Carbon Dioxide Emission Rates Research Articles

Operational level emissions modelling of on-road construction equipment through field data analysis

Abstract The construction industry is considered to be one of the largest contributors to greenhouse gas (GHG) emissions globally. Emissions from construction equipment are normally estimated through simulation or conducting emission tests in the laboratory, which may not represent real-world situations. Field data measurement is essential to quantify the emissions of equipment in use. This paper aims to develop an operational level model to estimate the emission rates of carbon monoxide (CO), carbon dioxide (CO 2 ), hydrocarbon (HC) and nitrogen oxides (NO x ) of on-road construction equipment. The data collection procedure included instrumentation, laboratory testing and field measurements. Three types of instruments, including a portable emission measurement system (PEMS), a global positioning system-aided inertial navigation system (GPS-INS) and an engine data logger, were used to collect emissions rates, operational parameters and engine data, respectively. The raw data collected from the three channels were then synchronized and validated. Further, the operational level emission model was developed by performing ordinary least square (OLS) and multivariable linear regression (MLR) analyses of the field data. The emission model considers engine specifications, operational factors and environmental parameters as affecting variables. The statistical analysis results verify the high correlation between emission rates and affecting parameters. The developed model is finally validated by comparing the estimated results with the real data collected by the PEMS and the engine data logger in the field experiments.

Evaluation of Gaseous Pollutants Emission Rate from Marvdasht Landfills

Unmanaged gasses emitted from the landfills can lead to various environmental and health problems for the resident of such regions. Despite various studies conducted on prediction of emission rates of gaseous pollutant in landfills, no study in currently being conducted on the emission rates of carbon dioxide, methane, and non-methane organic compounds from the Marvdasht landfills. In the first steps of this study the required information were gathered first and then the necessary prediction calculations were handled by the LandGEM software. The study results suggest that the within the years of 2003 and 2031, the generation rates of carbon dioxide, methane and non-methane organic compounds will respectively be equal to 14×10 11 , 4667×10 7 and 3.89×10 5 tons. Among the aforementioned gasses, in case of converting the methane energy capacity into the electrical energy, a total income of 1489 billion rials is achievable from the Marvdasht landfill within a course of 27 years of operation. However, it should be noted that no investigation was conducted on the initial and operation costs in this study. In this study, by calculating all of the required information for the design and construction of a biogas collection and extraction system in the landfill of Marvdasht, the necessary means for the appliance of such plan has been provided.

Alternative Fuel Vehicle Adoption Increases Fleet Gasoline Consumption and Greenhouse Gas Emissions under United States Corporate Average Fuel Economy Policy and Greenhouse Gas Emissions Standards.

The United States Corporate Average Fuel Economy (CAFE) standards and Greenhouse Gas (GHG) Emission standards are designed to reduce petroleum consumption and GHG emissions from light-duty passenger vehicles. They do so by requiring automakers to meet aggregate criteria for fleet fuel efficiency and carbon dioxide (CO2) emission rates. Several incentives for manufacturers to sell alternative fuel vehicles (AFVs) have been introduced in recent updates of CAFE/GHG policy for vehicles sold from 2012 through 2025 to help encourage a fleet technology transition. These incentives allow automakers that sell AFVs to meet less-stringent fleet efficiency targets, resulting in increased fleet-wide gasoline consumption and emissions. We derive a closed-form expression to quantify these effects. We find that each time an AFV is sold in place of a conventional vehicle, fleet emissions increase by 0 to 60 t of CO2 and gasoline consumption increases by 0 to 7000 gallons (26,000 L), depending on the AFV and year of sale. Using projections for vehicles sold from 2012 to 2025 from the Energy Information Administration, we estimate that the CAFE/GHG AFV incentives lead to a cumulative increase of 30 to 70 million metric tons of CO2 and 3 to 8 billion gallons (11 to 30 billion liters) of gasoline consumed over the vehicles' lifetimes - the largest share of which is due to legacy GHG flex-fuel vehicle credits that expire in 2016. These effects may be 30-40% larger in practice than we estimate here due to optimistic laboratory vehicle efficiency tests used in policy compliance calculations.

