@article{wang-li_cao_li_liu_beasley_2013, title={Concentration and particle size distribution of particulate matter inside tunnel-ventilated high-rise layer operation houses}, volume={66}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84871094175&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2012.03.064}, abstractNote={Particulate matter (PM) is a criteria pollutant emitted from animal feeding operation (AFO) facilities, especially from poultry operation buildings. Fundamental data regarding AFO PM either do not exist, or are not representative of different animal production systems or housing types. This field study investigated particle size distributions (PSDs) and concentrations of total suspended particulate (TSP) in a tunnel ventilated high-rise layer house under different operational conditions. Six low-volume (1 m3 h−1) TSP samplers were used to collect PM samples on two floors of the high-rise layer houses across four seasons through day/night sampling protocols. The day/night sampling design was to examine animal activity impact. The PM samples were analyzed by a multi-wave length laser diffraction particle size analyzer (LS13 320) for PSDs characterized by mass median diameters (MMDs) and geometric standard deviations (GSDs). It was discovered that the mean TSP concentrations ranged from 1.0 ± 0.5 mg m−3 to 5.33 ± 0.36 mg m−3 (mean ± SD). TSP concentrations in winter were higher than in summer; concentrations on the 2nd floor were higher than that on the 1st floor; concentrations of daytime samples were higher than those of nighttime samples. Animal activity (represented by day/night samples) had the highest impact on TSP concentration as compared to other influential factors (spatial, seasonal, ventilation). No significant seasonal variations of MMD and GSD were observed in most of samples. Majority of day/night MMDs and GSDs demonstrated no significant differences. Thus the impact of animal activity (day vs. night) on MMD and GSD were not significant. Mean MMDs ± SDs ranged from 16.81 ± 1.57 μm to 20.26 ± 3.53 μm, whereas means ± SDs of GSDs ranged from 2.38 ± 0.20 to 2.81 ± 0.30. Mean PM2.5 fractions ± SDs ranged from 5.03 ± 1.60% to 8.93 ± 0.97%, whereas mean PM10 fractions ± SDs ranged from 23.25 ± 5.18% to 38.55 ± 2.96%. Significant seasonal variation in both PM10 and PM2.5 mass fractions were observed.}, journal={ATMOSPHERIC ENVIRONMENT}, author={Wang-Li, Lingjuan and Cao, Zihan and Li, Qianfeng and Liu, Zifei and Beasley, David B.}, year={2013}, month={Feb}, pages={8–16} }
 @article{wang_oviedo-rondon_small_liu_sheldon_havenstein_williams_2010, title={Farm-Scale Evaluation of Ozonation for Mitigating Ammonia Concentrations in Broiler Houses}, volume={60}, ISSN={["2162-2906"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-77955613072&partnerID=MN8TOARS}, DOI={10.3155/1047-3289.60.7.789}, abstractNote={Abstract This study evaluated the effectiveness of in-house ozonation within the public health standard limit (0.1 parts per million [ppm]) for mitigating ammonia (NH3) concentrations inside commercial broiler houses. The project was conducted in four identical tunnel-ventilated houses. Two houses served as treatment and the other two served as control units. The experiment was replicated in five consecutive flocks. Except for ozonation treatment, all other operational parameters including feed, broiler strain, age and number of broilers, and ventilation system were the same among four houses. NH3 and carbon dioxide (CO2) concentrations in the treatment and control houses were measured for a minimum of 48 hr/week throughout the five flocks of 8 or 9 weeks each. The gas measurements were conducted using portable multigas units (PMUs). House temperatures were recorded with data loggers in each flock. Comparison of temperatures and CO2 concentrations among houses indicated no significant differences in ventilation rates among treatment and control houses in any of the five flocks. As a result, comparisons of NH3 concentrations inside houses were used to evaluate the effectiveness of house ozonation for NH3 emission mitigation. Statistical test of mean NH3 concentrations for each flock separated by house indicated that the house-to-house variation was significantly smaller than the flock-to-flock variation. There was a substantial variation in NH3 concentrations across different flocks, but no house had consistently higher or lower mean NH3 concentrations than any other. Evaluations for differences in mean NH3 from week to week, between treatment groups, and differences in week-to-week variations between treatment groups suggested that ozone effect was not uniform for each week and the effect was not statistically significant for any week. Tests of overall ozone treatment effect and treatment-week interaction indicated there was no difference in mean NH3 between the control and ozone treatment groups (P = 0.25), nor was the week effect different for control and treatment groups (P = 0.46). The results of this field evaluation indicate that there was no statistical evidence to suggest that the ozone treatment has any effect on average NH3 concentrations in these chicken houses.}, number={7}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Wang, Lingjuan and Oviedo-Rondon, Edgar O. and Small, John and Liu, Zifei and Sheldon, Brian W. and Havenstein, Gerald B. and Williams, C. Mike}, year={2010}, month={Jul}, pages={789–796} }
