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Assessment of particulate matter and ammonia emission concentrations and respective plume profiles from a commercial poultry house Full text
2018
Yao, Qi | Yang, Zijiang | Li, Hong | Buser, Michael D. | Wanjura, John D. | Downey, Peter M. | Zhang, Chen | Craige, Collin | Torrents, Alba | McConnell, Laura L. | Holt, Gregory A. | Hapeman, Cathleen J.
Assessment of particulate matter and ammonia emission concentrations and respective plume profiles from a commercial poultry house Full text
2018
Yao, Qi | Yang, Zijiang | Li, Hong | Buser, Michael D. | Wanjura, John D. | Downey, Peter M. | Zhang, Chen | Craige, Collin | Torrents, Alba | McConnell, Laura L. | Holt, Gregory A. | Hapeman, Cathleen J.
Poultry-emitted air pollutants, including particulate matter (PM) and ammonia, have raised concerns due to potential negative effects on human health and the environment. However, developing and optimizing remediation technologies requires a better understanding of air pollutant concentrations, the emission plumes, and the relationships between the pollutants. Therefore, we conducted ten field experiments to characterize PM (total suspended particulate [TSP], particulate matter less than 10 μm in aerodynamic diameter [PM10], and particulate matter less than 2.5 μm in aerodynamic diameter [PM2.5]) and ammonia emission-concentration profiles from a typical commercial poultry house. The emission factors of the poultry house, which were calculated using the concentrations and fan speed, were 0.66 (0.29–0.99) g NH3-N bird−1d−1 for ammonia, 52 (44–168) g d−1AU−1 (AU = animal unit = 500 kg) for TSP, 3.48 (1.16–9.03) g d−1AU−1 for PM10, and 0.07 (0.00–0.36) g d−1AU−1 for PM2.5. PM and ammonia emission concentrations decreased as distance from the fan increased. Although emission concentrations were similar in the daytime and nighttime, diurnal and nocturnal plume shapes were different due to the increased stability of the atmosphere at night. Particle size distribution analysis revealed that, at a given height, the percentage of PM10 and PM2.5 was consistent throughout the plume, indicating that the larger particles were not settling out of the airstream faster than the smaller particles. Overall, the direction of the measured air pollutant emission plumes was dominated by the tunnel fan ventilation airflow rate and direction instead of the ambient wind speed and direction. This is important because currently-available air dispersion models use ambient or modeled wind speed and direction as input parameters. Thus, results will be useful in evaluating dispersion models for ground-level, horizontally-released, point sources and in developing effective pollutant remediation strategies for emissions.
Show more [+] Less [-]Dispersión del amoníaco proveniente de una granja avícola y su valoración cualitativa en Santa Bárbara | Ammonia dispersión from a poultry farm and its qualitative assessment in Santa Bárbara (Cundinamarca, Colombia) Full text
2018
Ruiz, Katherine | Trilleras Motha, Jenny Maritza, dir. | Sanjuanelo Corredor, Danny Wilson, dir.