Global warming as affected by incorporation of variably aged biomass of hairy vetch for rice cultivation

Hairy vetch (Vicia villosa Roth) is cultivated during the cold fallow season in paddy soils of temperate countries such as South Korea and Japan, mostly as animal feed and green manure. Information on the effect of ageing of hairy vetch incorporation in relation to greenhouse gas (GHG) emissions and global warming potential (GWP) is not available. Therefore, hairy vetch biomass of ages 183, 190, 197, and 204 days was incorporated in paddy soil to estimate GWP during rice cultivation. The emission rates of methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O) gases were monitored once a week by using the closed-chamber method. The net ecosystem carbon budget was used to estimate pure CO2 emission fluxes. Biomass production of hairy vetch was 6.5 Mg ha–1 at 204 days, which was similar to other treatments. The GWP was lower with the 204-day-old vetch biomass incorporation than with other treatments. High content of cellulose and lignin in 204-day-old hairy vetch might have affected decomposition rate and subsequently reduced GHGs emissions during rice cultivation. Our results suggest that hairy vetch can be allowed to grow for 204 days before incorporation at 3 Mg ha–1 without sacrificing rice yield, while maximising biomass production and minimising GWP during rice cultivation.

A robust fuzzy optimization model for carbon-efficient closed-loop supply chain network design problem: a numerical illustration in electronics industry

Environmentalism has become an important global issue in the present century. During the recent years, the closed-loop green supply chain management has been increasingly a center of attention as a result of governmental laws and legislations (regarding the environmental effects of any activity) and the soaring consumers' expectations. In this study, effort has been made to investigate a facility location/allocation model for a multi-product closed-loop green supply chain network consisting of manufacturing/remanufacturing and collection/inspection centers as well as disposal center and markets. To design the network, we have proposed a mixed-integer linear programming model capable of reducing the network total costs. The model has been so developed as to consider such environmental objectives as reducing the rate of carbon dioxide emission in the environment throughout the network in question. Moreover, the model has been developed using a robust fuzzy programming approach to investigate the effects of uncertainties of the variable costs, as well as the demand rate, on the network design. To solve the bi-objective programming model, use has been made of the ε-constraint approach and a numerical illustration of Copiers Industry is used to show the applicability of the proposed optimization model. Results have revealed that the model is capable of controlling the network uncertainties as a result of which a robustness price will be imposed on the system.

The effects of slatted floors and manure scraper systems on the concentrations and emission rates of ammonia, methane and carbon dioxide in goat buildings

This study was designed to quantify the concentrations and emission rates of ammonia (NH3), methane (CH4) and carbon dioxide (CO2) and to evaluate their effects on the indoor environment of slatted floor and manure scraper systems in two goat buildings. One building had a slatted floor and a manure scraper system (building II); the other building did not, and manure removal was performed by workers (building I). This study was conducted from April 2014 until January 2015, with sampling during four seasons. The NH3, CH4 and CO2 emission rates were highest in the summer and lowest in the winter in both buildings. However, in building II, these emission rates were significantly lower (P<0.05) than those in building I in each season. In both buildings, the NH3, CH4 and CO2 concentrations were highest in the winter and lowest in the summer, although the gas concentrations were significantly lower (P<0.05) in building II than in building I. The results of this study suggest that the slatted floor and manure scraper systems substantially lower the emissions of harmful gases in goat buildings.

Differences in CO2 and N2O emission rates following crop residue incorporation with or without field burning: A case study of adzuki bean residue and wheat straw

In the context of sustainable soil-quality management and mitigating global warming, the impacts of incorporating raw or field-burned adzuki bean (Vigna angularis (Willd.) Ohwi & Ohashi) and wheat (Triticum aestivum L.) straw residues on carbon dioxide (CO2) and nitrous oxide (N2O) emission rates from soil were assessed in an Andosol field in northern Japan. Losses of carbon (C) and nitrogen (N) in residue biomass during field burning were much greater from adzuki bean residue (98.6% of C and 98.1% of N) than from wheat straw (85.3% and 75.3%, respectively). Although we noted considerable inputs of carbon (499 ± 119 kg C ha–1) and nitrogen (5.97 ± 0.76 kg N ha–1) from burned wheat straw into the soil, neither CO2 nor N2O emission rates from soil (over 210 d) increased significantly after the incorporation of field-burned wheat straw. Thus, the field-burned wheat straw contained organic carbon fractions that were more resistant to decomposition in soil in comparison with the unburned wheat straw. Our results and previously reported rates of CO2, methane (CH4) and N2O emission during wheat straw burning showed that CO2-equivalent greenhouse gas emissions under raw residue incorporation were similar to or slightly higher than those under burned residue incorporation when emission rates were assessed during residue burning and after subsequent soil incorporation.

