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1.
Int J Mol Sci ; 24(19)2023 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-37834414

RESUMO

It is meaningful to understand the conversion pathways of nitrogen during the hydrothermal liquefaction process of microalgae to reveal the related reaction mechanisms and develop effective methods to prevent N from ending in biocrude, which eventually increases the quality of biocrude. Extending from our previous works that mainly focused on two high-protein (>50 wt%) microalgae (Chlorella sp. and Spirulina sp.), Nannochloropsis sp., which has a high lipid content (>70 wt%), was used as the feedstock for this project using the same methodology. The high lipid content in Na. induced less nitrogen during the oil phase and as a result, reduced the heteroatom content while also improving the quality of biocrude. It is worth noting that another investigation was conducted on the model compounds with different types of amino acids to specify the effects of the types of amino acids in the proteins in microalgae on the N pathway and their distribution in the products (aqueous phase, oil, solid, and gas). It was found that the basic amino acid in microalgae caused the formation of more N-heterocyclic compounds in the biocrude. The mass flow based on the mass balance was demonstrated to further refine the map showing the predicted reaction pathway of nitrogen from the previous version.


Assuntos
Chlorella , Microalgas , Temperatura , Aminoácidos , Microalgas/química , Nitrogênio , Água , Lipídeos , Biocombustíveis , Biomassa
2.
Chem Eng J ; 420: 127633, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-33173406

RESUMO

Applying silver into coatings has become a prevalent method in fabricating antimicrobial surfaces. However, the concerns about durability always exist and limit its applications. Here, a highly inhibitory, active, durable, and easy-to-use silver ions-nanosilver antimicrobial additive for powder coatings was fabricated in this study. Silver nanoparticles were chemically bonded to the Ag, Cu, and Zn-ternary ion-exchanged zeolite by α -lipoic acid, which was then encapsulated by hydrophilic polymers. The fabricated silver ions and silver nanoparticles (Ag+-AgNPs) complementary structure provides a synergistic effect. Ag+ is the main antimicrobial agent, while AgNPs act as a supplementary reservoir of Ag+. As well, the formed thin layer of silver nanoparticles and hydrophilic film prolongs the release of active Ag+ from zeolite, and Ag+ facilitates the activation of AgNPs. The results show that this additive indicates excellent antimicrobial activity to E. coli, S. aureus, P. aeruginosa, and C. albicans, and that the coatings with the additive exhibit over 99.99% reduction rate for the tested bacteria and fungi. The coating film is able to maintain over 99% antimicrobial reduction even after 1200 repeated solution wipings, or over 30 wash cycles of artificial sweat solution, indicating high durability. Furthermore, the yellowness of the coating is not evident (Δb < 2) despite the high loading of silver, and the silver nanoparticles have little impact on gloss, haze, and distinctness of the coating film image.

3.
J Environ Manage ; 299: 113604, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34523539

RESUMO

Emerging technologies for wastewater treatment face an uphill battle to be adopted in practice because no large-scale costing data exists to prove their cost competitiveness. Similar technologies and their costing data offer some insight to the approximate cost, but more detailed estimates are required for a final decision on process selection. The circulating fluidized bed bioreactor (CFBBR) is one such technology, proven at the lab and pilot and scale, but is yet to be used on a large scale. In order to demonstrate the potential economic competitiveness of the CFBBR, a method of modifying the CapdetWorks costing software by first modeling the CFBBR in the GPS-X process simulation software was employed. The modelling was used to determine the necessary changes to a moving bed bioreactor (MBBR) process (media size, density, surface area, and bed fill fraction) in CapdetWorks to simulate the CFBBR and then generate costing estimates for both capital cost (CapEx) and operation and maintenance cost (OpEx). Benchmarking the cost estimates against simulations of conventional suspended and attached growth processes and external costing data from the US EPA was performed to both validate the costing method and analyze the CFBBR's economic competitiveness. The calculation of the net present value from the CapEx and OpEx showed that the CFBBR is predicted to have 10%-30% lower costs at low flows of 1.5 and 4.6 MGD and comparative costs to conventional processes at higher flows from 10 to 30 MGD. Furthermore, the smaller land footprint of the CFBBR-based plants and lower landfilled biosolids implies that the CFBBR's environmental footprint is superior to its competitors and offers advantages for both small-sized plants and large urban plants.


