Two years of near real-time chemical composition of submicron aerosols in the region of Paris using an Aerosol Chemical Speciation Monitor (ACSm) and a multi-wavelength Aethalometer

Abstract. Aerosol Mass Spectrometer (AMS) measurements have been successfully used towards a better understanding of non-refractory submicron (PM1) aerosol chemical properties based on short-term campaign. The recently developed Aerosol Chemical Speciation Monitor (ACSM) has been designed to deliver quite similar artefact-free chemical information but for low-cost, and to perform robust monitoring over long-term period. When deployed in parallel with real-time Black Carbon (BC) measurements, the combined dataset allows for a quasi-comprehensive description of the whole PM1 fraction in near real-time. Here we present a 2 year long ACSM and BC datasets, between mid-2011 and mid-2013, obtained at the French atmospheric SIRTA supersite being representative of background PM levels of the region of Paris. This large dataset shows intense and time limited (few hours) pollution events observed during wintertime in the region of Paris pointing to local carbonaceous emissions (mainly combustion sources). A non-parametric wind regression analysis was performed on this 2 year dataset for the major PM1 constituents (organic matter, nitrate, sulphate and source apportioned BC) and ammonia in order to better refine their geographical origins and assess local/regional/advected contributions which information are mandatory for efficient mitigation strategies. While ammonium sulphate typically shows a clear advected pattern, ammonium nitrate partially displays a similar feature, but less expected, it also exhibits a significant contribution of regional and local emissions. Contribution of regional background OA is significant in spring and summer while a more pronounced local origin is evidenced during wintertime which pattern is also observed for BC originating from domestic wood burning. Using time-resolved ACSM and BC information, seasonally differentiated weekly diurnal profiles of these constituents were investigated and helped to identify the main parameters controlling their temporal variations (sources, meteorological parameters). Finally, a careful investigation of all the major pollution episodes observed over the region of Paris between 2011 and 2013 was performed and classified in terms of chemical composition and BC-to-sulphate ratio used here as a proxy of the local/regional vs. advected contribution of PM. In conclusion, these first 2 year quality-controlled measurements of ACSM clearly demonstrate their great potential to monitor on a long term basis aerosol sources and their geographical origin and provide strategic information in near real-time during pollution episodes. They also support the capacity of the ACSM to be proposed as a robust and credible alternative to filter-based sampling techniques for long term monitoring strategies.

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Two years of near real-time chemical composition of submicron aerosols in the region of Paris using an Aerosol Chemical Speciation Monitor (ACSM) and a multi-wavelength Aethalometer

Atmospheric Chemistry and Physics ◽

10.5194/acp-15-2985-2015 ◽

2015 ◽

Vol 15 (6) ◽

pp. 2985-3005 ◽

Cited By ~ 81

Author(s):

J.-E. Petit ◽

O. Favez ◽

J. Sciare ◽

V. Crenn ◽

R. Sarda-Estève ◽

...

Keyword(s):