Emission of Carbon Dioxide and Methane from Duckweed Ponds for Stormwater Treatment.

This study determined the greenhouse gas emission from two laboratory-scale duckweed ponds for stormwater treatment. The rate of carbon dioxide (CO2) emission from the two duckweed systems was 1472 ± 721 mg/m(2)·d and 626 ± 234 mg/m(2)·d, respectively. After the removal of duckweeds, CO2 emissions decreased to 492 ± 281 mg/m(2)·d and 395 ± 53 mg/m(2)·d, respectively. The higher CO2 emissions in the duckweed systems were attributed to duckweed biomass decay on the pond soil surface. A thin-film model was able to predict the increasing CO2 concentrations in the closed static chamber during 2 weeks of sampling. The initial methane fluxes from the duckweed systems were 299 ± 74 mg/m(2)·d and 180 ± 91 mg/m(2)·d, respectively. After the removal of duckweeds, the flux increased to 559 ± 215 mg/m(2)·d and 328 ± 114 mg/m(2)·d, respectively.

Nutrient Effects on Belowground Organic Matter in a Minerogenic Salt Marsh, North Inlet, SC

Soil organic matter, roots, rhizomes, and carbon dioxide (CO2) emission rates were examined in minerogenic marshes of the North Inlet Estuary, a system dominated by sediment depositional processes and typical of the Southeast USA. Three marsh sites were sampled: a long-term nutrient enrichment experiment at Goat Island; the high marsh, low marsh, and creekbank of Crab Haul Creek, a fringing marsh that only receives drainage from a forested watershed; and three creekbank locations in Debidue Creek, which receives drainage from a residential and golf course development situated at its headwaters. Goat Island responses to 12 years of nutrient fertilization were an increase in soil organic matter (OM), an increase in number of rhizomes, enlarged rhizome diameters, and increased CO2 emission rates. At soil depths of 10–20 cm, all Debidue creekbank locations had significantly more rhizomes than the reference Crab Haul creekbank. The rhizome diameters at the mid and upper Debidue creekbank locations were significantly larger than the Debidue mouth and reference Crab Haul creekbank. The upper Debidue and the Crab Haul creekbanks had similar soil percent OM, which was significantly greater than the mid Debidue, which was greater than the Debidue mouth. CO2 emission rates at the fertilized Goat Island plots were similar in magnitude to the upper Debidue and significantly greater than the Goat Island control plots and the reference Crab Haul Creek. Inputs of sediment in marshes dominated by depositional processes may buffer the system from adverse effects of nutrient exposure, while increases in soil OM and rhizomes in response to nutrients may contribute to peat formation.

High methane emissions from a midlatitude reservoir draining an agricultural watershed.

Reservoirs are a globally significant source of methane (CH4), although most measurements have been made in tropical and boreal systems draining undeveloped watersheds. To assess the magnitude of CH4 emissions from reservoirs in midlatitude agricultural regions, we measured CH4 and carbon dioxide (CO2) emission rates from William H. Harsha Lake (Ohio, U.S.A.), an agricultural impacted reservoir, over a 13 month period. The reservoir was a strong source of CH4 throughout the year, emitting on average 176 ± 36 mg C m(-2) d(-1), the highest reservoir CH4 emissions profile documented in the United States to date. Contrary to our initial hypothesis, the largest CH4 emissions were during summer stratified conditions, not during fall turnover. The river-reservoir transition zone emitted CH4 at rates an order of magnitude higher than the rest of the reservoir, and total carbon emissions (i.e., CH4 + CO2) were also greater at the transition zone, indicating that the river delta supported greater carbon mineralization rates than elsewhere. Midlatitude agricultural impacted reservoirs may be a larger source of CH4 to the atmosphere than currently recognized, particularly if river deltas are consistent CH4 hot spots. We estimate that CH4 emissions from agricultural reservoirs could be a significant component of anthropogenic CH4 emissions in the U.S.A.