Assuntos
Reatores Biológicos , Purificação da Água , Biofilmes , Nutrientes , Eliminação de Resíduos Líquidos , Águas Residuárias
4.
Drug Discov Today ; 29(8): 104065, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38901669

RESUMO

While heparin has traditionally served as a key anticoagulant in clinical practice for nearly a century, recent years have witnessed a growing interest in its role as a potent antiinflammatory and antiviral agent, as well as an anticancer agent. To address challenges with injection-based delivery, exploring patient-friendly routes such as oral and pulmonary delivery is crucial. This review specifically highlights the multiple therapeutic benefits of inhaled heparin. In summary, this review serves as a valuable source of information, providing deep insights into the diverse therapeutic advantages of inhaled heparin and its potential applications within clinical contexts.

5.
Elife ; 122024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38488837

RESUMO

Hepatic ischemia/reperfusion injury (HIRI) is a common and inevitable factor leading to poor prognosis in various liver diseases, making the outcomes of current treatments in clinic unsatisfactory. Metformin has been demonstrated to be beneficial to alleviate HIRI in recent studies, however, the underpinning mechanism remains unclear. In this study, we found metformin mitigates HIRI-induced ferroptosis through reshaped gut microbiota in mice, which was confirmed by the results of fecal microbiota transplantation treatment but showed the elimination of the beneficial effects when gut bacteria were depleted using antibiotics. Detailedly, through 16S rRNA and metagenomic sequencing, we identified that the metformin-reshaped microbiota was characterized by the increase of gamma-aminobutyric acid (GABA) producing bacteria. This increase was further confirmed by the elevation of GABA synthesis key enzymes, glutamic acid decarboxylase and putrescine aminotransferase, in gut microbes of metformin-treated mice and healthy volunteers. Furthermore, the benefit of GABA against HIRI-induced ferroptosis was demonstrated in GABA-treated mice. Collectively, our data indicate that metformin can mitigate HIRI-induced ferroptosis by reshaped gut microbiota, with GABA identified as a key metabolite.


Assuntos
Ferroptose , Microbioma Gastrointestinal , Metformina , Traumatismo por Reperfusão , Humanos , Camundongos , Animais , Metformina/farmacologia , RNA Ribossômico 16S , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/metabolismo , Isquemia , Ácido gama-Aminobutírico/farmacologia
6.
Int J Pharm ; 642: 123116, 2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37302669

RESUMO

As inhaler design is rarely studied but critically important in pulmonary drug delivery, this study investigated the influence of inhaler designs, including a novel spiral channel, mouthpiece dimensions (diameter and length) as well as gas inlet. Experimental dispersion of a carrier-based formulation in conjugation with computational fluid dynamics (CFD) analysis, was performed to determine how the designs affect inhaler performance. Results reveal that inhalers with a narrow spiral channel could effectively increase drug-carrier detachment by introducing high velocity and strong turbulent flow in the mouthpiece, although the drug retention in the device is significantly high. It is also found that reducing mouthpiece diameter and gas inlet size could greatly improve the fine particle dose delivered to the lungs, whereas the mouthpiece length plays a trivial influence on the aerosolization performance. This study contributes toward a better understanding of inhaler designs as relevant to overall inhaler performance, and sheds light on how the designs affect device performance.


