cu-SMKP), this approach results in a uniform and stable sp2-c COF film, directly grown on commercial copper foam (COFTh-Cu). The COFTh-Cu demonstrates a high H2-evolution photocurrent density of 56 µA cm-2 at 0.3 V versus RHE, sustaining stability for 12 hours. The as-prepared COFTh-Cu represents a 4.5-fold increase in current density compared to traditional spin-coating methods and outperforms most COF photocathodes without cocatalysts. This innovative copper surface-mediated approach for preparing photocathodes opens up a crucial pathway towards the realization of highly active COF photocathodes.

3.
Small ; : e2404643, 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-39016121

RESUMEN

Nowadays, oral medications are the primary method of treating disease due to their convenience, low cost, and safety, without the need for complex medical procedures. To maximize treatment effectiveness, almost all oral medications utilize drug carriers, such as capsules, liposomes, and sugar coatings. However, these carriers rely on dissolution or fragmentation to achieve drug release, which leads to drugs and carriers coabsorption in the body, causing unnecessary adverse drug reactions, such as nausea, vomiting, abdominal pain, and even death caused by allergy. Therefore, the ideal oral drug carrier should avoid degradation and absorption and be totally excreted after drug release at the desired location. Herein, a gastrointestinally stable oral drug carrier based on porous aromatic framework-1 (PAF-1) is constructed, and it is modified with famotidine (a well-known gastric drug) and mesalazine (a well-known ulcerative colitis drug) to verify the excellent potential of PAF-1. The results demonstrate that PAF-1 can accurately release famotidine in stomach, mesalazine in the intestine, and finally be completely excreted from the body without any residue after 12 h. The use of PAF materials for the construction of oral drug carriers with no residue in the gastrointestinal tract provides a new approach for efficient disease treatment.

4.
Anal Bioanal Chem ; 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39085422

RESUMEN

Hydrolytic nanozyme-based visual colorimetry has emerged as a promising strategy for the detection of aluminum ions. However, most studies focus on simulating the structure of natural enzymes while neglecting to regulate the rate of hydrolysis-related steps, leading to low enzyme-like activity for hydrolytic nanozymes. Herein, we constructed a ruthenium dioxide (RuO2) in situ embedded cerium oxide (CeO2) nanozyme (RuO2/CeO2) with a Lewis acid-base pair (Ce-O-Ru-OH), which can simulate the catalytic behavior of phosphatase (PPase) and can be quantitatively quenched by Al3+ to achieve accurate and sensitive Al3+ colorimetric sensing detection. The incorporation of Ru into CeO2 nanorods accelerates the dissociation of H2O, followed by subsequent combination of hydroxide species to Lewis acidic Ce-O sites. This synergistic effect facilitates substrate activation and significantly enhances the hydrolysis activity of the nanozyme. The results show that the RuO2/CeO2 nanozyme exhibits a limit of detection as low as 0.5 ng/mL. We also demonstrate their efficacy in detecting Al3+ in various practical food samples. This study offers novel insights into the advancement of highly sensitive hydrolytic nanozyme engineering for sensing applications.

5.
Adv Mater ; 36(35): e2406807, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38923045

RESUMEN

Single-atom heterogeneous catalysts (SAHCs) provide an enticing platform for understanding catalyst structure-property-performance relationships. The 100% atom utilization and adjustable local coordination configurations make it easy to probe reaction mechanisms at the atomic level. However, the progressive deactivation of metal-single-atom (MSA) with high surface energy leads to frequent limitations on their commercial viability. This review focuses on the atomistic-sensitive reactivity and atomistic-progressive deactivation of MSA to provide a unifying framework for specific functionality and potential deactivation drivers of MSA, thereby bridging function, purpose-modification structure-performance insights with the atomistic-progressive deactivation for sustainable structure-property-performance accessibility. The dominant functionalization of atomically precise MSA acting on properties and reactivity encompassing precise photocatalytic reactions is first systematically explored. Afterward, a detailed analysis of various deactivation modes of MSA and strategies to enhance their durability is presented, providing valuable insights into the design of SAHCs with deactivation-resistant stability. Finally, the remaining challenges and future perspectives of SAHCs toward industrialization, anticipating shedding some light on the next stage of atom-economic chemical/energy transformations are presented.

