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With the rapid development of industrialization and urbanization in China, civil aviation plays an increasingly important role in the transportation industry. However, pollutants and greenhouse gas (GHG) emissions from civil aviation are becoming an increasingly concerning environmental problem. In order to mitigate the resulting environmental pollution, such as air quality deterioration, regional and global climate warming, and declining human health, more and more efforts have been devoted to reducing both pollutants and GHG emissions. Among these efforts, emissions inventories from civil aviation provide a basis for quantifying pollutants and GHG emissions, establishing evaluation standards of environmental impact, and formulating management policies for both air quality improvement and climate change mitigation. In this paper, we reviewed both compilation approaches and data collection methods for civil aviation emissions inventories, introduced several typical calculation methods for aviation emissions inventories, and analyzed specific cases of actual application based on typical methods of inventory compilation. We also described in detail the activity level and emission index calculation methods of several pollutants and greenhouse gases. Furthermore, based on the above research methods, four typical application cases were investigated, including a specific airport, the landing and takeoff (LTO) cycle of a nation, the entire period with the LTO cycle and the climb–cruise–descent (CCD) phase of a country, and global emissions inventories from civil aviation. The results suggest that, in addition to quantifying the emissions of both pollutants and GHG produced by civil aviation, the selection of inventory compilation methods is likely to be important for improving aviation emission inventory accuracy and for further reducing the environmental, economic, and health impacts resulting from aviation emissions. Moreover, this paper can also provide a reference and theoretical basis for the development of aviation emission inventory compilation methods in the future. [ABSTRACT FROM AUTHOR]

Polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) emissions during the roasting of green Arabica coffee and coffee formulations containing alcohol, sugar, and honey were investigated in this study. Fast and slow roasting methods, which took 5.62 and 9.65 min to achieve a light roast, respectively, were used to evaluate the emissions. The concentrations in the flue gas during the fast roasting of green coffee (0.0296 ng Nm−3 and 0.00364 ng WHO-TEQ Nm−3) were 13.9% and 70.5% higher than during slow roasting, respectively. However, this was only the trend for some formulations, and no significant differences in concentrations were found between the methods at p = 0.05. Thus, the slow roasting method might not necessarily reduce formation when additives are included. The emission factors were 2.86 ng kg−1 and 0.352 ng WHO-TEQ kg−1, and 4.17 ng kg−1 and 0.176 ng WHO-TEQ kg−1 for the fast and slow roasting of green coffee, respectively. Further investigations are warranted to understand the formation mechanism, assess potential health risks, and explore mitigation strategies. These findings have implications for both coffee processing industries and regulatory bodies, as understanding the impact of roasting methods and additives could inform the development of cleaner production practices and targeted emission reduction policies. [ABSTRACT FROM AUTHOR]

In this study, data from 23 domestic cremation facilities measured for 5 years (from 2016 to 2020) of 13 domestic cremation facilities was used to calculate the emission factors of dioxins (PCDD/DFs) of cremation facilities that use Liquified Natural Gas (LNG) as combustion fuel. We performed a statistical analysis for the first time to estimate the emission factor using limited measurement results from cremation facilities that are not easily accessible. We attempted to identify the emission concentration of dioxin as a representative persistent organic pollutants substance and developed a statistically based dioxin emission factor. The concentration of dioxins (PCDD/DFs) in the cremation facility ranged 0.001–4.440 ng I-TEQ/Sm3 with an average concentration of 0.719 ng I-TEQ/Sm3. The emission factor calculated using the 23 measured data showed 0.010–21.485 μg I-TEQ/Cremation. A Monte Carlo Simulation was conducted using probability density distribution and parameter estimation. Consequently, 10,000 emission factors were selected, and the Pareto distribution was predicted to be the most appropriate probability density distribution. The emission factor values through Monte Carlo simulation showed a minimum value of 1.490 × 10–08 μg I-TEQ/Cremation and a maximum value of 7816 μg I-TEQ/Cremation. The average value was calculated as 39.920 μg I-TEQ/Cremation. Each parameter of the Pareto distribution is shape parameter (α) 1.026, location parameter (μ) – 1.021, and scale parameter (λ) 1.021. As a result of this study, the median value of the cumulative density function was selected as a representative value for the dioxin emission factor of cremation facilities and the emission factor was 0.986 μg I-TEQ/ Cremation. The 95% confidence interval in the Pareto distribution was presented as 0.026 μg I-TEQ/Cremation to 36.216 μg I-TEQ/ Cremation. [ABSTRACT FROM AUTHOR]

Firewood and charcoal are the most dominant sources of fuel for domestic cooking applications in sub-Saharan Africa. In this study, performance and emission characteristics of firewood and charcoal from five commonly used species, namely, Dichrostachys cinerea, Morus Lactea, Piliostigma thonningii, Combretum molle, and Albizia grandibracteata were obtained. The water boiling test and emissions monitoring system for CO, CO2, and PM2.5 were used to determine fuel and energy consumption, thermal efficiency and emissions, and emissions' factors. The results showed that firewood combustion required higher energy consumption compared to charcoal combustion. High-power thermal efficiency was the highest (> 45%) for all charcoal derived from the firewood species. During hot-start, cold-start, and simmering operations, it was observed that thermal efficiencies were generally higher for charcoal fuels (≥ 80%) compared to the firewood (< 40%) from where they were pyrolyzed. Firewood has a much lower indoor CO emissions footprint when compared to using charcoal. Nonetheless, CO emission levels for both firewood and charcoal exceed the Environmental Protection Agency (EPA) guidelines of 35 ppm (1-h average). CO2 emission factors are the most dominant and highest contributors to greenhouse gas emissions from household use of firewood and charcoal. Overall, this work re-affirms the need for proper ventilation when firewood and charcoal are used in combustion. [ABSTRACT FROM AUTHOR]

Copyright of Power Generation Technology is the property of Power Generation Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the focus of highway development transitioning from construction to maintenance, a comprehensive understanding of the characteristics and influencing factors of carbon dioxide (CO2) emissions from highway maintenance activities is crucial for formulating effective strategies to promote the low-carbon development of road infrastructure. However, the quantitative relationships between CO2 emissions from highway maintenance schemes and factors such as pavement deterioration, traffic volume, and road grade remain unclear owing to a lack of comprehensive, multi-category, and real data. Using real maintenance data from 340 arterial highway segments in China, this study conducts the life cycle assessment (LCA) to estimate CO2 emissions from maintenance activities and examines the primary emission sources among various structural layers and materials. Furthermore, multiple linear regression (MLR) analysis is conducted to investigate the impact of traffic volume, road grade, and pavement deterioration on CO2 emissions from maintenance projects, and factors influencing the early-stage degradation of pavement performance. The results demonstrate that average CO2 emissions from heavy rehabilitation projects are 6.97 times higher than those from medium rehabilitation projects. Emissions from heavy rehabilitation projects exhibit a significantly negative linear relationship with the riding quality index (RQI) before maintenance (p

BACKGROUND AND OBJECTIVES: Agriculture significantly contributes to global economies, yet it concurrently generates waste in the form of crop residues. Conventional waste disposal methods, such as open burning, contribute to atmospheric particulate emissions, impacting air quality regionally and potentially globally. Exposure to these pollutants poses substantial risks to human health, including respiratory illnesses, cardiovascular diseases, and premature mortality. This study aims to assess the environmental implications of biomass waste combustion in Yogyakarta, Indonesia. Additionally, the study aims to investigate potential enhancements in biomass burning practices through experimental campaigns conducted in both open and closed burning conditions.METHODS: The study evaluates Yogyakarta's regional air quality using data from the Meteorology, Climatology, and Geophysical Agency for the period spanning from 2020 to 2022. Emission factors from open and closed burning practices are assessed using an experimental furnace equipped with real-time combustion parameters monitoring, including temperature, particulate matter concentration, and oxygen and carbon dioxide levels. The openburning experiments involve various combustion conditions for bagasse, leaf litter, and rice straw, encompassing variations in ignition location, initial mass, and air supply methods. Closed burning experiments explore variations in reloading frequency, air-fuel ratio, and air staging.FINDINGS: Yogyakarta's air quality assessment involves comparing rice harvest trends with atmospheric particulate matter concentrations during 2020-2022. Open burning practices in Yogyakarta exhibit a correlation with heightened rainfall, which in turn leads to higher emissions from April to August due to reduced rain frequency. Experimental campaigns have revealed that open burning practices result in a significant amount of emissions, ranging from 3 to 29 grams of particulate matter per kilogram of biomass.. Meanwhile, the utilization of closed combustion systems has been demonstrated to decrease the emission factor within the range of 0.37 to 1.98 grams of particulate matter per kilogram of biomass. This highlights the importance of operating conditions altering particulate emissions. Moreover, the emission reduction by factor nine, emphasizing the efficacy of controlled combustion techniques in comparison to open burning methods, in mitigating particulate emissions.CONCLUSION: The study identifies that greater initial biomass mass, mid-ignition, and natural airflow contribute to lower emissions in open burning practices. o achieve optimal closed combustion conditions, it is recommended to reload biomass more frequently with100 percent excess air allocation, distributing 30 percent to primary air and 70 percent to secondary air. These findings not only propose better practices for disposing of agricultural waste and minimizing air pollution but also emphasize the potential of utilizing biomass waste for energy conversion.

