Diurnal and Seasonal Patterns of Methane Emissions from a Dairy Operation in North China Plain

In China, dairy cattle managed in collective feedlots contribute about 30% of the milk production and are believed to be an important contributor to national methane emissions. Methane emissions from a collective dairy feedlot in North China Plain (NCP) were measured during the winter, spring, summer, and fall seasons with open-path lasers in combination with an inverse dispersion technique. Methane emissions from the selected dairy feedlot were characterized by an apparent diurnal pattern with three peaks corresponding to the schedule of feeding activities. On a per capita basis, daily methane emission rates of these four seasons were 0.28, 0.32, 0.33, and 0.30 kg head−1 d−1, respectively. In summary, annual methane emission rate was 112.4 kg head−1 yr−1associated with methane emission intensity of 32.65 L CH4L−1of milk and potential methane conversion factor Ymof 6.66% of gross energy intake for mature dairy cows in North China Plain.

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Methane emissions from a swine manure tank in western Canada

Canadian Journal of Animal Science ◽

10.4141/cjas2012-072 ◽

2013 ◽

Vol 93 (1) ◽

pp. 159-169 ◽

Cited By ~ 12

Author(s):

Thomas K. Flesch ◽

Xavier P. C. Vergé ◽

Raymond L. Desjardins ◽

Devon Worth

Keyword(s):

Swine Manure ◽

Methane Emissions ◽

Western Canada ◽

Emission Rates ◽

Storage Duration ◽

Intergovernmental Panel ◽

Inverse Dispersion ◽

Calculation Methodology ◽

Dispersion Technique ◽

Solids Content

Flesch, T. K., Vergé, X. P. C., Desjardins, R. L. and Worth, D. 2013. Methane emissions from a swine manure tank in western Canada. Can. J. Anim. Sci. 93: 159–169. The emission rate of methane (CH4) to the atmosphere was measured from a concrete manure tank at a farrow-to-finish swine facility in western Canada. Measurements were made during four seasonal campaigns using a bLS inverse-dispersion technique. Emission rates were highest in summer and lowest in winter, with intermediate rates in spring and fall. Annual emissions were estimated at 7600 kg CH4, or 6.3 kg CH4 m−2 of tank surface area. Site-specific factors used for estimating CH4 emissions were calculated from our measurements. A simple methane conversion factor, used by the Intergovernmental Panel on Climate Change to relate emissions to the volatile solids content of the manure, was calculated as 0.23. This value may be unrepresentatively high due to the long duration (15 mo) that manure was stored in the tank. A more sophisticated calculation methodology considers the influence of manure storage duration and temperature, and includes a critical management design practices (MDP) factor. The MDP factor was calculated as 0.31 for our tank. This MDP value implies that emissions from our manure tank were lower than expected given the results from other studies.

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Seasonal variations in the high time-resolved aerosol composition, sources, and chemical process of background submicron particles in North China Plain

10.5194/acp-2020-213 ◽

2020 ◽

Author(s):

Jiayun Li ◽

Liming Cao ◽

Wenkang Gao ◽

Lingyan He ◽

Yingchao Yan ◽

...

Keyword(s):