6.
Sci Total Environ ; 932: 173033, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38723954

RESUMEN

Microplastics (MPs) pollution has emerged as a global concern, and wastewater treatment plants (WWTPs) are one of the potential sources of MPs in the environment. However, the effect of polyethylene MPs (PE) on nitrogen (N) removal in moving bed biofilm reactor (MBBR) remains unclear. We hypothesized that PE would affect N removal in MBBR by influencing its microbial community. In this study, we investigated the impacts of different PE concentrations (100, 500, and 1000 µg/L) on N removal, enzyme activities, and microbial community in MBBR. Folin-phenol and anthrone colorimetric methods, oxidative stress and enzyme activity tests, and high-throughput sequencing combined with bioinformation analysis were used to decipher the potential mechanisms. The results demonstrated that 1000 µg/L PE had the greatest effect on NH4+-N and TN removal, with a decrease of 33.5 % and 35.2 %, and nitrifying and denitrifying enzyme activities were restrained by 29.5-39.6 % and 24.6-47.4 %. Polysaccharide and protein contents were enhanced by PE, except for 1000 µg/L PE, which decreased protein content by 65.4 mg/g VSS. The positive links of species interactions under 1000 µg/L PE exposure was 52.07 %, higher than under 500 µg/L (51.05 %) and 100 µg/L PE (50.35 %). Relative abundance of some metabolism pathways like carbohydrate metabolism and energy metabolism were restrained by 0.07-0.11 % and 0.27-0.4 %. Moreover, the total abundance of nitrification and denitrification genes both decreased under PE exposure. Overall, PE reduced N removal by affecting microbial community structure and species interactions, inhibiting some key metabolic pathways, and suppressing key enzyme activity and functional gene abundance. This paper provides new insights into assessing the risk of MPs to WWTPs, contributing to ensuring the health of aquatic ecosystems.


Asunto(s)
Biopelículas , Reactores Biológicos , Microbiota , Nitrógeno , Polietileno , Eliminación de Residuos Líquidos , Contaminantes Químicos del Agua , Nitrógeno/metabolismo , Reactores Biológicos/microbiología , Contaminantes Químicos del Agua/análisis , Eliminación de Residuos Líquidos/métodos , Microbiota/efectos de los fármacos , Microplásticos , Aguas Residuales/química
7.
Nat Commun ; 15(1): 4213, 2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38760369

RESUMEN

Nanofluidic membranes have demonstrated great potential in harvesting osmotic energy. However, the output power densities are usually hampered by insufficient membrane permselectivity. Herein, we design a polyoxometalates (POMs)-based nanofluidic plasmonic electron sponge membrane (PESM) for highly efficient osmotic energy conversion. Under light irradiation, hot electrons are generated on Au NPs surface and then transferred and stored in POMs electron sponges, while hot holes are consumed by water. The stored hot electrons in POMs increase the charge density and hydrophilicity of PESM, resulting in significantly improved permselectivity for high-performance osmotic energy conversion. In addition, the unique ionic current rectification (ICR) property of the prepared nanofluidic PESM inhibits ion concentration polarization effectively, which could further improve its permselectivity. Under light with 500-fold NaCl gradient, the maximum output power density of the prepared PESM reaches 70.4 W m-2, which is further enhanced even to 102.1 W m-2 by changing the ligand to P5W30. This work highlights the crucial roles of plasmonic electron sponge for tailoring the surface charge, modulating ion transport dynamics, and improving the performance of nanofluidic osmotic energy conversion.

