AMMONIA EMISSION AND CONTROL AFTER LAND SPREADING LIVESTOCK WASTE

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4249
Author(s):  
Xuan Yao ◽  
Man Zhang ◽  
Hao Kong ◽  
Junfu Lyu ◽  
Hairui Yang

After the implementation of the ultra-low emissions regulation on the coal-fired power plants in China, the problem of the excessive ammonia-slipping from selective catalytic reduction (SCR) seems to be more severe. This paper analyzes the operating statistics of the coal-fired plants including 300 MW/600 MW/1000-MW units. Statistics data show that the phenomenon of the excessive ammonia-slipping is widespread. The average excessive rate is over 110%, while in the small units the value is even higher. A field test data of nine power plants showed that excessive ammonia-slipping at the outlet of SCR decreased following the flue-gas process. After most ammonia reduced by the dust collector and the wet flue-gas desulfurization (FGD), the ammonia emission at the stack was extremely low. At same time, a method based on probability distribution is proposed in this paper to describe the relationship between the NH3/NOX distribution deviation and the De–NOX efficiency/ammonia-slipping. This paper also did some original work to solve the ammonia-slipping problem. A real-time self-feedback ammonia injection technology using neural network algorithm to predict and moderate the ammonia distribution is proposed to decrease the NH3/NOX deviation and excessive ammonia-slipping. The technology is demonstrated in a 600-MW unit and works successfully. The excessive ammonia-slipping problem is well controlled after the implementation of the technology.


2003 ◽  
Vol 8 (2) ◽  
pp. 261-284 ◽  
Author(s):  
Adam G. Drucker ◽  
Uwe Latacz-Lohmann

Building on the extensive theoretical and empirical work regarding the cost-minimizing properties of economic instruments, this article describes and analyses the Mexican legislation relevant to the treatment/disposal of pig slurry in the state of Yucatán. Using a linear programming model to determine the optimal level of pig production and abatement processes simultaneously, different policy instruments and scenarios are compared. Serious shortcomings associated with the recently introduced command-and-control (CAC) legislation, which establishes concentration-based standards for discharges, are identified. It is shown that it will be extremely difficult and expensive to comply with (cost: US$41.8 million per annum). An alternative mass-based CAC approach, which instead regulates nitrogen applications to land, has compliance costs of US$3.5–US$9.4 million per annum, depending on the strictness of the standard. By contrast, an environmentally equivalent economic instrument approach results in additional cost savings of 22–25 per cent. The results are of relevance to Mexican policy makers, extensionists, researchers, and farmers.


2021 ◽  
Author(s):  
Baojie Li ◽  
Lei Chen ◽  
Weishou Shen ◽  
Jianbing Jin ◽  
Teng Wang ◽  
...  

Abstract. As a major alkaline gas in the atmosphere, NH3 significantly impacts atmospheric chemistry, ecological environment, and biodiversity. Gridded NH3 emission inventories can significantly affect the accuracy of model concentrations and play a crucial role in the refinement of mitigation strategies. However, several uncertainties are still associated with existing NH3 emission inventories in China. Therefore, in this study, we focused on improving fertilizer application-related NH3 emission inventories. We comprehensively evaluated the dates and times of fertilizer application to the major crops that are cultivated in China, improved the spatial allocation methods for NH3 emissions from croplands with different rice types, and established a gridded NH3 emission inventory for mainland China with a resolution of 5 min × 5 min in 2016. The results showed that the atmospheric NH3 emissions in mainland China amounted to 12.11 Tg, with livestock waste (44.8 %) and fertilizer application (38.6 %) being the two main NH3 emission sources in China. Obvious spatial differences in NH3 emissions were also observed, and high emissions were predominantly concentrated in North China. Further, NH3 emissions tended to be high in summer and low in winter, and the ratio for the July–January period was 3.08. Furthermore, maize and rice fertilization in summer was primarily responsible for the increase in NH3 emissions in China, and the evaluation of the spatial and temporal accuracy of the NH3 emission inventory established in this study using the WRF-Chem and ground station- and satellite-based observations showed that it was more accurate than other inventories.


Agriculture ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 226 ◽  
Author(s):  
Min-Suk Kim ◽  
Jeong-Gyu Kim

This study was conducted with the aim of improving the dynamic camber-capture system, which estimates ammonia emissions during the application of liquid fertilizer from livestock manure. We focused on the volume of the chamber and headspace, the height of the solid media, the flow rate of the pump, and the ventilation rate. Total ammoniacal nitrogen (NH3 + NH4+) is an important factor affecting ammonia volatilization. Even though the characteristics of liquid fertilizer were changed, the effect of total ammoniacal nitrogen on ammonia volatilization remained the largest. Increasing the thickness of solid media inside the chamber has the effect of reducing ammonia emission by reducing the contact area between liquid fertilizer and air. Although it is very difficult to measure and control the wind velocity in a chamber using a general vacuum pump, it can be indirectly evaluated through the ventilation rate in the macroscopic aspect. The higher the ventilation rate, the faster the flow of air in the chamber, which is linear with the increase in ammonia emission flux. We find that it may be necessary to improve the steady wind velocity within the chamber and of the linkages to upscale the wind tunnel system.


