A Review of Practices and Technologies for Odor Control in Swine Production Facilities

The objective of this article is to provide a systematic review on practices and technologies for odor control in swine production facilities and to summarize available data on odor reduction effectiveness of promising technologies, as well as provide information on key parameters and associated costs. Odors from swine facilities comprise hundreds of chemicals, including volatile organic compounds (VOC), ammonia (NH₃), and hydrogen sulfide (H₂S). The medians of emission rates from swine houses in literature are 5 OU/s/pig for odor, and 0.4, 2.8, and 0.1 kg/yr/pig for VOC, NH₃, and H₂S respectively. The medians of emission rates from swine manure storage facilities in literature are 5 OU/s/m2 for odor, and 1.4, 2.1, and 0.2 kg/yr/pig for VOC, NH₃, and H₂S, respectively. Facility maintenance and management practices to reduce impact of odor are reviewed in regard to regular cleaning of facilities, ventilation, floor design, drainage and manure removal systems, frequent manure removal, manure storage, and odor separation distances. Approaches to control odor and air pollution can be classified into three categories: ration/diet modification, manure treatment, capture/treatment of emitted gases and enhanced dispersion. Each of these mitigation approaches includes several specific technologies, which are summarized in tables with an evaluation of overall cost and brief comments on advantages or limitations of each technology. Diet modification strategies have been shown to reduce NH₃ emissions effectively with low cost and should be considered as a best management practices, although their effectiveness in reducing odor is still uncertain. Permeable covers and biofilters seem to have great potential to be the most promising and cost effective technologies for manure storage facilities and swine houses respectively. However, both of the technologies need careful maintenance to perform effectively. Care must be taken to select technologies that are compatible with the management capabilities of the operation to prevent potential failure due to mismanagement

Ammonia and Methane Emission Factors from Cattle Operations Expressed as Losses of Dietary Nutrients or Energy

Citation: Liu, Z.; Liu, Y.; Murphy, J.P.; Maghirang, R. Ammonia and Methane Emission Factors from Cattle Operations Expressed as Losses of Dietary Nutrients or Energy. Agriculture 2017, 7, 16.The objective of this study was to conduct a systematic review of published literature on ammonia (NH3) and enteric methane (CH4) emissions from beef and dairy cattle operations to obtain statistically representative emission factors based on dietary intakes of nutrients or energy, and to identify major causes of emission variations. NH3emissions from lagoon or other manure storage facilities were not included in this review. The NH3 and CH4 emission rates, expressed as a percentage losses of dietary nutrients or energy, demonstrated much less variation compared with emission rates expressed in g/animal/day. Air temperature and dietary crude protein (CP) content were identified as two major factors that can affect NH3 emission rates in addition to farm type. Feed digestibility and energy intake were identified as two major factors that can affect CH4 emission rates expressed as a percentage losses of dietary energy. Generally, increasing productivity and feed efficiency represented the greatest opportunity for mitigating NH3 or CH4 emissions per unit of livestock product. Expressing CH4loss on a digestible energy basis rather than a gross energy intake basis can better represent the large variation among diets and the effects of varying dietary emission mitigation strategies

Estimating ventilation rates of animal houses through CO2 balance

Citation: Liu, Z., Powers, W., & Harmon, J. D. (2016). Estimating ventilation rates of animal houses through CO2 balance. Transactions of the Asabe, 59(1), 321-328. doi:10.13031/trans.59.10235The CO2 production rates from various animal species were measured as well as the ventilation rates (VR) in environmental rooms at Michigan State University over the course of 15 studies that considered dietary strategies to alter air emissions, including two dairy cow studies, four steer studies, two swine studies, one Turkey study, four laying hen studies, and two broiler chicken studies. The objectives of this article are to summarize the baseline data on CO2 production from various animal species and determine uncertainties of the CO2 balance approach for estimating VR of animal houses by evaluating the model performance in these studies. In the poultry (broiler, laying hen, and Turkey) and dairy studies, the CO2 production rates per heat production of animals or respiratory quotient (RQ) showed a decreasing trend with increasing animal age or days in milk (DIM). Higher variation in CO2 production rates per heat production of animals were observed in young broiler chicken (<3 weeks) and Turkeys (<10 weeks) and in the dairy cow studies. The modeled and measured CO2 production rates were generally comparable with each other for each species, and the standard deviation of model residuals was about 20% to 30% of the average measured CO2 production rate for each species except dairy cows. By only including data in which the differences between exhaust and inlet CO2 concentrations were larger than 50 ppm, the standard deviations of model residuals were less than 32% of the average measured VR in the broiler, laying hen, swine, and steer studies. Based on the results, when using the CO2 balance approach to estimate VR for broiler, laying hen, swine, and steer operations, a minimum of ten replicate measurements is required to achieve a margin of error less than 20% in modeled VR with 95% confidence. © 2016 American Society of Agricultural and Biological Engineers