Aqueous Phase ◽

Seasonal Variations ◽

North China Plain ◽

North China ◽

Organic Aerosol ◽

Submicron Particles ◽

Western China ◽

Aerosol Composition ◽

Oxidation Degree ◽

Four Seasons

Abstract. For the first time in the North China Plain (NCP), we investigated the seasonal variations of submicron particles (NR-PM1) and its chemical composition at a background mountain station using Aerodyne high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS). The averaged NR-PM1 were highest in autumn (15.1 μg m−3) and lowest in summer (12.4 μg m−3), with the abundance of more nitrate in spring (34 %), winter (31 %), and autumn (34 %), and elevated organics (40 %) and sulfate (38 %) proportion in summer. The submicron particles were almost neutralized by excess ammonium in all four seasons except summer, when the aerosol particles appeared to be slightly acidic. The size distribution of all PM1 species showed a consistent accumulation mode peaked at approximately 600–800 nm (dva), indicating the highly aged and internally mixed nature of the background aerosols, which further supported by the source appointment using multilinear engine (ME-2) and significant contributions of aged secondary organic aerosol (SOA) in organic aerosol (OA) were resolved in all seasons (> 77 %), especially in summer (95 %). The oxidation degree and evolution process of OAs in the four seasons were further investigated, and enhanced carbon oxidation state (−0.45–0.10), O / C (0.54–0.75) and OM / OC (1.86–2.13) ratios compared with urban studies were observed, with the highest oxidation degree of which appeared in summer, likely due to the relatively stronger photochemical processing which dominated the processes of both less oxidized OA (LO-OOA) and more oxidized OA (MO-OOA) formations. Aqueous-phase processing also contributed to the SOA formation but prevailed in autumn and winter and the role of which to MO-OOA and LO-OOA also varied in different seasons. In addition, compared with the urban atmosphere, LO-OOA formation in the background atmosphere exhibited more regional characteristics, as photochemical and aqueous-phase processing enhanced during the transport in summer and autumn, respectively. Furthermore, the backward trajectories analysis showed that higher submicron particles were associated with air mass for short distance transported from the southern regions in four seasons, while the long-range transport from Inner Mongolia (west and north regions) also contributed to the summer particle pollutions in the background areas of NCP. Our results illustrate the background particles in NCP are influenced significantly by aging processing and transport, and the more neutralized state of submicron particles with the abundance of nitrate compared with those in the background atmosphere in southern and western China, highlighting the regional reductions in emissions of nitrogen oxide and ammonia are critical for remedying the increased occurrence of nitrate-dominated haze event in the NCP.

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Influence of elevated carbon dioxide concentrations on methane emission and its associated soil microflora in rice ecosystem

Journal of Applied and Natural Science ◽

10.31018/jans.v13isi.2773 ◽

2021 ◽

Vol 13 (SI) ◽

pp. 26-34

Author(s):

S. K. Rajkishore ◽

M. Maheswari ◽

K. S. Subramanian ◽

R. Prabhu ◽

G. Vanitha

Keyword(s):

Elevated Co2 ◽

Methane Emission ◽

Methane Flux ◽

Methane Emissions ◽

Soil Microflora ◽

Mitigation Strategies ◽

Emission Rates ◽

Randomized Design ◽

Dry Soil ◽

Rice Ecosystem

The dynamics of methane emission and its associated soil microflora in rice ecosystem as a response to elevated CO2 concentrations were studied in open top chamber (OTC) conditions. The treatments consisted of three levels of CO2 (396, 550 and 750 µmol mol-1) and three levels of nitrogen (0, 150 and 200 kg ha-1) and replicated five times in a completely randomized design. The data showed that elevated [CO2] significantly (P ? 0.01) increased the DOC throughout the cropping period with the values ranging from 533 to 722 mg L-1 and 368 to 501 mg L-1 in C750 and Camb, respectively. Methane emission rates were monitored regularly during the experiment period and it was revealed that elevated [CO2] had increased the methane emissions regardless of stages of crop growth. It was observed that methane emissions were significantly higher under [CO2] of 750 µmol mol-1 by 33 to 54 per cent over the ambient [CO2] of 396 µmol mol-1. Consistent with the observed increases in methane flux, the enumeration of methanogens showed a significant (P ? 0.01) increase under elevated [CO2] with the population ranging from 5.7 to 20.1 x 104 CFU g-1 of dry soil and 5.1 to 16.9 x 104 CFU g-1 of dry soil under C750 and Camb concentrations, respectively. Interestingly, even though higher methanotrophs population was recorded under elevated [CO2], it could not circumvent the methane emission. Overall, the results of OTC studies suggest that methane mitigation strategies need to be explored for the future high CO2 environments.

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Estimating ammonia emissions from a winter wheat cropland in North China Plain with field experiments and inverse dispersion modeling

Atmospheric Environment ◽

10.1016/j.atmosenv.2015.01.003 ◽

2015 ◽

Vol 104 ◽

pp. 1-10 ◽

Cited By ~ 19

Author(s):

Qing Huo ◽

Xuhui Cai ◽

Ling Kang ◽

Hongsheng Zhang ◽

Yu Song ◽

...