Author(s):  
K. O. Olatunji ◽  
A. O. Adebayo ◽  
G. E. Bolaji

Aim: This research investigated the utilization of livestock manure as nutrient source in maize farming. Place and Duration: The field experiment was carried out at the research field of the Federal Ministry of Agriculture and Rural Development, Lagos State Field Office, Nigeria during the late planting season (July/August) of 2019. Methodology: An experimental field research was conducted to compare the variation in the vegetative parameters and yields of maize grown with different livestock wastes. The experiment consisted of six treatments, cattle, pig, poultry, sheep manures, NPK and control experiment set-up in a Randomized Complete Block Design with four replicates. The following data were recorded during the experiment: plant height, number of leaves, number of days to first tasselling and silking, number of cob, cob length, effective cob length, cob diameter, cob weight, ear weight, 100 grain weight, grain yield and shelling percentage. Data recorded were exposed to Analysis of Variance (ANOVA) and the means were separated with Duncan Multiple Range Test. Results: The plant height and number of leaves recorded at 9 Weeks After Planting were 215.53, 217.57, 219.69, 188.85, 219.19, 182.76 and 13.60, 13.40, 13.8, 12.4, 13.8, 12.2 cm for cattle, pig, poultry, sheep, NPK and control respectively while the yield were 3193.00, 3055.20, 3513.00, 2855.00, 3791.00 and 1523.80 kg/ha for cattle, pig, poultry, sheep, NPK and control respectively. Conclusion: Considering the yields recorded, it has shown that cattle, pig, poultry and sheep manures are suitable for sustainable maize growth and is a means of livestock waste management.


2020 ◽  
Vol 389 ◽  
pp. 124462 ◽  
Author(s):  
Dunzhu Li ◽  
Yunhong Shi ◽  
Fei Gao ◽  
Luming Yang ◽  
Daniel K. Kehoe ◽  
...  

Author(s):  
R. R. Dils ◽  
P. S. Follansbee

Electric fields have been applied across oxides growing on a high temperature alloy and control of the oxidation of the material has been demonstrated. At present, three-fold increases in the oxidation rate have been measured in accelerating fields and the oxidation process has been completely stopped in a retarding field.The experiments have been conducted with an iron-base alloy, Pe 25Cr 5A1 0.1Y, although, in principle, any alloy capable of forming an adherent aluminum oxide layer during oxidation can be used. A specimen is polished and oxidized to produce a thin, uniform insulating layer on one surface. Three platinum electrodes are sputtered on the oxide surface and the specimen is reoxidized.


Author(s):  
D. M. DePace

The majority of blood vessels in the superior cervical ganglion possess a continuous endothelium with tight junctions. These same features have been associated with the blood brain barrier of the central nervous system and peripheral nerves. These vessels may perform a barrier function between the capillary circulation and the superior cervical ganglion. The permeability of the blood vessels in the superior cervical ganglion of the rat was tested by intravenous injection of horseradish peroxidase (HRP). Three experimental groups of four animals each were given intravenous HRP (Sigma Type II) in a dosage of.08 to.15 mg/gm body weight in.5 ml of.85% saline. The animals were sacrificed at five, ten or 15 minutes following administration of the tracer. Superior cervical ganglia were quickly removed and fixed by immersion in 2.5% glutaraldehyde in Sorenson's.1M phosphate buffer, pH 7.4. Three control animals received,5ml of saline without HRP. These were sacrificed on the same time schedule. Tissues from experimental and control animals were reacted for peroxidase activity and then processed for routine transmission electron microscopy.


Author(s):  
G. Mazzocchi ◽  
P. Rebuffat ◽  
C. Robba ◽  
P. Vassanelli ◽  
G. G. Nussdorfer

It is well known that the rat adrenal zona glomerulosa steroidogenic activity is controlled by the renin-angiotensin system. The ultrastructural changes in the rat zona glomerulosa cells induced by renovascular hypertension were described previously, but as far as we are aware no correlated biochemical and morphometric investigations were performed.Twenty adult male albino rats were divided into 2 experimental groups. One group was subjected to restriction of blood flow to the left kidney by the application of a silver clip about the left renal artery. The other group was sham-operated and served as a control. Renovascular hypertension developed in about 10 days: sistolic blood pressure averaged 165 ± 6. 4 mmHg, whereas it was about 110 ± 3. 8 mmHg in the control animals. The hypertensive and control rats were sacrificed 20 days after the operation. The blood was collected and plasma renin activity was determined by radioimmunological methods. The aldosterone concentration was radioimmunologically assayed both in the plasma and in the homogenate of the left capsular adrenal gland.


Author(s):  
Henry I. Smith ◽  
D.C. Flanders

Scanning electron beam lithography has been used for a number of years to write submicrometer linewidth patterns in radiation sensitive films (resist films) on substrates. On semi-infinite substrates, electron backscattering severely limits the exposure latitude and control of cross-sectional profile for patterns having fundamental spatial frequencies below about 4000 Å(l),Recently, STEM'S have been used to write patterns with linewidths below 100 Å. To avoid the detrimental effects of electron backscattering however, the substrates had to be carbon foils about 100 Å thick (2,3). X-ray lithography using the very soft radiation in the range 10 - 50 Å avoids the problem of backscattering and thus permits one to replicate on semi-infinite substrates patterns with linewidths of the order of 1000 Å and less, and in addition provides means for controlling cross-sectional profiles. X-radiation in the range 4-10 Å on the other hand is appropriate for replicating patterns in the linewidth range above about 3000 Å, and thus is most appropriate for microelectronic applications (4 - 6).


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