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1.
Nat Commun ; 12(1): 960, 2021 02 11.
Article in English | MEDLINE | ID: mdl-33574252

ABSTRACT

Nitric oxide (NO) is an important signaling molecule overexpressed in many diseases, thus the development of NO-activatable probes is of vital significance for monitoring related diseases. However, sensitive photoacoustic (PA) probes for detecting NO-associated complicated diseases (e.g., encephalitis), have yet to be developed. Herein, we report a NO-activated PA probe for in vivo detection of encephalitis by tuning the molecular geometry and energy transformation processes. A strong donor-acceptor structure with increased conjugation can be obtained after NO treatment, along with the active intramolecular motion, significantly boosting "turn-on" near-infrared PA property. The molecular probe exhibits high specificity and sensitivity towards NO over interfering reactive species. The probe is capable of detecting and differentiating encephalitis in different severities with high spatiotemporal resolution. This work will inspire more insights into the development of high-performing activatable PA probes for advanced diagnosis by making full use of intramolecular motion and energy transformation processes.


Subject(s)
Biosensing Techniques/methods , Encephalitis/diagnosis , Encephalitis/metabolism , Nitric Oxide/isolation & purification , Photoacoustic Techniques/methods , Animals , Biosensing Techniques/instrumentation , Disease Models, Animal , Encephalitis/pathology , Male , Mice , Molecular Imaging/methods , Molecular Probes/chemistry , Photoacoustic Techniques/instrumentation
2.
PLoS One ; 15(4): e0231286, 2020.
Article in English | MEDLINE | ID: mdl-32275735

ABSTRACT

The application of photocatalyst in pavements has received comprehensive attention in recent years due to its ability to decontaminate nitrogen oxides (NOx). However, it's remarkable that NOx also accumulated extensively in parking lots. The purpose of this study is to develop a movable photocatalytic plate (remarked photocatalytic KT plates) coupled with high activity to purify NOx. Firstly, the type of photocatalytic KT plates was determined according to NO removal experiment in laboratory. Then the plates were employed in the parking lots for removing NOx. One sample T-test, normality test and paired sample T-test methods for NOx concentration variation were conducted to determine the appropriate comparative means of dates under both dark and illuminated conditions. The difference of NOX concentration between dark and illuminated conditions was obtained to evaluate the photocatalytic removal efficiency. The results indicated that NO removal efficiency in laboratory and parking lots were 51.31% and 9.2%, respectively.


Subject(s)
Graphite/chemistry , Nitrogen Compounds/chemistry , Parking Facilities , Titanium/chemistry , Catalysis , Cities , Light , Nitric Oxide/isolation & purification
3.
Chem Rev ; 120(16): 8130-8160, 2020 08 26.
Article in English | MEDLINE | ID: mdl-32207607

ABSTRACT

Materials capable of the safe and efficient capture or degradation of toxic chemicals, including chemical warfare agents (CWAs) and toxic industrial chemicals (TICs), are critically important in the modern age due to continuous threats of these chemicals to human life, both directly and indirectly. Metal-organic frameworks (MOFs), atomically precise hybrid materials that are synthesized via the self-assembly of metal cations or clusters and organic linkers, offer a unique solid adsorbent design platform due to their great synthetic versatility. This review will focus on recent advancements in MOF-based adsorbent design for protection against chemical warfare agents (organophosphorus nerve agents, blistering agents, and their simulants) and toxic industrial chemicals such as H2S, NH3, SO2, CO, NO2, and NO.


Subject(s)
Metal-Organic Frameworks/chemistry , Protective Agents/chemistry , Adsorption , Ammonia/chemistry , Ammonia/isolation & purification , Carbon Monoxide/chemistry , Carbon Monoxide/isolation & purification , Chemical Warfare Agents/chemistry , Chemical Warfare Agents/isolation & purification , Hydrogen Sulfide/chemistry , Hydrogen Sulfide/isolation & purification , Metal-Organic Frameworks/chemical synthesis , Nitric Oxide/chemistry , Nitric Oxide/isolation & purification , Nitrogen Dioxide/chemistry , Nitrogen Dioxide/isolation & purification , Protective Agents/chemical synthesis , Sulfur Dioxide/chemistry , Sulfur Dioxide/isolation & purification
4.
Chemosphere ; 249: 126095, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32044608