Keyword(s):

Winter Wheat ◽

North China Plain ◽

North China ◽

Field Experiments ◽

Dispersion Modeling ◽

Ammonia Emissions ◽

Inverse Dispersion ◽

Inverse Dispersion Modeling

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Seasonal effects of additional HONO sources and the heterogeneous reactions of N2O5 on nitrate in the North China Plain

10.5194/egusphere-egu2020-1476 ◽

2020 ◽

Author(s):

Yu Qu ◽

Junling An

Keyword(s):

North China Plain ◽

North China ◽

Heterogeneous Reaction ◽

Heterogeneous Reactions ◽

Seasonal Effects ◽

Weather Research And Forecasting ◽

The North ◽

The North China Plain ◽

Four Seasons ◽

Hydrolysis Of

We coupled the heterogeneous hydrolysis of N2O5 into the newly updated Weather Research and Forecasting model with Chemistry (WRF-Chem) to reveal the relative importance of the hydrolysis of N2O5 and additional nitrous acid (HONO) sources for the formation of nitrate during high PM2.5 events in the North China Plain (NCP) in four seasons. The results showed that additional HONO sources produced the largest nitrate concentrations in winter and negligible nitrates in summer, leading to a 10% enhancement of a PM2.5 peak in southern Beijing and a 15% enhancement in southeastern Hebei in winter. In contrast, the hydrolysis of N2O5 produced high nitrate in summer and low nitrate in winter, with the largest contribution of nearly 20% for a PM2.5 peak in southeastern Hebei in summer. During PM2.5 explosive growth events, the additional HONO sources played a key role in nitrate increases in southern Beijing and southwestern Hebei in winter, whereas the hydrolysis of N2O5 contributed the most to a rapid increase in nitrate in other seasons. HONO photolysis produced more hydroxyl radicals, which were greater than 1.5 &#956;g m-3 h-1 in the early explosive stage and led to a rapid nitrate increase at the southwestern Hebei sites in winter, while the heterogeneous reaction of N2O5 contributed greatly to a significant increase in nitrate in summer. The above results suggest that the additional HONO sources and the heterogeneous hydrolysis of N2O5 contributed the most to nitrate formation in NCP in winter and summer, respectively.

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PSIX-2 Feeding 3-nitrooxypropanol reduces methane emissions by feedlot cattle

Journal of Animal Science ◽

10.1093/jas/skaa278.727 ◽

2020 ◽

Vol 98 (Supplement_4) ◽

pp. 416-417

Author(s):

Tiago Luís Da Ros de Araújo ◽

Alvair Hoffmann ◽

Diego M Renesto ◽

Rhaony G Leite ◽

Carlos H S Rabelo ◽

...

Keyword(s):

