• 상하수도학회지
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• 제12권1호
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• pp.45-51
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• 1998

The determinations of ammonia in water for drinking purpose served as one basis of judging the sanitary quality of water for a great many years. However, presently ammonia regulation varies depending on countries. In USA and Canada, ammonia is added to water for chloramination process. However, for korea, there is ammonia regulation of treated water in Korea which should not exceed 0.5mg/l as $NH_3-N$. There was a report exceeding 0.5mg/l of ammonia in chlorinated water when the famous drinking water contamination episode happened in the downstream of Nadong River, 1994. With lack of sewer distribution system and treatment plants of domestic wastes, many water treatment plants have a difficulty of complying with ammonia regulation in treated water. Breakpoint chlorination is usually performed to get rid of ammonia. The method which is allowed to measure ammonia in Korea is Phenate method. However, it would be undesirable to use Phenate method for measuring ammonia in chlorinated water if Phenate method would not differentiate ammonia from chloramine. A good possibility of interferences in measurement of ammonia exists because Phenate method include the step of the formation of chlorine and would not differentiate chloramine which is formed as a result of reaction between chlorine and ammonia. This study was on inaccuracy of Phenate method for measuring ammonia of chlorinated water when chloramine and ammonia coexist. This study found that Phenate method measured all chlormaine as ammonia. Ammonia measurement by ion chromatography confirmed this results. Finally, the result from this study suggests that ammonia measurement by Phenate method in chlorinated water should be revised accordingly.

• 설비공학논문집
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• 제13권10호
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• pp.1034-1041
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• 2001

A numerical model which simulates the flow boiling process of the ammonia/water solution within a plate type generator for ammonia/water absorption refrigerators was developed. The ammonia/water solution flows downward under gravity and the ammonia/water vapor generated by flow boiling flows upward. The heating medium flows counter to the ammonia/water solution. The flow pattern within the generator was assumed to be a bubbly flow, and the liquid and vapor phases 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 heating medium inlet temperature, the mass flow rate of the heating medium and the mass flow rate of ammonia/water solution into the generator on the generation of ammonia/water vapor were investigated.

• 한국융합학회논문지
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• 제12권5호
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• pp.185-190
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• 2021

전기분해 공정으로 제조한 전해산성수를 이용하여 생활 악취의 원인인 암모니아를 제거하는 방법을 연구하였다. 제조한 전해산성수는 pH와 ORP 변화 측정을 통해 안정적으로 알칼리성 암모니아를 중화 시킬 수 있는 전해수(중화제)로 확인되었다. 자외-가시선 흡광도 분석과 전기화학적 개방회로 전위 측정으로 전해산성수와 암모니아수를 혼합한 용액에서 암모니아가 제거되는 것을 확인하였다. 암모니아 가스 발생량 측정을 통해 전해산성수가 암모니아를 중화시켜 악취 발생시키는 암모니아가 효과적으로 제거되는 것으로 조사되었다. 친환경적인 전해산성수가 악취의 원인 물질인 암모니아를 효과적으로 안전하게 제거할 수 있는 것으로 확인되었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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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.

• Environmental Engineering Research
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• 제23권2호
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• pp.136-142
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• 2018

The river water source of Saidabad Surface Water Treatment Plant at Dhaka, Bangladesh, is deteriorated too much to be treated by conventional treatment process due to excessive ammonia pollution. In order to improve the raw water quality before it enters into the main treatment chain, a pilot study was conducted for pre-treatment of the raw water. The objective is to investigate the rate of reduction of ammonia using the Meteor pilot, a biological pretreatment system, which is a laboratory scale Moving Bed Biofilm Reactor with a nominal volume of hundred liters, filled with 50 L of Meteor 660 media. The reduction of ammonia was quite significant on average 73%, while the reduction of COD was in a range from 20 to 60%. The Meteor pilot was able to treat and nitrify the raw water and produce an effluent that respects the guarantee of ammonia < $4.0mg\;NH_3-N/L$ when the raw water ammonia concentration was < $15mg\;NH_3-N/L$. The study identified operating parameters necessary to achieve the desired goal of adequate ammonia removal. The study results would benefit a range of systems across the country by providing guidance on the design and operation of a biological pre-treatment system for ammonia removal.