[Display omitted] • The deviation of N 2 O emission factor (EF) from short-term monitoring can reach 20%. • The N 2 O EF for sludge incineration in China may be smaller than the default value. • The N 2 O EF decreases as the temperature in the furnace increases. • The N 2 O EF of the sludge incinerators with smaller heat loads fluctuates more. • The fluctuation range of the N 2 O EF narrows with the increase of temperature. The N 2 O emissions resulting from sludge incineration are estimated using the default values published by the Intergovernmental Panel on Climate Change (IPCC), which may differ significantly from the actual emissions. In this investigation, N 2 O emissions from four sludge incineration lines in two plants were monitored for varying durations. The variation in N 2 O emission factors (EFs) between incineration lines of the same plant was much smaller than the difference between different plants. Data on N 2 O EFs obtained from brief monitoring may contain variabilities of up to 30%. N 2 O EFs were more sensitive to temperature changes at low temperatures, necessitating extended monitoring periods to improve the reliability of N 2 O monitoring outcomes in cases of low furnace temperatures. Excessive use of the SNCR system to reduce NOx emissions resulted in concentrations of N 2 O and NH 3 in the exhaust gases exceeding NOx levels. In the case of furnace temperature control and advanced reburning technology, it is advisable to utilize actual monitoring data or the smaller default values provided by the IPCC in China. Otherwise, the estimated N 2 O emissions may exceed the actual emissions. [ABSTRACT FROM AUTHOR]

Cattle manure deposited in pastures is an important source of nitrous oxide (N2O–N) and methane (CH4) emissions. Environmental conditions and soil characteristics affect emissions of these two gases, and therefore, it is important to conduct studies in local conditions to generate emission factors to improve greenhouse gas (GHG) estimates, as well as to identify mitigation strategies. N2O–N and CH4 fluxes from soil, feces and urine were determined for two cattle production systems during two seasons, and emission factors (EFs) were calculated. The static closed chambers technique was used in three conventional systems (CSs) and three silvopastoral systems (SPSs) with Tithonia diversifolia in the Colombian Amazon piedmont. SPSs presented lower emission factors than CSs for N2O–N from urine patches in both seasons (2.64 vs.1.49% and 1.69 vs. 0.89% of nitrogen (N) deposited for the transition and rainy season, respectively) (p = 0.004), N2O–N from feces in the rainy season (0.17 vs. 0.13% of N deposited for CSs and SPSs) (p = 0.046), and CH4 in the transition rainy season (1.08 vs. 0.83 g of CH4/kg of dry matter of feces for CSs and SPSs, respectively) (p = 0.005); with the EFs determined, the cumulative emissions for each system were estimated in 176.8 and 145.3 kg of CO2 equivalent per hectare per year in the CSs and SPSs. We concluded that SPSs can emit lower amounts of CH4 and N2O–N from manure and provide an alternative for mitigation of these gases generated by bovine manure under tropical humid conditions. [ABSTRACT FROM AUTHOR]

Vegetable production in Subtropical China is distinguished by excessive nitrogen (N) fertilization, frequent irrigation, and multiple crop rotations in a single year. The aforementioned variables are closely related to soil nitrous oxide (N2O) and methane (CH4) emissions. Hence, we conducted a field trial to measure N2O and CH4 emissions using static chamber–gas chromatograph. Four treatments were used: control (CK) with no fertilizer, 100% chemical N fertilization (CN), the conventional 30% chicken manure N plus 70%CN (CMN + CN), and 30% chicken manure biochar N plus 70%CN (CMBN + CN). The annual cumulative N2O emissions reached 12.4, 63.5, 111.8, and 44.1 kg N2O-N ha−1 for the CK, CN, CMN + CN, and CMBN + CN treatments, respectively. Compared to the CN and CMN + CN treatments, the CMBN + CN treatment reduced N2O emissions by 35.9%–65.7%, while it simultaneously increased the total vegetable yield by 16.1% compared to the CN treatment. Seven seasons mean N2O emission factors are 1.3% for CN, 3.8% for CMN + CN, and 0.9% for CMBN + CN. The CH4 emission was negligible, ranging from 0.07 kg CH4-C ha−1 for the CK treatment to 0.8 kg CH4-C ha−1 for the CN treatment. N2O emissions peaked under the conditions of an interior chamber temperature of around 31.9 °C and the water-filled pore space (WFPS) of the soil being approximately 60%. Future climate change will intensify, triggering higher N2O emissions from subtropical vegetable fields. CMB can be one of the best substitutes for direct chicken manure application as a soil supplement because it has a beneficial effect on improving vegetable yield and reducing N2O emissions in Subtropical China. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO), as a short-lived climate forcer, has direct and indirect detrimental impacts on environmental quality and human health. The amount of nitrogen (N) fertilizer application to agricultural soils is considered a robust predictor of total NO emissions, but the estimates of cropland NO emissions have large uncertainties due to the widely used constant emission factors (EF) as e.g., default values recommended by Intergovernmental Panel on Climate Change (IPCC) methodologies. By compiling 223 field experiments with at least three N-input levels across various croplands, we performed a meta-analysis to determine how soil NO emissions respond to N inputs. Our results showed for the first time that the mean change in EF per unit of additional N input (∆EF) across all available data was significantly higher as compared to zero, indicating that the NO response to N additions increased significantly faster than the assumed linear. On average, upland grain crops showed significantly higher ∆EF than that of horticultural crops or lowland rice. A higher ∆EF was also appeared in sites with mean annual precipitation < 600 mm, mean annual temperature ≥ 15 °C, soil organic carbon ≥ 14 g C kg− 1 or total N ≥ 1.4 g N kg− 1, and where synthetic N fertilizers were usually applied. By assuming various N application rates, the IPCC default (0.7% or 1.1%) EF model would have overestimated or underestimated NO emissions compared to our ∆EF model. Overall, our meta-analysis results exert high potential to improve estimates of cropland NO inventories, and help address disparities in global NO budgets and develop more targeted mitigation efforts. [ABSTRACT FROM AUTHOR]

The emission factor method (Tier 1) recommended by the Intergovernmental Panel on Climate Change (IPCC) is commonly used to estimate greenhouse gas (GHG) emissions from livestock and poultry farms. However, the estimation accuracy may vary due to practical differences in manure management across China. The objectives of this study were to estimate the direct and indirect nitrous oxide (N2O) emissions from dairy manure management between 1990 and 2021 in China and characterize its spatial and temporal variations following IPCC guideline Tier 2. The N2O emission factor (EF) of dairy cow manure management systems was determined at the national level and regional level as well. The results showed that the national cumulative N2O emission of manure management from 1990 to 2021 was 113.1million tons of CO2 equivalent, ranging from 90.3 to 135.9 million tons with an uncertainty of ±20.2%. The annual EF was 0.021 kg N2O-N (kg N)−1 for total emissions, while it was 0.014 kg N2O-N (kg N)−1 for direct emissions. The proportions of N2O emissions in North China, Northeast China, East China, Central and Southern China, Southwest China and Northwest China were 32.3%, 18.6%, 11.4%, 5.8%, 6.1% and 25.8%, respectively. In addition, N2O emissions varied among farms in different scales. The respective proportions of total N2O emissions from small-scale and large-scale farms were 64.8% and 35.2% in the past three decades. With the improvement in farm management and milk production efficiency, the N2O emissions per unit mass of milk decreased from 0.77 × 10−3 kg to 0.48 × 10−3 kg in 1990–2021. This study may provide important insights into compiling a GHG emission inventory and developing GHG emission reduction strategies for the dairy farming system in China. [ABSTRACT FROM AUTHOR]