Chemical Composition ◽

Real Time ◽

Chemical Speciation ◽

Chemical Properties ◽

Temporal Variations ◽

Mitigation Strategies ◽

Chemical Information ◽

Data Set ◽

Pollution Episodes

Abstract. Aerosol mass spectrometer (AMS) measurements have been successfully used towards a better understanding of non-refractory submicron (PM1) aerosol chemical properties based on short-term campaigns. The recently developed Aerosol Chemical Speciation Monitor (ACSM) has been designed to deliver quite similar artifact-free chemical information but for low cost, and to perform robust monitoring over long-term periods. When deployed in parallel with real-time black carbon (BC) measurements, the combined data set allows for a quasi-comprehensive description of the whole PM1 fraction in near real time. Here we present 2-year long ACSM and BC data sets, between mid-2011 and mid-2013, obtained at the French atmospheric SIRTA supersite that is representative of background PM levels of the region of Paris. This large data set shows intense and time-limited (a few hours) pollution events observed during wintertime in the region of Paris, pointing to local carbonaceous emissions (mainly combustion sources). A non-parametric wind regression analysis was performed on this 2-year data set for the major PM1 constituents (organic matter, nitrate, sulfate and source apportioned BC) and ammonia in order to better refine their geographical origins and assess local/regional/advected contributions whose information is mandatory for efficient mitigation strategies. While ammonium sulfate typically shows a clear advected pattern, ammonium nitrate partially displays a similar feature, but, less expectedly, it also exhibits a significant contribution of regional and local emissions. The contribution of regional background organic aerosols (OA) is significant in spring and summer, while a more pronounced local origin is evidenced during wintertime, whose pattern is also observed for BC originating from domestic wood burning. Using time-resolved ACSM and BC information, seasonally differentiated weekly diurnal profiles of these constituents were investigated and helped to identify the main parameters controlling their temporal variations (sources, meteorological parameters). Finally, a careful investigation of all the major pollution episodes observed over the region of Paris between 2011 and 2013 was performed and classified in terms of chemical composition and the BC-to-sulfate ratio used here as a proxy of the local/regional/advected contribution of PM. In conclusion, these first 2-year quality-controlled measurements of ACSM clearly demonstrate their great potential to monitor on a long-term basis aerosol sources and their geographical origin and provide strategic information in near real time during pollution episodes. They also support the capacity of the ACSM to be proposed as a robust and credible alternative to filter-based sampling techniques for long-term monitoring strategies.

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Hygroscopic properties of the Paris urban aerosol in relation to its chemical composition

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-737-2014 ◽

2014 ◽

Vol 14 (2) ◽

pp. 737-749 ◽

Cited By ~ 17

Author(s):

K. A. Kamilli ◽

L. Poulain ◽

A. Held ◽

A. Nowak ◽

W. Birmili ◽

...

Keyword(s):

Growth Factors ◽

Chemical Composition ◽

Chemical Properties ◽

Temporal Variations ◽

Summation Method ◽

Urban Site ◽

Hygroscopic Growth ◽

Differential Mobility ◽

Hygroscopic Properties ◽

Particle Sizer

Abstract. Aerosol hygroscopic growth factors and chemical properties were measured as part of the MEGAPOLI "Megacities Plume Case Study" at the urban site Laboratoire d'Hygiène de la Ville de Paris (LHVP) in the city center of Paris from June to August 2009, and from January to February 2010. Descriptive hygroscopic growth factors (DGF) were derived in the diameter range from 25 to 350 nm at relative humidities of 30, 55, 75, and 90% by applying the summation method on humidified and dry aerosol size distributions measured simultaneously with a humidified differential mobility particle sizer (HDMPS) and a twin differential mobility particle sizer (TDMPS). For 90% relative humidity, the DGF varied from 1.06 to 1.46 in summer, and from 1.06 to 1.66 in winter. Temporal variations in the observed mean DGF could be well explained with a simple growth model based on the aerosol chemical composition measured by aerosol mass spectrometry (AMS) and black carbon photometry (MAAP). In particular, good agreement was observed when sulfate was the predominant inorganic factor. A clear overestimation of the predicted growth factor was found when the nitrate mass concentration exceeded values of 10 μg m−3, e.g., during winter.

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Impact of Physico-Chemical Properties of Cellulose Nanocrystal/Silver Nanoparticle Hybrid Suspensions on Their Biocidal and Toxicological Effects

Nanomaterials ◽

10.3390/nano11071862 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1862

Author(s):

Dafne Musino ◽

Julie Devcic ◽

Cécile Lelong ◽

Sylvie Luche ◽

Camille Rivard ◽

...

