Methane, nitrous oxide and ammonia emissions from an Australian piggery with short and long hydraulic retention-time effluent storage

2016 ◽  
Vol 56 (9) ◽  
pp. 1376 ◽  
Author(s):  
E. J. McGahan ◽  
F. A. Phillips ◽  
S. G. Wiedemann ◽  
T. A. Naylor ◽  
B. Warren ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Production Systems ◽  
Ghg Emissions ◽  
N2o Emissions ◽  
Ch4 Emissions ◽  
Volatile Solids ◽  
High Emission ◽  
Reduce Emissions

In the Australian pork industry, manure is the main source of greenhouse gases (GHG). In conventional production systems, effluent from sheds is transferred into open anaerobic ponds where the effluent is typically stored for many months, with the potential of generating large quantities of GHG. The present study measured methane (CH4), nitrous oxide (N2O) and ammonia (NH3) emissions from a conventional anaerobic effluent pond (control), a short hydraulic retention-time tank (short HRT, mitigation) and from the animal housing for a flushing piggery in south-eastern Queensland, over two 30-day trials during summer and winter. Emissions were compared to determine the potential for a short HRT to reduce emissions. Average CH4 emissions from the pond were 452 ± 37 g per animal unit (AU; 1 AU = 500 kg liveweight) per day, during the winter trial and 789 ± 29 g/AU.day during the summer trial. Average NH3 emissions were 73 ± 8 g/AU.day during the winter trial and 313 ± 18 g/AU.day during the summer trial. High emission factors during summer will be temperature driven and influenced by the residual volatile solids and nitrogen (N) deposited in the pond during winter. Average NH3 emissions from the piggery shed were 0.707 ± 0.050 g/AU.day and CH4 emissions were 0.344 ± 0.116 g/AU.day. The N2O concentrations from both the pond and shed were close to, or below, the detection limits. Total emissions from the short HRT during the winter and summer trials, respectively, were as follows: CH4 10.65 ± 0.616 mg/AU.day and 4108 ± 473 mg/AU.day; NH3-N 1.15 ± 0.07 mg/AU.day and 29.8 ± 2.57 mg/AU.day; N2O-N 0.001 ± 0.00052 mg/AU.day and 5.9 ± 0.321 mg/AU.day. On the basis of a conservative analysis of CH4 emissions relative to the inflow of volatile solids, and NH3 and N2O emissions as a fraction of the excreted N, GHG emissions were found to be 79% lower from the short-HRT system. This system provides a potential mitigation option to reduce GHG emissions from conventional pork production in Australia.

Impact of dicyandiamide application on nitrous oxide emissions from urine patches in northern Victoria, Australia

2008 ◽  
Vol 48 (2) ◽  
pp. 156 ◽  
Author(s):  
K. B. Kelly ◽  
F. A. Phillips ◽  
R. Baigent
Keyword(s):  
Nitrous Oxide ◽  
New Zealand ◽  
Dairy Cow ◽  
Production Systems ◽  
Animal Production ◽  
Soil Conditions ◽  
N2o Emissions ◽  
Cow Urine ◽  
Reduce Emissions ◽  
Animal Production Systems

Animal production systems in Australia are a significant contributor to nitrous oxide (N2O) emissions from soil, with the Australian Greenhouse Gas Inventory attributing ~25% of the N2O emissions from agricultural soils to animal production. Recent studies in New Zealand using dicyandiamide (DCD) in association with the application of urine to pastoral soil have reported reductions in N2O emission of up to 78% and reduced nitrate leaching of up to 45%. As such, the application of DCD to grazed pastures offers potential to reduce emissions resulting directly from animal production. This study was conducted on a border-check irrigated perennial pasture used for dairy production in northern Victoria. Automated enclosure chambers were linked to a fourier transformed infrared spectrometer to determine N2O emissions. The three treatments were a control, dairy cow urine (1000 kg N/ha) and dairy cow urine (1000 kg N/ha) with DCD included (10 kg/ha). The treatments were applied in mid-spring (15 September 2005) and again in mid-summer (25 January 2006) to a new area of pasture with N2O emissions measured for 120 and 70 days, respectively. Soil temperature and soil water content were monitored continuously. Soil inorganic-N was measured (0–100 mm) every 7 to 14 days for up to 120 days. Application of DCD reduced N2O emissions from a urine patch by 47% when applied in mid-spring and 27% when applied in mid-summer. The impact of the application of DCD on emissions from single urine patches lasted for ~50 days in mid-spring and 25 days in mid-summer. These reductions are lower than those reported in New Zealand studies and are likely to be related to soil conditions, principally temperature. The surface application of DCD has potential to reduce emissions from urine patches in northern Victoria; however, the effects are likely to be short-lived given the soil temperatures and high clay content typical of many Australian soils. More research is required to examine emission reduction options that are cost effective for animal production systems.