Methane, the second most prevalent greenhouse gas globally, is characterized by its high global warming potential and short atmospheric lifetime. It is primarily emitted from sectors such as coal mining, oil and gas production, agriculture, livestock rearing, and waste management. Active, prudent, and orderly control of methane emissions offers a multifaceted benefit: it mitigates global warming, enhances the economic value through the resource utilization of energy, provides environmental advantages by control of pollutants, and improves safety by reducing production accidents. Methane is also the principal greenhouse gas emitted in coal mine operations. Currently, monitoring and researching the distribution of methane emissions and their concentration within the three-dimensional space of coal mines have become a key focus in China’s methane emission control efforts, which is of significant importance for coal mining enterprises to align with national strategies. A study conducted on a high-gas mine in Shanxi and a low-gas mine in Shaanxi for methane emission monitoring and accounting utilized fixed monitoring, manual monitoring, drone monitoring, and post-mining activity monitoring to investigate the distribution of methane in high and low gas mines in China and to analyze their methane emissions. The results indicate that: ① The methane emission volumes for a certain high-gas mine in Shanxi and a low-gas mine in Shaanxi published by the U.S.-based Climate TRACE website for the year 2022 show a significant discrepancy from the results calculated using the ground measurement method, with the published annual methane emission volume for a certain low-gas mine being 10.92 times that of the ground measurement calculation. The top-down monitoring and accounting methods have been found to be insufficiently accurate and unable to provide reliable data support for carbon trading. ② In the monitoring and accounting of post-mining activities, the use of default values recommended by the IPCC results in methane emissions that are 3 to 5 times higher than those calculated using the ground measurement method, and there is a significant variation in the emissions calculated based on coal samples of different sizes and exposure durations. There is an urgent need for a unified and precise testing standard to ensure fair and accurate data for future carbon market transactions.

Nitrous oxide (N2O) is an ozone-depleting greenhouse gas that contributes significantly to the carbon footprint of a wastewater treatment plant (WWTP). Plant-specific measurement campaigns are required to reliably quantify the emission level that has been found to significantly vary between WWTPs. In this study, the N2O emissions were quantified from five full-scale WWTPs during 4–19-day measurement campaigns conducted under both cold period conditions (water temperature below 12 °C) and warm period conditions (water temperature from 12 to 20 °C). The measurement data were studied alongside long-term monitoring data from a sixth WWTP. The calculated emission factors (EFs) varied from near 0 to 1.8% relative to the influent total nitrogen load. The results confirmed a significant seasonality of N2O emissions as well as a notable variation between WWTPs in the emission level, which a single fixed EF cannot represent. Wastewater temperature was one explanatory factor for the emission seasonality. Both low and high emissions were measured from denitrifying–nitrifying activated sludge (AS) processes, while the emissions from only nitrifying AS processes were consistently high. Nitrite (NO2-) at the end of the aerobic zones of the AS process was linked to the variability in N2O emissions during the cold period. HIGHLIGHTS N2O emissions exhibit seasonal variability that can be linked to wastewater temperature.; Fixed emission factors are highly unrepresentative of the variability in N2O emissions between treatment plants.; N2O emissions are higher in only nitrifying processes than in nitrifying–denitrifying processes.; Process disturbances may significantly affect the N2O emission level during short-term monitoring.;

In the operation of coal-fired power plants (CFPPs), the generation of particulate matter (PM) is monitored using a continuous emission monitoring system (CEMS); this data is useful for emission dispersion, planning, and reduction. However, due to local variability in the coal used, control technologies, and policies, emission factors need to be established. Notably, no PM emission factor has been derived or can be applied to CFPPs owned by the National Electricity Company of Indonesia/PT PLN (Persero) and other CFPPs. This study considered 52 CEMS-equipped CFPP units with emission factor values differing according to the boiler type, installed capacity, and air pollution control device (APCD). The PM concentration, volumetric flow rate, coal consumption, and electricity production data were assessed to determine PM emission factors for these units. A correlation test was also conducted to determine the effect of various parameters (based on the boiler type, installed capacity, and APCD type) on the PM emission factor by categorizing the CFPP units into two or three similar subcategories.Furthermore, using calorific values and carbon contents, dynamic emission factors were developed – expressed in terms of a simple or multiple linear regression equation – and their accuracy was determined. The different configurations of the 52 investigated CFPP units led to variations in the obtained emission factor values. The precision of the PM emission factors was enhanced by grouping the CFPP units based on similarities in the boiler type, installed capacity, or APCD type. The boiler type (represented by the superficial gas velocity) has the largest influence on the emission factor (in g PM/kg coal), with a moderate positive correlation, followed by the type of APCD installed (represented by the theoretical PM removal efficiency) and the installed capacity (represented by the heat rate or specific coal consumption). The dynamic PM emission factor is expressed by the equation y = 0.763 + (−0.016x), where only the fixed carbon content (from the proximate analysis results) – the independent variable on the x-axis – has a significant correlation with it.

ABSTRACTMaize production requires a large amount of nitrogen (N). However, a greater part of the N used gets lost to the environment as reactive forms including nitrous oxide (N2O). N2O emissions and associated soil-related factors were measured in a maize (Zea mays L.) field in the 5th crop after initiation of the experiment in an annual maize-rice sequence. The treatments comprised two levels of crop residues (no residue, NR vs. 30 cm residue, CR) with four levels of N fertilizers (control; farmers’ practice, FP; national recommended dose, RD, and 125% of RD, 1.25 RD). Mean and cumulative N2O emissions increased with N rate coupled with either residue level. The CR coupled with 1.25 RD had 10% higher N2O emissions than the same rate as NR. In contrast, yield-scaled N2O emissions were equal in 1.25 RD coupled with either residue level. However, higher N2O emissions in CR than in NR can be offset by the corresponding improvement in soil elemental quality, e.g. soil organic carbon, total N, P, K and S. The N2O emission factor, ranged from 0.99 to 1.34, and was higher in CR coupled with 1.25 RD than in any other combination suggesting that optimization of N rate is one of the best options to reduce N2O emissions. Maize grain yield was higher in RD and 1.25 RD than in the farmers’ practice where the former two were similar to each other. Step-wise multiple regression showed that N application rate, soil organic carbon, total N and pH are the dominant factors controlling N2O emissions. Our results suggest that maize production can benefit from residue retention with the current N rate (RD) for better yield, soil quality and N2O mitigation.

