Characterisation of atmospheric pollution near an industrial site with a biogas production and combustion plant in southern Italy

Although biogas production can have some benefits, there is a research gap on potential influence of biogas plant emissions on local air quality, thus an accurate and comprehensive evaluation of impacts of this technology is needed. This study deals with this issue by means of a characterisation of air pollution near an industrial area including a biogas production (from biomass) and combustion plant located in South Italy. The methodology consists in advanced statistical analysis on concentration of gaseous pollutants, particles concentration and size distribution in number and mass, and PM_2.5 chemical composition. High-temporal resolution measurements, supported by ancillary meteorological parameters, and source apportionment of PM_2.5 using Positive Matrix Factorization (PMF) receptor model, are performed. The integrated approach provides the emissive picture consisting in different anthropogenic sources (i.e. traffic, biomass burning, and industrial facilities) with particular focus on biogas plant emissions. Results showed that CO and nitrogen oxides were influenced by vehicular traffic and biomass combustion, however, a contribution of the plant to NO was observed. SO₂ was influenced mainly by transport from the industrial zone, but a second local contribution compatible with the emissions of the biogas plant was detected. Number particle concentrations were analysed in four size ranges: nanoparticles (D < 0.05 μm), ultrafine particles (D < 0.3 μm), accumulation (0.3 < D < 1 μm) and coarse particles (D > 1 μm). Nanoparticles and ultrafine particles were mainly influenced by vehicular traffic and biomass burning, instead, a contribution of the plant was individuated in the accumulation mode. PMF5 identified the contribution of six sources: crustal (14.7% ± 2.1% of measured PM_2.5); marine aerosol (aged) (12.9% ± 2.3%); biomass burning (32.8% ± 1.4%); secondary sulphate (19.7% ± 2.4%); primary industrial emissions (5.4% ± 2.3%); traffic and secondary nitrate (17.0% ± 3.9%). The plant is likely to contribute to both sources, the industrial and the traffic plus secondary nitrate.

Measurement of volatile organic compounds (VOCs) in libraries and archives in Florence (Italy)

Indoor air samples from libraries and archives in Florence, Italy, were collected and analysed for a variety of volatile organic compounds. The aim was to perform a characterisation of the indoor air quality, and try to elucidate if there are VOCs that may cause or result from the determination of the cultural heritage institutions. All compounds of interest were regularly detected, with BTEXs (Benzene, Toluene, Ethylbenzene, Xylenes) being the most abundant and followed by cyclic volatile methylsiloxanes, aldehydes, terpenes and organic acids. The prevalence and qualitative characteristics, such as concentrations, profiles and indoor/outdoor ratios of BTEXs underline the important influence of the outdoor air infiltrations on the indoor air concentrations. Acetic acid that is a substance that can oxidise books and other exposed objects was detected at concentrations ranging between 1.04 and 18.9μgm^-3, while furfural, that is a known marker of paper degradation, was constantly present at concentrations that ranged between 5.26 and 32.6μgm^-3. This work shows the importance that indoor air quality monitoring campaigns can have in order to give early warning to cultural heritage institution managers about the impact that indoor air quality can have on exposed and/or preserved objects.

Comparison between two different nanoparticle size spectrometers

A commercial differential mobility particle sizer (DMPS), long and medium column DMA (Grimm Aerosol Technik L-DMA model 5.400; M-DMA model 5500), condensation particle counter (CPC, Grimm Aerosol Technik 5.403), and a fast mobility particle sizer (FMPS-TSI, model 3091), were deployed to determine the size distributions of ultrafine particles. Comparisons were performed using atmospheric aerosol, as well as laboratory aerosol generated by nebulizing Milli-Q water (Millipore Corporation) and a water suspension of Fe2O3 in a Collison type atomizer. Results show that the DMPS generally measured higher particle number concentrations than the FMPS, above all for atmospheric aerosol compared to laboratory generated aerosol. With regard to size distribution, in both the atmospheric and laboratory-generated aerosols, the FMPS always showed a small peak around 10 nm, which was not shown by the M-DMPS. The agreement of the particle number concentration between the DMPS and FMPS was better in the 25-116 nm range for atmospheric aerosol, and in the 10-65 nm range for laboratory-generated aerosols. Since these instruments are scheduled to be run for air quality measurements and not only aerosol research purposes, there is an urgent need to establish working protocols in compliance with requirements with ISO 15900 requirements.

IMPLICATIONS

Epidemiological studies have shown that high ultrafine particulate concentrations are associated with an increase in mortality. Measuring exposure against mass alone is not sufficient, but it is also necessary to consider exposure against number concentration. Therefore, continuous measurements of aerosol size and number concentrations are important. This paper provides a comparison between two different nanoparticle size spectrometers widely used in air quality measurements. We found significantly different total number particle concentrations and size distributions in both laboratory-generated and atmospheric aerosols. Results show that the DMPS generally measured higher particle number concentrations than the FMPS. Since these instruments are scheduled to be run for air quality measurements and not only aerosol research purposes, there is an urgent need to establish working protocols in compliance with ISO 15900 requirements.

The direct influence of ship traffic on atmospheric PM2.5, PM10 and PAH in Venice

The direct influence of ship traffic on atmospheric levels of coarse and fine particulate matter (PM(2.5), PM(10)) and fifteen polycyclic aromatic hydrocarbons (PAHs) has been estimated in the urban area of Venice. Data analysis has been performed on results collected at three sites over the summer, when ship traffic is at a maximum. Results indicate that monitoring of the PM daily concentrations is not sufficiently detailed for the evaluation of this contribution, even though it could be useful for specific markers such as PAHs. Therefore a new methodology, based on high temporal resolution measurements coupled with wind direction information and the database of ship passages of the Harbour Authority of Venice has been developed. The sampling sites were monitored with optical detectors (DustTrack(®) and Mie pDR-1200) operating at a high temporal resolution (20s and 1s respectively) for PM(2.5) and PM(10). PAH in the particulate and gas phases were recovered from quartz fibre filters and polyurethane foam plugs using pressurised solvent extraction, the extracts were then analysed by gas chromatography- high-resolution mass spectrometry. Our results shows that the direct contribution of ships traffic to PAHs in the gas phase is 10% while the contribution to PM(2.5) and to PM(10) is from 1% up to 8%.