Fig 2 - uploaded by Jesper Nørlem Kamp
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Experimental setup for all tests and instruments. Setup B was used for water and VOCs interferences.
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Emissions from agriculture are a worldwide problem as it is the major anthropogenic source of ammonia,methane, and nitrous oxide. Several efforts have been made to mitigate emissions. To achieve this, reliable measuring techniques are necessary to quantify the impact of the emissions. Different techniques relying on different principles are availab...
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... was tested using the setup from Fig. 2. The flow of the gases was controlled with mass flow controllers (MFC) (Bronkhorst High-Tech B.V., Ruurlo, Netherlands). To test interferences of NH 3 on measurements of N 2 O, mass flow controllers 1, 3, and 4 (MFC 1, MCF 3, and MFC 4 in Fig. 2) were set accordingly to obtain the desired concentrations of both gases. The interference ...
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... was tested using the setup from Fig. 2. The flow of the gases was controlled with mass flow controllers (MFC) (Bronkhorst High-Tech B.V., Ruurlo, Netherlands). To test interferences of NH 3 on measurements of N 2 O, mass flow controllers 1, 3, and 4 (MFC 1, MCF 3, and MFC 4 in Fig. 2) were set accordingly to obtain the desired concentrations of both gases. The interference of NH 3 on CH 4 and N 2 O background levels was determined by setting MFC 4 to zero. Pressurized ambient air was chosen for adjusting concentrations during the experiments since this is closer to realistic measurement scenarios than using ...
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... water with a diffuser or led through the headspace above the surface of an aqueous solution containing one of the twelve different VOCs tested. After the bottle with either Milli-Q water or VOC solution, the two airstreams were recombined. A water trap was used to avoid water reaching the mass flow controllers. The MFCs were calibrated before use (Fig. S2 in ...
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... as seen in Fig. 4a. The deviation between the maximum and minimum N 2 O concentration was 7.5, 12, and 34 ppb for a fixed N 2 O concentration of 1, 2, and 4 ppm, respectively. In percentage, 0.58%, 0.55%, and 0.84%. A negligible bias considering the deviation from propagated random errors related to the mass flow controllers and CRDS calibration (Figs. S1-S2), and the uncertainty of the N 2 O concentration in the gas cylinder ...
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At the energy-chemistry nexus, key molecules include carbon dioxide (CO2), hydrogen (H2), methane (CH4), and ammonia (NH3). The position of these four molecules and that of the more general family of synthetic macromolecular polymer blends (found in plastics) were cross-analyzed with the planetary boundary framework, and as part of five scientific...
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... The up-and downwind concentrations were measured with CRDS instruments (model G2509, Picarro Inc., Santa Clara, CA, USA). The CRDS (model G2509) instrument has been used with the bLS model to determine agricultural emissions from liquid manure storage (Lemes, Garcia, Nyord, Feilberg, & Kamp, 2022) and proven to be a reliable instrument in agricultural environments (Garcia, Støckler, Feilberg, & Kamp, 2024). The downwind concentration was measured with a Table 1 Characteristics of the pure litter material and the stockpiled broiler litter at the beginning and end of the experiment. ...
Poultry litter, a mix of excreta, bedding material, and discarded feed, is extracted from poultry houses, and used as fertiliser. The litter is often stored in stockpiles outside before field application thereby posing a risk for negative environmental and climatic impact from emissions of ammonia (NH3) and greenhouse gases (GHG). This study investigated the emissions of methane (CH4), NH3, and nitrous oxide (N2O) from a 22 tonnes broiler litter stockpile over 44 days. The emissions were measured on a farm-scale stockpile with and without coverage using the backward Lagrangian Stochastic method. The results showed distinct emission patterns for each gas during the measurement periods. For all compounds, the emissions during the covered period were significantly lower than during the two uncovered periods. The reduction due to coverage was 92–95% for NH3, 25–40% for CH4, and 82–89% for N2O. NH3 emissions were highest immediately after coverage removal and during stockpile removal. CH4 emissions were highest during stockpile removal and lowest during coverage. N2O emissions were lowest during coverage but a notable increase after coverage removal was observed. The temperature within the stockpile showed variations at different heights, with the highest temperatures recorded in the middle of the stockpile. GHG emissions, based on global warming potential, indicate substantial contributions from N2O, accounting for 55–72% of emissions in CO2-equivalents during uncovered periods and 27% during coverage. Furthermore, GHG emissions were reduced 63–72% during coverage compared to the uncovered periods highlighting the importance for immediate coverage of stockpiles to minimise NH3 and GHG emissions.