Assuntos
Baías , Inaladores de Pó Seco , Aerossóis , Sistemas de Liberação de Medicamentos , Portadores de Fármacos , Tamanho da Partícula , Desenho de Equipamento , Administração por Inalação , Pós , Hidrodinâmica
7.
Chirality ; 24(2): 119-28, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22173987

RESUMO

The chiral discrimination mechanism in the resolution of sertraline with mandelic acid was investigated by examining the weak intermolecular interactions (such as hydrogen bond, CH/π, and van der Waals interactions) and molecular packing difference in crystal structures of the resulting diastereomeric salts. A new one-dimensional chain-like hydrogen-bonding network and unique supramolecular packing mode are disclosed. The investigation demonstrated that stable hydrogen-bonding pattern, herringbone-like arrangement of aromatic rings, and planar boundary surface in the hydrophobic region are the three most important structural characteristics expected in less soluble diastereomeric salts. The existence and magnitude of hydrogen bond, CH/π interaction, and van der Waals interaction related to three characteristic structures, determine the stability of diastereomeric salt. The hydrogen bond is not necessarily the dominant factor while the synergy and optimization of all weak intermolecular interactions attribute to the chiral recognition.


Assuntos
Ácidos Mandélicos/química , Sertralina/química , Cristalografia por Raios X , Ligação de Hidrogênio , Modelos Moleculares , Sais/química , Solubilidade , Estereoisomerismo
8.
Environ Technol ; 33(4-6): 455-65, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22629617

RESUMO

A respirometric approach has been developed to determine heterotrophic biofilm kinetics using fluidized bioparticles--particles with attached biomass. Lava rock particles of 600 microm were used as a biomass carrier medium. The modified respirometer successfully estimates in situ biofilm kinetics of the bioparticles collected from a pilot-scale liquid-solid circulating fluidized bed (LSCFB) bioreactor. The observed maximum specific growth rates (micro(max)) of 3.69 +/- 0.44 d(-1) and biomass yields (Y(H)) of 0.36 +/- 0.03 g COD/g COD in the fluidized bed respirometers were significantly different from the micro(max) of 5.57-5.72 d(-1) and Y(H) of 0.54-0.59 g COD/g COD observed in the conventional respirometric tests for bioparticles and detached biomass. The higher Monod half-saturation coefficient (K(S)) of 186-219mg COD/L observed in the fluidized bed respirometers relative to the 49-58 mg COD/L in the conventional respirometers reveals the presence of mass transfer resistance in the LSCFB despite fluidization. Significantly reduced yields in the fluidized bed respirometers and the estimated maintenance coefficient of 1.16 d(-1) for the particulate biofilm in the LSCFB clearly emphasize that a substantial amount of substrate was utilized for cell maintenance at the low food to microorganism (S/X) ratio of 0.5 g COD/g VSS.


Assuntos
Fenômenos Fisiológicos Bacterianos , Biofilmes/crescimento & desenvolvimento , Reatores Biológicos/microbiologia , Consumo de Oxigênio/fisiologia , Oxigênio/análise , Desenho de Equipamento , Análise de Falha de Equipamento , Cinética
9.
Int J Pharm ; 614: 121457, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35026316

RESUMO

Dry powder inhalation therapy has been shown to be an effective method for treating respiratory diseases like asthma, Chronic Obstructive Pulmonary Diseases and Cystic Fibrosis. It has also been widely accepted and used in clinical practices. Such success has led to great interest in inhaled therapy on treating systemic diseases in the past two decades. The current coronavirus (COVID-19) pandemic also has increased such interest and is triggering more potential applications of dry powder inhalation therapy in vaccines and antivirus drugs. Would the inhaled dry powder therapy on systemic disorders be as encouraging as expected? This paper reviews the marketed and in-development dry powder inhaler (DPI) products on the treatment of systemic diseases, their status in clinical trials, as well as the potential for COVID-19 treatment. The advancements and unmet problems on DPI systems are also summarized. With countless attempts behind and more challenges ahead, it is believed that the dry powder inhaled therapy for the treatment of systemic disorders still holds great potential and promise.


