• Journal of Environmental Health Sciences
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• v.27 no.1
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• pp.93-99
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• 2001

This study aims at finding out pertinent reaction conditions for treating high concentration ammonia contained in N-chemical factory wastewater with decompressed ammonia stripping method that was designed. And it also tries to investigate adsorption capability of removed ammonia to soil. The results from experiments are as follows ; 1. The removal rate of N $H_3$-N of synthetic wastewater was under 85% at pH 10 with decompressed ammonia stripping method. The reaction time in pressure 360 mmHg at pH 11 and 12 was shorter than in 460 mmHg, and the removal rate of N $H_3$-N with decompressed ammonia stripping method at 9$0^{\circ}C$ was 11~15% higher than air stripping 2. The optimum conditions for decompressed ammonia stripping with synthetic sample were shown as pH 12, temperature 9$0^{\circ}C$, internal reaction pressure 460 mmHg and reaction time 50 minutes. These conditions were applied to treat the wastewater containing organic-N 290.5mg/$\ell$, N $H_3$-N 168.9mg/$\ell$, N $O_2$-N 23.2mg/$\ell$, N $O_3$-N 252.4mg/$\ell$, T-N 735mg/$\ell$. Organic-N turned out to be removed 60%, the removal rate of N $H_3$-N IS 94%, T-N is 50%. But N $O_2$-N and N $O_3$-N were increased with 7.8% and 14.9% respectively. 3. The CO $D_{Sr}$ removal rate in decompressed ammonia stripping reaction was 42% and S $O_4$$^{2-}$ was removed 8.2%. It was turned out caused with higher pH and thermolysis. 4. In soil adsorption of ammonia desorbed from the decompressed stripping process of wastewater, the recovery rate was 76% in wet soil.

• Journal of Environmental Health Sciences
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• v.36 no.1
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• pp.33-43
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• 2010

Atmospheric ammonia is a very important constituent of the environment because it is the dominant alkaline gaseous species present in the atmosphere. Ammonia is known to affect ecosystems at relatively low concentration. In this study flux profiles of ammonia emitted from the cattle housing were evaluated using a dynamic flux chamber (DFC). We have developed the emission factor of $NH_3$ from the cattle housing. Analysis of ammonia flux variation was made with respect to such variables as manure surface temperature, pH, and ammonium concentration. Ammonia flux has been measured up to summer in 2007 at calf and cattle housing. In the fall, average ammonia flux from calf and cattle housing was estimated as 1.406 (${\pm}0.947$) and 1.534 ((${\pm}0.956$) $mg\;m^2\;min^1$, respectively. In the winter, average ammonia flux was estimated 1.060 ((${\pm}0.569$) from the calf housing and 1.216 ((${\pm}0.655$) $mg\;m^2\;min^1$ from the cattle housing. The correlation coefficient (R=0.732) between ammonia flux and manure surface ammonium concentration exhibited stronger relationship than manure surface pH and temperature. In the fall, ammonia emission factor from calf and cattle housing was estimated as 3.94 ((${\pm}2.66$) and 11.41 ((${\pm}5.86$) kg-$NH_3$ animal$^1\;yr^1$, respectively. In the winter, ammonia average flux was estimated as 2.89 ((${\pm}1.59$) from the calf housing and 6.51 ((${\pm}3.67$) kg-$NH_3$ animal$^1\;yr^1$ from the cattle housing.

• Microbiology and Biotechnology Letters
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• v.37 no.4
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• pp.408-412
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• 2009

A study on the screening and isolation of microorganism was performed for the removal of main malodor, such as ammonia, produced from the livestock farm. The main malodor components in livestock farm are ammonia, volatile fatty acids, sulfur compounds and trimethylamine. Damages to man and livestock were originated from malodors mainly due to ammonia, and thus ammonia reduction experiments were performed. Sludge of sewage treatment plant was inoculated in the sesame dregs culture, from which ammonia gas was produced. An aerobically grown, pure cultured isolated from the 10th enrichment culture was analyzed by 16S rRNA sequencing and identified as Alcaligenes sp. NS-1. This strain NS-1 precultured in the sesame dregs was found to remove ammonia gas with an efficiency of approximately 99-100% at an average concentration of 40 ppmv of ammonia gas. When the strain NS-1 sprayed to pig excrements, the removal efficiency at an average concentration of 100 ppmv of ammonia was approximately 60% after 16 hr.