As fleet electrification progresses, vehicles are continuously becoming heavier, while the used electric motors, with their high torques, enable longitudinal dynamics to be maintained or even increased. This raises the question of what effect electric vehicles have on the emission of tire–road particulate matter (PM). To answer this question, investigations were carried out in this study on a tire internal drum test bench with real road surfaces. In addition to the vertical load, the tire inflation pressure and the driving speed were varied. PM emissions were recorded in real time, resulting in emission factors (emission per kilometer driven) for different load conditions. This allows statements to be made about both the effect on the total emission and on the particle size distribution. It was shown that the PM emission increases linearly with the vertical load at constant longitudinal dynamics. If the tire inflation pressure is increased, the emission also increases linearly, and the increases in emission are equally large for both influences. A clear influence of the driving speed on the emission factor could not be determined. With regard to the particle size distribution, the following correlations were found: higher vertical load and higher tire inflation pressure result in a larger mean particle diameter, while a higher driving speed reduces it. Thus, this study contributes to a better understanding of the expected changes in tire-road PM emissions as a result of electrification. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In tandem with the advancement of urban intelligent technology, the construction of remote monitoring platforms and databases for non-road mobile machinery is gradually improving in various provinces and cities. Employing the remote monitoring platform for non-road mobile machinery enables a detailed big data analysis of the actual operational state of the machinery. This method yields precise data on the activity levels of various machinery types. Importantly, it addresses the issue of reduced accuracy in emission inventories, which often arises from the conventional practice of using standard recommended values from the Guide to determine machinery activity levels during the compilation of non-road mobile machinery emission inventories. Based on the remote monitoring and management system of non-road mobile machinery, the actual value of the activity level of non-road mobile machinery was obtained, and the emission inventory of non-road mobile machinery in Shandong Province was established. The emission levels of PM, HC, NOx, and CO from main non-road mobile machinery, including forklifts, excavators, loaders, off-road trucks, and road rollers, were measured. The findings indicate that the operational activity levels of non-road mobile machinery in Shandong Province typically exceeded the guideline's recommended values. Among them, the annual use time of port terminal ground handling equipment was the longest, with an average annual working time of 4321.5 h per equipment, more than six times the recommended value. Among all types of non-road mobile machinery, loader emissions accounted for the highest proportion, reaching 43.13% of the total emissions of various pollutants. With the tightening of the national standard for non-road mobile machinery from Stage II to Stage III, a significant reduction in actual mechanical emissions was observed, primarily manifested as a 91% decrease in NOx emissions. Based on the data from the remote monitoring platform, a new method for compiling the emission inventory of non-road mobile machinery is proposed in this paper. The calculated emission inventory can reflect more real emission situations and provide a reference and basis for emission control and sustainable emission reduction policy measures for non-road mobile machinery. [ABSTRACT FROM AUTHOR]

This work conducted experimental combustion on a closed chamber using two different materials: mixture (1:1) sugarcane bagasse/straw and pre-treated biomass. The sampling method was an Andersen cascade impactor with eight stages. Tests were carried out on untreated biomass varying the velocities observed in the sampling duct (4.18; 5.20, 6.85, and 8.21 m.s−1). Pre-treated biomass tests were performed at 4.19 m.s−1 because in this condition there is a higher speed stability inside the duct. During the combustion tests, the concentration of emitted particles was higher for the lower speed range, with an order of 4.19 > 5.40 > 6.85 > 8.21 m.s−1. The higher speeds observed inside the duct behaved as a dragging agent for particulate material. For the tests at the speed of 8.21 m.s−1 where the flow inside the duct was 0.088 m3s−1, this behavior is more evident. Considering the fine diameter particles (< 2.5 µm), they were emitted in a higher concentration, due to the biomass combustion process, which results in higher emission of ultrafine particles. The emission factors (EFs) obtained for PM10 for untreated biomass were in the range of 0.414 and 0.840. On the other hand, considering the pre-treated biomass, these factors were 0.70 and 1.51. The EFs of PM from the burning of the pre-treated biomass were higher when compared to untreated biomass, which is mainly due to the higher temperature of the process due to the higher HHV (higher heating value) of this material, caused by the removal of hemicellulose (4.71 times) and a proportional increase in lignin (1.52 times). Biomass combustion has the potential to partially replace fossil fuels in heat and energy generation. Nevertheless, more stringent and comprehensive legislation should be established to ensure that air quality is maintained. Furthermore, the emission factors obtained in this study might be useful as input data for air quality modeling in the context of sugarcane's burning biomass, thus, contributing to the generation of inventories that include emissions of this nature. [ABSTRACT FROM AUTHOR]

We explored the microplastic (MPs) emissions of Japanese municipal solid waste incinerators (MSWIs); specifically, the numbers and types of MPs in wastewaters discharged by three MSWIs. We calculated the MSWI MPs emission factors and inventories, and we discuss the results. More than fifteen types of MPs, principally fragments shape were detected. It was important to obtain composite samples because the nature of raw wastewater fluctuated significantly during both day and night in response to the MSWI treatments. MSWI wastewater treatments tended to remove larger particles; over 99% of MPs (in terms of both number and weight) were ultimately removed. The MP emission inventory from MSWIs to public water bodies was 7.22 × 105–1.64 × 106 MPs/year for MPs sized 100–5000 µm. This is very low, at only 0.0053–0.026% of the total MP emission inventory Japanese WWTPs. It is, therefore, possible to remove almost 100% plastics in input waste via incineration and wastewater treatment. [ABSTRACT FROM AUTHOR]

• A portable open-path instrument based on DOAS was developed for mobile measurement of ambient NH 3. • The on-road NH 3 and NO concentrations were measured for the arterial highway of Shanghai. • The measured NH 3 /NO was associated to the proportions of light gasoline vehicles and heavy-duty diesel vehicles in the fleet. • The mileage-based NH 3 emission factor was estimated to be 17.9 ± 6.3 mg/km per vehicle based on the tunnel measurement. Increased attentions to vehicle emission of NH 3 have been paid since it is generally regarded as an important source in urban areas. Here, we developed a movable instrument based on Differential Optical Absorption Spectroscopy (DOAS) principle for detecting on-road NH 3 , which can avoid the losses in the sampling process attributed to the non-sampling methods. For this mobile DOAS, the temporal resolution, detection limit and relative error for NH 3 were 1 min, 2.29 ppbv and 4.57% ± 2.44%, respectively. By employed to the on-road measurements along the arterial highway in Shanghai, the spatial distributions of NH 3 and NO were obtained, and their dependence of traffic and road conditions were studied. The slopes of linear regression between NH 3 and NO were 0.40, 0.02 and 0.07 on the Middle Ring Road, Outer Ring Road and Chongming Island Ring Road. It indicates that light gasoline vehicles (LGVs) were found to be the main contributor to NH 3 emissions, while heavy-duty diesel vehicles (HDVs) mainly emitted NO. Based on the measured NH 3 in the tunnel, the mileage-based NH 3 emission factor per vehicle was estimated to be 17.9 ± 6.3 mg/km. The reported open-path instrument can be broadly used in on-road pollutant monitoring or vehicle emissions, and the measurements can reveal the real situation of emission characteristics, even find the abnormal operations of vehicle catalyst system. [Display omitted] [ABSTRACT FROM AUTHOR]

Thermal power plants are one of the most important sources of mercury emissions. Mercury deposition in nature has a negative implication on human health. According to Article 8 of the Minamata Convention, all parties are obliged to estimate mercury emissions from anthropogenic sources and provide the best available control technologies. In this research, the analysis of mercury emissions from Iran’s power sector has been illustrated using the UNEP toolkit and the STIRPAT model for the period from 2011 to 2021. The average amount of mercury emissions and mercury emission factor were estimated as 505.6 kg and 1.85 kg/TWh respectively. The average emission factor of mercury for natural gas, heavy oil and gas oil combustion was calculated as 0.05 kg/TWh, 14 kg/TWh, and 1.29 kg/TWh respectively. The average amount of the external cost of electricity generation due to mercury emissions was calculated as 2,616.67 US$/TWh and 5,931.11 US$/TWh in two scenarios with and without the minimum exposure threshold respectively. The results of the STIRPAT model, it was indicated that a one-percent increase in factors including population, the share of electricity generation from natural-gas consumption, and the share of electricity generation from liquid fuels consumption led to an increase of 14.83, 0.3 and 1.49 percent respectively in mercury emissions. In addition, as a result of a one-percent increase in factors including gross national product per capita, intensity of electric energy generation and the share of electricity generation using non-fossil sources led to a decrease of 4.8, 4.74 and 0.15 percent respectively in mercury emissions. [ABSTRACT FROM AUTHOR]

This dataset comprises thorough measurements of light-duty vehicles emissions conducted in Siilinjärvi and Kuopio, Finland, during February 2021, using a mobile laboratory. The measurements focused on subfreezing conditions to capture emissions nuances during cold weather. Measurements were carried out on minimally trafficked roads to diminish external disturbances. The dataset includes a large number of variables from gas and particle emissions. Gaseous emissions of CO, CO2, and NOx were measured. Measured variables of particle emissions were number concentration (CPC), size distribution (ELPI+), black carbon concentration (AE33), and chemical composition (SP-AMS).A total of six light-duty vehicles were investigated, featuring three diesel and three gasoline engines. The measurements incorporated three distinct drive scenarios: subfreezing–cold start, preheated–cold start (utilizing either electrical or fuel-operated auxiliary heaters), and hot start (where a vehicle engine has reached the optimal temperature through prior driving). Each drive type was replicated twice, resulting in six driven rounds per vehicle and 36 rounds in total. Additionally, daily background measurements were conducted by following the same route without chasing a specific vehicle. Meteorological conditions during the measurements were representative of winter in Finland, with outside temperatures ranging from –9 °C to –28 °C. The effect of weather conditions on the measurements were minimal. Only a minor effect was due to the occasional snowfall, especially on the last day when the road surface was snowy, and the car being chased lifted the snow from the road surface. We didn't recognize other factors, such as high wind speeds or major road dust emissions, that could have affected the measurement results.This dataset serves as a valuable resource for comparing emissions under diverse environmental conditions, particularly in real-life winter settings where data are scarce. Furthermore, it provides an opportunity for meta-analysis of emission factors from various passenger vehicle types. The dataset's richness and specificity make it a valuable contribution to the understanding of winter-time vehicular emissions.