잔디밭에서 계절 변화에 따른 이산화탄소 플럭스 변동

In this study, the variations of the carbon dioxide fluxes were investigated with soil temperatures in the grassplot and seasonal variations of carbon dioxide concentrations and fluxes were analysed. Soil temperatures, carbon dioxide concentrations and fluxes were measured on the grassplot in Pukyong National University. Field measurements were carried out 25 times from March in 2010 to March in 2011 with nine points on the grassplot. Seasonal variations of carbon dioxide concentrations and fluxes showed an inverse relation. In summer, carbon dioxide concentrations are lower and carbon dioxide fluxes are higher. In winter, carbon dioxide concentrations are higher and carbon dioxide fluxes are lower. On the grassplot, carbon dioxide emission rate increase when the soil temperature is more than <TEX>$20^{\circ}C$</TEX> and the emission rate decrease when the soil temperatures are less than <TEX>$10^{\circ}C$</TEX>. When the accumulated rainfall for five days before measurement day is 20~100 mm, it is showed that the more rainfall, the more carbon dioxide emissions. Carbon dioxide emission rate from the grassplot to the upper atmosphere was increased or decreased by the factors such as soil temperature, growth and wither of grass and rainfall. The results of this study showed that the emission of carbon dioxide in the grassplot is dominantly controlled by seasonal factors (especially soil temperature and rainfall).

Below the disappearing marshes of an urban estuary: historic nitrogen trends and soil structure.

Marshes in the urban Jamaica Bay Estuary, New York, USA are disappearing at an average rate of 13 ha/yr, and multiple stressors (e.g., wastewater inputs, dredging activities, groundwater removal, and global warming) may be contributing to marsh losses. Among these stressors, wastewater nutrients are suspected to be an important contributing cause of marsh deterioration. We used census data, radiometric dating, stable nitrogen isotopes, and soil surveys to examine the temporal relationships between human population growth and soil nitrogen; and we evaluated soil structure with computer-aided tomography, surface elevation and sediment accretion trends, carbon dioxide emissions, and soil shear strength to examine differences among disappearing (Black Bank and Big Egg) and stable marshes (JoCo). Radiometric dating and nitrogen isotope analyses suggested a rapid increase in human wastewater nutrients beginning in the late 1840s, and a tapering off beginning in the 1930s when wastewater treatment plants (WWTPs) were first installed. Current WWTPs nutrient loads to Jamaica Bay are approximately 13 995 kg N/d and 2767 kg P/d. At Black Bank, the biomass and abundance of roots and rhizomes and percentage of organic matter on soil were significantly lower, rhizomes larger in diameter, carbon dioxide emission rates and peat particle density significantly greater, and soil strength significantly lower compared to the stable JoCo Marsh, suggesting Black Bank has elevated decomposition rates, more decomposed peat, and highly waterlogged peat. Despite these differences, the rates of accretion and surface elevation change were similar for both marshes, and the rates of elevation change approximated the long-term relative rate of sea level rise estimated from tide gauge data at nearby Sandy Hook, New Jersey. We hypothesize that Black Bank marsh kept pace with sea level rise by the accretion of material on the marsh surface, and the maintenance of soil volume through production of larger diameter rhizomes and swelling (dilation) of waterlogged peat. JoCo Marsh kept pace with sea-level rise through surface accretion and soil organic matter accumulation. Understanding the effects of multiple stressors, including nutrient enrichment, on soil structure, organic matter accumulation, and elevation change will better inform management decisions aimed at maintaining and restoring coastal marshes.

Optimal Design and Synthesis of Algal Biorefinery Processes for Biological Carbon Sequestration and Utilization with Zero Direct Greenhouse Gas Emissions: MINLP Model and Global Optimization Algorithm

We develop a novel superstructure of algal biorefinery processes for biological carbon sequestration and utilization, encompassing off-gas purification, algae cultivation, harvesting and dewatering, lipid extraction, remnant treatment, biogas utilization, and algal oil upgrading stages. Based on the superstructure, we propose a mixed-integer nonlinear programming (MINLP) model to minimize the unit carbon sequestration and utilization cost and apply a tailored branch-and-refine algorithm based on successive piecewise linear approximation to globally optimize the resulting nonconvex MINLP problem efficiently. The minimum unit carbon sequestration and utilization cost of $1.48/ton of CO2 is obtained when the diesel price is $3.91/gal and feed gas is delivered to the biorefinery only during daytime at a flow rate of 5003.46 ktons/year corresponding to the carbon dioxide emission rate of a 600 MW coal-fired power plant. The resulting algal biorefinery design reuses all the CO2 produced within the process, leading to zero direct greenhouse gas emission of the entire process.