ABSTRACT

A microbial electrolysis cell (MEC) has been developing for enhanced absorbent regeneration in a chemical absorption-biological reduction integrated process for NO removal. In this work, the kinetics of electron transfer involved in the biocathodes along Fe(III)EDTA and Fe(II)EDTA-NO reduction was analyzed simultaneously. A modified Nernst-Monod kinetics considering the Faraday efficiency was applied to describe the electron transfer kinetics of Fe(III)EDTA reduction. The effects of substrate concentration, biocathodic potential on current density predicted by the model have been validated by the experimental results. Furthermore, extended from the kinetics of Fe(III)EDTA reduction, the electron transfer kinetics of Fe(II)EDTA-NO reduction was developed with a semi-experimental method, while both direct electrochemical and bioelectrochemical processes were taken into consideration at the same time. It was revealed that the developed model could simulate the electron transfer kinetics well. This work could not only help advance the biocathodic reduction ability and the utilization efficiency of electric power, but also provide insights into the industrial scale-up and application of the system.


Subject(s)
Electrochemical Techniques , Electron Transport , Nitric Oxide/isolation & purification , Edetic Acid , Electrolysis , Electrons , Kinetics , Oxidation-Reduction
5.
Chemosphere ; 243: 125309, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31751925

ABSTRACT

In the present work, a serial of Cu0.02Fe0.2CeyTi1-yOx catalysts are prepared by sol-gel method and applied for NH3-SCR of NO, meanwhile Cu0.02Fe0.2Ce0.2Ti0.8Ox shows good low-temperature NH3-SCR performance with/without water and an outstanding water resistance. The bulk structure, redox ability, surface acidity and surface species of Cu0.02Fe0.2CeyTi1-yOx are measured and discussed by series of characterization in details to illuminate the reasons for the good low-temperature activity and water resistance. The Ce modification can tune the surface acidic distribution, improve the surface oxygen content and surface oxidation reduction cycle (Ce4+ + Fe2+ ↔ Ce3+ + Fe3+), which contribute the good activity. In addition, the effect of water on NH3-SCR performance over Cu0.02Fe0.2TiOx and Cu0.02Fe0·2Ce0·2Ti0.8Ox are investigated emphatically by in situ DRIFTS.


Subject(s)
Catalysis , Cerium/chemistry , Cold Temperature , Nitric Oxide/isolation & purification , Ammonia/chemistry , Cerium/pharmacology , Nitric Oxide/chemistry , Oxidation-Reduction , Titanium/chemistry , Water/chemistry
6.
Environ Sci Pollut Res Int ; 27(4): 4197-4205, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31828709

ABSTRACT

The micronano bubble water system (MNBW) generated by a micronano bubble generator (MNBG) has the superior oxidation properties and can improve gas solubility. In the study, a new wet recycling process based on MNBW is proposed to simultaneously remove nitric oxide (NO) and sulfur dioxide (SO2). The important experimental parameters such as initial water pH, initial water temperature, NO and SO2 concentrations, and the presence of oxygen (O2) were investigated to explore the feasibility of desulfurization and denitration with MNBW. The experimental results showed that decreasing initial water pH or increasing initial water temperature and NO and SO2 concentrations were not conducive to the removal of NO or SO2. O2 could promote the removal of NO, but it had no effect on SO2 removal. In addition, SO2 removal efficiency always remained high and did not change obviously during the experimental period. However, NO removal efficiency gradually decreased in the first 50 min and then became stable.


