scholarly journals Influence of Aeration Method on Gaseous Emissions and the Losses of the Carbon and Nitrogen during Cow Manure Composting

2021 ◽  
Vol 11 (24) ◽  
pp. 11639
Author(s):  
Youling Wang ◽  
Huizhen Qiu ◽  
Mengchan Li ◽  
Philip Ghanney

The objective of this research was to explore the effects of different aeration methods on NH3 and greenhouse gas (GHG) emissions and the losses of carbon and nitrogen from composting of cow manure and corn stalks in the laboratory-scale reactors. Here, we designed three treatments, including continuous aerated treatment C1 (aeration rates 0.21 L·kg−1 dry matter (DM)·min−1) and intermittent aerated treatments I1 (aeration rates 0.42 L·kg−1 DM·min−1; aerate 10 min, stop 10 min) and I2 (aeration rates 0.84 L·kg−1 DM·min−1; aerate 5 min, stop 15 min). The results showed that the physicochemical parameters (temperature, pH values, and germination index) of composting products met the requirements of maturity and sanitation. Compared with continuous aerated treatment C1, the cumulative NH3 emissions of I1 and I2 treatments decreased by 24.37% and 19.27%, while the cumulative CO2 emissions decreased by 13.01% and 20.72%. On the contrary, the cumulative N2O emissions of I1 and I2 treatments increased by 22.22% and 43.14%. CO2 emission was the principal pathway for the TOC losses, which comprised over 65% of TOC losses. C1 treatment had the highest TOC losses due to its highest cumulative CO2 emissions. The TN losses of I1 and I2 treatments reduced 9.07% and 6.1% compared to C1 treatment, so the intermittent aerated modes could reduce the TN loss. Due to the potential for mitigation of gaseous emissions, I1 treatment was recommended to be used in aerobic composting of cow manure.

2017 ◽  
Vol 14 (10) ◽  
pp. 2611-2626 ◽  
Author(s):  
Amanuel W. Gebremichael ◽  
Bruce Osborne ◽  
Patrick Orr

Abstract. Given their increasing trend in Europe, an understanding of the role that flooding events play in carbon (C) and nitrogen (N) cycling and greenhouse gas (GHG) emissions will be important for improved assessments of local and regional GHG budgets. This study presents the results of an analysis of the CO2 and N2O fluxes from a coastal grassland ecosystem affected by episodic flooding that was of either a relatively short (SFS) or long (LFS) duration. Compared to the SFS, the annual CO2 and N2O emissions were 1.4 and 1.3 times higher at the LFS, respectively. Mean CO2 emissions during the period of standing water were 144 ± 18.18 and 111 ± 9.51 mg CO2–C m−2 h−1, respectively, for the LFS and SFS sites. During the growing season, when there was no standing water, the CO2 emissions were significantly larger from the LFS (244 ± 24.88 mg CO2–C m−2 h−1) than the SFS (183 ± 14.90 mg CO2–C m−2 h−1). Fluxes of N2O ranged from −0.37 to 0.65 mg N2O–N m−2 h−1 at the LFS and from −0.50 to 0.55 mg N2O–N m−2 h−1 at the SFS, with the larger emissions associated with the presence of standing water at the LFS but during the growing season at the SFS. Overall, soil temperature and moisture were identified as the main drivers of the seasonal changes in CO2 fluxes, but neither adequately explained the variations in N2O fluxes. Analysis of total C, N, microbial biomass and Q10 values indicated that the higher CO2 emissions from the LFS were linked to the flooding-associated influx of nutrients and alterations in soil microbial populations. These results demonstrate that annual CO2 and N2O emissions can be higher in longer-term flooded sites that receive significant amounts of nutrients, although this may depend on the restriction of diffusional limitations due to the presence of standing water to periods of the year when the potential for gaseous emissions are low.


Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 563
Author(s):  
Kelsey Anderson ◽  
Philip A. Moore ◽  
Jerry Martin ◽  
Amanda J. Ashworth

Gaseous emissions from poultry litter causes production problems for producers as well as the environment, by contributing to climate change and reducing air quality. Novel methods of reducing ammonia (NH3) and greenhouse gas (GHG) emissions in poultry facilities are needed. As such, our research evaluated GHG emissions over a 42 d period. Three separate flocks of 1000 broilers were used for this study. The first flock was used only to produce litter needed for the experiment. The second and third flocks were allocated to 20 pens in a randomized block design with four replicated of five treatments. The management practices studied included an unamended control; a conventional practice of incorporating aluminum sulfate (referred to as alum) at 98 kg/100 m2); a novel litter amendment made from alum mud, bauxite, and sulfuric acid (alum mud litter amendment, AMLA) applied at different rates (49 and 98 kg/100 m2) and methods (surface applied or incorporated). Nitrous oxide emissions were low for all treatments in flocks 2 and 3 (0.40 and 0.37 mg m2 hr−1, respectively). The formation of caked litter (due to excessive moisture) during day 35 and 42 caused high variability in CH4 and CO2 emissions. Alum mud litter amendment and alum did not significantly affect GHGs emissions from litter, regardless of the amendment rate or application method. In fact, litter amendments such as alum and AMLA typically lower GHG emissions from poultry facilities by reducing ventilation requirements to maintain air quality in cooler months due to lower NH3 levels, resulting in less propane use and concomitant reductions in CO2 emissions.


2019 ◽  
Vol 1 (2) ◽  
pp. 145-152 ◽  
Author(s):  
Martin Ngwabie ◽  
Andrew VanderZaag ◽  
Paulicle Nji ◽  
Gerald Tembong ◽  
Theodore Chenwi

Abattoirs are potentially a significant source of greenhouse gas (GHG) methane (CH4) and nitrous oxide (N2O) emissions. Measurements were conducted in a beef cattle abattoir located in Bamenda, Cameroon, to characterise waste production and quantify GHG emissions. A male and female cattle were randomly selected on each day for waste measurement over a period of two weeks. Waste from each cattle was quantified by collecting all the intestinal/stomach contents after slaughtering and determining the mass of dry matter (DM) and volatile solids (VS). Emissions from the outdoor solid waste storage heap was measured using flux chambers. The average cattle weight was 420 kg and the average intestinal/stomach waste was 37 ± 6 kg cattle−1, half of which was dumped outdoor in a heap, while the rest was discarded with wastewater into a stream. The DM produced was 4.19 ± 0.85 kg cattle−1, representing 11% of the wastes, and the VS produced was 3.42 ± 0.82 kg cattle−1. The average ratio of waste DM to cattle weight was 1.0%, while the ratio of waste VS to cattle weight was 0.8%. Modelled CH4 emissions from the total waste was estimated at 37.84 ± 8 g CH4 cattle−1 with a range of 27.57–56.03 g CH4 cattle−1. Measured GHG emission from the outdoor heap was 5.89 ± 4.78 mg CH4 m−2 min−1, 0.137 ± 0.151 mg N2O m−2 min−1, and 95 ± 83 mg CO2 m−2 min−1. The total GHG (CH4 + N2O) emission rate was 229 mg CO2e m−2 min−1, indicating that CH4 contributes 82% of the total GHG. Improved waste management strategies, such as anaerobic digestion for biogas production or using covers over waste heaps, would help abattoirs mitigate GHG emissions.


Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 662
Author(s):  
Bassim Mohammed Hashim ◽  
Maitham Abdullah Sultan ◽  
Ali Al Maliki ◽  
Nadhir Al-Ansari

The energy sector is integral to the wellbeing of the entire Iraqi economy and will remain so well into the future. In the current study, the Intergovernmental Panel on Climate Change (IPCC) methodology was used to estimate CO2, CH4, and N2O emissions from oil refining and electricity generation in Iraq for a period exceeding 25 years. From 1990, Iraq experienced two wars and an economic siege, then faced political, social, and security instability, which affected its energy production. The results showed that the CO2, CH4, and N2O emissions from the oil refining and electricity generation in Iraq experienced a sharp decline in the years 1991, 2003, and 2007 due to a decrease in the production of oil derivatives in refineries, according to political and security conditions. The total CO2 emissions from the types of fuel used in electricity generation in Iraq was approximately 14,000 Gg and 58,000 Gg in 1990 and 2017, respectively. The increase in CO2 emissions was greater than 300% between 1990 and 2017. The continued use of poor types of fuel, such as fuel oil and crude oil, will lead to an increase in greenhouse gas (GHG) emissions from these sources, and higher levels of environmental pollution.