Assuntos
Tratamento Farmacológico da COVID-19 , Administração por Inalação , Inaladores de Pó Seco , Humanos , Pós , SARS-CoV-2
10.
Int J Pharm ; 627: 122230, 2022 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-36162608

RESUMO

The grid structure is an indispensable part of most dry powder inhalers, but the effects of grid geometry on inhaler performance are rarely reported. This study aims to systemically investigate the influence of grid design on the aerosolization performance of capsule-based inhalers through experiments and computational analysis. In-vitro aerosolization and deposition performance of commercial and 3D-printed customized inhalers with different grid mesh designs were experimentally studied using a Next Generation Impactor (NGI). Flow fields in the inhalers were generated, and average turbulence kinetic energy (TKE) and airstream trajectories were obtained through Computational Fluid Dynamics (CFD) analysis, delineating the effects of the different grid designs. Comparative studies using the commercial inhalers and the 3D-printed inhalers show a slightly better performance for the latter, probably due to the different materials used for the inhalers, confirming the suitability of 3D printing. Experimental results show that intensive grid meshes with a relatively small aperture size are beneficial to enhancing inhaler performance. Computational results illustrate that the intensive grid meshes can reduce vortexed airstreams and increase turbulent kinetic energy at the grids in general, which also supports the experimental results. In summary, inhalers with intensive grid meshes are preferred for capsule-based inhalers to enhance aerosolization performance. These findings have significant implications for the comprehensive understanding of how grid designs influence inhaler performance.


Assuntos
Inaladores de Pó Seco , Hidrodinâmica , Desenho de Equipamento , Impressão Tridimensional , Aerossóis , Administração por Inalação , Tamanho da Partícula , Pós
11.
Environ Technol ; 43(23): 3507-3518, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33908820

RESUMO

The performance and energy consumption of a gas-liquid-solid inverse fluidised bed bioreactor (GLS-IFBBR) using polyethylene (PE) particles with different surface coatings (zeolite, lava rock, activated carbon and multi-plastic) as media for synthetic wastewater treatment were investigated at loading rates of 1.64-3.38 kg COD/(m3·d) and 0.17-0.34 kg N/(m3·d) to determine the optimum carrier media. The results showed that PE coated with other inorganic materials could increase the nutrient removal efficiency at the same influent conditions. Compared with other media, PE coated with zeolite (PEZ) was the optimal carrier particles in this study as reflected by the highest COD and nitrogen removal, stable effluent, low biomass yield at different hydraulic retention times (HRT). In addition, the energy consumption of lavarock-coated PE (PEL) with a highest density was the lowest.


Assuntos
Purificação da Água , Zeolitas , Reatores Biológicos , Nitrogênio , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos
12.
ACS Appl Mater Interfaces ; 13(1): 1323-1332, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33382573

RESUMO

Superhydrophobicity originating from the "lotus effect" enables novel applications such as self-cleaning, anti-fouling, anti-icing, anti-corrosion, and oil-water separation. However, their real-world applications are hindered by some main shortcomings, especially the organic solvent problem, complex chemical modification of nanoparticles, and poor mechanical stability of obtained surfaces. Here, we report for the first time the solvent-free, chemical modification-free, and mechanically, chemically, and UV robust superhydrophobic powder coatings. The coatings were fabricated by adding commercially available polytetrafluoroethylene (PTFE) particles into powder coatings and by following the regular powder-coating processing route. The formation of such superhydrophobic surfaces was attributed to PTFE particles, which hindered the microscale leveling of powder coatings during curing. Through adjusting the dosage of PTFE, the hydrophobicity of obtained coatings can be tuned in a large range (water contact angle from 92 to 162°). The superhydrophobic coatings exhibited remarkable mechanical robustness against abrasion because of the unique hierarchical micro/nanoscale roughness and low surface energy throughout the coating and the solid lubrication effect of PTFE particles. The coatings also have robustness against chemical corrosion and UV irradiation owing to high bonding energy and chemical inertness of PTFE. Moreover, the coatings show attractive performances including self-cleaning, anti-rain, anti-snow, and anti-icing. With these multifaceted features, such superhydrophobic coatings are promising for outdoor applications. This study also contributes to the preparation of robust superhydrophobic surfaces in an environmentally friendly way.