8.
J Hazard Mater ; 473: 134579, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38761761

RESUMEN

Ciprofloxacin (CIP) has received considerable attention in recent decades due to its high ecological risk. However, little is known about the potential response of macrophytes and microbes to varying levels of CIP exposure in constructed wetlands. Therefore, lab-scale manganese ore-based tidal flow constructed wetlands (MO-TFCWs) were operated to evaluate the responses of macrophytes and microbes to CIP over the long term. The results indicated that total nitrogen removal improved from 79.93% to 87.06% as CIP rose from 0 to 4 mg L-1. The chlorophyll content and antioxidant enzyme activities in macrophytes were enhanced under CIP exposure, but plant growth was not inhibited. Importantly, CIP exposure caused a marked evolution of the substrate microbial community, with increased microbial diversity, expanded niche breadth and enhanced cooperation among the top 50 genera, compared to the control (no CIP). Co-occurrence network also indicated that microorganisms may be more inclined to co-operate than compete. The abundance of the keystone bacterium (involved in nitrogen transformation) norank_f__A0839 increased from 0.746% to 3.405%. The null model revealed drift processes (83.33%) dominated the community assembly with no CIP and 4 mg L-1 CIP. Functional predictions indicated that microbial carbon metabolism, electron transfer and ATP metabolism activities were enhanced under prolonged CIP exposure, which may contribute to nitrogen removal. This study provides valuable insights that will help achieve stable nitrogen removal from wastewater containing antibiotic in MO-TFCWs.


Asunto(s)
Ciprofloxacina , Manganeso , Nitrógeno , Contaminantes Químicos del Agua , Humedales , Ciprofloxacina/farmacología , Ciprofloxacina/metabolismo , Manganeso/metabolismo , Nitrógeno/metabolismo , Contaminantes Químicos del Agua/metabolismo , Antibacterianos , Bacterias/metabolismo , Bacterias/efectos de los fármacos , Microbiota/efectos de los fármacos , Plantas/metabolismo , Biodegradación Ambiental , Eliminación de Residuos Líquidos/métodos
9.
Environ Sci Ecotechnol ; 20: 100412, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38560759

RESUMEN

Effective management of large basins necessitates pinpointing the spatial and temporal drivers of primary index exceedances and urban risk factors, offering crucial insights for basin administrators. Yet, comprehensive examinations of multiple pollutants within the Yangtze River Basin remain scarce. Here we introduce a pollution inventory for urban clusters surrounding the Yangtze River Basin, analyzing water quality data from 102 cities during 2018-2019. We assessed the exceedance rates for six pivotal indicators: dissolved oxygen (DO), ammonia nitrogen (NH3-N), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total phosphorus (TP), and the permanganate index (CODMn) for each city. Employing random forest regression and SHapley Additive exPlanations (SHAP) analyses, we identified the spatiotemporal factors influencing these key indicators. Our results highlight agricultural activities as the primary contributors to the exceedance of all six indicators, thus pinpointing them as the leading pollution source in the basin. Additionally, forest coverage, livestock farming, chemical and pharmaceutical sectors, along with meteorological elements like precipitation and temperature, significantly impacted various indicators' exceedances. Furthermore, we delineate five core urban risk components through principal component analysis, which are (1) anthropogenic and industrial activities, (2) agricultural practices and forest extent, (3) climatic variables, (4) livestock rearing, and (5) principal polluting sectors. The cities were subsequently evaluated and categorized based on these risk components, incorporating policy interventions and administrative performance within each region. The comprehensive analysis advocates for a customized strategy in addressing the discerned risk factors, especially for cities presenting elevated risk levels.