scholarly journals The Effects of System Changes in Grazed Dairy Farmlet Trials on Greenhouse Gas Emissions

Animals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 234 ◽  
Author(s):  
Tony van der Weerden ◽  
Pierre Beukes ◽  
Cecile de Klein ◽  
Kathryn Hutchinson ◽  
Lydia Farrell ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
New Zealand ◽  
Greenhouse Gas ◽  
Production Systems ◽  
Current System ◽  
Ghg Emissions ◽  
N Leaching ◽  
N2o Emissions ◽  
System Changes ◽  
Emissions Intensity

An important challenge facing the New Zealand (NZ) dairy industry is development of production systems that can maintain or increase production and profitability, while reducing impacts on receiving environments including water and air. Using research ‘farmlets’ in Waikato, Canterbury, and Otago (32–200 animals per herd), we assessed if system changes aimed at reducing nitrate leaching can also reduce total greenhouse gas (GHG) emissions (methane and nitrous oxide) and emissions intensity (kg GHG per unit of product) by comparing current and potential ‘improved’ dairy systems. Annual average GHG emissions for each system were estimated for three or four years using calculations based on the New Zealand Agricultural Inventory Methodology, but included key farmlet-specific emission factors determined from regional experiments. Total annual GHG footprints ranged between 10,800 kg and 20,600 kg CO2e/ha, with emissions strongly related to the amount of feed eaten. Methane (CH4) represented 75% to 84% of the total GHG footprint across all modelled systems, with enteric CH4 from lactating cows grazing pasture being the major source. Excreta deposition onto paddocks was the largest source of nitrous oxide (N2O) emissions, representing 7–12% of the total GHG footprint for all systems. When total emissions were represented on an intensity basis, ‘improved’ systems are predicted to generally result in lower emissions intensity. The ‘improved’ systems had lower GHG footprints than the ‘current’ system, except for one of the ‘improved’ systems in Canterbury, which had a higher stocking rate. The lower feed supplies and associated lower stocking rates of the ‘improved’ systems were the key drivers of lower total GHG emissions in all three regions. ‘Improved’ systems designed to reduced N leaching generally also reduced GHG emissions.

Effect of hydraulic retention time on pretreatment of blended municipal sludge

2011 ◽  
Vol 64 (4) ◽  
pp. 967-973
Author(s):  
S. Koyunluoglu-Aynur ◽  
R. Riffat ◽  
S. Murthy
Keyword(s):  
Retention Time ◽  
Volatile Fatty Acids ◽  
Hydraulic Retention Time ◽  
Operating Conditions ◽  
Methane Yield ◽  
Municipal Sludge ◽  
Volatile Solids ◽  
Significant Difference ◽  
Autothermal Thermophilic Aerobic Digestion ◽  
Pretreatment Processes

The objective of the present work was to evaluate the effect of hydraulic retention time (HRT) on hydrolysis and acidogenesis for the pretreatment processes: acid phase digestion (APD) and autothermal thermophilic aerobic digestion (ATAD) using blended municipal sludge. The effect of the different pretreatment steps on mesophilic anaerobic digestion (MAD) was evaluated in terms of methane yield, keeping the operating conditions of the MAD the same for all systems. Best operating conditions for both APD and ATAD were observed for 2.5 d HRT with high total volatile fatty acids (tVFA), and the highest methane yield observed for MAD. No significant difference was observed between the two processes in terms of overall volatile solids (VS) reduction with same total HRT. The autothermal process produced heat of 14,300 J/g VS removed from hydrolytic and acetogenic reactions without compromising overall methane yields when the HRT was 2.5 d or lower and the total O2 used was 0.10 m3 O2/g VS added or lower. However, the process needs the input of oxygen and engineering analysis should balance these differences when considering the relative merits of the two pretreatment processes. This is the first study of its kind directly comparing these two viable pretreatment processes with the same sludge.