23 páginas | El estudio hizo un análisis de la dispersión del amoníaco proveniente de una granja avícola en la vereda 30 de Santa Bárbara, municipio de Tena (Cundinamarca, Colombia). Se utilizaron cuatro galpones de 31 ambiente no controlado en el que se hicieron mediciones de las concentraciones de amoníaco en el 32 centro y luego cada 250 metros siguiendo las orientaciones de acuerdo con el sistema de referencia 33 cartesiano (norte, sur, este y oeste). Las mediciones se hicieron durante un ciclo productivo de 50 días, 34 con tres lecturas al día (8am, 12m y 18pm). También se hizo una valoración cualitativa de percepciones 35 sociales a las personas que viven en los alrededores de la granja avícola a no más de un kilómetro. Se 36 encontró que las emisiones de amoníaco están relacionadas con el ciclo reproductivo y no con la 37 variación a lo largo del día. También se encontró que la concentración de amoníaco está relacionada con 38 la temperatura, pero no con la velocidad del viento. Además, se encontró que la distancia máxima a la 39 que se reporta concentraciones de amoníaco importantes es a 361 m, lo que no representa una amenaza 40 para la población aledaña. Sin embargo la población percibe impactos a la calidad de vida asociados a 41 olores ofensivos provenientes de la granja avícola | The present study analyzed the dispersion of ammonia from a poultry farm in the village of Santa 46 Barbara, municipality of Tena (Cundinamarca, Colombia). Four barns of uncontrolled environment 47 were used in which measurements of ammonia concentrations were made in the center and then every 48 250 meters following the orientations according to the Cartesian reference system (north, south, east and 49 west). The measurements were made during a productive cycle of 50 days, with three readings per day 50 (8am, 12m and 18pm). A qualitative assessment of social perceptions was also made to people living in 51 the vicinity of the poultry farm no more than one kilometer away. It was found that ammonia emissions 52 are related to the reproductive cycle and not to the variation throughout the day. It was also found that 53 the concentration of ammonia is related to temperature, but not to wind speed. In addition, it was found 54 that the maximum distance at which important ammonia concentrations are reported is 361 m, which does not represent a threat to the surrounding population. However, the population perceives impacts to 56 the quality of life associated with offensive odors coming from the poultry farm. | Incluye bibliografía | Maestría | Magíster en Ciencias Ambientales
Show more [+] Less [-]Impacts of environmental factors on the whole microbial communities in the rhizosphere of a metal-tolerant plant: Elsholtzia haichowensis Sun Full text
2018
Deng, Songqiang | Ke-tan, | Li, Longtai | Cai, Shenwen | Zhou, Yuyue | Liu, Yue | Guo, Limin | Chen, Lanzhou | Zhang, Dayi
Rhizospheric microbes play important roles in plant growth and heavy metals (HMs) transformation, possessing great potential for the successful phytoremediation of environmental pollutants. In the present study, the rhizosphere of Elsholtzia haichowensis Sun was comprehensively studied to uncover the influence of environmental factors (EFs) on the whole microbial communities including bacteria, fungi and archaea, via quantitative polymerase chain reaction (qPCR) and high-throughput sequencing. By analyzing molecular ecological network and multivariate regression trees (MRT), we evaluated the distinct impacts of 37 EFs on soil microbial community. Of them, soil pH, HMs, soil texture and nitrogen were identified as the most influencing factors, and their roles varied across different domains. Soil pH was the main environmental variable on archaeal and bacterial community but not fungi, explaining 25.7%, 46.5% and 40.7% variation of bacterial taxonomic composition, archaeal taxonomic composition and a-diversity, respectively. HMs showed important roles in driving the whole microbial community and explained the major variation in different domains. Nitrogen (NH4-N, NO3-N, NO2-N and TN) explained 47.3% variation of microbial population composition and 15.9% of archaeal taxonomic composition, demonstrating its influence in structuring the rhizospheric microbiome, particularly archaeal and bacterial community. Soil texture accounted for 10.2% variation of population composition, 28.9% of fungal taxonomic composition, 19.2% of fungal a-diversity and 7.8% of archaeal a-diversity. Rhizosphere only showed strong impacts on fungi and bacteria, accounting for 14.7% and 4.9% variation of fungal taxonomic composition and bacterial a-diversity. Spatial distance had stronger influence on bacteria and archaea than fungi, but not as significant as other EFs. For the first time, our study provides a complete insight into key influential EFs on rhizospheric microbes and how their roles vary across microbial domains, giving a hand for understanding the construction of microbial communities in rhizosphere.