10.
Water Res ; 256: 121600, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38640563

RESUMEN

A limited understanding of microbial interactions and community assembly mechanisms in constructed wetlands (CWs), particularly with different substrates, has hampered the establishment of ecological connections between micro-level interactions and macro-level wetland performance. In this study, CWs with distinct substrates (zeolite, CW_A; manganese ore, CW_B) were constructed to investigate the nutrient removal efficiency, microbial interactions, metabolic mechanisms, and ecological assembly for treating rural sewage with a low carbon-to-nitrogen ratio. CW_B showed higher removal of ammonia nitrogen and total nitrogen by about 1.75-6.75 % and 3.42-5.18 %, respectively, compared to CW_A. Candidatus_Competibacter (denitrifying glycogen-accumulating bacteria) was the dominant microbial genus in CW_A, whereas unclassified_f_Blastocatellaceae (involved in carbon and nitrogen transformation) dominated in CW_B. The null model revealed that stochastic processes (drift) dominated community assembly in both CWs; however, deterministic selection accounted for a higher proportion in CW_B. Compared to those in CW_A, the interactions between microbes in CW_B were more complex, with more key microbes involved in carbon, nitrogen, and phosphorus conversion; the synergistic cooperation of functional bacteria facilitated simultaneous nitrification-denitrification. Manganese ores favour biofilm formation, increase the activity of the electron transport system, and enhance ammonia oxidation and nitrate reduction. These results elucidated the ecological patterns exhibited by microbes under different substrate conditions thereby contributing to our understanding of how substrates shape distinct microcosms in CW systems. This study provides valuable insights for guiding the future construction and management of CWs.


Asunto(s)
Carbono , Nitrógeno , Eliminación de Residuos Líquidos , Aguas Residuales , Humedales , Nitrógeno/metabolismo , Carbono/metabolismo , Eliminación de Residuos Líquidos/métodos , Bacterias/metabolismo
11.
Sci Total Environ ; 929: 172651, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38653406

RESUMEN

The widespread use of microplastics (MPs) has led to an increase in their discharge to wastewater treatment plants. However, the knowledge of impact of MPs on macro-performance and micro-ecology in simultaneous nitrification, denitrification, and phosphorus removal (SNDPR) systems is limited, hampering the understanding of potential risks posed by MPs. This study firstly comprehensively investigated the performance, species interactions, and community assembly under polystyrene (PS) and polyvinyl chloride (PVC) exposure in SNDPR systems. The results showed under PS (1, 10 mg/L) and PVC (1, 10 mg/L) exposure, total nitrogen removal was reduced by 3.38-10.15 %. PS and PVC restrained the specific rates of nitrite and nitrate reduction (SNIRR, SNRR), as well as the activities of nitrite and nitrate reductase enzymes (NIR, NR). The specific ammonia oxidation rate (SAOR) and activity of ammonia oxidase enzyme (AMO) were reduced only at 10 mg/L PVC. PS and PVC enhanced the size of co-occurrence networks, niche breadth, and number of key species while decreasing microbial cooperation by 5.85-13.48 %. Heterogeneous selection dominated microbial community assembly, and PS and PVC strengthened the contribution of stochastic processes. PICRUSt prediction further revealed some important pathways were blocked by PS and PVC. Together, the reduced TN removal under PS and PVC exposure can be attributed to the inhibition of SAOR, SNRR, and SNIRR, the restrained activities of NIR, NR, and AMO, the changes in species interactions and community assembly mechanisms, and the suppression of some essential metabolic pathways. This paper offers a new perspective on comprehending the effects of MPs on SNDPR systems.


Asunto(s)
Desnitrificación , Microplásticos , Nitrificación , Fósforo , Eliminación de Residuos Líquidos , Contaminantes Químicos del Agua , Fósforo/metabolismo , Contaminantes Químicos del Agua/metabolismo , Contaminantes Químicos del Agua/análisis , Eliminación de Residuos Líquidos/métodos , Aguas Residuales , Microbiota
12.
Bioresour Technol ; 399: 130643, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38552855

RESUMEN

This study proposed an efficient framework for optimizing the design and operation of combined systems of wastewater treatment plants (WWTP) and constructed wetlands (CW). The framework coupled a WWTP model with a CW model and used a multi-objective evolutionary algorithm to identify trade-offs between energy consumption, effluent quality, and construction cost. Compared to traditional design and management approaches, the framework achieved a 27 % reduction in WWTP energy consumption or a 44 % reduction in CW cost while meeting strict effluent discharge limits for Chinese WWTP. The framework also identified feasible decision variable ranges and demonstrated the impact of different optimization strategies on system performance. Furthermore, the contributions of WWTP and CW in pollutant degradation were analyzed. Overall, the proposed framework offers a highly efficient and cost-effective solution for optimizing the design and operation of a combined WWTP and CW system.