2020 ◽  
Vol 17 (8) ◽  
pp. 2149-2167 ◽  
Author(s):  
Sheila Wachiye ◽  
Lutz Merbold ◽  
Timo Vesala ◽  
Janne Rinne ◽  
Matti Räsänen ◽  
...  

Abstract. Field measurement data on greenhouse gas (GHG) emissions are still scarce for many land-use types in Africa, causing a high level of uncertainty in GHG budgets. To address this gap, we present in situ measurements of carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) emissions from the lowlands of southern Kenya. We conducted eight chamber measurement campaigns on gas exchange from four dominant land-use types (LUTs) comprising (1) cropland, (2) bushland, (3) grazing land, and (4) conservation land between 29 November 2017 and 3 November 2018, accounting for regional seasonality (wet and dry seasons and transitions periods). Mean CO2 emissions for the whole observation period were the highest by a significant margin (p value < 0.05) in the conservation land (75±6 mg CO2-C m−2 h−1) compared to the three other sites, which ranged from 45±4 mg CO2-C m−2 h−1 (bushland) to 50±5 mg CO2-C m−2 h−1 (grazing land). Furthermore, CO2 emissions varied between seasons, with significantly higher emissions in the wet season than the dry season. Mean N2O emissions were highest in cropland (2.7±0.6 µg N2O-N m−2 h−1) and lowest in bushland (1.2±0.4  µg N2O-N m−2 h−1) but did not vary with season. In fact, N2O emissions were very low both in the wet and dry seasons, with slightly elevated values during the early days of the wet seasons in all LUTs. On the other hand, CH4 emissions did not show any significant differences across LUTs and seasons. Most CH4 fluxes were below the limit of detection (LOD, ±0.03 mg CH4-C m−2 h−1). We attributed the difference in soil CO2 emissions between the four sites to soil C content, which differed between the sites and was highest in the conservation land. In addition, CO2 and N2O emissions positively correlated with soil moisture, thus an increase in soil moisture led to an increase in emissions. Furthermore, vegetation cover explained the seasonal variation in soil CO2 emissions as depicted by a strong positive correlation between the normalized difference vegetation index (NDVI) and CO2 emissions, most likely because, with more green (active) vegetation cover, higher CO2 emissions occur due to enhanced root respiration compared to drier periods. Soil temperature did not show a clear correlation with either CO2 or N2O emissions, which is likely due to the low variability in soil temperature between seasons and sites. Based on our results, soil C, active vegetation cover, and soil moisture are key drivers of soil GHG emissions in all the tested LUTs in southern Kenya. Our results are within the range of previous GHG flux measurements from soils from various LUTs in other parts of Kenya and contribute to more accurate baseline GHG emission estimates from Africa, which are key to reducing uncertainties in global GHG budgets as well as for informing policymakers when discussing low-emission development strategies.


Author(s):  
Wang ◽  
Yang ◽  
Ren ◽  
He ◽  
Wei ◽  
...  