Methane Emission ◽

Sulfur Hexafluoride ◽

Dietary Supplementation ◽

Experimental Period ◽

Methane Emissions ◽

Feedlot Cattle ◽

Experimental Unit ◽

Gross Energy ◽

And Performance ◽

The Individual

Abstract Our objective was to evaluate the effects of feeding 3-nitrooxypropanol (3NOP; Bovaer®, DSM Nutritional Products) at two doses on methane emissions and performance by feedlot cattle. The experiment was designed as a completely randomized block, in which 138 Nellore bulls (iBW, 360 ± 37.3 kg) were placed in collective pens (9 pens per treatment) and fed a high-concentrate diet (R:C, 11:89) according with the following three treatments: 1) 0ppm 3NOP /day; 2) 100ppm 3NOP/day, or 3) 150ppm 3NOP/day. For performance and DMI assessments the pen was the experimental unit. For methane emission evaluations, CH4 and DMI were assessed individually in 12 pens (2 bulls/pen, 8 bulls (experimental units)/treatment). Methane emission was measured for 6 consecutive days using the sulfur hexafluoride (SF6) tracer technique in two times over the experimental period (d15d -d21) and (105d to 111d), whereby the gross energy (GE) variables were calculated using equations. The individual DMI was measured using the two markers technique (Chromium oxide and indigestible NDF). The data were analyzed using the Mixed procedure of SAS and means comparison were carried out by Tukey’s test. Regardless of the level, dietary supplementation with 3NOP decreased (P < 0.001) methane emissions by 49.7% as expressed as g/d (146.0 vs. ~74 g/d−1); by 38.6% when expressed as g/kg ADG (91 vs ~56 g/kg ADG), and by 40.7% when expressed as g/kg DMI (13.5 vs. ~8 g/kg DMI). Likewise, dietary supplementation with 3NOP decreased (P < 0.001) the GE loss as a percentage of the GE intake by 42.4% (4.74 vs ~2.73%). However, feeding 3NOP had no effect on animalsˈ DM intake (~2.43 %BW; P = 0.23), ADG (~1.52 kg/d; P = 0.11) and HCW (~284 kg, P = 0.26). We conclude that Bovaer® can be used to effectively reduce methane emission by feedlot cattle without adverse effects on performance.

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Seasonal variations in the highly time-resolved aerosol composition, sources and chemical processes of background submicron particles in the North China Plain

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-4521-2021 ◽

2021 ◽

Vol 21 (6) ◽

pp. 4521-4539

Author(s):

Jiayun Li ◽

Liming Cao ◽

Wenkang Gao ◽

Lingyan He ◽

Yingchao Yan ◽

...

Keyword(s):

Oxidation State ◽

Seasonal Variations ◽

North China Plain ◽

North China ◽

Organic Aerosol ◽

Submicron Particles ◽

Regional Transport ◽

The North ◽

The North China Plain ◽

Four Seasons

Abstract. For the first time in the North China Plain (NCP) region, we investigated the seasonal variations in submicron particles (NR-PM1) and their chemical composition at a background mountainous site of Xinglong using an Aerodyne high-resolution time-of-flight aerosol mass spectrometer. The average concentration of NR-PM1 was highest in autumn (15.1 µg m−3) and lowest in summer (12.4 µg m−3), with a greater abundance of nitrate in spring (34 %), winter (31 %) and autumn (34 %) and elevated organics (40 %) and sulfate (38 %) in summer. PM1 in Xinglong showed higher acidity in summer and moderate acidity in spring, autumn and winter, with average pH values of 2.7±0.6, 4.2±0.7, 3.5±0.5 and 3.7±0.6, respectively, which is higher than those estimated in the United States and Europe. The size distribution of all PM1 species showed a consistent accumulation mode peaking at approximately 600–800 nm (dva), indicating a highly aged and internally mixed nature of the background aerosols, which was further supported by the source appointment results using positive matrix factorization and multilinear engine analysis. Significant contributions of aged secondary organic aerosol (SOA) in organic aerosol (OA) were resolved in all seasons (>77 %), especially in summer. The oxidation state and the process of evolution of OAs in the four seasons were further investigated, and an enhanced carbon oxidation state (−0.45–0.10) and O/C (0.54–0.75) and OM/OC (1.86–2.13) ratios – compared with urban studies – were observed, with the highest oxidation state appearing in summer, likely because of the relatively stronger photochemical processing that dominated the formation processes of both less oxidized OA (LO-OOA) and more oxidized OA (MO-OOA). Aqueous-phase processing also contributed to the SOA formation and prevailed in winter, with the share to MO-OOA being more important than that to LO-OOA. In addition, regional transport also played an important role in the variations in SOA. Especially in summer, continuous increases in SOA concentration as a function of odd oxygen (Ox=O3+NO2) were found to be associated with the increases in wind speed. Furthermore, backward trajectory analysis showed that higher concentrations of submicron particles were associated with air masses transported short distances from the southern regions in all four seasons, while long-range transport from Inner Mongolia (western and northern regions) also contributed to summertime particulate pollution in the background areas of the NCP. Our results illustrate that the background particles in the NCP are influenced significantly by aging processes and regional transport, and the increased contribution of aerosol nitrate highlights how regional reductions in nitrogen oxide emissions are critical for remedying occurrence of nitrate-dominated haze events over the NCP.

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