Asunto(s)
Eliminación de Residuos Líquidos , Purificación del Agua , Humedales , Aguas Residuales , Aprendizaje Automático
13.
Bioresour Technol ; 396: 130383, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38316227

RESUMEN

The addition of biochar resulted in a 31.5 % to 44.6 % increase in decolorization efficiency and favorable decolorization stability. Biochar promoted extracellular polymeric substances (EPS) secretion, especially humic-like and fulvic-like substances. Additionally, biochar enhanced the electron transfer capacity of anaerobic sludge and facilitated surface attachment of microbial cells. 16S rRNA gene sequencing analysis indicated that biochar reduced microbial species diversity, enriching fermentative bacteria such as Trichococcus. Finally, a machine learning model was employed to establish a predictive model for biochar characteristics and decolorization efficiency. Biochar electrical conductivity, H/C ratio, and O/C ratio had the most significant impact on RR2 anaerobic decolorization efficiency. According to the results, the possible mechanism of RR2 anaerobic decolorization enhanced by different types of biochar was proposed.


Asunto(s)
Compuestos Azo , Carbón Orgánico , Colorantes , Compuestos Azo/metabolismo , Colorantes/metabolismo , Anaerobiosis , ARN Ribosómico 16S/genética , Aguas del Alcantarillado
14.
ChemSusChem ; 17(7): e202301170, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38062976

RESUMEN

Due to the drastic required thermodynamical requirements, a photoelectrode material that can function as both a photocathode and a photoanode remains elusive. In this work, we demonstrate for the first time that, under simulated solar light and without co-catalysts, donor-acceptor conjugated acetylenic polymers (CAPs) exhibit both impressive oxygen evolution (OER) and hydrogen evolution (HER) photocurrents in alkaline and neutral medium, respectively. In particular, poly(2,4,6-tris(4-ethynylphenyl)-1,3,5-triazine) (pTET) provides a benchmark OER photocurrent density of ~200 µA cm-2 at 1.23 V vs. reversible hydrogen electrode (RHE) at pH 13 and a remarkable HER photocurrent density of ~190 µA cm-2 at 0.3 V vs. RHE at pH 6.8. By combining theoretical investigations and electrochemical-operando Resonance Raman spectroscopy, we show that the OER proceeds with two different mechanisms, with the electron-depleted triple bonds acting as single-site OER in combination with the C4-C5 atoms of the phenyl rings as dual sites. The HER, instead, occurs via an electron transfer from the tri-acetylenic linkages to the triazine rings, which act as the HER active sites. This work represents a novel application of organic-based materials and contributes to the development of high-performance photoelectrochemical catalysts for the solar fuels' generation.

15.
Chem Asian J ; 18(23): e202300876, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37886875

RESUMEN

The potential of harnessing osmotic energy from the interaction between seawater and river water has been recognized as a promising, eco-friendly, renewable, and sustainable source of power. The reverse electrodialysis (RED) technology has gained significant interest for its ability to generate electricity by combining concentrated and diluted streams with different levels of salinity. Nanofluidic membranes with tailored ion transport dynamics enable efficient harvesting of renewable osmotic energy. In this regard, anodic aluminum oxide (AAO) membranes with abundant nanochannels provide a cost-effective nanofluidic platform to obtain structures with a high density of ordered pores. AAO can be utilized in constructing asymmetric composite membranes with enhanced ion flux and selectivity to improve output power generation. In this review, we first present the fundamental structure and properties of AAO, followed by summarizing the fabrication techniques for asymmetric membranes using AAO and other nanostructured materials. Subsequently, we discuss the materials employed in constructing asymmetric structures incorporating AAO while emphasizing how material selection and design can resist and promote efficient energy conversion. Finally, we provide an outlook on future applications and address the challenges that need to be overcome for successful osmotic energy conversion.

