TY - JOUR AB - Emissions from road traffic and residential heating contribute to urban air pollution. Advances in emission reduction technologies may alter the composition of emissions and affect their fate during atmospheric processing. Here, emissions of a gasoline car and a wood stove, both equipped with modern emission mitigation technology, were photochemically aged in an oxidation flow reactor to the equivalent of one to five days of photochemical aging. Fresh and aged exhausts were analyzed by ultrahigh resolution mass spectrometry. The gasoline car equipped with a three-way catalyst and a gasoline particle filter emitted minor primary fine particulate matter (PM2.5), but aging led to formation of particulate low-volatile, oxygenated and highly nitrogen-containing compounds, formed from volatile organic compounds (VOCs) and gases incl. NOx, SO2, and NH3. Reduction of the particle concentration was also observed for the application of an electrostatic precipitator with residential wood combustion but with no significant effect on the chemical composition of PM2.5. Comparing the effect of short and medium photochemical exposures on PM2.5 of both emission sources indicates a similar trend for formation of new organic compounds with increased carbon oxidation state and nitrogen content. The overall bulk compositions of the studied emission exhausts became more similar by aging, with many newly formed elemental compositions being shared. However, the presence of particulate matter in wood combustion results in differences in the molecular properties of secondary particles, as some compounds were preserved during aging. AU - Schneider, E.* AU - Czech, H. AU - Hartikainen, A.* AU - Hansen, H.J.* AU - Gawlitta, N. AU - Ihalainen, M.* AU - Yli-Pirilä, P.* AU - Somero, M.* AU - Kortelainen, M.* AU - Louhisalmi, J.* AU - Orasche, J. AU - Fang, Z.* AU - Rudich, Y.* AU - Sippula, O.* AU - Rüger, C.P.* AU - Zimmermann, R. C1 - 70791 C2 - 55935 CY - Thomas Graham House, Science Park, Milton Rd, Cambridge Cb4 0wf, Cambs, England TI - Molecular composition of fresh and aged aerosols from residential wood combustion and gasoline car with modern emission mitigation technology. JO - Environ. Sci. Process Impacts PB - Royal Soc Chemistry PY - 2024 SN - 2050-7887 ER - TY - JOUR AB - Future permafrost thaw will likely lead to substantial release of greenhouse gases due to thawing of previously unavailable organic carbon (OC). Accurate predictions of this release are limited by poor knowledge of the bioavailability of mobilized OC during thaw. Organic carbon bioavailability decreases due to adsorption to, or coprecipitation with, poorly crystalline ferric iron (Fe(III)) (oxyhydr)oxide minerals but the maximum binding extent and binding selectivity of permafrost OC to these minerals is unknown. We therefore utilized water-extractable organic matter (WEOM) from soils across a permafrost thaw gradient to quantify adsorption and coprecipitation processes with poorly crystalline Fe(III) (oxyhydr)oxides. We found that the maximum adsorption capacity of WEOM from intact and partly thawed permafrost soils was similar (204 and 226 mg C g-1 ferrihydrite, respectively) but decreased to 81 mg C g-1 ferrihydrite for WEOM from the fully thawed site. In comparison, coprecipitation of WEOM from intact and partly thawed soils with Fe immobilized up to 925 and 1532 mg C g-1 Fe respectively due to formation of precipitated Fe(III)-OC phases. Analysis of the OC composition before and after adsorption/coprecipitation revealed that high molecular weight, oxygen-rich, carboxylic- and aromatic-rich OC was preferentially bound to Fe(III) minerals relative to low molecular weight, aliphatic-rich compounds which may be more bioavailable. This selective binding effect was stronger after adsorption than coprecipitation. Our results suggest that OC binding by Fe(III) (oxyhydr)oxides sharply decreases under fully thawed conditions and that small, aliphatic OC molecules that may be readily bioavailable are less protected across all thaw stages. AU - Voggenreiter, E.* AU - Schmitt-Kopplin, P. AU - ThomasArrigo, L.* AU - Bryce, C.* AU - Kappler, A.* AU - Joshi, P.