Analysis of [formula omitted] emission in traffic flow and numerical tests

We investigated the carbon dioxide emission rate in traffic flow analytically and numerically. The emission model was derived based on Bando’s optimal velocity model with a consideration of slope. Simulations were conducted to examine the relationship between the CO2 emission rate of vehicles and slope of road, traffic density, and road length. Analysis of the results shows that some original laws of CO2 emission in traffic flow with congestion were exhibited.

Influence of the nutritional conditions on haloalcohol dehalogenase HheC production by recombinant Escherichia coli P84A/MC1061

In this research, we first determined the three most significant nutrient factors affecting haloalcohol dehalogenase HheC production by Escherichia coli P84A/MC1061. These were glycerol, yeast extract, and ammonium sulfate. The steepest ascent method was then applied to obtain the optimal design intervals of the three factors. An application of center composite design was used, and the ingredients of the optimized medium were 1.8 g l−1 glycerol, 48 g l−1 yeast extract, 2.2 g l−1 ammonium sulfate, 5 g l−1 compound phosphate, 1 g l−1 magnesium sulfate, and 1.19 × 10−5 g l−1 ferric sulfate. The enzyme activity reached 109,365 U ml−1 under the most favorable conditions, which is a 277.7 % increase compared with the control group. Our study of cellular respiration parameters (oxygen uptake rate and carbon dioxide emission rate) revealed that the metabolic activity of the strain was strongly promoted under these optimal nutrient conditions and that yeast extract had a positive effect on respiratory intensity and the expression levels of HheC.

Measuring the human contribution to atmospheric carbon dioxide

Although it is well established that humans are responsible for the modern increase in atmospheric carbon dioxide concentrations, the precise emission rates of carbon dioxide and other environmentally important gases are less well known. Traditionally, the reported usages of coal, oil, and other commodities are used to estimate emission rates. Though this economics‐based approach is thought to work well at global and national scales, uncertainties increase for smaller regional scales or time scales shorter than a year. Drawing on 6 years of gas concentration measurements taken every 2 weeks from an airplane at two sites over the northeastern United States, Miller et al. developed a system to measure the anthropogenic contribution to atmospheric gas concentrations that is independent of accounting‐based approaches.

The Pricing of Climate Risk

This study investigates whether corporate climate risk is priced by the capital markets. Using carbon dioxide emission rates of publicly traded U.S. electric companies, we find that climate risk is positively associated with cost of capital measures, more specifically the implied cost of equity and the cost of debt. Additionally, we find that equity and debt investors evaluate corporate climate risk differently. The results show that the cost of debt decreases with the level of capital intensity, suggesting that debt investors value the increase in efficiency resulting from current capital investments. The results also show that the cost of equity decreases and the cost of debt increases with the newness of assets in places. Newer equipment is likely to be operationally and environmentally more efficient. While the results concerning the cost of debt are puzzling, we consider that debt investors may account for other performance indicators. We conclude that equity and debt investors evaluate climate risk differently according to their different payoff functions.

Prime Movers of Globalization: The History and Impact of Diesel Engines and Gas Turbines