High emission factor of identified air pollutants from the artisanal petroleum refineries in the Niger Delta region may be key to the degrading air quality of the region. This study determined air emission factor for the identified pollutants from the local refining technology in the region. The operational sites of these refineries are inaccessible due to security and proximity to raw material, making air quality evaluation and management impossible. However, Emission Factors are one of the best ways to quantify an activity-related air pollution especially in difficult terrain like those of the artisanal refineries. In this regard, air emissions resulting from the operation of these refineries were characterized/quantified with the use of E8500 Portable Industrial Combustion Analyzer. The measured concentrations were used to calculate the emission factors and emission rates for the identified air pollutants. The overall combined emission factors (g/kg) estimated in percentage of emissions for the pollutants characterized at the various unit operation, showed that; at the Oven Heating/Crude Oil Boiling Unit, HC had 52%, 41% for CO, 3% for NOx (NO + NO2), 2% for SO2 and 2% for H2S. Other process units emitted 53% and 55% for HC, 40% and 38% for CO, all 3% for NOx, all 2% for SO2 and all 2% for H2S for the Vapour Condensation and Refined Products Collection Units respectively. It therefore concluded that the high emission factors observed from the activities of these local petroleum refineries could be a contributing factor to the degraded air quality of the region.

Abstract Background Following global pledges to reduce greenhouse gas (GHG) emissions by 30% by 2030 compared to the baseline level of 2020, improved quantification of GHG emissions from developing countries has become crucial. However, national GHG inventories in most Sub-Saharan African countries use default (Tier I) emission factors (EFS) generated by the Intergovernmental Panel on Climate Change (IPCC) to estimate enteric CH4 emissions from animal agriculture. The present study provides an improved enteric CH4 emission estimate (Tier II) based on animal energy requirements derived from animal characteristics and performance data collected from about 2500 cattle in 480 households from three smallholder farming systems to represent the common dairy farming in the central highlands of Ethiopia. Using average seasonal feed digestibility data, we estimated daily methane production by class of animal and farming system and subsequently generated improved EF. Results Our findings revealed that the estimated average EF and emission intensities (EI) vary significantly across farming systems. The estimated value of EF for adult dairy cows was 73, 69, and 34 kg CH4/cow/year for urban, peri-urban, and rural farming systems, respectively. Rural dairy farming had significantly higher emission intensity (EI) estimated at 1.78 CO2-eq per kg of fat protein-corrected milk (FPCM) than peri-urban and urban 0.71 and 0.64 CO2-eq kg−1 FPCM dairy farming systems, respectively. The EF estimates in this study are lower than the IPCC's (2019) default value for both stall-fed high-productive and dual-purpose low-productive cows. Conclusions The current findings can be used as a baseline for the national emission inventory, which can be used to quantify the effects of future interventions, potentially improving the country's commitment to reducing GHG emissions. Similarly, this study suggests that increased animal productivity through improved feed has a considerable mitigation potential for reducing enteric methane emissions in smallholder dairy farming systems in the study area.

Polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) emissions during the roasting of green Arabica coffee and coffee formulations containing alcohol, sugar, and honey were investigated in this study. Fast and slow roasting methods, which took 5.62 and 9.65 min to achieve a light roast, respectively, were used to evaluate the emissions. The concentrations in the flue gas during the fast roasting of green coffee (0.0296 ng Nm−3 and 0.00364 ng WHO-TEQ Nm−3) were 13.9% and 70.5% higher than during slow roasting, respectively. However, this was only the trend for some formulations, and no significant differences in concentrations were found between the methods at p = 0.05. Thus, the slow roasting method might not necessarily reduce formation when additives are included. The emission factors were 2.86 ng kg−1 and 0.352 ng WHO-TEQ kg−1, and 4.17 ng kg−1 and 0.176 ng WHO-TEQ kg−1 for the fast and slow roasting of green coffee, respectively. Further investigations are warranted to understand the formation mechanism, assess potential health risks, and explore mitigation strategies. These findings have implications for both coffee processing industries and regulatory bodies, as understanding the impact of roasting methods and additives could inform the development of cleaner production practices and targeted emission reduction policies.

SDGs or Sustainable Development Goals have become a global and national commitment. Greenhouse gases (GHG) are indicators of climate change which is one of the 17 SDG’s goals. In the national food logistics system with rice as a staple food, there are some regions with surplus production and other deficits. Hence, the distribution involved the transportation activities that need to be carried out. In transportation, the carbon footprints are generated from exhaust gases as residue from the fuel combustion process. The carbon footprint efficiency is one of the indicators in green logistics. Green logistics for decarbonization in the transportation sector for a better environment has to start massively. Indonesia is committed to implementing the green logistics concept in logistics distribution. In this case, the author determined the surplus area and the deficit one based on statistical data on the production and consumption of each city in Java. Furthermore, a distribution network model is designed that involves emission level as a parameter in determining the route on the network. In the design, the selected mode of freight transportation was limited to land transportation modes besides trains. The design makes environmental aspects a major consideration in the distribution as well as the shipping costs. [ABSTRACT FROM AUTHOR]

In developing nations, solid residential fuels are the major sources of primary energy for various domestic activities. To date, the emission inventory of inorganic trace gases over National Capital Territory (NCT) was prepared using either default or country-specific emission factors. In this paper, we report (for the first time) the spatial variation of emission factors (EFs) of inorganic trace gases (SO2, NO, NO2, CO, CO2, and CH4) from the residential fuels used in slums and rural areas of NCT determined using dilution chamber in the laboratory. 147 residential fuel samples, including fuelwood, dung cake, crop residues, coal, etc., were collected at 149 NCT locations out of 675 slum clusters and 146 rural villages. The range of EF(s) of SO2 (0.02 ± 0.01 to 0.04 ± 0.01 g kg−1), CH4 (0.10 to 0.34 g kg−1), NO2 (0.01 to 0.02 g kg−1) is lower than the CO (3.55 ± 1.72 to 6.07 ± 1.53 g kg−1) and CO2 (0 to 129.45 ± 46.94 g kg−1). The north and north west districts of NCT are emission hotspots for CH4, NO, and NO2 emissions, whereas, the southern and northern areas of NCT are for CO2. These citywide emission inventories (0.05° × 0.05°) of inorganic trace gases are prepared using laboratory-determined EFs and available consumption data determined by recent survey information. Among solid residential fuels, fuel wood, and dung cake are two major contributors to inorganic trace gases in NCT. [ABSTRACT FROM AUTHOR]

Greenhouse gas emissions are related to non-renewable sources. For this reason, the methodological guide for the estimation of methane and carbon dioxide emissions in flooded lands was published in 2006 by the Intergovernmental Panel on Climate Change. Since 2016, several studies have been carried out in temperate and tropical zones reservoirs. Costa Rica is a Central American country known for its large hydroelectric resources and its highly renewable electricity generation matrix. This work represents the first study for 11 of 24 hydroelectric plants managed by the Costa Rican Electricity Institute. Methane emissions, energy density and emission factors for electricity generation are determined. Furthermore, a static mathematical model is used to determine these factors with little input data. It is estimated that the greatest contribution to methane emissions corresponds to the Arenal reservoir, which has the largest surface area and the lowest energy density. [ABSTRACT FROM AUTHOR]