* C1 - 71141 C2 - 56006 CY - Thomas Graham House, Science Park, Milton Rd, Cambridge Cb4 0wf, Cambs, England TI - Emerging investigator series: Preferential adsorption and coprecipitation of permafrost organic matter with poorly crystalline iron minerals. JO - Environ. Sci. Process Impacts PB - Royal Soc Chemistry PY - 2024 SN - 2050-7887 ER - TY - JOUR AB - Atrazine is a frequently detected groundwater contaminant. It can be microbially degraded by oxidative dealkylation or by hydrolytic dechlorination. Compound-specific isotope analysis is a powerful tool to assess its transformation. In previous work, carbon and nitrogen isotope effects were found to reflect these different transformation pathways. However, chlorine isotope fractionation could be a particularly sensitive indicator of natural transformation since chlorine isotope effects are fully represented in the molecular average while carbon and nitrogen isotope effects are diluted by non-reacting atoms. Therefore, this study explored chlorine isotope effects during atrazine hydrolysis with Arthrobacter aurescens TC1 and oxidative dealkylation with Rhodococcus sp. NI86/21. Dual element isotope slopes of chlorine vs. carbon isotope fractionation (?ArthroCl/C = 1.7 +/- 0.9 vs. ?RhodoCl/C = 0.6 +/- 0.1) and chlorine vs. nitrogen isotope fractionation (?ArthroCl/N = -1.2 +/- 0.7 vs. ?RhodoCl/N = 0.4 +/- 0.2) provided reliable indicators of different pathways. Observed chlorine isotope effects in oxidative dealkylation (epsilon(Cl) = -4.3 +/- 1.8 parts per thousand) were surprisingly large, whereas in hydrolysis (epsilon(Cl) = -1.4 +/- 0.6 parts per thousand) they were small, indicating that C-Cl bond cleavage was not the rate-determining step. This demonstrates the importance of constraining expected isotope effects of new elements before using the approach in the field. Overall, the triple element isotope information brought forward here enables a more reliable identification of atrazine sources and degradation pathways. AU - Lihl, C. AU - Heckel, B.* AU - Grzybkowska, A.* AU - Dybala-Defratyka, A.* AU - Ponsin, V.* AU - Torrentó, C.* AU - Hunkeler, D.* AU - Elsner, M. C1 - 58770 C2 - 48311 CY - Thomas Graham House, Science Park, Milton Rd, Cambridge Cb4 0wf, Cambs, England SP - 792-801 TI - Compound-specific chlorine isotope fractionation in biodegradation of atrazine. JO - Environ. Sci. Process Impacts VL - 22 IS - 3 PB - Royal Soc Chemistry PY - 2020 SN - 2050-7887 ER - TY - JOUR AB - Hydraulic fracturing requires the injection of large volumes of fluid to extract oil and gas from low permeability unconventional resources (e.g., shale, coalbed methane), resulting in the production of large volumes of highly complex and variable waste fluids. Shale gas fluid samples were collected from two hydraulically fractured wells in Morgantown, WV, USA at the Marcellus Shale Energy and Environment Laboratory (MSEEL) and analyzed using ultrahigh resolution mass spectrometry to investigate the dissolved organic sulfur (DOS) pool. Using a non-targeted approach, ions assigned DOS formulas were analyzed to identify dominant DOS classes, describe their temporal trends and their implications, and describe the molecular characteristics of the larger DOS pool. The average molecular weight of organic sulfur compounds in flowback decreased and was lowest in produced waters. The dominant DOS classes were putatively assigned to alcohol sulfate and alcohol ethoxysulfate surfactants, likely injected as fracturing fluid additives, on the basis of exact mass and homolog distribution matching. This DOS signature was identifiable 10 months after the initial injection of hydraulic fracturing fluid, and an absence of genes that code for alcohol ethoxysulfate degrading proteins (e.g., sulfatases) in the shale well genomes and metagenomes support that these additives are not readily degraded biologically and may continue to act as a chemical signature of the injected fluid. Understanding the diversity, lability, and fate of organic sulfur compounds in shale wells is important for engineering productive wells and preventing gas souring as well as understanding the consequences of unintended fluid release to the environment. The diversity of DOS, particularly more polar compounds, needs further investigation to determine if the identified characteristics and temporal patterns are unique to the analyzed wells or represent broader patterns found in other formations and under other operating conditions. AU - Luek, J.L.* AU - Harir, M. AU - Schmitt-Kopplin, P. AU - Mouser, P.J.* AU - Gonsior, M.