16.
J Hazard Mater ; 458: 131971, 2023 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-37413798

RESUMEN

Microplastics (MPs) are a significant component of global pollution and cause widespread concern, particularly in wastewater treatment plants. While understanding the impact of MPs on nutrient removal and potential metabolism in biofilm systems is limited. This work investigated the impact of polystyrene (PS) and polyethylene terephthalate (PET) on the performance of biofilm systems. The results revealed that at concentrations of 100 and 1000 µg/L, both PS and PET had almost no effect on the removal of ammonia nitrogen, phosphorus, and chemical oxygen demand, but reduced the removal of total nitrogen by 7.40-16.6%. PS and PET caused cell and membrane damage, as evidenced by increases in reactive oxygen species and lactate dehydrogenase to 136-355% and 144-207% of the control group. Besides, metagenomic analysis demonstrated both PS and PET changed the microbial structure and caused functional differences. Some important genes in nitrite oxidation (e.g. nxrA), denitrification (e.g. narB, nirABD, norB, and nosZ), and electron production process (e.g. mqo, sdh, and mdh) were restrained, meanwhile, species contribution to nitrogen-conversion genes was altered, therefore disturbing nitrogen-conversion metabolism. This work contributes to evaluating the potential risks of biofilm systems exposed to PS and PET, maintaining high nitrogen removal and system stability.


Asunto(s)
Desnitrificación , Microbiota , Aguas Residuales , Microplásticos , Plásticos , Nitrógeno/metabolismo , Reactores Biológicos , Biopelículas , Poliestirenos
17.
Sci Total Environ ; 893: 164997, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37336410

RESUMEN

Sulfate-reducing ammonium oxidation (sulfammox), a novel and promising process that has emerged in recent years, is essential to nitrogen and sulfur cycles and offers significant potential for the elimination of ammonium and sulfate. This review discussed the development of sulfammox process, the mechanism, characteristics of microbes, potential influencing factors, applicable bioreactors, and proposed the research needs and future perspective. The sulfammox process could be affected by many factors, such as the NH4+/SO42- ratio, carbon source, pH, and temperature. However, these potential influencing factors were only obtained based on what has been seen in papers studying related processes such as denitrification, sulfate-reduction, etc., and have to be further tested in bioreactors carrying out the sulfammox process in the future. Currently, sulfammox is predominantly used in granular activated carbon anaerobic fluidized beds, up-flow anaerobic sludge blanket reactors, anaerobic expanded granular bed reactors, rotating biological contact reactors, and moving bed biofilm reactors. In the future, the operating parameters of sulfammox should be further optimized to improve the processing performance, and the system can be further scaled up for actual wastewater treatment. In addition, the isolation, identification, and characterization of key functional microbes and the analysis of microbial interrelationships will also be focused on in future studies to enable an in-depth analysis of the sulfammox mechanism.


Asunto(s)
Compuestos de Amonio , Nitrógeno , Sulfatos , Azufre , Anaerobiosis , Reactores Biológicos , Desnitrificación , Nitrógeno/análisis , Oxidación-Reducción , Aguas del Alcantarillado/química
18.
J Mater Chem B ; 11(22): 4890-4898, 2023 06 07.
Artículo en Inglés | MEDLINE | ID: mdl-37184107