Keyword(s):

Mammalian Cells ◽

Low Cost ◽

Aqueous Suspension ◽

Chemical Properties ◽

Molar Ratio ◽

Biocidal Activity ◽

Phagocytic Capacity ◽

Toxicological Effects ◽

Physico Chemical

There is a demand for nanoparticles that are environmentally acceptable, but simultaneously efficient and low cost. We prepared silver nanoparticles (AgNPs) grafted on a native bio-based substrate (cellulose nanocrystals, CNCs) with high biocidal activity and no toxicological impact. AgNPs of 10 nm are nucleated on CNCs in aqueous suspension with content from 0.4 to 24.7 wt%. XANES experiments show that varying the NaBH4/AgNO3 molar ratio affects the AgNP oxidation state, while maintaining an fcc structure. AgNPs transition from 10 nm spherical NPs to 300 nm triangular-shaped AgNPrisms induced by H2O2 post-treatment. The 48 h biocidal activity of the hybrid tested on B. Subtilis is intensified with the increase of AgNP content irrespective of the Ag+/Ag0 ratio in AgNPs, while the AgNSphere−AgNPrism transition induces a significant reduction of biocidal activity. A very low minimum inhibitory concentration of 0.016 mg AgNP/mL is determined. A new long-term biocidal activity test (up to 168 h) proved efficiency favorable to the smaller AgNPs. Finally, it is shown that AgNPs have no impact on the phagocytic capacity of mammalian cells.

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MIRRA: A Modular and Cost-Effective Microclimate Monitoring System for Real-Time Remote Applications

Sensors ◽

10.3390/s21134615 ◽

2021 ◽

Vol 21 (13) ◽

pp. 4615

Author(s):

Olivier Pieters ◽

Emiel Deprost ◽

Jonas Van Der Donckt ◽

Lore Brosens ◽

Pieter Sanczuk ◽

...

Keyword(s):

Climate Change ◽

Real Time ◽

Monitoring System ◽

Low Cost ◽

Cost Effective ◽

Time Data ◽

Real Time Data ◽

Microclimate Monitoring ◽

Weather Stations

Monitoring climate change, and its impacts on ecological, agricultural, and other societal systems, is often based on temperature data derived from official weather stations. Yet, these data do not capture most microclimates, influenced by soil, vegetation and topography, operating at spatial scales relevant to the majority of organisms on Earth. Detecting and attributing climate change impacts with confidence and certainty will only be possible by a better quantification of temperature changes in forests, croplands, mountains, shrublands, and other remote habitats. There is an urgent need for a novel, miniature and simple device filling the gap between low-cost devices with manual data download (no instantaneous data) and high-end, expensive weather stations with real-time data access. Here, we develop an integrative real-time monitoring system for microclimate measurements: MIRRA (Microclimate Instrument for Real-time Remote Applications) to tackle this problem. The goal of this platform is the design of a miniature and simple instrument for near instantaneous, long-term and remote measurements of microclimates. To that end, we optimised power consumption and transfer data using a cellular uplink. MIRRA is modular, enabling the use of different sensors (e.g., air and soil temperature, soil moisture and radiation) depending upon the application, and uses an innovative node system highly suitable for remote locations. Data from separate sensor modules are wirelessly sent to a gateway, thus avoiding the drawbacks of cables. With this sensor technology for the long-term, low-cost, real-time and remote sensing of microclimates, we lay the foundation and open a wide range of possibilities to map microclimates in different ecosystems, feeding a next generation of models. MIRRA is, however, not limited to microclimate monitoring thanks to its modular and wireless design. Within limits, it is suitable or any application requiring real-time data logging of power-efficient sensors over long periods of time. We compare the performance of this system to a reference system in real-world conditions in the field, indicating excellent correlation with data collected by established data loggers. This proof-of-concept forms an important foundation to creating the next version of MIRRA, fit for large scale deployment and possible commercialisation. In conclusion, we developed a novel wireless cost-effective sensor system for microclimates.