Subject(s)
Nanotechnology , Nitric Oxide/isolation & purification , Sulfur Dioxide/isolation & purification , Water Purification , Oxygen , Recycling , Water
7.
ACS Nano ; 13(8): 9332-9341, 2019 08 27.
Article in English | MEDLINE | ID: mdl-31369239

ABSTRACT

Weavable sensing fibers with superior mechanical strength and sensing functionality are crucial for the realization of wearable textile sensors. However, in the fabrication of previously reported wearable sensing fibers, additional processes such as reduction, doping, and coating were essential to satisfy both requirements. The sensing fibers should be continuously synthesized in a scalable process for commercial applications with high reliability and productivity, which was challenging. In this study, we first synthesize mass-producible wearable sensing fibers with good mechanical properties and sensing functionality without additional processes by incorporating carbon nanotubes (CNTs) into distinct nanocellulose. Nanocellulose extracted from tunicate (TCNF) is homogeneously composited with single-walled CNTs, and composite fibers (TCNF/CNT) are continuously produced in aligned directions by wet spinning, facilitating liquid-crystal properties. The TCNF/CNT fibers exhibit a superior gas (NO2)-sensing performance with high selectivity and sensitivity (parts-per-billion detection). In addition, the TCNF/CNT fibers can endure complex and harsh distortions maintaining their intrinsic sensing properties and can be perfectly integrated with conventional fabrics using a direct weaving process. Our meter-scale scalable synthesis of functional composite fibers is expected to provide a mass production platform of versatile wearable sensors.


Subject(s)
Biosensing Techniques , Cellulose/chemistry , Nanotubes, Carbon/chemistry , Wearable Electronic Devices , Animals , Humans , Nanofibers/chemistry , Nitric Oxide/chemistry , Nitric Oxide/isolation & purification , Textiles , Urochordata/chemistry
8.
Environ Sci Pollut Res Int ; 26(28): 28808-28816, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31377926

ABSTRACT

The effect of Mn powder addition on the simultaneous removal of SO2 and NO coupled with FeII(EDTA) absorption was investigated in this work. In the NO absorption system with FeII(EDTA), SO2 reduced FeII(EDTA)-NO to FeII(EDTA) with a reduction efficiency reaching 88.5% under the conditions of 4000 mg/m3 SO2, pH 8.0, 44 °C, and the flow rate of 1.2 L/min within 60 min. Introducing 0.1 M Mn powder with SO2 increased the FeII(EDTA)-NO reduction efficiency to 96.8% within 5 min. SO2 was also removed by reducing FeII(EDTA)-NO and converted into SO42- at a removal efficiency of 100%. After adding Mn powder, NO was removed through the following reaction: [Formula: see text]. Mn powder functioned as a reductant to regenerate the absorption of solution, and the coordinated NO in FeII(EDTA)-NO was reduced to NH4+. The resource utilization rate of N reached approximately 77.2%. The integrated technology is a potential solution for flue gas treatment in industrial sectors with coal-fired power plants and industrial boiler. Graphical abstract.


Subject(s)
Edetic Acid/chemistry , Ferrous Compounds/chemistry , Manganese/chemistry , Nitric Oxide/isolation & purification , Sulfur Dioxide/isolation & purification , Edetic Acid/analysis , Ferrous Compounds/analysis , Nitric Oxide/chemistry , Powders , Sulfur Dioxide/chemistry
9.
Biosens Bioelectron ; 143: 111606, 2019 Oct 15.
Article in English | MEDLINE | ID: mdl-31466049

ABSTRACT

A disposable gas-sensing paper-based device (gPAD) was fabricated in origami design which integrates the gas adsorbent and the electrochemical detection zone in a single device. The gPAD for the determination of NOx gas uses a screen-printed graphene electrode modified with copper nanoparticles (CuNP/SPGE) to achieve high sensitivity and selectivity. The gPAD detects both, NO and NO2 (as NOx) with same current responses. The measurement could be performed directly through differential pulse voltammetry (DPV) with a detection limit as low as 0.23 vppm and 0.03 vppm with exposure times of 25 min and 1 h, respectively. The reproducibility in terms of relative standard deviation was less than 5.1% (n = 7 devices) at 25, 75 and 125 vppm NO2 and the life-time of this device was more than 30 days. The gPAD was applied to detect NOx in air and exhaust gases from cars. In comparison with spectrophotometry, there are no significant differences between both methods using a paired t-test of the results on a 95% confidence level. The designed gPAD can provide a new template model for other gas sensors with features of disposability and portability for fieldwork analysis at low cost.