* C1 - 54504 C2 - 45644 CY - Thomas Graham House, Science Park, Milton Rd, Cambridge Cb4 0wf, Cambs, England SP - 206-213 TI - Organic sulfur fingerprint indicates continued injection fluid signature 10 months after hydraulic fracturing. JO - Environ. Sci. Process Impacts VL - 21 IS - 2 PB - Royal Soc Chemistry PY - 2019 SN - 2050-7887 ER - TY - JOUR AB - Soot is an important carbonaceous nanoparticle (CNP) frequently found in natural environments. Its entry into surface waters can occur directly via surface runoff or infiltration, as well as via atmospheric deposition. Pristine soot is likely to rapidly undergo aggregation and subsequent sedimentation in aquatic environments. Further, soot can sorb a variety of organic contaminants, such as S-metolachlor (log K-D = 3.25 +/- 0.12). During atmospheric transport, soot can be chemically transformed by reactive oxygen species including NO2. The presence of natural organic matter (NOM) in surface waters can further affect the aquatic fate of soot. To better understand the processes driving the fate of soot and its interactions with contaminants, pristine and NO2-transformed model soot suspensions were investigated in the presence and absence of NOM. NO2-oxidized soot showed a smaller particle size, a higher number of particles remaining in suspension, and a decreased sorption of S-metolachlor (log K-D = 2.47 +/- 0.40). In agreement with findings for other CNPs, soot stability against aggregation was increased for both pristine and NO2 transformed soot in the presence of NOM. AU - Sigmund, G.* AU - Castan, S.* AU - Wabnitz, C.* AU - Bakkour, R.* AU - Hüffer, T.* AU - Hofmann, T.* AU - Elsner, M. C1 - 57204 C2 - 47607 CY - Thomas Graham House, Science Park, Milton Rd, Cambridge Cb4 0wf, Cambs, England SP - 1729-1735 TI - NO2 and natural organic matter affect both soot aggregation behavior and sorption of S-metolachlor. JO - Environ. Sci. Process Impacts VL - 21 IS - 10 PB - Royal Soc Chemistry PY - 2019 SN - 2050-7887 ER - TY - JOUR AB - During many measurements it is important to account for possible changes in the gas-particle distribution of aerosols containing semi-volatile organic compounds (SVOCs). If denuders are combined with currently used personal air samplers, a simultaneous differential sampling of the gas and particle phase is possible. Here we analysed the transmission efficiency of denuders based on multi-channel silicone rubber traps (setup: 9 cm long glass liner (ID 4 mm), containing 22 parallel silicone rubber tubes (55 mm long, ID 0.3 mm, OD 0.5 mm)) with polystyrene latex (PSL) particles for different scenarios. n-Hexadecane, dimethyl phthalate and diethylene glycol gases were used to measure the time-dependent gas phase collection efficiency of a denuder. Additionally, the evaporation of n-hexadecane aerosol particles passing through the denuders was investigated. Our results showed high transmission efficiencies from 91 to 100% (variation coefficients 3.69-9.65%) for the denuders operated vertically at a flow rate of 0.5 l min(-1). With regard to the gas phase collection efficiency, nonpolar n-hexadecane gas was trapped with higher efficiency (87% after 22 h) than dimethyl phthalate gas (27% after 22 h), while for highly polar diethylene glycol the gas phase collection efficiency was 50% after 2 h. Regarding the evaporation of aerosol particles, smaller particles and lower flow rates led to higher particle volume reduction inside the denuders. In conclusion, the tested denuders are suitable for determining the gas-particle partitioning of SVOC aerosols of nonpolar substances and show above 90% transmission for all tested particle sizes. AU - Kohlmeier, V. AU - Dragan, G.-C. AU - Karg, E.W. AU - Schnelle-Kreis, J. AU - Breuer, D.* AU - Forbes, P.B.C.* AU - Rohwer, E.R.* AU - Zimmermann, R. C1 - 50891 C2 - 42573 CY - Cambridge SP - 676-686 TI - Multi-channel silicone rubber traps as denuders for gas-particle partitioning of aerosols from semi-volatile organic compounds. JO - Environ. Sci. Process Impacts VL - 19 IS - 5 PB - Royal Soc Chemistry PY - 2017 SN - 2050-7887 ER - TY - JOUR AB - The sampling of semi volatiles (SV) in workplaces may lead to different results as measurements may be affected by sampling bias. The new European Standard EN 13936 defines "semi-volatiles" as substances with vapour pressures in the range between 0.001 and 100 Pa at room temperature. EN 13936 regulates the basic requirements for SV compounds that can occur as vapour and particle at the same time. Vapour and particles shall not be sampled separately and particles have to be sampled as inhalable