Estimating Ambient Ozone Effect of Kansas Rangeland Burning with Receptor Modeling and Regression Analysis

Citation: Liu, Z. F., Liu, Y., Murphy, J. P., & Maghirang, R. (2017). Estimating Ambient Ozone Effect of Kansas Rangeland Burning with Receptor Modeling and Regression Analysis. Environments, 4(1), 14. doi:10.3390/environments4010014Prescribed rangeland burning in April is a long-standing practice in the Flint Hills region of eastern Kansas to maintain the tallgrass prairie ecosystem. The smoke plumes originating from these fires increases ambient PM2.5 concentrations and potentially contributes to ozone (O-3) exceedances in downwind communities. Source apportionment research using Unmix modeling has been utilized to estimate contributions of Kansas rangeland burning to ambient PM2.5 concentrations. The objective of this study was to investigate the potential correlations between O-3 and various sources of PM2.5 that are derived from receptor modeling, and then to specifically estimate contributions of Kansas rangeland burning to ambient O-3 concentrations through regression analysis. Various daily meteorological data were used as predictor variables. Multiple regression models were developed for the eight-hour daily maximum O-3 as well as the daily contributions of the five PM2.5 source categories that were derived from receptor modeling. Cross correlation was analyzed among residuals of the meteorological regression models for O-3 and the daily contributions of the five PM2.5 source categories in order to identify the potential hidden correlation between O-3 and PM2.5. The model including effects of meteorological variables and episodic contributions from fire and industrial emissions can explain up to 78% of O-3 variability. For non-rainy days in April, the daily average contribution from prescribed rangeland burning to O-3 was 1.8 ppb. On 3% of the days in April, prescribed rangeland burning contributed over 12.7 ppb to O-3; and on 7% of the days in April, burning contributed more than 7.2 ppb to O-3. When the intensive burning activities occur in days with high O-3 background due to high solar radiation or O-3 carryover from the previous day, the contributions from these episodic fire emissions could result in O-3 exceedances of the National Ambient Air Quality Standards (NAAQS). The regression models developed in this study demonstrated that the most valuable predictors for O-3 in the Flint Hills region include the O-3 level on the previous day, total solar radiation, difference between daily maximum and minimum air temperature, and levels of episodic fire and industrial emissions. The long term goal is to establish an online O-3 forecasting tool that can assist regulators and land managers in smoke management during the burning season so that the intensive burning activities can be planned to avoid forecasted high O-3 days and thus prevent O-3 exceedance

CO2 Balance and Estimation of Ventilation Rates in Animal Studies

The CO 2 emissions were measured in environmental rooms in 15 animal operation studies, including studies of dairy cow, steer, swine, turkey, laying hen and broiler. The objectives of this paper are to summarize CO 2 emission data in these 15 studies;, to investigate the possible diet effect; and to evaluate the performance of the CO 2 balance approach to estimate ventilation rate (VR) of animal houses. Lower CO 2 emissions were observed from steers fed diets containing 60% DDGs as compared to that from steers fed the control diets (0% DDGs). Significant differences in CO2 emissions were observed among different studies for each species of broiler, laying hen, swine, and steer, which could be the result of different management practices, different stages of production, or different weather conditions. In 10 out of the 15 studies, the measured CO2 emissions were significantly larger than the estimated CO2 productions, which could represent the corresponding amount of CO2 generation that was not accounted in the metabolic CO 2 production as well as uncertainties in measurements of CO2 emissions. The overall R2 was 0.97 when treating each of the 15 studies as one data point. The relative differences between measured and estimated VR were in the range of 6.3% to 20.5%. Uncertainties in estimated VR in dairy cow studies were relatively large because the relatively large variations in measured CO2 emissions in these studies were not well represented by the relatively constant estimated CO2 production values

Health and Environmental Impacts of Smoke from Vegetation Fires: A Review

Citation: Liu, Z. , Murphy, J. , Maghirang, R. and Devlin, D. (2016) Health and Environmental Impacts of Smoke from Vegetation Fires: A Review. Journal of Environmental Protection, 7, 1860-1885. doi: 10.4236/jep.2016.712148.Smoke exposure is often an inevitable side effect of open vegetation fires (both planned and wild) and is an important public health concern. The objective of this paper is to summarize state-of-the-art knowledge on health and environmental impacts of smoke from vegetation fires, to identify research gaps, and to provide needed information to researchers, land managers, policymakers, health care workers, and the general public. The main components of vegetation fire smoke and their characterizations are identified and evaluated. Concentrations, emission ratios, and emission factors of smoke components and the combined health and environmental effects of all hazardous smoke components from vegetation fire smoke exposure are summarized. Trends in risk assessment of vegetation fire smoke, limitations of current research, and future research needs are discussed