13.
Sci Total Environ ; 750: 141665, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33182169

RESUMO

Reusing microplastics and zeolite waste as free ammonia (FA)-mitigating carrier particle was proven a value-added step towards promoting the serviceability of fluidized bed bioreactor (FBBR) in treating wastewater with a low carbon to nitrogen ratio (i.e. C/N <3.0) in this study. Ammonia (NH4+) adsorption property capacitates zeolite as an FA mitigator. The microplastics and reused zeolite were processed into reused-zeolite/microplastic composite particle (RZ), whose merit of FA mitigation was fully developed via an optimally thermal modification to process modified-zeolite/microplastic particle (MZ). The 171-day biological nutrient removal (BNR) performance in a single integrated fluidized bed bioreactor (SIFBBR) shows that the bioreactor with MZ particle (SIFBBR-MZ) achieved nitrogen removal efficiency 10.0% higher than the bioreactor with RZ particle (SIFBBR-RZ) over the enhanced short-cut nitrification and denitrification. Analysis of microbial community structure unveils that the long-term lower FA inhibition favored more significant ammonia-oxidizing bacteria (AOB) enrichment and acclimated specific MZ biofilm predominant by nitrite (NO2-) denitrifier, contributing to the outperformance in nitrogen removal. Apart from fluidization energy conservation, the techno-economic analysis confirms that using MZ as an FA-mitigating carrier could be of great benefit for FBBR system: realizing waste utilization, reducing carbon addition and alleviating sludge treatment.


Assuntos
Nitrogênio , Águas Residuárias , Amônia , Reatores Biológicos , Carbono , Desnitrificação , Nitrificação , Plásticos , Eliminação de Resíduos Líquidos
14.
Environ Technol ; 42(12): 1911-1921, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-31631798

RESUMO

To meet the increasing wastewater treatment demand while minimizing the land footprint of the treatment systems and plants, more efficient and compact processes are needed. The circulating fluidized bed bioreactor (CFBBR) has been proven to achieve high levels of biological nutrient removal. Past studies at the lab and pilot scale achieved 94% COD removal and 80% nitrogen removal at HRT's of 2-4 h. A collaborative project between Western University and the Guangzhou Institute of Energy Conversion (GIEC), in Guangzhou, China, further explored the treatment of municipal wastewater with the CFBBR. A pilot CFBBR, with aerobic and anoxic columns for nitrification and denitrification, was constructed at the GIEC for in-situ treatment of septic tank effluent from a residential building. Due to high concentrations of ammonia (NH4-N), the wastewater had a COD/N ratio of 2-3. Thus, operating at a longer HRT and supplementing COD, in the form of glucose, was necessary to achieve a high nitrogen removal efficiency. The system was run both with and without supplemental COD at HRT's between 16 and 21 h, treating approximately 1000-1270 L/d. Overall, a COD removal efficiency of at least 92%, ammonia removal of 97%, and nitrogen removal of 82% was achieved. The CFBBR system achieved an effluent with BOD and NH4-N concentrations both below 5 mg/L, a NO3-N concentration below 15 mg/L, and a total nitrogen concentration below 25 mg/L. The compact design of this pilot-CFBBR, coupled with its high BNR performance make it an excellent option for decentralized treatment of urban wastewaters.


Assuntos
Eliminação de Resíduos Líquidos , Purificação da Água , Reatores Biológicos , China , Humanos , Nitrogênio , Projetos Piloto , Águas Residuárias
15.
Chirality ; 22(8): 707-16, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20143411

RESUMO

The crystal structures of diastereomeric salts of chloromandelic acid and phenylethylamine were determined and are presented herein. The structure comparison between less soluble salts and more soluble salts shows that weak interactions such as CH/pi interactions and van der Waals gain importance and contribute to chiral recognition when the hydrogen bonding patterns are very similar.