Alternative irrigation between saline water and groundwater can alleviate shortages of available agricultural water while effectively slowing the adverse effects of saline water on the soil-crop system when compared with continuous irrigation with saline water and blending irrigation between saline water and groundwater. In 2018, we tested the effect on soil CO2 and N2O emissions by two types of irrigation regimes (alternating groundwater and saline water (GW-SW), and alternating groundwater, followed by two cycles of saline water (GW-SW-SW)) between groundwater and three levels of salinity of irrigation water (mineralization of 2 g/L, 3.5 g/L, and 5 g/L), analyzed the correlation between gas emissions and soil properties, calculated comprehensive global warming potential (GWP), and investigated the maize yield. The results show that, with the same alternate irrigation regime, cumulative CO2 emissions decreased with increasing irrigation water salinity, and cumulative N2O emissions increased. Cumulative CO2 emissions were higher in the GW-SW regime for the same irrigation water salinity, and cumulative N2O emissions were higher in the GW-SW-SW regime. The GW-SW-SW regime had less comprehensive GWP and maize yield as compared to the GW-SW regime. The 2 g/L salinity in both regimes showed larger comprehensive GWP and maize yield. The 3.5 g/L salinity under the GW-SW regime will be the best choice while considering that the smaller comprehensive GWP and the larger maize yield are appropriate for agricultural implication. Fertilizer type and irrigation amount can be taken into consideration in future research direction.


Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 189
Author(s):  
Jinbiao Li ◽  
Jin-Hyeob Kwak ◽  
Scott X. Chang ◽  
Xiaoqiang Gong ◽  
Zhengfeng An ◽  
...  

Forestlands are widely distributed in the dominantly agricultural landscape in western Canada, and they play important ecological functions; such forestlands (e.g., shelterbelts) accumulate soil organic matter and may receive a substantial amount of nitrogen in the form of surface and subsurface runoff from adjacent croplands and become a significant source of emissions of greenhouse gases (GHGs) such as CO2, N2O, and CH4. Biochar and nitrapyrin applications could potentially mitigate GHG emissions, but their co-application in forest soils has not been studied. We investigated the effect of the application of biochars produced at low (300 °C; BC300) and high temperatures (700 °C; BC700) using canola (Brassica napus L.) straw and the effect of their co-application with nitrapyrin on GHG emissions and soil properties in a 35-day laboratory incubation experiment using forest soils collected from five shelterbelt sites. Results showed no significant interaction effect of biochar and nitrapyrin on the global warming potential (GWP) of the GHG emissions, and the GWP was 15.8% lower in the soil with nitrapyrin than without nitrapyrin application treatments. The GWP was significantly enhanced by BC300 addition due to a 26.9% and 627.1% increase in cumulative CO2 and N2O emissions, respectively, over the 35-day incubation. The GWP significantly decreased by BC700 addition due to a 27.1% decrease in cumulative CO2 emissions. However, biochar addition did not affect CH4 emissions, while nitrapyrin decreased CH4 uptake by 50.5%. With BC300 addition, soil-dissolved organic carbon and microbial biomass carbon increased by 26.5% and 33.9%, respectively, as compared to no biochar addition (CK). Soil pH increased by 0.16 and 0.37 units after the addition of BC300 and BC700, respectively. Overall, the effect of biochar and nitrapyrin was independent in mitigating GHG emissions and was related to the type of biochar applied and changes in soil properties.


2017 ◽  
Author(s):  
Amanuel W. Gebremichael ◽  
Bruce Osborne ◽  
Patrick Orr

Abstract. Given their increasing trend in Europe, an understanding of the role that flooding events play in carbon and nitrogen cycling and greenhouse gas (GHG) emissions will be important for improved assessments of local and regional GHG budgets. This study presents the results of an analysis of the CO2 and N2O fluxes from a coastal grassland ecosystem affected by episodic flooding that was of either a relatively short or long duration (SFS and LFS sites, respectively). Compared to the SFS, the annual CO2 and N2O emissions were 1.4 and 1.3 times higher at the LFS, respectively. Mean CO2 emissions during the period of standing water were 144 ± 18.18 and 111 ± 9.51 mg CO2-C m−2 h−1, respectively, for the LFS and SFS sites. During the growing season, when there was no standing water, the CO2 emissions were significantly larger from the LFS (244 ± 24.88 mg CO2-C m−2 h−1) than the SFS (183 ± 14.90 mg CO2-C m−2 h−1). Fluxes of N2O ranged from −0.37 to 0.65 mg N2O-N m−2 h−1 at the LFS and from −0.50 to 0.55 mg N2O-N m−2 h−1 at the SFS, with the larger emissions associated with the presence of standing water at the LFS and during the growing season at the SFS. Overall, soil temperature and moisture content were identified as the main drivers of the seasonal changes in CO2 fluxes, but neither adequately explained the variations in N2O fluxes. Analysis of total Carbon (C), Nitrogen (N), microbial biomass and Q10 values, indicated that the higher CO2 emissions from the LFS were linked to the flooding-associated influx of nutrients and alterations in soil microbial populations. These results demonstrate that annual CO2 and N2O emissions can be higher in longer-term flooded sites that receive significant amounts of nutrients and where diffusional limitations due to the presence of standing water is limited to periods of the year when the temperatures are lowest.