Subject(s)
Biosensing Techniques , Electrochemical Techniques , Nitric Oxide/isolation & purification , Nitrogen Dioxide/isolation & purification , Copper/chemistry , Graphite/chemistry , Humans , Metal Nanoparticles/chemistry , Nitric Oxide/chemistry , Nitrogen Dioxide/chemistry , Paper
10.
Environ Sci Pollut Res Int ; 26(16): 16195-16209, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30972683

ABSTRACT

CO2, SO2, and NO are the main components of flue gas and can cause serious environmental issues. Utilization of these compounds in oleaginous microalgae cultivation not only could reduce air pollution but could also produce feedstock for biodiesel production. However, the continuous input of SO2 and NO inhibits microalgal growth. In this study, the toxicity of simulated flue gas (15% CO2, 0.03% SO2, and 0.03% NO, balanced with N2) was reduced through automatic pH feedback control. Integrated lipid production and CO2 fixation with the removal of SO2 and NO was achieved. Using this technique, a lipid content of 38.0% DW was achieved in Chlorella pyrenoidosa XQ-20044. The lipid composition and fatty acid profile indicated that lipid production by C. pyrenoidosa XQ-20044 cultured with flue gas is suitable as a biodiesel feedstock; 81.2% of the total lipids were neutral lipids and 99.5% of the total fatty acids were C16 and C18. The ratio of saturated fatty acids to monounsaturated fatty acids in the microalgal lipid content was 74.5%. In addition, CO2, SO2, and NO from the simulated flue gas were fixed and converted to biomass and lipids with a removal efficiency of 95.9%, 100%, and 84.2%, respectively. Furthermore, the utilization efficiencies of CO2, SO2, and NO were equal to or very close to their removal efficiencies. These results provide a novel strategy for combining biodiesel production with biofixation of flue gas.


Subject(s)
Biotechnology/methods , Chlorella/drug effects , Chlorella/metabolism , Lipids/biosynthesis , Air Pollutants/chemistry , Air Pollutants/isolation & purification , Air Pollutants/toxicity , Biofuels , Biomass , Biotechnology/instrumentation , Carbon Dioxide/isolation & purification , Carbon Dioxide/toxicity , Chlorella/growth & development , Fatty Acids/analysis , Fatty Acids/metabolism , Hydrogen-Ion Concentration , Microalgae/drug effects , Microalgae/growth & development , Microalgae/metabolism , Nitric Oxide/isolation & purification , Nitric Oxide/toxicity , Sulfur Dioxide/isolation & purification , Sulfur Dioxide/toxicity
11.
Biosensors (Basel) ; 9(1)2019 Feb 27.
Article in English | MEDLINE | ID: mdl-30818887

ABSTRACT

Rheumatoid arthritis (RA) has been associated with a higher risk of developing cardiovascular (CV) diseases. It has been proposed that systemic inflammation plays a key role in premature atherosclerosis development, and is therefore crucial to determine whether systemic components from RA patients promotes endothelial cell-oxidative stress by affecting reactive oxygen species (ROS) and nitric-oxide (NO) production. The aim of this study was to evaluate whether plasma from RA patients impair NO synthesis and ROS production by using the cell-line ECV-304 as a biosensor. NO synthesis and ROS production were measured in cells incubated with plasma from 73 RA patients and 52 healthy volunteers by fluorimetry. In addition, traditional CV risk factors, inflammatory molecules and disease activity parameters were measured. Cells incubated with plasma from RA patients exhibited reduced NO synthesis and increased ROS production compared to healthy volunteers. Furthermore, the imbalance between NO synthesis and ROS generation in RA patients was not associated with traditional CV risk factors. Our data suggest that ECV-304 cells can be used as a biosensor of systemic inflammation-induced endothelial cell-oxidative stress. We propose that both NO and ROS production are potential biomarkers aimed at improving the current assessment of CV risk in RA.