Show more [+] Less [-]Nitrogen losses to the environment following food-based digestate and compost applications to agricultural land Full text
2017
Nicholson, Fiona | Bhogal, Anne | Cardenas, L. (Laura) | Chadwick, Dave | Misselbrook, T. (Tom) | Rollett, A. (Alison) | Taylor, Matt | Thorman, Rachel | Williams, John
The anaerobic digestion of food waste for energy recovery produces a nutrient-rich digestate which is a valuable source of crop available nitrogen (N). As with any ‘new’ material being recycled to agricultural land it is important to develop best management practices that maximise crop available N supply, whilst minimising emissions to the environment. In this study, ammonia (NH3) and nitrous oxide (N2O) emissions to air and nitrate (NO3−) leaching losses to water following digestate, compost and livestock manure applications to agricultural land were measured at 3 sites in England and Wales. Ammonia emissions were greater from applications of food-based digestate (c.40% of total N applied) than from livestock slurry (c.30% of total N applied) due to its higher ammonium-N content (mean 5.6 kg/t compared with 1–2 kg/t for slurry) and elevated pH (mean 8.3 compared with 7.7 for slurry). Whilst bandspreading was effective at reducing NH3 emissions from slurry compared with surface broadcasting it was not found to be an effective mitigation option for food-based digestate in this study. The majority of the NH3 losses occurred within 6 h of spreading highlighting the importance of rapid soil incorporation as a method for reducing NH3 emissions. Nitrous oxide losses from food-based digestates were low, with emission factors all less than the IPCC default value of 1% (mean 0.45± 0.15%). Overwinter NO3− leaching losses from food-based digestate were similar to those from pig slurry, but much greater than from pig farmyard manure or compost. Both gaseous N losses and NO3− leaching from green and green/food composts were low, indicating that in these terms compost can be considered as an ‘environmentally benign’ material. These findings have been used in the development of best practice guidelines which provide a framework for the responsible use of digestates and composts in agriculture.
Show more [+] Less [-]High-throughput profiling and analysis of antibiotic resistance genes in East Tiaoxi River, China Full text
2017
Zheng, Ji | Gao, Ruixia | Wei, Yuanyuan | Chen, Tao | Fan, Jiqing | Zhou, Zhenchao | Makimilua, Tiimub Benjamin | Jiao, Yanan | Chen, Hong
The rapid human activities and urbanization exacerbate the human health risks induced by antibiotic resistance genes (ARGs). In this study, the profiling of ARGs was investigated using high-throughput qPCR from water samples of 13 catchment areas in East Tiaoxi River, China. High prevalence of ARGs indicated significant antibiotic resistance pollution in the research area (absolute abundance: 6.1 × 108–2.1 × 1010 copies/L; relative abundance: 0.033–0.158 copies/cell). Conventional water qualities (COD, TN, TP, NH3-N), bacterial communities and mobile gene elements (MGEs) were detected and analyzed as factors of ARGs shift. Nutrient and MGEs showed positive correlation with most ARGs (P < 0.05) and bacteria community was identified as the key contributing factor driving ARGs alteration. With the land-use study and field investigation, country area, especially arable, was expected as a high spot for ARGs shift and pathogen breeding. Comparing to environmental background, promotion of ARGs and marked shift of bacterial community were observed in country and urban city areas, indicating that human activities may lead to the spread of ARGs. Analysis of factors affecting ARGs in this study may shed new light on the mechanism of the maintenance and propagation of ARGs in urban rivers.
Show more [+] Less [-]Effects of myclobutanil on soil microbial biomass, respiration, and soil nitrogen transformations Full text
2016
Ju, Chao | Xu, Jun | Wu, Xiaohu | Dong, Fengshou | Liu, Xingang | Zheng, Yongquan
A 3-month-long experiment was conducted to ascertain the effects of different concentrations of myclobutanil (0.4 mg kg⁻¹ soil [T1]; 1.2 mg kg⁻¹ soil [T3]; and 4 mg kg⁻¹ soil [T10]) on soil microbial biomass, respiration, and soil nitrogen transformations using two typical agricultural soils (Henan fluvo-aquic soil and Shanxi cinnamon soil). Soil was sampled after 7, 15, 30, 60, and 90 days of incubation to determine myclobutanil concentration and microbial parameters: soil basal respiration (RB), microbial biomass carbon (MBC) and nitrogen (MBN), NO−3–N and NH+4–N concentrations, and gene abundance of total bacteria, N2-fixing bacteria, fungi, ammonia-oxidizing archaea (AOA), and ammonia-oxidizing bacteria (AOB). The half-lives of the different doses of myclobutanil varied from 20.3 to 69.3 d in the Henan soil and from 99 to 138.6 d in the Shanxi soil. In the Henan soil, the three treatments caused different degrees of short-term inhibition of RB and MBC, NH+4–N, and gene abundance of total bacteria, fungi, N2-fixing bacteria, AOA, and AOB, with the exception of a brief increase in NO−3–N content during the T10 treatment. The MBN (immobilized nitrogen) was not affected. In the Shanxi soil, MBC, the populations of total bacteria, fungi, and N2-fixing bacteria, and NH+4–N concentration were not significantly affected by myclobutanil. The RB and MBN were decreased transitorily in the T10 treatment. The NO−3–N concentrations and the abundance of both AOA and AOB were erratically stimulated by myclobutanil. Regardless of whether stimulation or suppression occurred, the effects of myclobutanil on the two soil types were short term. In summary, myclobutanil had no long-term negative effects on the soil microbial biomass, respiration, and soil nitrogen transformations in the two types of soil, even at 10-fold the recommended dosage.