• Environmental Engineering Research
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• v.19 no.4
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• pp.381-385
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• 2014

Microwave (MW) radiation was developed to remove and recover ammonia nitrogen in the real swine wastewater. The effect of operating parameters of MW radiation such as initial pH, power, radiation time, aeration, and stirring for removal ammonia nitrogen in swine wastewater was determined. The pH, radiation time, and power were significantly influenced on the removal of ammonia nitrogen, and aeration and stirring showed relatively minor effect on the removal of ammonia nitrogen. Optimum condition was achieved to retrieve the nitrogen efficiently at pH 11, 700 W for 5 min in MW radiation process. Through this process, 83.1% of ammonia nitrogen concentration was reduced in swine wastewater and also 82.6% of ammonia nitrogen was recovered as ammonium sulfate at the optimized condition. The high ammonia removal and recovery efficiency of the MW radiation method indicated that MW radiation was an effective technique to remove and recover ammonia nitrogen in the swine wastewater.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.4
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• pp.503-510
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• 2011

Ammonia in water which is toxic to human, its concentration is regulated below 0.5 mg/L in drinking water. Current study aimed to develop appropriate models for ammonia stripping using hollow fiber membrane contactor. Two different models were developed during the study. Model 1 was assumed only free ammonia ($NH_3$) transfer in stripping process, whereas the Model 2 was assumed with total ammonia ($NH_3+{NH_4}^+$) transfer. Ammonium chloride ($NH_4CI$), sodium hydroxide(NaOH) were used to make ammonia solution, which was concentration of 25 mg as N/L at a pH of 10.5. The experimental conditions were such that, the liquid flow was in tube-side in upward direction and t he gas flow was on shell-side in downward direction a t room temperature. The experimental and modeling results showed that marginal difference were observed at low gas flux. However the difference between the both models and experimental value were increased when the gas flux was increased. The study concludes that the Model 1 with free ammonia is more appropriate when both models were compared and useful in ammonia stripping process at low gas flux.

• Textile Coloration and Finishing
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• v.6 no.3
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• pp.1-7
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• 1994

Cotton fiber and NaOH-mercerized cotton fiber had been treated by liquid ammonia and were dyed with two direct dyes, C.I. Direct Red 2 and Blue 1. The effect of the treatment on the rate of dyeing, dye adsorption isotherm, and affinity were studied. The rate of dyeing was increased in the order of NaOH-mercerized> NaOH/liquid ammonia-treated > liquid ammonia-treated>Untreated cotton irrespective of kind of dyes. The rate of dyeing for NaOH-treated fiber considerably increased, whereas liquid ammonia-treated or NaOH/liquid ammonia-treated did not because the structural transformation was not enough for the dyes to penetrate easily into the liquied ammonia-treated cottons. The time of half-dyeing was considerably reduced by mercerizing with NaOH, but lengthened by liquid ammonia treatment because of increased equilibrium dye exhaustion especially in dyeing with C.I. Dierect Red 2. In spite of a short time of the ammonia treatment for 4 seconds, the equilibrium exhaustions of both of direct dyes, C.I. Direct Red 2 and C.I. Direct Blue 1, were increased in proportion to internal volume of treated cotton under a condition of fixed affinity.