Subject(s)
Biosensing Techniques , Inflammation/blood , Nitric Oxide/isolation & purification , Plasma , Arthritis, Rheumatoid/blood , Atherosclerosis/blood , Atherosclerosis/pathology , Cell Line , Endothelial Cells/drug effects , Humans , Inflammation/pathology , Nitric Oxide/biosynthesis , Oxidative Stress/drug effects , Reactive Oxygen Species/chemistry , Reactive Oxygen Species/isolation & purification
12.
Sensors (Basel) ; 19(2)2019 Jan 11.
Article in English | MEDLINE | ID: mdl-30641922

ABSTRACT

A single exhale breathalyzer comprises a gas sensor that satisfies the following stringent conditions: high sensitivity to the target gas, high selectivity, stable response over extended period of time and fast response. Breathalyzer implementation includes a front-end circuit matching the sensitivity of the sensor that provides the readout of the sensor signal. We present here the characterization study of the response stability and response time of a selective Nitric Oxide (NO) sensor using designed data acquisition system that also serves as a foundation for the design of wireless handheld prototype. The experimental results with the described sensor and data acquisition system demonstrate stable response to NO concentration of 200 ppb over the period of two weeks. The experiments with different injection and retraction times of the sensor exposure to constant NO concentration show a fast response time of the sensor (on the order of 15 s) and the adequate recovery time (on the order of 3 min) demonstrating suitability for the single exhale breathalyzer.


Subject(s)
Biosensing Techniques/instrumentation , Breath Tests/instrumentation , Nitric Oxide/isolation & purification , Wireless Technology/instrumentation , Biomarkers/analysis , Exhalation/physiology , Humans
14.
J. investig. allergol. clin. immunol ; 29(3): 231-238, 2019. tab
Article in English | IBECS | ID: ibc-184089

ABSTRACT

Background: Fractional exhaled nitric oxide (FeNO) is a marker of type-2 inflammation in the airways. Elevated FeNO may precede the development of allergic disease. The aim of the present study was to investigate the association between elevated FeNO and the development of allergic symptoms. Methods: A total of 959 adolescents from the general population and their parents completed a standardized questionnaire. Lung function and FeNO were assessed at baseline. Four years later, 921 of these individuals (96%) completed the same version of the baseline questionnaire. Results: Adolescents with self-reported incident allergic symptoms to cat (n=50) or dog (n=33) had higher baseline FeNO (P<.001) than those without allergic symptoms to cat and dog at both time points (n=776 and n=838, respectively). Adolescents with incident allergic symptoms to pollen did not have elevated baseline FeNO. The adjusted odds ratio (aOR [95%CI]) for incident allergic symptoms to cat was 4.2 (2.2-8.0) times higher if FeNO was >75th percentile (vs <75th percentile) at baseline. This was consistent after exclusion of individuals with reported asthma, wheeze, or rhinitis at baseline (8.6 [3.0-24.1]). Conclusion: Elevated FeNO in adolescents was associated with an increased risk of developing allergic symptoms to cat and dog allergens, but not to pollen allergens, after 4 years


Introducción: La fracción de óxido nítrico exhalado (FeNO) es un marcador de inflamación de tipo 2 en las vías respiratorias y un valor de FeNO elevado puede preceder al desarrollo de enfermedad alérgica. El objetivo del presente estudio fue investigar la asociación entre FeNO elevado y el desarrollo posterior de síntomas alérgicos. Métodos: Un total de 959 adolescentes, procedentes de población general, respondieron, junto con sus padres, a un cuestionario estandarizado, realizaron una prueba de función pulmonar y una medición de FeNO en una visita basal. Cuatro años después, 921 de estos sujetos (96%) completaron, la misma versión, en gran medida, del cuestionario de referencia. Resultados: Los adolescentes con síntomas alérgicos incidentes autoinformados por gato (n=50) o perro (n=33) tenían mayor FeNO inicial (p <0,001) que los sujetos sin síntomas alérgicos por estos alérgenos, en cualquier momento del estudio (n=776 y n=838, respectivamente). Por el contrario, los adolescentes con síntomas alérgicos incidentes por polen no presentaban un FeNO inicial elevado. La razón de riesgo ajustada [aOR (intervalo de confianza del 95%)] para síntomas alérgicos incidentes por gato fue 4,2 (2,2, 8,0) veces mayor si el FeNO fue mayor que percentil 75 de la muestra (vs. menor del percentil 75) al inicio del estudio. Este resultado se mantuvo también después de la exclusión de los sujetos con asma, sibilancias o rinitis notificados al inicio del estudio [aOR (IC 95%) 8,6 (3,0, 24,1)].Conclusiones: El FeNO elevado en adolescentes se relacionó con un mayor riesgo de desarrollar en los cuatro años siguientes síntomas alérgicos inducidos por gatos y perros, pero no por los alérgenos del polen