... Emission depends on several factors, including the application technique, weather, and slurry and soil properties (Hafner et al., 2018;Huijsmans et al., 2016;Webb et al., 2010). However, there are significant knowledge gaps regarding the effects of factors that influence emission, including interactions. ...
Field-applied liquid animal manure (slurry) is a significant source of ammonia (NH3) emission, which is harmful to the environment and human health. To evaluate mitigation options, reliable emission measurement methods are needed. A new system of dynamic flux chambers (DFCs) with high-temporal-resolution online measurements was developed. The system was investigated in silico with computational fluid dynamics and tested using three respective field trials, with each trial assessing the variability in the measured emission after application with trailing hose at different scales: manual (handheld) application, a 3 m experimental slurry boom, and a 30 m farm-scale commercial slurry boom. For the experiments with machine application, parallel NH3 emission measurements were made using an inverse dispersion modeling method (backward Lagrangian stochastic, bLS, modeling). The lowest coefficient of variation among replicate DFC measurements was obtained with manual application (5 %), followed by the 3 m slurry boom (14 %), and lastly the 30 m slurry boom (20 %). Conditions in DFCs resulted in a consistently higher NH3 flux than that measured with the inverse dispersion technique, but both methods showed a similar emission reduction by injection compared with the trailing hose: 89 % by DFC and 97 % by bLS modeling. The new measurement system facilitates NH3 emission measurement with replication after both manual and farm-scale slurry application with relatively high precision.
... Concentrations were measured continuously every 2 s with two CRDS instruments (model G2103 or G2509, Picarro Inc., Santa Clara, CA, USA). The instrument models have been evaluated for potential interference in an agricultural environment (Garcia et al., 2024;Kamp et al., 2019), while the model G2509 has been evaluated with the bLS method with release of know quantities of ammonia and methane (Yolanda Maria Lemes et al., 2023). With a sampling line, methane emission measured by bLS was 95 ± 8 % of the released amount, but only 82 ± 5 % for ammonia with the best sampling line when measuring some distance from the source. ...
Ammonia emission following field application of animal slurry is a significant problem for the environment and human health. Accurate emission measurements are crucial for inventories, research, and mitigation. However, there may be large differences between results obtained with different methods. In this study measurement methods were compared in two field experiments: in Denmark (I-AU, trailing hose application, summer, arable land) and the Netherlands (II-WUR, slurry shallow injection, autumn, grassland) over 7 days each. Two micrometeorological methods (Integrated Horizontal Flux (IHF) and backward Lagrangian stochastic (bLS)) and three enclosure methods (Dräger tube method (DTM), wind tunnels (WT), and dynamic flux chambers (FC)) were included in one or both. Measuring in parallel eliminated effects of local factors influencing emission. Relative systematic error in micrometeorological methods (bLS variants and IHF) was estimated from measurements as about 25 % as a standard deviation among methods based on random-effects models. DTM emission measurements were lower than other methods by as much as 34 % of applied TAN compared to bLS. The emission rate measured by IHF followed the same pattern as the other methods soon after slurry application, but total emission was lower (5 % of applied TAN lower than bLS). Different concentration measurement methods used with bLS showed differences of 1-13 % of applied TAN. FC emission was 9-15 % of applied TAN higher than IHF and bLS, but 13 % lower than WT. WT emissions were high and depended on the air exchange rate. Overall relative uncertainty in total emission measured with micrometeorological methods was estimated at 24 and 31 % of the measured value (standard deviation), implying a 95 % confidence interval of about 60 %-160 % of emission measured in a single plot using a micrometeorological method.