Anaerobic thermophilic digestion of sewage sludge with a thickened sludge recycle

2012 ◽  
Vol 65 (3) ◽  
pp. 403-409 ◽  
Author(s):  
A. Ya. Vanyushina ◽  
Yu. A. Nikolaev ◽  
A. M. Agarev ◽  
M. V. Kevbrina ◽  
M. N. Kozlov
Keyword(s):  
Retention Time ◽  
Municipal Wastewater ◽  
Hydraulic Retention Time ◽  
Biogas Production ◽  
Wastewater Sludge ◽  
Recycling Process ◽  
Digested Sludge ◽  
Volatile Solids ◽  
Solids Retention ◽  
Thermophilic Digestion

The process of anaerobic thermophilic digestion of municipal wastewater sludge with a recycled part of thickened digested sludge, was studied in semi-continuous laboratory digesters. This modified recycling process resulted in increased solids retention time (SRT) with the same hydraulic retention time (HRT) as compared with traditional digestion without recycling. Increased SRT without increasing of HRT resulted in the enhancement of volatile substance reduction by up to 68% in the reactor with the recycling process compared with 34% in a control conventional reactor. Biogas production was intensified from 0.3 L/g of influent volatile solids (VS) in the control reactor up to 0.35 L/g VS. In addition, the recycling process improved the dewatering properties of digested sludge.

scholarly journals Greenhouse gas emissions profiles of neighbourhoods in Durban, South Africa – an initial investigation

2017 ◽  
Vol 30 (1) ◽  
pp. 191-214 ◽  
Author(s):  
Meryl Jagarnath ◽  
Tirusha Thambiran
Keyword(s):  
Greenhouse Gas ◽  
Ghg Emissions ◽  
Mitigation Strategies ◽  
Low Carbon ◽  
Economic Activities ◽  
Emissions Inventory ◽  
High Emission ◽  
Development Goals ◽  
Reduce Emissions ◽  
The City

Because current emissions accounting approaches focus on an entire city, cities are often considered to be large emitters of greenhouse gas (GHG) emissions, with no attention to the variation within them. This makes it more difficult to identify climate change mitigation strategies that can simultaneously reduce emissions and address place-specific development challenges. In response to this gap, a bottom-up emissions inventory study was undertaken to identify high emission zones and development goals for the Durban metropolitan area (eThekwini Municipality). The study is the first attempt at creating a spatially disaggregated emissions inventory for key sectors in Durban. The results indicate that particular groups and economic activities are responsible for more emissions, and socio-spatial development and emission inequalities are found both within the city and within the high emission zone. This is valuable information for the municipality in tailoring mitigation efforts to reduce emissions and address development gaps for low-carbon spatial planning whilst contributing to objectives for social justice.

Experimental Investigation of Effects of Split Diesel-Pilot Injection on Emissions From Ammonia-Diesel Dual Fuel Engine

2021 ◽  
Author(s):  
Yoichi Niki
Keyword(s):  
Diesel Fuel ◽  
Internal Combustion Engines ◽  
Ghg Emissions ◽  
High Reactivity ◽  
Dual Fuel ◽  
N2o Emissions ◽  
Injection Timing ◽  
Pilot Injection ◽  
Reduce Emissions ◽  
And Performance

Abstract NH3 has been investigated for its use as an alternative fuel including for use in internal combustion engines. In NH3 combustion, emissions of unburned NH3 with toxicity and N2O as a combustion product with high global warming potential (GWP) are important issues. However, few researchers have investigated NH3 and N2O emissions from NH3 assisted diesel engines operated using NH3–diesel dual fuel. We investigate a combustion strategy to reduce these emissions with a single-cylinder diesel engine mixed NH3 gas into the intake air. We found that an early diesel pilot injection reduced unburned NH3 and N2O emissions while HC and CO emissions increased. It was also reported that NH3 and diesel fuel work as low and high reactivity fuel for reactivity controlled compression ignition combustion (RCCI), respectively. Our previous study reports the aspects of RCCI on NH3–diesel dual fuel engine to some extent. The injection timing of diesel fuel and the quantity of NH3 govern the emissions and performance on RCCI combustion. These effects need to be investigated to manipulate the RCCI combustion and reduce emissions. This paper reports the efficiency and emissions for the diesel pilot injection timing sweep at various NH3 supply quantities and the effects of a split injection on the emissions and a combustion phase. In addition, we estimated the reduction in GHG emissions using a NH3–diesel dual fuel engine, which applied the early diesel pilot injection, compared with the diesel only operation, considering the N2O GWP.