Subject(s)
Humans , Male , Female , Adolescent , Pulmonary Elimination/immunology , Nitric Oxide/isolation & purification , Hypersensitivity/diagnosis , Dander/adverse effects , Exhalation/physiology , Biomarkers/analysis , Prospective Studies , Respiratory Function Tests/statistics & numerical data , Hypersensitivity/epidemiology , Morbidity Surveys
15.
Environ Sci Pollut Res Int ; 25(25): 25526-25537, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29959731

ABSTRACT

To remove NO and SO2 from flue gas simultaneously, a heterogeneous catalytic oxidation system was developed with the nanoscale zero-valent iron (nZVI), vaporized H2O2, and sodium humate (HA-Na) acting as the catalyst, oxidant, and absorbent, respectively. The experimental results indicated that the desulfurization was mainly influenced by the absorption, and the denitrification was significantly affected by the catalytic oxidation parameters. Under the optimal conditions, the simultaneous removal efficiencies of SO2 and NO were 100 and 88.4%, respectively. The presence of ·OH during the removal process was proved by the scavenger tests, and the production of ·OH with and without nZVI was indirectly evaluated by the electron paramagnetic resonance (EPR) and methylene blue experiments. Moreover, the fresh and aged nZVI were characterized by a series of techniques and the results suggested that the redox pair Fe2+/Fe3+ released by nZVI could react with H2O2 to provide the sustainable ·OH, which was important for the oxidation from NO and SO2 to NO3- and SO42-. The removal mechanism was proposed preliminarily based on the correlative experiments, characterizations, and references.


Subject(s)
Gases/chemistry , Hydrogen Peroxide/chemistry , Iron/chemistry , Nitric Oxide/isolation & purification , Sulfur Dioxide/isolation & purification , Waste Management/methods , Catalysis , Denitrification , Humic Substances , Metal Nanoparticles/chemistry , Oxidation-Reduction
17.
Bioresour Technol ; 265: 170-179, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29894911

ABSTRACT

A novel AnammoxDeNOx process was designed to simultaneously remove NOx in flue gas and ammonium wastewater, with the aim of exploring the possibility of using NO as a long-term and stable electron acceptor for anammox bacteria. The performance of the AnammoxDeNOx process indicated a NOx removal efficiency from simulated flue gas (including CO2, SO2, O2 and NO2) of 87-96% using simulated ammonium wastewater. With municipal wastewater, the removal efficiencies for NOx were 70-90%, total nitrogen 40-70%, and COD 80-90% (NO concentration: 100-500 ppm). The anammox genus underwent considerable changes from the dominant Candidatus Kuenenia in the stage of domestication to the predominant Candidatus Brocadia, which then became the dominant species in the simulated flue gas and actual municipal wastewater stages.


Subject(s)
Bioreactors , Nitric Oxide/isolation & purification , Sewage , Ammonium Compounds , Nitrogen , Oxidation-Reduction , Wastewater
18.
Biosens Bioelectron ; 103: 26-31, 2018 Apr 30.
Article in English | MEDLINE | ID: mdl-29277011

ABSTRACT

Using heme entrapped in recombinant silk films, we have produced 3rd generation biosensors, which allow direct electron transfer from the heme center to an electrode avoiding the need for electron mediators. Here, we demonstrate the use of these heme-silk films for the detection of nitric oxide (NO) at nanomolar levels in the presence and absence of oxygen. The sensor was prepared by drop-casting a silk solution on a glassy carbon electrode modified with multiwalled carbon nanotubes (MWCNT) followed by infusion with heme. The sensor was characterized by cyclic voltammetry and showed well defined and reversible Fe+/ Fe3+ redox couple activity, with NO detection by oxidation at potentials above +0.45V or reduction at potentials below - 0.7V. Evaluation of the effect of pH on the sensor response to NO reduction indicated a maximum response at pH 3. The sensor showed good linearity in the concentration range from 19 to 190nM (R2 = 0.99) with a detection limit of 2nM. The sensor had excellent selectivity towards NO with no or negligible interference from oxygen, nitrite, nitrate, dopamine and ascorbic acid and retained 86% of response after 2 months of operation and storage at room temperature.