 @article{li_wang_liu_kamens_2009, title={Could ozonation technology really work for mitigating air emissions from animal feeding operations?}, volume={59}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-70449729852&partnerID=MN8TOARS}, DOI={10.3155/1047-3289.59.10.1239}, abstractNote={Abstract Among various mitigation technologies for ammonia (NH3) emission control at animal feeding operations (AFOs), room ozonation technology is the most controversial. This paper aims to present full perspectives of ozonation techniques through a literature review and a series of laboratory experiments. In the literature review, ozone chemistry was summarized to address (1) ozone and NH3 reactions, (2) ozone and odor reactions, (3) ozone and particulate matter reactions, and (4) ozone and microorganism reactions. A series of laboratory experiments were conducted in a dual large outdoor aerosol smog chamber (270 m3). NH3 and fine particle number concentrations from ozone-treated and control experiments were compared. The experimental results indicated that (1) ozone has no significant effect on NH3 emissions concentrations or NH3 decay of an outdoor chamber; and (2) with ozone treatment, high concentration of particles in the “high-risk” respiratory fraction (in submicron range) are generated.}, number={10}, journal={Journal of the Air and Waste Management Association}, author={Li, Q. and Wang, L. and Liu, Z. and Kamens, R.M.}, year={2009}, pages={1239–1246} }
 @article{liu_wang_beasley_shah_2009, title={Modeling ammonia emissions from broiler litter at laboratory scale}, volume={52}, DOI={10.13031/2013.29131}, abstractNote={The objectives of this study were to develop a mechanistic emission model to estimate ammonia flux from broiler litter and to evaluate the model at laboratory scale. In the proposed model, the ammonia flux is essentially a function of the litter's total ammoniacal nitrogen (TAN) content, moisture content, pH, and temperature, as well as the Freundlich partition coefficient (Kf), mass transfer coefficient (KG), ventilation rate (Q), and emission surface area (A). The Freundlich partition coefficient (Kf) was used as a fitting parameter in the model. A dynamic flow-through chamber system and a wind tunnel were designed to measure ammonia fluxes from broiler litter. The dynamic flow-through chamber experiments evaluated the proposed model with various litter samples under a constant temperature and wind profile. The wind tunnel experiments evaluated the proposed model under various temperatures and wind profiles. Model parameters such as Kf and KG were estimated. The results from the two experiments were consistent with each other. The estimated KG ranged from 1.11 to 27.64 m h-1, and the estimated Kf ranged from 0.56 to 4.48 L kg-1. A regression sub-model was developed to estimate Kf as function of litter pH and temperature, which indicated that Kf increased with increasing litter pH and decreased with increasing temperature. The proposed model was used to estimate the equilibrium gas phase ammonia concentration (Cg,0) in litter, and the model-predicted values were compared with the observed values. The normalized mean error (NME), the normalized mean square error (NMSE), and fractional bias (FB) were calculated to be 25%, 12%, and -0.3%, respectively, for all 94 measurements, and the model was able to reproduce 80% of the variability of the data. Sensitivity analysis of the model showed that ammonia flux is very sensitive to litter pH and to a lesser extent temperature. The relative sensitivity of pH or temperature increases as the pH or temperature increases.}, number={5}, journal={Transactions of the ASABE}, author={Liu, Z. and Wang, L. and Beasley, D. B. and Shah, Sanjay}, year={2009}, pages={1683–1694} }
 @inproceedings{liu_wang_beasley_2008, title={Comparison of three techniques for determining ammonia emission fluxes from broiler litter}, volume={51}, DOI={10.13031/2013.25304}, abstractNote={This article reports an experimental study of three techniques in ammonia emission flux determination. Ammonia concentrations in a dynamic flow-through chamber with broiler litter were measured simultaneously by a chemiluminescence ammonia analyzer and an acid scrubber. At the beginning and ending of each test, the litter samples were analyzed for conducting nitrogen mass balance. Ammonia emissions were estimated from the two concentration measurements and the mass balance approach. It was observed that the chemiluminescence analyzer measurements tended to overestimate ammonia concentration compared with the acid scrubber measurements, especially when litter moisture was high. Statistical results indicated that the effect of litter moisture content on the ratios of the average chemiluminescence analyzer measurements over the acid scrubber measurements was significant, and a p-value of 0.0104 was obtained. Great uncertainties were observed for the mass balance approach, especially when the percentages of the total nitrogen losses in litter samples were small (less than 2%). In order to apply the mass balance approach to estimate ammonia emissions and to achieve acceptable accuracy, a substantially long testing period (more than 80 h) is needed under the observed ammonia emission level (104 to 1137 mg N h-1 m-2), and great efforts are needed to reduce the uncertainties associated with sampling and analyzing litter nitrogen content.}, number={5}, booktitle={Transactions of the ASABE}, author={Liu, Z. and Wang, L. and Beasley, D. B.}, year={2008}, pages={1783–1790} }
 @article{liu_wang_beasley_oviedo_2007, title={Effect of moisture content on ammonia emissions from broiler litter: A laboratory study}, volume={58}, ISSN={["1573-0662"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-34548108638&partnerID=MN8TOARS}, DOI={10.1007/s10874-007-9076-8}, number={1}, journal={JOURNAL OF ATMOSPHERIC CHEMISTRY}, author={Liu, Zifei and Wang, Lingjuan and Beasley, David and Oviedo, Edgar}, year={2007}, month={Sep}, pages={41–53} }