scholarly journals Modelling Methane and Nitrous Oxide Emissions from Rice Paddy Wetlands in India Using Artificial Neural Networks (ANNs)

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2169 ◽  
Author(s):  
Tabassum Abbasi ◽  
Tasneem Abbasi ◽  
Chirchom Luithui ◽  
Shahid Abbas Abbasi
Keyword(s):  
Nitrous Oxide ◽  
Paddy Fields ◽  
Anthropogenic Sources ◽  
Nitrous Oxide Emissions ◽  
Soil Conditions ◽  
N2o Emissions ◽  
Ch4 Emissions ◽  
Artificial Neural ◽  
Ch4 And N2o

Paddy fields, which are shallow man-made wetlands, are estimated to be responsible for ~11% of the total methane emissions attributed to anthropogenic sources. The role of water use in driving these emissions, and the apportioning of the emissions to individual countries engaged in paddy cultivation, are aspects that have been mired in controversy and disagreement. This is largely due to the fact that methane (CH4) emissions not only change with the cultivar type but also regions, climate, soil type, soil conditions, manner of irrigation, type and quantity of fertilizer added—to name a few. The factors which can influence these aspects also encompass a wide range, and have origins in causes which can be physical, chemical, biological, and combinations of these. Exceedingly complex feedback mechanisms, exerting different magnitudes and types of influences on CH4 emissions under different conditions, are operative. Similar is the case of nitrous oxide (N2O); indeed, the present level of understanding of the factors which influence the quantum of its emission is still more patchy. This makes it difficult to even understand precisely the role of the myriad factors, less so model them. The challenge is made even more daunting by the fact that accurate and precise data on most of these aspects is lacking. This makes it nearly impossible to develop analytical models linking causes with effects vis a vis CH4 and N2O emissions from paddy fields. For situations like this the bioinspired artificial intelligence technique of artificial neural network (ANN), which can model a phenomenon on the basis of past data and without the explicit understanding of the mechanism phenomena, may prove useful. However, no such model for CH4 or N2O has been developed so far. Hence the present work was undertaken. It describes ANN-based models developed by us to predict CH4 and N2O emissions using soil characteristics, fertilizer inputs, and rice cultivar yield as inputs. Upon testing the predictive ability of the models with sets of data not used in model development, it was seen that there was excellent agreement between model forecasts and experimental findings, leading to correlations coefficients of 0.991 and 0.96, and root mean square error (RMSE) of 11.17 and 261.3, respectively, for CH4 and N2O emissions. Thus, the models can be used to estimate CH4 and N2O emissions from all those continuously flooded paddy wetlands for which data on total organic carbon, soil electrical conductivity, applied nitrogen, phosphorous and potassium, NPK, and grain yield is available.

Targeted technologies for nitrous oxide abatement from animal agriculture

2008 ◽  
Vol 48 (2) ◽  
pp. 14 ◽  
Author(s):  
C. A. M. de Klein ◽  
R. J. Eckard
Keyword(s):  
Nitrous Oxide ◽  
Animal Feed ◽  
Ghg Emissions ◽  
Housing System ◽  
Soil Conditions ◽  
N2o Emissions ◽  
Nitrification Inhibitors ◽  
Emission Rates ◽  
Animal Agriculture ◽  
Management Interventions

Nitrous oxide (N2O) emissions account for ~10% of global greenhouse gas (GHG) emissions, with most of these emissions (~90%) deriving from agricultural practices. Animal agriculture potentially contributes up to 50% of total agricultural N2O emissions. In intensive animal agriculture, high N2O emission rates generally coincide with anaerobic soil conditions and high soil NO3–, primarily from animal urine patches. This paper provides an overview of animal, feed-based and soil or management abatement technologies for ruminant animal agriculture targeted at reducing the size of the soil NO3– pool or improving soil aeration. Direct measurements of N2O emissions from potential animal and feed-based intervention technologies are scarce. However, studies have shown that they have the potential to reduce urinary N excretion by 3–60% and thus reduce associated N2O emissions. Research on the effect of soil and water management interventions is generally further advanced and N2O reduction potentials of up to 90% have been measured in some instances. Of the currently available technologies, nitrification inhibitors, managing animal diets and fertiliser management show the best potential for reducing emissions in the short-term. However, strategies should always be evaluated in a whole-system context, to ensure that reductions in one part of the system do not stimulate higher emissions elsewhere. Current technologies reviewed here could deliver up to 50% reduction from an animal housing system, but only up to 15% from a grazing-based system. However, given that enteric methane emissions form the majority of emissions from grazing systems, a 15% abatement of N2O is likely to translate to a 2–4% decrease in total GHG emissions at a farm scale. Clearly, further research is needed to develop technologies for improving N cycling and reducing N2O emissions from grazing-based animal production systems.

