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Advanced treatment processes
Published in Rumana Riffat, Taqsim Husnain, Fundamentals of Wastewater Treatment and Engineering, 2022
The process consists of pretreatment of the wastewater with lime to raise the pH above 11.5. Enough lime has to be added to precipitate the alkalinity and raise the pH to the desired level. Once the conversion to gaseous ammonia is complete, stripping or degasification is conducted. One of the most efficient reactors is the counter-current spray tower, illustrated in Figure 13.10 (Peavy et al., 1985). Large volumes of air are required. Packing material is provided to minimize film resistance to gas transfer, and to aid in the formation of liquid droplets. Air pollution control may be required for ammonia emissions. Another disadvantage is the reduction in efficiency at cold temperatures. The process is economical when lime precipitation of phosphorus is also desired.
Gaseous air pollutants
Published in Abhishek Tiwary, Ian Williams, Air Pollution, 2018
A further class of emissions is often grouped as NHy, meaning the sum of ammonia (NH3) and ammonium (NH4). The three main sources of atmospheric ammonia are livestock farming and animal wastes, with emissions primarily due to the decomposition of urea from large animal wastes and uric acid from poultry wastes. The overall total emission from these sources has increased with the intensification of agriculture, which has also changed the nature of the emissions from area to point sources. Emissions from housed and field animals are relatively steady in nature, while operations such as slurry and manure spreading result in more intense short-term emissions. Ammonia emissions can be changed by feed N content, the conversion of feed N to meat N (and hence the N content of animal wastes), and the management practices applied to the animals.
Seasonal variability of the PM and ammonia concentrations in uninsulated loose-housing cowshed
Published in Thomas Banhazi, Andres Aland, Jörg Hartung, Air Quality and Livestock Farming, 2018
Marek Maasikmets, Erik Teinemaa, Allan Kaasik, Veljo Kimmel
Air pollution is part of the impact that agricultural activity has on the environment. The large number of animals raised in concentrated animal feeding operations can affect air quality by emissions of odor, volatile organic compounds (VOCs) and other gases, and particulate matter (PM) (NRCNA, 2003). Livestock production is a major contributor to ammonia emissions (Groot Koerkamp et al., 1998; Steinfeld et al., 2006). Ammonia released from near-surface sources into the atmosphere generally has a relatively short lifetime of 1–5 days and may deposit near the source through dry or wet deposition processes. However, ammonia can also participate in atmospheric reactions (e.g., gas-to-particle conversion) once airborne, forming ammonium aerosols such as ammonium sulfate, ammonium nitrate and ammonium chloride, which tend to have longer atmospheric residence lifetimes (1–15 days) due to a decrease in dry deposition velocity (Aneja et al., 2001) and may, therefore, be transported and deposited further downwind from the source (Blunden et al., 2008). Gaseous ammonia emissions from livestock production are deemed responsible for the acidification of several ecosystems and for the formation of secondary particulate matter (PM2.5) (Bluteau et al., 2009). The presence of ammonium sulfate in the air is an important mitigation impact for ammonia because particles can stay in the air for several days and cause decrease visibility (USEPA, 2001). High concentrations of PM can threaten the environment, as well as the health and welfare of humans and animals.
Estimation of interannual trends of ammonia emissions from agriculture in Jiangsu Province from 2000 to 2017
Published in Atmospheric and Oceanic Science Letters, 2020
Jiayu HUANG, Ruonan XIONG, Li FANG, Tianling LI, Weishou SHEN
Ammonia emissions derive mainly from anthropogenic sources, including agricultural emissions, industrial processes, traffic emissions, waste treatment, and other human activities (Huang et al. 2012; Clarisse et al. 2009; Zeng, Tian, and Pan 2018), among which the largest contributor is agricultural emissions, including two main pathways: nitrogen fertilizer application, and livestock and poultry farming. Of these, nitrogen fertilizer application accounts for approximately 40%, and livestock and poultry farming approximately 50%, of total anthropogenic NH3 emissions worldwide (Zhang et al. 2018). Therefore, estimating the characteristics of NH3 emissions from agricultural sources, especially from livestock and poultry farming and nitrogen fertilizer application, is imperative for developing NH3 reduction strategies for specific regions.
Degradation of ammonia from gas stream by advanced oxidation processes
Published in Journal of Environmental Science and Health, Part A, 2020
Kamila Kočí, Martin Reli, Ivana Troppová, Tomáš Prostějovský, Radim Žebrák
Some potential strategies for mitigation of ammonia emissions from livestock buildings include changing animal diet, renovating buildings, treating manure and improving the application of manure to land and also cleaning the exhaust air from buildings. Methods for mitigation the ammonia emissions in manure include the reduction of pH (shifting of the equilibrium); use of other chemical additives that bind ammonium-N; and the use of biological nitrification–denitrification (conversion of ammonium into nonvolatile N-species such as nitrite, nitrate, or gaseous N2). Other methods for reduction of ammonia emissions are focused on capturing air (using physical covers) and treating the captured air to remove ammonia (using bio-filters or bio-covers, and scrubbers).[2]
A strategy for ammonia odor monitoring, prediction, and reduction from livestock manure wastes in Korea: a short review
Published in Geosystem Engineering, 2022
Ammonia emissions from the domestic livestock sector result mainly from the ammonia generated in the management of livestock manure, which contains significant levels of nitrogen compounds relevant to ammonia/ammonium. Emission sources include manure excreted from livestock, manure storage facilities, and/or compost using livestock manure (KEI, 2017). Thus, various ammonia emissions can be assessed by considering the types and activity levels (i.e., number of pigs) of livestock facilities. For example, the typical prediction of the ammonia emission rate (g/yr) from livestock manure treatment is calculated by multiplying the number of livestock animals annually (No./yr) by emission factor (g-NH3/no.; KEI, 2017; National Institute of Animal Science [NIAS], 2015).