RESUMEN

The accurate and timely detection of bacteria is critically important for human health as it helps to determine the original source of bacterial infections and prevent disease spread. Herein, gold nanoparticles (AuNPs) were synthesized using polyoxometalates (POMs) as the stabilizing agent. Since AuNPs have glucose oxidase (GOx)-like activity and POMs possess peroxidase (HRP)-like activity, the as-prepared Au@POM nanoparticles have double enzyme-like activities and facilitate cascade reaction. As known, glucose is required as an energy resource during bacterial metabolism, the concentration of glucose decreases with the increase of bacteria content in a system with bacteria and glucose. Therefore, when we use Au@POM nanozymes to trigger the cascade catalysis of glucose and 3,3',5,5'-tetramethylbenzidine (TMB), the concentration of glucose and bacteria can be sensitively detected using the absorbance intensity at 652 nm in the visible spectrum. As demonstration, S. aureus and E. coli were used as model bacteria. The experimental results show that the present method has a good linear relationship in the bacterial concentration range of 1 to 7.5 × 107 colony-forming units (CFU) mL-1 with a detection limit of 5 CFU mL-1. This study shows a great promise of nanozyme cascade reactions in the construction of biosensors and clinical detections.


Asunto(s)
Oro , Nanopartículas del Metal , Humanos , Escherichia coli , Staphylococcus aureus , Glucosa , Catálisis
19.
J Hazard Mater ; 452: 131341, 2023 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-37023576

RESUMEN

In recent years, microplastics/nanoplastics (MPs/NPs) have received substantial attention worldwide owing to their wide applications, persistence, and potential risks. Wetland systems are considered to be an important "sink" for MPs/NPs, which can have potential ecological and environmental effects on the ecosystem. This paper provides a comprehensive and systematic review of the sources and characteristics of MPs/NPs in wetland ecosystems, together with a detailed analysis of MP/NP removal and associated mechanisms in wetland systems. In addition, the eco-toxicological effects of MPs/NPs in wetland ecosystems, including plant, animal, and microbial responses, were reviewed with a focus on changes in the microbial community relevant to pollutant removal. The effects of MPs/NPs exposure on conventional pollutant removal by wetland systems and their greenhouse gas emissions are also discussed. Finally, current knowledge gaps and future recommendations are presented, including the ecological impact of exposure to various MPs/NPs on wetland ecosystems and the ecological risks of MPs/NPs associated with the migration of different contaminants and antibiotic resistance genes. This work will facilitate a better understanding of the sources, characteristics, and environmental and ecological impacts of MPs/NPs in wetland ecosystems, and provide a new perspective to promote development in this field.


Asunto(s)
Contaminantes Ambientales , Microbiota , Contaminantes Químicos del Agua , Animales , Ecosistema , Humedales , Plásticos , Microplásticos
20.
Environ Sci Technol ; 57(8): 3031-3041, 2023 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-36790312

RESUMEN

Tenebrio molitor and Tenebrio obscurus (Coleoptera: Tenebrionidae) larvae are two commercial insects that eat plant and crop residues as diets and also biodegrade synthetic plastics polyethylene (PE). We examined biodegradation of low-density PE (LDPE) foam (Mn = 28.9 kDa and Mw = 342.0 kDa) with and without respective co-diets, i.e., wheat brain (WB) or corn flour (CF), corn straw (CS), and rice straw (RS) at 4:1 (w/w), and their gut microbiome and genetic metabolic functional groups at 27.0 ± 0.5 °C after 28 days of incubation. The presence of co-diets enhanced LDPE consumption in both larvae and broad-depolymerized the ingested LDPE. The diet type shaped gut microbial diversity, potential pathways, and metabolic functions. The sequence of effectiveness of co-diets was WB or CF > CS > RS for larval development and LDPE degradation. Co-occurrence networks indicated that the larvae co-fed with LDPE displayed more complex correlations of gut microbiome than the larvae fed with single diets. The primary diet of WB or CF and crop residues CS and RS provided energy and nitrogen source to significantly enhance LDPE biodegradation with synergistic activities of the gut microbiota. For the larvae fed LDPE and LDPE plus co-diets, nitrogen fixation function was stimulated compared to normal diets and associated with LDPE biodegradation.


Asunto(s)
Escarabajos , Microbioma Gastrointestinal , Tenebrio , Animales , Larva/metabolismo , Tenebrio/metabolismo , Polietileno , Poliestirenos , Carbono/metabolismo , Escarabajos/metabolismo , Dieta
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