scholarly journals ESTIMATION OF NITROUS OXIDE EMISSIONS FROM AGRICULTURAL SOILS IN VOIVODESHIPS IN POLAND

2020 ◽  
Vol XXII (4) ◽  
pp. 94-104
Author(s):  
Anna Jędrejek
Keyword(s):  
Nitrous Oxide ◽  
Winter Wheat ◽  
Agricultural Soils ◽  
Ghg Emissions ◽  
Organic Content ◽  
Nitrous Oxide Emissions ◽  
Regional Differentiation ◽  
N2o Emissions ◽  
Winter Rape ◽  
Winter Triticale

The purpose of this study was to estimate nitrogen oxide emissions from soils used for agricultural purposes by voivodships. Compared N2O emissions were estimated according to the recommended IPCC (tier 1) method with simulated emissions using the DNDC (tier 3) model. Analyses were done for crop rotation (winter rape, winter wheat, winter wheat, winter triticale) in four cropping systems. Moreover, simulated N2O emissions from winter rape and winter triticale cultivation showed lower emissions and constituted 1475% and 13-76% of IPCC estimated emissions, respectively. The use of the model also enabled the determination of factors, which have an impact on nitrous oxide emissions and define its regional differentiation. The analysis showed that with increasing initial soil organic content, emissions of N2O rise and decrease with increasing precipitation or carbon sequestration. Considering the requirements for reduction GHG emissions, improving the methodology used in estimating nitrous oxide emissions is of significant practical value.

Emissions of nitrous oxide, ammonia and methane from Australian layer-hen manure storage with a mitigation strategy applied

2016 ◽  
Vol 56 (9) ◽  
pp. 1367 ◽  
Author(s):  
T. A. Naylor ◽  
S. G. Wiedemann ◽  
F. A. Phillips ◽  
B. Warren ◽  
E. J. McGahan ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Greenhouse Gas ◽  
Emission Factors ◽  
Control Treatment ◽  
N2o Emissions ◽  
Gaseous Emissions ◽  
Total N ◽  
Volatile Solids ◽  
Manure Storage ◽  
The Relationship

Greenhouse gas and ammonia emissions are important environmental impacts from manure management in the layer-hen industry. The present study aimed to quantify emissions of nitrous oxide (N2O), methane (CH4) and ammonia (NH3) from layer-hen manure stockpiles, and assess the use of an impermeable cover as an option to mitigate emissions. Gaseous emissions of N2O, CH4 and NH3 were measured using open-path FTIR spectroscopy and the emission strengths were inferred using a backward Lagrangian stochastic model. Emission factors were calculated from the relationship between gaseous emissions and stockpile inputs over a 32-day measurement period. Total NH3 emissions were 5.97 ± 0.399 kg/t (control) and 0.732 ± 0.116 kg/t (mitigation), representing an 88% reduction due to mitigation. Total CH4 emissions from the mitigation stockpile were 0.0832 ± 0.0198 kg/t. Methane emissions from the control and N2O emissions (control and mitigation) were below detection. The mass of each stockpile was 27 820 kg (control) and 25 120 kg (mitigation), with a surface area of ~68 m2 and a volume of ~19 m3. Total manure nitrogen (N) and volatile solids (VS) were 25.2 and 25.8 kg/t N, and 139 and 106 kg/t VS for the control and mitigation stockpiles respectively. Emission factors for NH3 were 24% and 3% of total N for the control and mitigation respectively. Methane from the mitigation stockpile had a CH4 conversion factor of 0.3%. The stockpile cover was found to reduce greenhouse gas emissions by 74% compared with the control treatment, primarily via reduced NH3 and associated indirect N2O emissions.

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