Assuntos
Cloro/química , Ácidos Mandélicos/química , Fenetilaminas/química , Sais/química , Cristalografia por Raios X , Modelos Moleculares , Conformação Molecular , Solubilidade , Estereoisomerismo
16.
Water Environ Res ; 82(9): 772-81, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20942332

RESUMO

A pilot-scale liquid-solid circulating fluidized bed (LSCFB) bioreactor was developed at the Adelaide Pollution Control Plant, London, Ontario, Canada, to study its commercial viability for biological nutrient removal. Lava rock particles of 600 microm were used as a biomass carrier media. The LSCFB removed approximately 90% organic, 80% nitrogen, and 70% phosphorus at loading rates of 4.12 kg COD/m3 x d, 0.26 kg N/m3 x d, and 0.052 kg P/m3 x d, and an empty bed contact time of 1.5 hours. Effluent characterized by < 1.0 mg NH4-N/L, < 5.0 mg NO3-N/ L, < 1.0 mg PO4-P/L, < 10 mg TN/L, < 10 mg SBOD/L, and 10 to 15 mg volatile suspended solids (VSS)/L can easily meet the criteria for nonpotable reuse of treated wastewater. The system removed nutrients without using any chemicals, and the secondary clarifier removed suspended solids removal without chemicals. A significant reduction (approximately 75%) in biomass yield to 0.12 to 0.16 g VSS/g chemical oxygen demand (COD) was observed, primarily because of long biological solids retention time (SRT) of 20 to 39 days and a combination of anoxic and aerobic COD consumption.


Assuntos
Biomassa , Reatores Biológicos , Nitrogênio/metabolismo , Fósforo/metabolismo , Eliminação de Resíduos Líquidos/métodos , Biodegradação Ambiental , Nitratos/química , Nitratos/metabolismo , Nitrogênio/química , Fósforo/química , Projetos Piloto , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/metabolismo , Poluentes Químicos da Água/química , Poluentes Químicos da Água/metabolismo , Purificação da Água/métodos
17.
Int J Pharm ; 583: 119359, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32334066

RESUMO

Mechanical ventilation may contribute to the impairment of the pulmonary surfactant system, which is one of the mechanisms leading to the progression of acute lung injury. To investigate the potential protective effects of pulmonary surfactant in a rat model of ventilator-induced lung injury, the surfactant powder was aerosolized using an in-house made device designed to deliver the aerosolized powder to the inspiratory line of a rodent ventilator circuit. Rats were randomized to (i) administration of aerosolized recombinant surfactant protein C based pulmonary surfactant, (ii) intratracheally instillation of the same surfactant re-constituted in saline, and (iii) no treatment. Animals were monitored during 2 h of high-tidal volume mechanical ventilation, after which rats were sacrificed, and further analysis of lung mechanics and surfactant function were completed. Blood gas measurements during ventilation showed extended maintenance of oxygen levels above 400 mmHg in aerosol treated animals over non-treated and instilled groups, while total protein analysis showed reduced levels in the aerosol compared to non-treated groups. Dynamic captive bubble surface tension measurements showed the activity of surfactant recovered from aerosol treated animals is maintained below 1 mN/m. The prophylactic treatment of aerosolized surfactant powder reduced the severity of lung injury in this model.