Show more [+] Less [-]Evaluation of in situ simulated dredging to reduce internal nitrogen flux across the sediment-water interface in Lake Taihu, China Full text
2016
Yu, Juhua | Fan, Chengxin | Zhong, Jicheng | Zhang, Yinlong | Wang, Changhui | Zhang, Lei
Sediment dredging is considered an effective restoration method to reduce internal loading of nitrogen (N) and phosphorus (P) in eutrophic lakes. However, the effect of dredging on N release from sediments to overlying water is not well understood. In this study, N exchange and regeneration across the sediment-water interface (SWI) were investigated based on a one-year simulated dredging study in Lake Taihu, China. The results showed low concentrations of inorganic N in pore water with low mobilization from the sediments after dredging. The calculated fluxes of NO3−-N from post-dredged sediments to overlying water significantly increased by 58% (p < 0.01), while those of NH4+-N dramatically decreased by 78.2% after dredging (p < 0.01). N fractionation tests demonstrated that the contents and lability of N generally declined in post-dredged sediments. Further high-throughput sequencing analysis indicated that relative abundance of the bacterial communities decreased, notably by 30% (compared with undredged sediments). The estimated abundance of Nitrospira enhanced, although the relative abundance of Thiobacillus, Sterolibacterium, Denitratisoma, Hyphomicrobium, Anaeromyxobacter and Caldithrix generally declined after dredging. Therefore, dredging reduced N mobilization from the sediments, which primarily due to decreases in N mobility, in organic matter (OM) mineralization potential and in the bacterial abundance of post-dredged sediments. Overall, to minimize internal N pollution, dredging is capable of effectively reducing N release from sediments. In addition, the negative side effect of dredging on removal of NO3−-N and NO2−-N from aquatic ecosystems should be paid much more attention in future.
Show more [+] Less [-]The importance of ammonium mobility in nitrogen-impacted unfertilized grasslands: A critical reassessment Full text
2009
Mian, Ishaq Ahmad | Riaz, Muhammad | Cresser, Malcolm S.
The physico-chemical absorption characteristics of ammonium-N for 10 soils from 5 profiles in York, UK, show its high potential mobility in N deposition-impacted, unfertilized, permanent grassland soils. Substantial proportions of ammonium-N inputs were retained in the solution phase, indicating that ammonium translocation plays an important role in the N cycling in, and losses from, such soils. This conclusion was further supported by measuring the ammonium-N leaching from intact plant/soil microcosms. The ammonium-N absorption characteristics apparently varied with soil pH, depth and soil texture. It was concluded for the most acid soils especially that ammonium-N leached from litter horizons could be seriously limiting the capacity of underlying soils to retain ammonium. Contrary to common opinion, more attention therefore needs to be paid to ammonium leaching and its potential role in biogeochemical N cycling in semi-natural soil systems subject to atmospheric pollution. mmonium mobility is more important than previously thought in N-impacted, unfertilized grasslands.