Review: Prime Movers of Globalization: The History and Impact of Diesel Engines and Gas Turbines By Vaclav Smil Reviewed by Byron Anderson DeKalb, Illinois, USA Smil, Vaclav. Prime Movers of Globalization: The History and Impact of Diesel Engines and Gas Turbines. Cambridge, MA: The MIT Press, 2010. 261 pp. ISBN: 9780262014434, US $29.95, cloth. Prime Movers of Globalization is about the history and impact of the internal combustion engine invented by Rudolf Diesel in the 1890s and the gas turbine invented by Frank Whittle and Hans-Joachin Pabst von Ohain in the 1930s. Diesel’s engines evolved to power ships, railroads, trucks and generators, and gas turbines evolved to power jet airplanes. Gas turbines and diesel engines eventually became indispensible technologies to worldwide trade and transportation, yet are commonly overlooked as movers of the global economy. The book will help correct this gap. Smil, Distinguished Professor at the University of Manitoba and author of many books on energy, ecology and globalization, describes development of the engines, including the inventions that led to the diesel and turbine engines and the subsequent alterations, advancements and transformations made to the engines. These would include key inventors, for example, the gas-fueled engines of Nicolaus Otto, Gottlieb Daimler, and Karl Benz, and companies that furthered turbine technology through research, such as General Electric, Rolls Royce, and Pratt and Whitney. Clearly, Smil admires what it took to develop these massive engines, though the associated problems are also mentioned, for example, job losses incurred by the move of manufacturing plants to overseas locations made possible by large bulk carriers. While categorized as a book of history and globalization, environmental issues are included, for example, greenhouse gas-emissions from ships, trucks and aircraft, and the global spread of microbes and invertebrate species in ballast waste of commercial ships. Surprisingly, diesel engines and gas turbines are the most efficient machines ever for moving bulk cargo long-distances, and “maritime shipments have the lowest carbon dioxide emission rates when compared to other modes of cargo traffic in terms of per tons kilometer…” (p. 162). No practical replacements will challenge these movers anytime soon, and Smil believes that in the long run, there will always be more globalization, not less. The ecological footprint of diesel engines and gas turbines has been continuously improved by technology, and new devices and procedures under development should provide further efficiencies. Interestingly, prime movers have probably reached their maximum size, and making ships or jets larger or faster than what exist today will cause them lose their efficiency and economy of scale. This book is not casual reading. The level of technical detail may challenge some, though most interested readers should come away with a deeper appreciation of the history and technology. The text is nicely supplemented graphs, charts, maps and pictures. The book concludes with a useful glossary of measurement units, references, and name and subject indices. Recommended for academic libraries. Byron Anderson, , retired from Northern Illinois University Libraries, DeKalb, IL 60115, USA. Electronic Green Journal, Issue 32, Fall 2011, ISSN:1076-7975

Air Emissions from Broiler Houses in California

The emission rates (ER) of ammonia, carbon dioxide, hydrogen sulfide, and particulate matter (PM) (PM2.5, PM10, and total suspended particulate, TSP) were monitored at two broiler houses in California from September 2007 to October 2009. Each of the two identical buildings housed an average of 21,000 broilers raised in 46 d growth cycles with a space allowance of 1430 cm2 bird-1 and an average market weight of 2.65 kg. The litter in each house was partially replaced after the first and second flocks and completely replaced after the third flock in a three-flock litter management cycle. The environment of each house was controlled by 11 single-speed ventilation fans, two evaporative cooling cells, and 17 heaters. The average daily mean (±SD) ERs of ammonia, carbon dioxide, and hydrogen sulfide were 0.503 ±0.436, 78.3 ±47.5, and 0.00289 ±0.00251 g d-1 bird-1, respectively. The average daily mean ER of PM10 was 45.0 ±39.0 mg d-1 bird-1. The influences of environmental conditions and other factors on ERs were assessed. The ERs were influenced by broiler weight or age, ambient temperature, and litter status, with the exception of PM, which was not influenced by litter status.

Ammonia, hydrogen sulfide, carbon dioxide and particulate matter emissions from California high-rise layer houses

Abstract Ammonia and hydrogen sulfide are hazardous substances that are regulated by the U.S. Environmental Protection Agency through community right-to-know legislation (EPCRA, EPA, 2011 ). The emissions of ammonia and hydrogen sulfide from large commercial layer facilities are of concern to legislators and nearby neighbors. Particulate matter (PM10 and PM2.5) released from layer houses are two of seven criteria pollutants for which EPA has set National Ambient Air Quality Standards as required by the Clean Air Act. Therefore, it is important to quantify the baseline emissions of these pollutants. The emissions of ammonia, hydrogen sulfide, carbon dioxide and PM from two California high-rise layer houses were monitored for two years from October 2007 to October 2009. Each house had 32,500 caged laying hens. The monitoring site was setup in compliance with a U.S. EPA-approved quality assurance project plan. The results showed the average daily mean emission rates of ammonia, hydrogen sulfide and carbon dioxide were 0.95 ± 0.67 (standard deviation) g d−1 bird−1, 1.27 ± 0.78 mg d−1 bird−1 and 91.4 ± 16.5 g d−1 bird−1, respectively. The average daily mean emission rates of PM2.5, PM10 and total suspended particulate (TSP) were 5.9 ± 12.6, 33.4 ± 27.4, and 78.0 ± 42.7 mg d−1 bird−1, respectively. It was observed that ammonia emission rates in summer were lower than in winter because the high airflow stabilized the manure by drying it. The reductions due to lower moisture content were greater than the increases due to higher temperature. However, PM10 emission rates in summer were higher than in winter because the drier conditions coupled with higher internal air velocities increased PM10 release from feathers, feed and manure.