• 한국수소및신에너지학회논문집
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• 제24권6호
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• pp.510-517
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• 2013

The ammonia-water based power generation cycle utilizing liquefied natural gas (LNG) as its heat sink has attracted much attention, since the ammonia-water cycle has many thermodynamic advantages in conversion of low-grade heat source in the form of sensible energy and LNG has a great cold energy. In this paper, we carry out thermodynamic performance analysis of a combined power generation cycle which is consisted of an ammonia-water regenerative Rankine cycle and LNG power generation cycle. LNG is able to condense the ammonia-water mixture at a very low condensing temperature in a heat exchanger, which leads to an increased power output. Based on the thermodynamic models, the effects of the key parameters such as source temperature, ammonia concentration and turbine inlet pressure on the characteristics of system are throughly investigated. The results show that the thermodynamic performance of the ammonia-water power generation cycle can be improved by the LNG cold energy and there exist an optimum ammonia concentration to reach the maximum system net work production.

• KEPCO Journal on Electric Power and Energy
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• 제2권3호
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• pp.437-445
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• 2016

This paper discussed the effect of ammonia concentration adsorbed on fly ash for the ammonia emission as AAFA (Ammonia Adsorbed Fly Ash) produced from coal fired plants due to operation of NOx reduction technologies was landfilled with distilled or sea water at closed and open systems, respectively. Ammonia bisulfate and sulfates adsorbed on fly ash is highly water soluble. The pH of ammonium bisulfate and sulfate solution had significant effect on ammonia odor emission. The effect of temperature on ammonia odor emission from mixture was less than pH, the rate of ammonia emission increased with increased temperature when the pH conditions were kept at constant. Since AAFA increases the pH of solution substantially, $NH_3$ in the ash can release the ammonia order unless it is present at low concentration. $NH_4{^+}$ ion is unstable in fly ash and water mixtures of high pH at open system, which is changed to nitrite or nitrate and then released as ammonia gas. The proper conditions for < 20 ppm of ammonia concentration released from the AAFAs landfilled in ash pond were explored using an open system with sea water. It was therefore proposed that optimal operation to collect AAFA of less than 168 ppm ammonia at the electrostatic precipitator were controlled to ammonia slip with less than 5 ppm at SCR/SNCR installations, and, ammonia odor released from mixture of fly ash of 168 ppm ammonia with sea water under open system has about 20 ppm.

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2003년도 추계정기총회 및 국제심포지엄
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• pp.170-173
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• 2003

Activated Rice-Hull carbon was developed to remove ammonia compounds in water matrix. Isotherm adsorption tests of ammonia were conducted using a bottle-point technique and column test. Residual ammonia after Jar-Test or passing through the column was determined by Indophenol method, and assessed the removal efficiency for ammonia of the adsorbent. As a result, the adsorption capacity for ammonia of activated racehull carbon was very larger than that of coconut shell carbon, because the rice hull carbon had the higher BET surface area of silicate. The activated racehull carbon is under the development as adsorbent to remove ammonia in drinking water and waste water.

• 한국환경보건학회지
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• 제27권1호
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• pp.1-7
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• 2001

Ammonia is used in the manufacture of fertilizers, refrigerants, stabilizers and many household cleaning agents. These wide applications resulted in ammonia contamination in water. Ammonia can be removed from water by physical, biological, and chemical methods. Ozonation is effictive in the treatment of water with low concentration of ammonia. This study is undertaken to provide kinetic data for the ozonation of ammonia with or without hydrogen peroxide. The results were as follows; The destruction rate of ammonia increased gradually with the influent hydrogen peroxide concentration up to 0.23 mM and inhibited in the range of 0.23~11.4mM, and the maximum removal rate of ammonia achieved at 0.23mM of hydrogen peroxide, and the overall kinetics was first order. The combination effect of hydrogen and ozone to oxide ammonia in aqueous solution was better than ozone alone. The reacted ammonia was converted completely to nitrate ion.

• 환경위생공학
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• 제17권2호
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• pp.1-10
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• 2002

Ammonia is used in the manufacture of fertilizers, refrigerants, stabilizers and many household cleaning agents. The wide applications result in ammonia contamination in water. Ammonia can be removed from water by physical, biological, and chemical methods. Especially ozonation is effective in the treatment of water with low concentration of ammonia. Therefore, this study is undertaken to provide kinetic data for the ozonation of ammonia with bromide. The results were as follows; Ammonia oxidized by ozone with bromide catalysis. The denitrification rate of the ammonia increased proportionally to the concentration of bromide, and the overall reaction order was zero. It was also found that the effect of bromide ion concentration on the denitrification can be expressed by Monod type equation and there was no more effect above a proper bromide ion concentration. The reacted ammonia was converted completely to nitrate ion without bromide, but the denitrification of ammonia by ozone was conducted in the presence of bromide.