Subject(s)
Biosensing Techniques , Heme/chemistry , Nitric Oxide/isolation & purification , Silk/chemistry , Catalysis , Dopamine/chemistry , Electrochemical Techniques/methods , Electrodes , Hydrogen Peroxide/chemistry , Limit of Detection , Nanotubes, Carbon/chemistry , Nitric Oxide/chemistry , Oxidation-Reduction
19.
Chemosphere ; 190: 431-441, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29024887

ABSTRACT

Simultaneous removal process of SO2 and NO from flue gas using vacuum ultraviolet light (VUV)/heat/peroxymonosulfate (PMS) in a VUV spraying reactor was proposed. The key influencing factors, active species, reaction products and mechanism of SO2 and NO simultaneous removal were investigated. The results show that vacuum ultraviolet light (185 nm) achieves the highest NO removal efficiency and yield of and under the same test conditions. NO removal is enhanced at higher PMS concentration, light intensity and oxygen concentration, and is inhibited at higher NO concentration, SO2 concentration and solution pH. Solution temperature has a double impact on NO removal. CO2 concentration has no obvious effect on NO removal. and produced from VUV-activation of PMS play a leading role in NO removal. O3 and ·O produced from VUV-activation of O2 also play an important role in NO removal. SO2 achieves complete removal under all experimental conditions due to its very high solubility in water and good reactivity. The highest simultaneous removal efficiency of SO2 and NO reaches 100% and 91.3%, respectively.


Subject(s)
Air Pollutants/isolation & purification , Environmental Restoration and Remediation/methods , Hot Temperature , Nitric Oxide/isolation & purification , Peroxides/chemistry , Sulfur Dioxide/isolation & purification , Ultraviolet Rays , Gases , Oxygen/chemistry , Vacuum , Water/chemistry
20.
Chemosphere ; 168: 623-629, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27836274

ABSTRACT

(NH2)2CO as well as FeIIEDTA is an absorbent for simultaneous desulfurization and denitrification. However, they have their own drawbacks, like the oxidation of FeIIEDTA and the low solubility of NO in urea solution. To overcome these defects, A mixed absorbent containing both (NH2)2CO and FeIIEDTA was employed. The effects of various operating parameters (urea and FeIIEDTA concentration, temperature, inlet oxygen concentration, pH value) on NO removal were examined in the packed tower. The results indicated that the NO removal efficiency increased with the decrease of oxygen concentration as well as the increase of FeIIEDTA concentration. The NO removal efficiency had little change with a range of 25-45 °C, and sharply decreased at the temperature of above 55 °C. The NO removal efficiency initially increases up to the maximum value and then decreases with the increase of pH value as well as the raise of urea concentration. In addition, the synergistic mechanism of (NH2)2CO and FeIIEDTA on NO removal was investigated. Results showed that urea could react with FeIIEDTA-NO to produce FeIIEDTA, N2, and CO2, and hinder oxidation of FeIIEDTA. Finally, to evaluate the effect of SO32- on NO removal, a mixed absorbent containing FeIIEDTA, urea, and Na2SO3 was employed to absorb NO. The mixed absorbent could maintain more than 78% for 80 min at 25 °C, pH = 7.0, (NH2)2CO concentration of 5 wt%, FeIIEDTA concentration of 0.02 M, O2 concentration of 7% (v/v), and Na2SO3 concentration of 0.2 M.


Subject(s)
Air Pollutants/isolation & purification , Edetic Acid/chemistry , Ferrous Compounds/chemistry , Nitric Oxide/isolation & purification , Urea/chemistry , Absorption, Physicochemical , Denitrification , Kinetics , Oxidation-Reduction , Solutions
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