Assuntos
Peptídeos/administração & dosagem , Substâncias Protetoras/administração & dosagem , Surfactantes Pulmonares/administração & dosagem , Lesão Pulmonar Induzida por Ventilação Mecânica/tratamento farmacológico , Aerossóis , Animais , Modelos Animais de Doenças , Pulmão/efeitos dos fármacos , Pulmão/fisiopatologia , Masculino , Pós , Ratos Sprague-Dawley , Lesão Pulmonar Induzida por Ventilação Mecânica/fisiopatologia
18.
Sci Total Environ ; 718: 137288, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32087585

RESUMO

The performance of a lab-scale integrated anoxic and aerobic inverse fluidized bed bioreactors (IFBBR) for biological nutrient removal from synthetic municipal wastewater was studied at chemical oxygen demand (COD) loading rates of 0.34-2.10 kg COD/(m3-d) and nitrogen loading rates of 0.035-0.213 kg N/(m3-d). Total COD removal efficiencies of >84% were achieved, concomitantly with complete nitrification. The overall nitrogen removal efficiencies were >75%. Low biomass yields of 0.030-0.101 g VSS/g COD were achieved. Compared with other FBBR systems, the energy consumption for this IFBBR system was an average 59% less at organic loading rates (OLRs) of 1.02 and 2.10 kg COD/(m3-d). Bacterial community structures of attached and suspended biomass revealed that the dominant phyla were Proteobacteria, Bacteroidetes, and Epsilonbacteraeota, etc. The relative abundance of ammonia-oxidizing bacteria (AOBs) and nitrite-oxidizing bacteria (NOBs) in the aerobic attached biomass were 0.451% and 0.110%, respectively. COD mass balance in the anoxic zone was closed by consideration of sulfate reduction, which was confirmed by the presence of genus Chlorobium (sulfate-reducing bacteria) in the anoxic attached biofilm with a relative abundance of 0.32%.


Assuntos
Reatores Biológicos , Eliminação de Resíduos Líquidos , Análise da Demanda Biológica de Oxigênio , Nitrificação , Nitrogênio , Águas Residuárias
19.
Environ Technol ; 40(1): 94-101, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28911270

RESUMO

A lab-scale fluidized bed bioreactor with high-density polyethylene as biofilm carrier media was operated to study partial nitrification (PN) performance with high ammonia concentrations. The system was run at nitrogen loading rates (NLRs) from 1.2 to 4.8 kg N/(m3 d) with empty bed contact time of 2.0 and 2.7 h and four different influent ammonia concentrations of 100, 200, 300 and 400 mg/L. Dissolved oxygen concentration and temperature were maintained around 1.3 mg/L and 35°C, respectively. Stable PN was successfully achieved during the whole period with low effluent NO3-N concentration at less than 15 mg/L, due to effective suppression of nitrite-oxidizing bacteria activity at high concentrations of free ammonia (5.3-27.3 mg N/L) and low alkalinity-to-ammonia ratio. At the NLR of 3.6 kg N/(m3 d), NH4-N conversion and NO2-N accumulation ratios were 57.8% and 53.9%, respectively, which could be further used in the anaerobic ammonium oxidation process (ANAMMOX) as the effluent NO2-N/NH4-N ratio was 1.27.


Assuntos
Amônia , Nitrificação , Reatores Biológicos , Nitritos , Nitrogênio
20.
Int J Pharm ; 358(1-2): 16-22, 2008 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-18467045

RESUMO

Dry coating is a coating technology for solid pharmaceutical dosage forms derived from powder coating of metals. In this technology, powdered coating materials are directly coated onto solid dosage forms without using any solvent, and then heated and cured to form a coat. As a result, this technology can overcome such disadvantages caused by solvents in conventional liquid coating as serious air pollution, high time- and energy-consumption and expensive operation cost encountered by liquid coating. Several dry coating technologies, including plasticizer-dry-coating, electrostatic-dry-coating, heat-dry-coating and plasticizer-electrostatic-heat-dry-coating have been developed and extensively reported. This mini-review summarized the fundamental principles and coating processes of various dry coating technologies, and thoroughly analyzed their advantages and disadvantages as well as commercialization potentials.


Assuntos
Química Farmacêutica/métodos , Formas de Dosagem , Composição de Medicamentos , Excipientes , Tamanho da Partícula , Plastificantes
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