• Young wildfire plumes were observed and documented for the first time in suburban Orléans city, France. • Regional air quality was reduced by the wildfire emissions. • Emission factors of various pollutants were derived and compared with the literature. • Current biomass burning emission inventories have uncertainties in estimating small fire emissions. Wildfire events are increasing globally which may be partly associated with climate change, resulting in significant adverse impacts on local, regional air quality and global climate. In September 2020, a small wildfire (burned area: 36.3 ha) event occurred in Souesmes (Loir-et-Cher, Sologne, France), and its plume spread out over 200 km on the following day as observed by the MODIS satellite. Based on measurements at a suburban site (∼ 50 km northwest of the fire location) in Orléans and backward trajectory analysis, young wildfire plumes were characterized. Significant increases in gaseous pollutants (CO, CH 4 , N 2 O, VOCs, etc.) and particles (including black carbon) were found within the wildfire plumes, leading to a reduced air quality. Emission factors, defined as EF (X) = ∆ X /∆CO (where, X represents the target species), of various trace gases and black carbon within the young wildfire plumes were determined accordingly and compared with previous studies. Changes in the ambient ions (such as ammonium, sulfate, nitrate, chloride, and nitrite in the particle- and gas- phase) and aerosol properties (e.g., aerosol water content, aerosol pH) were also quantified and discussed. Moreover, we estimated the total carbon and climate-related species (e.g., CO 2 , CH 4 , N 2 O, and BC) emissions and compared them with fire emission inventories. Current biomass burning emission inventories have uncertainties in estimating small fire burned areas and emissions. For instance, we found that the Global Fire Assimilation System (GFAS) may underestimate emissions (e.g., CO) of this small wildfire while other inventories (GFED and FINN) showed significant overestimation. Considering that it is the first time to record wildfire plumes in this region, related atmospheric implications are presented and discussed. [Display omitted] [ABSTRACT FROM AUTHOR]

Aims: Reduction of the nitrogen (N) footprint of agroecosystems is currently a hot topic in various research disciplines and fields. However, the effect of machine-planted rice with side-deep fertilization (MRSF) on N loss and footprint of double-cropping rice fields in Hunan is still unclear. Methods: We established a field experiment in which we applied various N compositions (N 135/148.5–90/99 kg ha-1) to early-season rice (ESR) and late-season rice (LSR). The loss of different N forms during the whole growth period of double cropping rice was measured. The N footprint of double cropping rice in the red soil region of Dongting Lake area was calculated using the life cycle assessment method. Results: Compared with the conventional fertilizer, with a N level of 150/160 kg ha-1, the MRSF treatments significantly decreased both NH4+-N and NO3−-N runoff by 26.2–40.9% and 9.0–36.5%, respectively, for ESR, and by 54.4–79.0% and 6.6–40.7%, respectively, for LSR. Moreover, relative to the conventional fertilization (CF) treatment, the MRSF treatments significantly reduced leaching loss by 21.8–41.2% and 20.5%–42.1%, respectively, for ESR, and 26.7–41.8% and 20.9%–51.0%, respectively, for LSR. While urease activity decreased with increasing soil depth, MRSF treatments increased relative soil urease activity in the later rice growth stages. Compared with the CF treatment, they also decreased the total N footprint by 42.3–53.5% and 45.1–57.1% for ESR and LSR, respectively. Correlation analysis further showed that mineral N loss and total N footprint increased exponentially with the N-application rate under the MRSF strategy. Conclusions: Overall, MRSF reduced environmental risks associated with N loss caused by paddy field leaching and runoff while maintaining the topsoil N content. In this manner, MRSF can attenuate the total N footprint of double-cropping rice systems in the Dongting Lake area. [ABSTRACT FROM AUTHOR]

Tropical peat swamp degradation can modify net peat greenhouse gas (GHG) emissions even without drainage. However, current Intergovernmental Panel on Climate Change (IPCC) guidelines do not provide default emission factors (EF) for anthropogenically-degraded undrained organic soils. We reviewed published field measurements of peat GHG fluxes in undrained undegraded and degraded peat swamp forests in Southeast Asia (SEA) and Latin America and the Caribbean (LAC). Degradation without drainage shifted the peat from a net CO2 sink to a source in both SEA (− 2.9 ± 1.8 to 4.1 ± 2.0 Mg CO2–C ha−1 yr−1) and LAC (− 4.3 ± 1.8 to 1.4 ± 2.2 Mg CO2–C ha−1 yr−1). It raised peat CH4 emissions (kg C ha−1 yr−1) in SEA (22.1 ± 13.6 to 32.7 ± 7.8) but decreased them in LAC (218.3 ± 54.2 to 165.0 ± 4.5). Degradation increased peat N2O emissions (kg N ha−1 yr−1) in SEA forests (0.9 ± 0.5 to 4.8 ± 2.3) (limited N2O data). It shifted peat from a net GHG sink to a source in SEA (− 7.9 ± 6.9 to 20.7 ± 7.4 Mg CO2-equivalent ha−1 yr−1) and increased peat GHG emissions in LAC (9.8 ± 9.0 to 24.3 ± 8.2 Mg CO2-equivalent ha−1 yr−1). The large observed increase in net peat GHG emissions in undrained degraded forests compared to undegraded conditions calls for their inclusion as a new class in the IPCC guidelines. As current default IPCC EF for tropical organic soils are based only on data collected in SEA ombrotrophic peatlands, expanded geographic representation and refinement of peat GHG EF by nutrient status are also needed. [ABSTRACT FROM AUTHOR]

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Vehicular particle number (PN) emissions have garnered increasing attention. In this study, nine light-duty vehicles, involving conventional internal combustion engine gasoline vehicles (ICEVs) and hybrid electric vehicles (HEVs), underwent testing on a chassis dynamometer to elucidate key factors influencing PN emissions. We found that with more stringent emission standards Gasoline Direct Injection (GDI) vehicles exhibited a reduction in PN emission factors. Higher PN emissions for GDI vehicles than vehicles with Multi-Port Fuel Injection (PFI) engines were observed; meanwhile, HEV showed lower PN emissions than ICEVs. PN emissions for cold start consistently exceeded warm start across vehicles with different standards and technologies. Notably, China VI HEV exhibited a substantial 19.2-fold increase in PN emissions for cold start compared to warm start. Analysis on a second-by-second basis revealed that cold-start emissions concentrated in low speed, while warm-start emissions were prominent in extra-high speed. Concerning vehicle specific power (VSP), the lowest mean PN emission rate occurred during idle conditions. PN emissions for China IV-VI ICEVs with GDI engines would increase with the increasing VSP, whereas China VI ICEVs with PFI engines and HEV with GDI engines showed varied patterns of PN emissions, especially under cold start. Our study would further facilitate formulating effective strategies for vehicular PN emissions. [ABSTRACT FROM AUTHOR]

Anthropogenic greenhouse gas (GHG) emissions from croplands are primarily attributed to nitrogen (N) fertilization in agricultural production. However, the interactive effects of various agricultural management practices, climatic conditions, soil properties, and fertilization on non-CO2 GHG emissions (specifically methane (CH4) and nitrous oxide (N2O)) and gross global warming potential (GGWP) have been scarcely discussed. In this study, we conducted a meta-analysis of 326 agricultural treatments in China from 76 literature sources to elucidate the relationship between the response ratio (RR) of GGWP (GGWP RR), CH4 (CH4 RR), and N2O emissions (N2O RR) and various explanatory variables using redundancy analysis. Generally, nitrogen fertilizer application increased the N2O and CH4 emissions and GGWP by 120.0%, 32.5%, and 107.9%, respectively. We found that the GGWP RR was closely related to the rate of organic fertilizer application and initial bulk density, while it showed a negative association with the initial total soil nitrogen content. We found that CH4-RR was positively associated with the rate of synthetic fertilizer application, and N2O-RR exhibited a positive association with initial soil organic carbon and annual mean precipitation. Notably, the total fertilizer application rate had the most significant impact on both the GGWP RR and the N2O RR, while mean annual precipitation contributed the most to CH4-RR. Furthermore, a sensitivity analysis using a machine learning model suggested that the GGWP RR was more sensitive to synthetic fertilizer than to straw application, and reducing synthetic fertilizer by 30% from the current condition is likely to be the most effective way to alleviate the effect of fertilization on GGWP. [ABSTRACT FROM AUTHOR]