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Hot water extracted organic matter: chemical composition and temporal variations in a long-term field experiment

Biology and Fertility of Soils ◽

10.1007/bf00307836 ◽

1995 ◽

Vol 20 (1) ◽

pp. 17-23 ◽

Cited By ~ 103

Author(s):

P. Leinweber ◽

H. -R. Schulten ◽

M. K�rschens

Keyword(s):

Organic Matter ◽

Chemical Composition ◽

Field Experiment ◽

Temporal Variations ◽

Hot Water ◽

Term Field

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PtOEP–PDMS-Based Optical Oxygen Sensor

Sensors ◽

10.3390/s21165645 ◽

2021 ◽

Vol 21 (16) ◽

pp. 5645

Author(s):

Camila M. Penso ◽

João L. Rocha ◽

Marcos S. Martins ◽

Paulo J. Sousa ◽

Vânia C. Pinto ◽

...

Keyword(s):

Oxygen Sensor ◽

Low Cost ◽

Chemical Properties ◽

Cost Effective ◽

Luminescent Properties ◽

Low Oxygen ◽

Pdms Film ◽

Sensing Applications ◽

Optical Oxygen Sensor

The advanced and widespread use of microfluidic devices, which are usually fabricated in polydimethylsiloxane (PDMS), requires the integration of many sensors, always compatible with microfluidic fabrication processes. Moreover, current limitations of the existing optical and electrochemical oxygen sensors regarding long-term stability due to sensor degradation, biofouling, fabrication processes and cost have led to the development of new approaches. Thus, this manuscript reports the development, fabrication and characterization of a low-cost and highly sensitive dissolved oxygen optical sensor based on a membrane of PDMS doped with platinum octaethylporphyrin (PtOEP) film, fabricated using standard microfluidic materials and processes. The excellent mechanical and chemical properties (high permeability to oxygen, anti-biofouling characteristics) of PDMS result in membranes with superior sensitivity compared with other matrix materials. The wide use of PtOEP in sensing applications, due to its advantage of being easily synthesized using microtechnologies, its strong phosphorescence at room temperature with a quantum yield close to 50%, its excellent Strokes Shift as well as its relatively long lifetime (75 µs), provide the suitable conditions for the development of a miniaturized luminescence optical oxygen sensor allowing long-term applications. The influence of the PDMS film thickness (0.1–2.5 mm) and the PtOEP concentration (363, 545, 727 ppm) in luminescent properties are presented. This enables to achieve low detection levels in a gas media range from 0.5% up to 20%, and in liquid media from 0.5 mg/L up to 3.3 mg/L at 1 atm, 25 °C. As a result, we propose a simple and cost-effective system based on a LED membrane photodiode system to detect low oxygen concentrations for in situ applications.

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Hygroscopic properties of the Paris urban aerosol in relation to its chemical composition

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-14297-2013 ◽

2013 ◽

Vol 13 (5) ◽

pp. 14297-14330

Author(s):

K. A. Kamilli ◽

L. Poulain ◽

A. Held ◽

A. Nowak ◽

W. Birmili ◽

...

Keyword(s):

Growth Factors ◽

Chemical Composition ◽

Chemical Properties ◽

Temporal Variations ◽

Summation Method ◽

Urban Site ◽

Hygroscopic Growth ◽

Differential Mobility ◽

Hygroscopic Properties ◽

Particle Sizer

Abstract. Aerosol hygroscopic growth factors and chemical properties were measured as part of the MEGAPOLI "Megacities Plume Case Study" at the urban site LHVP in the city center of Paris from June to August 2009, and from January to February 2010. Descriptive hygroscopic growth factors (DGF) were derived in the diameter range from 25 to 350 nm at relative humidities of 30, 55, 75, and 90% by applying the summation method on humidified and dry aerosol size distributions measured simultaneously with a humidified differential mobility particle sizer (HDMPS) and a twin differential mobility particle sizer (TDMPS). For 90% relative humidity, the DGF varied from 1.06 to 1.46 in summer, and from 1.06 to 1.66 in winter. Temporal variations in the observed mean DGF could be well explained with a simple growth model based on the aerosol chemical composition measured by aerosol mass spectrometry (AMS) and black carbon photometry (MAAP). In particular, good agreement was observed when sulfate was the predominant inorganic factor. A clear overestimation of the predicted growth factor was found when the nitrate mass concentration exceeded values of 10 μg m3, e.g. during winter.

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