Show more [+] Less [-]Importance of ammonia nitrogen potentially released from sediments to the development of eutrophication in a plateau lake Full text
2022
Ding, Shuai | Dan, Solomon Felix | Liu, Yan | He, Jia | Zhu, Dongdong | Jiao, Lixin
Sedimentary nitrogen (N) in lakes significantly influenced by eutrophication plays a detrimental role on the ecological sustainability of aquatic ecosystems. Here, we conducted a thorough analysis of the importance of N potentially released from sediments during the shift of “grass-algae” ecosystem in plateau lakes. From 1964 to 2013, the average total amount of sedimentary potential mineralizable organic nitrogen (PMON) and exchangeable N in whole Lake Dianchi were 5.50 × 10³ t and 3.44 × 10³ t, respectively. NH₄⁺-N was the main product (>90%) of sedimentary PMON mineralization. The PMON in sediments had great release potential, which tended to regulate the distribution of aquatic plants and phytoplankton in Lake Dianchi and facilitated the replacement of dominant populations. Moreover, NH₄⁺-N produced by sedimentary PMON mineralization and exchangeable NH₄⁺-N have increased the difficulty and complexity of ecological restoration in Lake Dianchi to a certain extent. This study highlights the importance of sedimentary N in lake ecosystem degradation, showing the urgent need to reduce the continuous eutrophication of lakes and restore the water ecology.
Show more [+] Less [-]Identifying key drivers of harmful algal blooms in a tributary of the Three Gorges Reservoir between different seasons: Causality based on data-driven methods Full text
2022
Su, Yuming | Hu, Mingming | Wang, Yuchun | Zhang, Haoran | He, Chao | Wang, Yanwen | Wang, Dianchang | Wu, Xinghua | Zhuang, Yanhua | Hong, Song | Trolle, Dennis
Intense harmful algal blooms (HABs) can occur in the backwaters of tributaries supplying large-scale reservoirs. Due to the characteristics of process-based models and difficulties in modelling complex nonlinear processes, traditional models have difficulties disentangling the driving factors of HABs. In this study, we used data-driven methods (i.e., correlation analysis and machine-learning models) to identify the most important drivers of HABs in the Xiangxi River, a tributary of the Three Gorges Reservoir, China (2017–2018), for the dry season (from October to mid-April) and wet season (from April to September). We utilized the maximal information coefficient (MIC) combined with a time lag strategy and prior knowledge to quantitatively identify the driving variables of HABs. An extra trees regression (ETR) model was developed to assess the relative importance of causal variables driving algal blooms for the different periods. The results showed that water temperature was the most important driver for the duration of the study, followed by total nitrogen. Nitrogen had a stronger effect on algal blooms than phosphorus during both the wet and dry seasons. HABs were mainly affected by ammonia nitrogen in the wet season and by other forms of nitrogen in the dry season. In contrast, rather than the water temperature and nutrients, the operation of the Three Gorges Dam (difference between inflow and outflow discharge rate) was the most significant factor for algal blooms during the dry season, but its influence sharply declined during the wet season. This study showed that the key drivers of HABs can differ between seasons and suggests that HAB management should take seasonality into account.
Show more [+] Less [-]Reduction of nitrate using biochar synthesized by Co-Pyrolyzing sawdust and iron oxide Full text
2021
Han, Eun-Yeong | Kim, Bo-Kyong | Kim, Hye-Bin | Kim, Jong-Gook | Lee, Jae-Young | Baek, Kitae
Nitrate is the most common contaminant in groundwater in Korea, as well as across the world. Reduction of nitrate to ammonia is one of the options available to remediate groundwater. In this study, nitrate in groundwater was removed using a zero-valent iron (ZVI) containing biochar synthesized by co-pyrolyzing iron oxide and sawdust biomass. Among the various biogases generated during the pyrolysis of biomass, CO and H₂ act as reducing agents to transform iron oxides to ZVI. Approximately 71% of nitrate was reduced to ammonium by ZVI-biochar at initial pH 2.0, and the reduction decreased sharply by the increase in pH. The mass of nitrate-N decreased is exactly same with the mass of ammonia-N formed. However, ammonium remained in the aqueous phase after reduction by ZVI-biochar, and the total nitrogen was not lowered. Acid-washed zeolite adsorbed most ammonium reduced by the ZVI-biochar and maintained the pH to acidic condition to facilitate the reduction of nitrate. The results of this study imply that nitrate-contaminated groundwater can be properly treated within the guidelines of water quality by synthesized ZVI-containing biochar.
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