fraction. Following EN 13936, the Institute for Occupational Safety and Health (Institut für Arbeitsschutz - IFA) has developed a miniaturized droplet-vapour sampler (GGP-Mini) which is designed to sample the inhalable aerosol fraction at low flow rates. The GGP-Mini uses 13 mm filters for particle sampling combined with adsorption tubes for vapour sampling. Laboratory tests were performed on 11 polar and non-polar compounds in a boiling point range from 188 °C to 318 °C. The substances were spiked directly on the filter followed by aspiration of 40 litres of air. Substances with boiling points below 230 °C were almost completely evaporated. Substances with boiling points above 230 °C up to 300 °C were found on both filter and charcoal tube. Lower-volatile compounds remained almost completely on the filter. For polar substances, the atmospheric humidity had a considerable influence upon the distribution of the liquid and vaporous components. A strong influence of the sampling temperature was found in the range from 0 °C to 50 °C. Droplet-vapour mixtures of n-hexadecane and diethylene glycol with droplet sizes between 1 μm and 4 μm were generated in a flow tube to verify the laboratory results. The aerosol concentrations were analysed on-line with a particle sizer and a flame ionisation detector, while parallel off-line samples were taken with the GGP-Mini. Evaporation losses from filters could be studied by comparing the on-line with off-line measurements. All sampling simulations, both spiking and tests on a droplet aerosol, have shown that the distribution between vapour and droplets is not constant and influenced e. g. by volatility, concentration, temperature and humidity. Only the sum of vapour and droplets constitutes a reproducible result. AU - Breuer, D.* AU - Dragan, G.-C. AU - Friedrich, C.* AU - Möhlmann, C.* AU - Zimmermann, R. C1 - 43062 C2 - 35952 CY - Cambridge SP - 278-287 TI - Development and field testing of a miniaturized sampling system for simultaneous sampling of vapours and droplets. JO - Environ. Sci. Process Impacts VL - 17 IS - 2 PB - Royal Soc Chemistry PY - 2015 SN - 2050-7887 ER - TY - JOUR AB - Semi-Volatile (SV) aerosols still represent an important challenge to industrial hygienists due to toxicological and sampling issues. Particularly problematic is the sampling of hazardous SV that are present in both particulate and vapour phases at a workplace. In this study we investigate the potential evaporation losses of SV aerosols when using off-line filter-adsorber personal samplers. Furthermore, we provide experimental data showing the extent of the evaporation loss that can bias the workplace risk assessment. An experimental apparatus consisting of an aerosol generator, a flow tube and an aerosol monitoring and sampling system was set up inside a temperature controlled chamber. Aerosols from three n-alkanes were generated, diluted with nitrogen and sampled using on-line and off-line filter-adsorber methods. Parallel measurements using the on-line and off-line methods were conducted to quantify the bias induced by filter sampling. Additionally, two mineral oils of different volatility were spiked on filters and monitored for evaporation depending on the samplers flow rate. No significant differences between the on-line and off-line methods were detected for the sum of particles and vapour. The filter-adsorber method however tended to underestimate up to 100 % of the particle mass, especially for the more volatile compounds and lower concentrations. The off-line sampling method systematically returned lower particle and higher vapour values, an indication for particle evaporation losses. We conclude that using only filter sampling for the assessment of semi-volatiles may considerably underestimate the presence of the particulate phase due to evaporation. Thus, this underestimation can have a negative impact on the occupational risk assessment if the evaporated particle mass is no longer quantified. AU - Dragan, G.-C. AU - Breuer, D.* AU - Blaskowitz, M.* AU - Karg, E.W. AU - Schnelle-Kreis, J. AU - Arteaga-Salas, J.M. AU - Nordsieck, H.* AU - Zimmermann, R. C1 - 32586 C2 - 35138 CY - Cambridge SP - 270-277 TI - An evaluation of the "GGP" personal samplers under semi-volatile aerosols: Sampling losses and their implication on occupational risk assessment. JO - Environ. Sci. Process Impacts VL - 17 IS - 2 PB - Royal Soc Chemistry PY - 2015 SN - 2050-7887 ER -