2021 ◽  
Vol 18 (17) ◽  
pp. 4855-4872
Author(s):  
Xinyu Liu ◽  
Xixi Lu ◽  
Ruihong Yu ◽  
Heyang Sun ◽  
Hao Xue ◽  
...  

Abstract. Gradual riparian wetland drying is increasingly sensitive to global warming and contributes to climate change. Riparian wetlands play a significant role in regulating carbon and nitrogen cycles. In this study, we analyzed the emissions of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) from riparian wetlands in the Xilin River basin to understand the role of these ecosystems in greenhouse gas (GHG) emissions. Moreover, the impact of the catchment hydrology and soil property variations on GHG emissions over time and space was evaluated. Our results demonstrate that riparian wetlands emit larger amounts of CO2 (335–2790 mgm-2h-1 in the wet season and 72–387 mgm-2h-1 in the dry season) than CH4 and N2O to the atmosphere due to high plant and soil respiration. The results also reveal clear seasonal variations and spatial patterns along the transects in the longitudinal direction. N2O emissions showed a spatiotemporal pattern similar to that of CO2 emissions. Near-stream sites were the only sources of CH4 emissions, while the other sites served as sinks for these emissions. Soil moisture content and soil temperature were the essential factors controlling GHG emissions, and abundant aboveground biomass promoted the CO2, CH4, and N2O emissions. Moreover, compared to different types of grasslands, riparian wetlands were the potential hotspots of GHG emissions in the Inner Mongolian region. Degradation of downstream wetlands has reduced the soil carbon pool by approximately 60 %, decreased CO2 emissions by approximately 35 %, and converted the wetland from a CH4 and N2O source to a sink. Our study showed that anthropogenic activities have extensively changed the hydrological characteristics of the riparian wetlands and might accelerate carbon loss, which could further affect GHG emissions.


Author(s):  
Hongsheng Guo ◽  
Brian Liko ◽  
Jennifer Littlejohns

Abstract The Paris agreement is exerting pressure on industries that generate significant greenhouse gas (GHG) emissions, such as transportation. Electrification can help reduce GHG emissions from light duty vehicles, but it is unfeasible for heavy duty vehicles that are predominately powered by diesel engines. Fuel switching from diesel to low carbon fuels is a more practical way helping reduce GHG emissions from heavy duty vehicles. Natural gas and renewable natural gas are low carbon or renewable fuels that generate much less carbon dioxide (CO2) emissions than diesel during combustion. Natural gas/renewable natural gas – diesel dual fuel combustion is an efficient way to replace diesel by natural gas/renewable natural gas in heavy duty diesel engines. This paper reports an experimental investigation on combustion and GHG emissions of a heavy duty natural gas – diesel dual fuel engine at different load/speed conditions. The variation in the effect of natural gas fraction on engine performance with changing engine load was compared and analyzed. Nitrous oxide (N2O), nitrogen oxides (NOx), methane (CH4) and CO2 emissions were experimentally investigated and analyzed. The results revealed that the effect of natural gas fraction on engine performance changed with varying engine load and speed condition. N2O emissions from a dual fuel engine changed with increasing natural gas fraction, but the effect of N2O emissions on overall GHG emissions was not significant. However, CH4 emissions contributed significantly to the overall GHG emissions in a dual fuel engine, especially at low load conditions.


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