Greenhouse gas (GHG) emissions from paddy fields depend on water management practices and rice varieties. Lysimeter experiments were conducted to determine the effect of rice varieties (lowland; Koshihikari (KH) and upland; Dourado Precoce (DP)) on GHG emissions under two water management practices: alternate wetting and drying (AWD) and continuous flooding (CF). A repeated cycle of drying and wetting in AWD irrigation was performed by drying the soil to −40 kPa soil matric potential and then rewetting. Consequently, the closed chamber method was used to measure direct emissions of methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2). The result revealed that water management significantly affected CH4 and N2O emissions (p < 0.05), while no significant effect was observed between different rice varieties. Although, AWD irrigation reduced CH4 emissions, it increased N2O emissions compared to CF irrigation, likely due to increased oxygen supply. AWD irrigation decreased GWP by 55.6% and 59.6% in KH and DP, respectively, compared to CF irrigation. Furthermore, CH4 and N2O emissions significantly correlated with soil redox potential and volumetric water content. These results suggest that AWD irrigation might be an effective water management method for mitigating GHG emissions from rice fields in central Japan. [ABSTRACT FROM AUTHOR]

The objective of this study was to experimentally determine the mathematical correlations between the loading of the tire, being longitudinal and lateral forces, and the emission of particulate matter (PM) from the tire–road contact. Existing emission factors (EF, emission per vehicle and distance traveled) are the result of long-term measurements, which means that no conclusion can be drawn about the exact driving condition. To determine meaningful emission factors, extensive driving tests were conducted on an internal drum test bench while measuring PM emissions from the tire–road contact in real-time. This showed that the increases in emission over longitudinal and lateral forces can be approximated with fourth-order functions, with lateral forces leading to significantly higher emissions than longitudinal forces for the summer tire investigated. Using the emission functions obtained, a three-dimensional map was created that assigns an EF to each load condition consisting of different longitudinal and lateral forces for one vertical load. With known driving data, the map can be used for future simulation models to predict the total emission of real driving cycles. Furthermore, the results show that the average particle size increases with increasing horizontal force. The particles collected during the tests were analyzed to determine the proportions of tire and road material. According to the results, the tire contributes only about 20% of the particle mass, while 80% is attributable to the road surface. In terms of volume, these shares are 32% and 68%, respectively. [ABSTRACT FROM AUTHOR]

The high altitude in mountainous regions results in lower atmospheric pressure, oxygen concentration and temperature, leading to lower combustion efficiency in motor vehicles. Therefore, there may be differences in carbon dioxide (CO2), carbon monoxide (CO), and nitrogen oxides (NOx) emissions characteristics at different altitudes. In this study, a portable emission measurement system was used to investigate the effects of varying elevations on the emission factors of CO2, CO, and NOx on diesel and gasoline-powered vehicles at altitudes ranging from 2270 to 4540 m in the Qinghai–Tibet Plateau of China. Additionally, the influencing factors of CO2, CO, and NOx emissions were studied. Results showed that the CO2, CO, and NOx emission factors for diesel vehicles varied in the range of 161.83–195.54, 0.59–0.77, and 4.61–6.58 g/km; the population means with 90% confidence intervals were 178.54, 0.68, and 5.60 g/km, respectively. For gasoline vehicles, the CO2, CO, and NOx emission factors varied in the range of 161.66–181.98, 0.95–1.06, and 0.12–0.25 g/km; the population means with 90% confidence intervals were 171.82, 1.01, and 0.19 g/km, respectively. Overall, the emission factors of diesel vehicles were higher than those of gasoline vehicles, and the emissions increased with increasing altitude. Atmospheric pressure was identified as the primary environmental factor affecting CO2, CO, and NOx emissions. As the speed of motor vehicles increased, the emission of CO2 also increased, while there was a quadratic relationship with acceleration. This study provides a reference and guidance for vehicle pollution control in high-altitude regions. [ABSTRACT FROM AUTHOR]

Cow dung is the most familiar and commonly used domestic fuel in the Qinghai-Tibet Plateau, and the atmospheric pollutants emitted due to burning cow-dung affect the atmospheric environment of the Qinghai-Tibet Plateau. In this study, in order to acquire the emission factors and constituent characteristics of PM2.5 in association with cow-dung combastion in different seasons and at different altitudes, a series of researches were carried out in Linzhi City, Naqu City and Linzhou County of Lahsa City. By use of the dilution channel method PM2.5 generated from buring cow-dung was collected and analyzed in terms of constituent. The results showed that in spring PM2.5 emission factors of Linzhi, Linzhou and Naqu were (6.260±0.870) g/kg, (8.204±2.085) g/kg and (8.281 ±0.300) g/kg, respectively, and in summer, the PM2.5 emission factors of Linzhi, Linzhou and Naqu were (6.426± 1.761) g/kg, (7.669±2.005) g/kg and (11.912± 1.741) g/kg, respectively; the relative humidity in summer was higher than that in spring, and the PM2.5 emission factors of Linzhi and Linzhou differed not very much in spring and summer, while the emission factors of Naqu in summer were slightly greater than those in spring. With the increase of altitude, atmospheric oxygen content declined, and the PM2.5 emission factor went up. As to the PM2.5 constituent characteristics of cow-dung combastion, the carbon content of PM2.5 was in the range of 59.7%~77.8%, water-soluble ions 17.8%~31.4%, and metal elements 3.21%~5.09%; as to organic carbon (OC) and elementary carbon (EC), the content of OC in PM2.5 increased with altitude, and the ratio of OC to EC ranged from 31.35 to 42.16; in regard to PO43- in PM2.5, which originated mainly from the application of phosphate fertilizer, the content of which was much higher than that of other water-soluble ions, and the proportion of PO43- ranged 5.34%~10.16%. Besides, there was a significant linear correlation between the reconstructed mass and the membrane sampling mass, the correlation coefficient R² ranged 0.7238~0.961 5; and the result of reconstructed mass suggested that the PM2.5 derived from cow-dung combustion was mainly composed of organic matter, mineral components and phosphate. [ABSTRACT FROM AUTHOR]

Background: Following global pledges to reduce greenhouse gas (GHG) emissions by 30% by 2030 compared to the baseline level of 2020, improved quantification of GHG emissions from developing countries has become crucial. However, national GHG inventories in most Sub-Saharan African countries use default (Tier I) emission factors (EFS) generated by the Intergovernmental Panel on Climate Change (IPCC) to estimate enteric CH4 emissions from animal agriculture. The present study provides an improved enteric CH4 emission estimate (Tier II) based on animal energy requirements derived from animal characteristics and performance data collected from about 2500 cattle in 480 households from three smallholder farming systems to represent the common dairy farming in the central highlands of Ethiopia. Using average seasonal feed digestibility data, we estimated daily methane production by class of animal and farming system and subsequently generated improved EF. Results: Our findings revealed that the estimated average EF and emission intensities (EI) vary significantly across farming systems. The estimated value of EF for adult dairy cows was 73, 69, and 34 kg CH4/cow/year for urban, peri-urban, and rural farming systems, respectively. Rural dairy farming had significantly higher emission intensity (EI) estimated at 1.78 CO2-eq per kg of fat protein-corrected milk (FPCM) than peri-urban and urban 0.71 and 0.64 CO2-eq kg−1 FPCM dairy farming systems, respectively. The EF estimates in this study are lower than the IPCC's (2019) default value for both stall-fed high-productive and dual-purpose low-productive cows. Conclusions: The current findings can be used as a baseline for the national emission inventory, which can be used to quantify the effects of future interventions, potentially improving the country's commitment to reducing GHG emissions. Similarly, this study suggests that increased animal productivity through improved feed has a considerable mitigation potential for reducing enteric methane emissions in smallholder dairy farming systems in the study area. [ABSTRACT FROM AUTHOR]