• Journal of Environmental Science International
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• v.30 no.12
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• pp.1093-1100
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• 2021

The present study investigated the effect of ammonia load on microbial communities in mesophilic anaerobic digestion of propionic acid. A laboratory-scale continuous anaerobic digester treating propionic acid as a sole organic substrate was operated under non-inhibitory condition and inhibitory conditions with ammonia (1.5 g and 3.5 g ammonia-N/L, respectively), and bacterial and archaeal communities in the steady states of each ammonia condition were analyzed using high-throughput sequencing. Thirteen bacterial families were detected as abundant bacterial groups in mesophilic anaerobic digestion of propionic acid. Increase in ammonia concentration resulted in significant shifts in microbial community structures. Syntorophobacter, Pelotomaculum, and Thermovigra were determined as the dominant groups of (potential) propionate oxidizing bacteria in the non-inhibitory condition, whereas Cryptanaerobacter and Aminobacterium were the dominant groups of (potential) propionate oxidizing bacteria in the ammonia-inhibitory condition. Methanoculleus and Methanosaeta were the dominant methanogens. Acetate-oxidation coupled with hydrogenotrophic methanogenesis might be enhanced with increases in the relative abundances of Methanoculleus and Tepidanaerobacter acetatoxydans under the ammonia-inhibitory condition. The results of the present study could be a valuable reference for microbial management of anaerobic digestion systems that are exposed to ammonia inhibition and propionic acid accumulation.

• Journal of the Korean institute of surface engineering
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• v.56 no.6
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• pp.371-379
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• 2023

Ammonia, which is closely related to our lives, has a significant impact on our lives as a representative substance for crop cultivation. Recently, it has gained attention as an efficient and productive hydrogen/storing substance that can replace fossil fuels. Efforts are being made to utilize it as a renewable energy source through thermochemical and electrochemical reactions. However, the use of ammonia, which encompasses the era, carries inherent toxicity, so a comprehensive understanding of ammonia safety is necessary. To ensure safety in the transportation and storage of ammonia and chemical substances domestically and internationally, national and organizational standards are being developed and provided through documents and simple symbols to help people understand. This review explores the chemical characteristics of ammonia, its impact on human health, and the global trends in safety standards related to ammonia. Through this examination, the paper aims to contribute to the discourse on the safety and risk management of ammonia transport and storage, crucial for achieving carbon neutrality and expanding the hydrogen economy.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.304-310
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• 2001

A numerical model which simulates the heat and mass transfer processes within a counter-current plate type generator for ammonia/water absorption refrigerators was developed. Ammonia/water solution flows downward under gravity and ammonia/water vapor generated by flow boiling flows upward. The flow pattern within the generator was assumed to be a bubbly flow, and the liquid and vapor phase were assumed to be saturated. It was shown that the boiling of ammonia occurred mainly in the upper part of the generator. The effects of the generator length, the wall temperature and the mass flow rate of ammonia/water solution into the generator on the generation of ammonia/water vapor were investigated.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.1
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• pp.102-108
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• 2002

The effects of ammonia on mesophilic anaerobic digestion were investigated by operating lab-scale two-stage ASBF reactors using swine wastewaters as influent without and with ammonia removal at HRT of 1-2 days and OLR of $2.2{\sim}9.6kg-COD/m^3{\cdot}d$ for 250 days. The COD removal efficiency and biogas generation of two-stage ASBF reactors was decreased by increasing influent ammonia concentrations to 1,580 mg(T-N)/L with increasing OLR to $6.3kg-COD/m^3{\cdot}d$, while those were increased by maintaining influent ammonia concentrations below 340 mg(T-N)/L by MAP precipitation with increasing OLR to $9.6kg-COD/m^3{\cdot}d$. Initial inhibirion of ammonia on anaerobic processes was observed at a concentration of 760 mg(T-N)/L and the COD removal efficiency and biogas generation dropped to 1/2 at ammonia concentration ranges of 1,540~1,870 mg(T-N)/L. It is essential to remove ammonia in swine wastewaters to an initial inhibition level before anaerobic processes for the effective removal of COD.