This study determined the nitrous oxide emission factors (EF1, the percentage of N2O emitted as a proportion of fertiliser N applied) for fertilisers ammonium sulphate (AS), diammonium phosphate (DAP), and urea under the same field conditions. Trials were conducted on pasture soils across four sites (Waikato, Manawatu, Canterbury and Otago) in New Zealand during late autumn and spring of 2022. The average EF1 values for urea across all four sites were 0.128% (95% C.I., 0.023% and 0.249%) in late autumn and 0.136% (95% C.I., 0.031% and 0.259%) in spring. The corresponding EF1 values for AS were 0.125% (95% C.I., – 0.021% and 0.246%) in late autumn and 0.083% (95% C.I., 0.015% and 0.197%) in spring, while for DAP, they were 0.049% (95% C.I., – 0.044% and 0.157%) in late autumn and 0.090% (95% C.I., -0.009% and 0.205%) in spring. The mean EF1 values across all four sites and two seasons were calculated as 0.132% (95% C.I., 0.016% and 0.269%) for urea, 0.104% (95% C.I., – 0.008% and 0.235%) for AS, and 0.069% (95% C.I., – 0.036 and 0.194) for DAP. No significant differences in EF1 were observed between the three fertilisers (P > 0.05) at individual sites or when considering all four sites collectively. [ABSTRACT FROM AUTHOR]

Simple Summary: This study examined the levels of certain pollutants, primarily ammonia and particulate matter (PM), emitted by a commercial pig farm in Korea. Understanding these levels is vital for reducing the environmental impact of pig farming and ensuring a sustainable future for this industry. Interestingly, the study found that previous guidelines in Korea might have overestimated these pollution levels, although the current findings are consistent with global research. Seasonal variations also impacted pollution levels: more ammonia was released in spring and autumn, while other pollutants increased in summer. Factors such as the number and age of the pigs significantly influenced these emission levels, as did airflow and ventilation. In essence, continued research in this area will help to improve pig farming practices in Korea, ensuring a balance between successful farming and environmental preservation. Quantifying emission factors of ammonia and particulate matter (PM) in livestock production systems is crucial for assessing and mitigating the environmental impact of animal production and for ensuring industry sustainability. This study aimed to determine emission factors of ammonia, total suspended particles (TSPs), PM10, and PM2.5 for piglets and growing–finishing pigs at a commercial pig farm in Korea. It also sought to identify factors influencing these emission factors. The research found that the emission factors measured were generally lower than those currently used in Korea, but were consistent with findings from individual research studies in the literature. Seasonal variations were observed, with ammonia emissions peaking in spring and autumn, and PM emissions rising in summer. Correlation analyses indicated that the number of animals and their average age correlated positively with both ammonia and PM emission factors. Ventilation rate was also positively correlated with PM emissions. Future extended field measurements across diverse pig farms will offer deeper insights into the emission factors of pig farms in Korea, guiding the development of sustainable livestock management practices. [ABSTRACT FROM AUTHOR]

The brick industry is a significant contributor to economy of Nepal, but it is also a key source of greenhouse gas (GHG) emissions and air pollution. This study explores the current state of the brick industry in Nepal, the technologies used for brick production, and the feasibility of cleaner technologies using desk reviews, field surveys, and consultations. A total of 1.30 mT CO2-e (million tons of CO2 equivalent) emission is estimated from 1236 brick kilns in 41 districts of Nepal. The majority of brick kilns use traditional technologies, which are highly inefficient and produce large amounts of emissions. Several cleaner technologies are identified as viable alternatives, including Zigzag Kilns, Vertical Shaft Brick Kilns (VSBK), and Hybrid Hoffman Kilns (HHKs). Based on the evaluation of technological, environmental, financial, resource, and legal feasibilities, the zigzag and HHKs are identified as the most promising options for reducing emissions and improving environmental sustainability in the brick industry in Nepal. We conclude that while there are technical and economic barriers to adopting cleaner technologies in the brick industry, there are also opportunities for government support and private sector investment to drive more sustainable brick production in Nepal. A combination of policy incentives, financial support, and technical assistance help to accelerate the adoption of cleaner technologies in the brick industry, leading to significant environmental and economic benefits for the country.

Abstract The rapidly growing areal extent of oil palm (Elaeis guineensis Jacq.) plantations and their high fertilizer input raises concerns about their role as substantial N2O sources. In this study, we present the first eddy covariance (EC) measurements of ecosystem‐scale N2O fluxes in an oil palm plantation and combine them with vented soil chamber measurements of point‐scale soil N2O fluxes. Based on EC measurements during the period August 2017 to April 2019, the studied oil palm plantation in the tropical lowlands of Jambi Province (Sumatra, Indonesia) is a high source of N2O, with average emission of 0.32 ± 0.003 g N2O‐N m−2 year−1 (149.85 ± 1.40 g CO2‐equivalent m−2 year−1). Compared to the EC‐based N2O flux, average chamber‐based soil N2O fluxes (0.16 ± 0.047 g N2O‐N m−2 year−1, 74.93 ± 23.41 g CO2‐equivalent m−2 year−1) are significantly (~49%, p 2 days), soil temperature and water‐filled pore space gained importance on N2O flux variation. These results suggest a plant‐mediated N2O transport, providing important input for modelling approaches and strategies to mitigate the negative impact of N2O emissions from oil palm cultivation through appropriate site selection and management.

Shale gas is an important alternative natural gas source that can meet China's growing energy demand. However, methane emissions during shale gas production could largely determine whether it could be considered as a bridging clean energy source. In this study, we performed methane emission measurements using three methods (on-site optical gas imaging, on-site methane patrolling, and downwind measurement) at shale gas production sites in Sichuan province, China, covering 18 well sites with 81 wells. The results showed that flowback water tanks were the major methane sources, with valves, separators, chemical injection pumps, and pneumatic controllers as other sources. The methane concentrations inside the 18 sites ranged from 1.42 to 459 μmol mol−1, with over 59% of the sites having the highest concentration less than 50 μmol mol−1. The optical gas imaging method, with its low detection limit over 5000 μmol mol−1, could not capture the emission effectively. The three successful downwind measurements resulted in site level emission rates between 0.02 and 0.17 kg h−1. When divided by the number of wells at each site, the emission intensity was 4%–28% of the wellhead emission factor for natural gas production in China. More measurements are required to better quantify methane emissions from shale gas sites in China. For sites in mountainous regions or long-term low-wind regions, detection methods other than downwind measurements should be suitable for quantifying site-level emissions.

The emission factor method (Tier 1) recommended by the Intergovernmental Panel on Climate Change (IPCC) is commonly used to estimate greenhouse gas (GHG) emissions from livestock and poultry farms. However, the estimation accuracy may vary due to practical differences in manure management across China. The objectives of this study were to estimate the direct and indirect nitrous oxide (N2O) emissions from dairy manure management between 1990 and 2021 in China and characterize its spatial and temporal variations following IPCC guideline Tier 2. The N2O emission factor (EF) of dairy cow manure management systems was determined at the national level and regional level as well. The results showed that the national cumulative N2O emission of manure management from 1990 to 2021 was 113.1million tons of CO2 equivalent, ranging from 90.3 to 135.9 million tons with an uncertainty of ±20.2%. The annual EF was 0.021 kg N2O-N (kg N)−1 for total emissions, while it was 0.014 kg N2O-N (kg N)−1 for direct emissions. The proportions of N2O emissions in North China, Northeast China, East China, Central and Southern China, Southwest China and Northwest China were 32.3%, 18.6%, 11.4%, 5.8%, 6.1% and 25.8%, respectively. In addition, N2O emissions varied among farms in different scales. The respective proportions of total N2O emissions from small-scale and large-scale farms were 64.8% and 35.2% in the past three decades. With the improvement in farm management and milk production efficiency, the N2O emissions per unit mass of milk decreased from 0.77 × 10−3 kg to 0.48 × 10−3 kg in 1990–2021. This study may provide important insights into compiling a GHG emission inventory and developing GHG emission reduction strategies for the dairy farming system in China.