• 한국농공학회논문집
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• 제63권5호
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• pp.13-25
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• 2021

The particulate matters (PM₁₀ and PM_2.5) and ammonia emitted from livestock farms as dispersed to urban and residential areas can increase the public's concern over the health problem, social conflicts, and air quality. Understanding the atmospheric dispersion of such matters is important to prevent the problems for the regulatory purposes. In this study, AERMOD modeling was performed to predict the dispersion of livestock particulate matters and ammonia in Gwangju metropolitan city and five surrounding cities. The five cities were divided into 40 sub-zones to model the area-based emissions which varied with the number of livestock farms, species and growth stages of the animals. As a result, the concentrations of PM₁₀, PM_2.5 and ammonia resulted from livestock farms located in the surrounding cities were 2.00 ㎍ m^-3, 0.30 ㎍ m^-3 and 0.04 ppm in the southwestern part of Gwangju based on the average concentration of 1 hour. These values accounted for 0.7% of PM₁₀ concentration, 0.5% of PM_2.5 concentration, and 0.4% of the ammonia concentration in Gwangju, contributing to a small amount of air pollution compared to other sources. As preventive measures, the plantation was applied to high emission source areas to reduce particulate matters and ammonia emissions by 35% and 31%, respectively, and resulted in decrease of the area of influence by 57% for particulate matters and 59% for ammonia.

• 유기물자원화
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• 제28권4호
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• pp.35-41
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• 2020

본 연구는 수로 표면에 고정된 히드록실아민-산화환원효소가 암모니아 흡수에 미치는 영향에 대하여 해석하였다. 이 효소에 의한 반응은 히드록실아민을 아질산으로 변화시키는 것으로서 신속하게 진행된다. 영향의 해석을 위하여, 무차원 물질전달 지배방정식이 수립되었고 상온 기준의 일정한 물성치들이 사용되었다. 물에서의 암모니아 확산계수와 물의 동점도계수는 각각 2.45×10-9 ㎡/s와 1×10-6 ㎡/s이었다. 물에서의 암모니아 농도 분포는 암모니아에 노출되기 시작하는 지점으로부터의 위치에 대하여 산출되었다. 혼합 깊이에 따른 정량적인 분포 또한 도출되었다. 이와 같은 정량적인 해석은 수로 표면에 고정화된 효소가 암모니아 제거에 효율적으로 이용될 수 있는지에 대한 통찰력을 제시할 수 있다.

• 한국수산과학회지
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• 제56권6호
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• pp.870-877
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• 2023

The purpose of this study was to assess the efficiency of nitrification based on ammonia loading rates and hydraulic air-loading rates in a moving bed bioreactor (MBBR) under seawater conditions. The goal was to provide foundational data for the design of these bio reactors. At an ammonia loading rate of 0.2 g TAN·m^-2 surface area·day^-1, the influent TAN concentration was determined to be 1.76±0.33 mg·L^-1, which is below the safe concentration for fish survival (2 mg·L^-1). Considering operational aspects, the optimal ammonia-loading rate was derived. Subsequently, experimental results for nitrification efficiency at the optimal ammonia-loading rate revealed that the optimum hydraulic air-loading rate was 1.8 L·air·m^-2 surface area·min^-1. This condition resulted in the lowest concentrations of TAN and NO₂-N in the influent water, thus establishing the optimal hydraulic air-loading rate. A regression equation was derived for the ammonia-removal rate (Y) based on the ammonia-loading rate (x) and expressed as a 0.5-order equation (Y=ax^0.5+b). Specifically, for TAN concentrations of 0-6 mg·L-1, the regression equation Y=0.1683x^0.5-0.13628, was established.

• 한국응용곤충학회지
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• 제2권
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• pp.16-21
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• 1963

우리나라에서 참깨나 목화에 기생하여 위조병을 일으키는데 Fusarium oxsporum f. vasinfectum의 생육에 미치는 질소원의 종류 및 농도의 영향을 구명하고자 본연구에 착수하였다. 본연구의 결과로부터 질소원의 종류 및 농도의 차이가 Fusarium oxysporum f. vasinfectum의 생육에 큰 영향을 미친다는 것을 알았다. 공시한 4종의 질소원 중에서 Nitrate N나 Urea N가 Ammonia N 또는 Ammonium and Nitrate N 보다 공시균의 생육에 대하여 더욱 알맞는 질소원이었다. 그 중에서도 Nirtrate N는 타른 N원보다 훨씬 넓은 농도범위에서 본균에 의하여 이용되므로 가장 알맞는 질소원이라고 할 수 있다. 한편 Ammonia N는 공시균의 균계생장이나 포자형성의 현저한 감소와 더불어 기형적인 파형균총 또는 염주상균계세포를 농도에 관계없이 형성하므로 질소원으로서의 이용가치가 거의 없다. Ammonia N가 공시균의 생육에 미치는 영향은 파형균총 또는 염주상균계형성으로 보아 Phenoxy 화합물이 타른 진균의 생육에 미치는 영향과 흡사하다. Ammonium and Nitrate N도 50meg. 이상의 농도에서 공시균의 균계생장 또는 포자형성을 감소시키는 한편 파형균총과 같은 이상생육이 다소간음폐되기는 하나 적제 Ammonia N에서 유래하는 파형균총을 유기하므로 알맞는 질소원이라고 생각할 수 없다. 따라서 Ammonia N 단독 또는 타질소원과 Ammonia N의 결합태는 Fusarium oxysporum f. vasifectum의 생육을 위한 질소원으로서는 부적당하다.

• 한국환경과학회지
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• 제12권3호
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• pp.281-286
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• 2003

This study was conducted to evaluate the feasibility of ammonia removal by zeolite adsorption in drinking water treatment. In generally, drinking water treatment process is conducted coagulation/flocculation, sedimentation, sand filtration and disinfection. We tested feasibility with two method, one is powdered zeolite dosing to coagulation tank and the other is to substitute granular zeolite for sand of sand filter. In powdered zeolite test, raw water is used tap water with putting of 2 mg/l of NH$_4$$\^$+/-N. Filtration of granular zeolite was conducted with 80 cm of effective column high and 120 m/d of flow rate. At above 100 mg/1 of zeolite dosage, ammonia concentration was decreased below 0.5 mg/l of NH$_4$$\^$+/-N in powdered zeolite test. But, turbidity was increased to 30 NTU by powdered zeolite dosage. That turbidity was scarcely decreased in generally coagulant using condition in drinking water treatment. In granular zeolite test, ammonia was not detected in treated water until 8 days. This result suggest that using of granular zeolite in sand filter could be removal ammonia in winter. But we need regeneration at zeolite filtration for ammonia removal. So, it is to make clear that zeolite regeneration ability was compared KCl with NaCl. The result reveal that KCl was more excellent than NaCl. Optimum regeneration concentration of KCl was revealed 100 mM. Regeneration efficient was not increased at pH range 10∼12.5.

• 미생물학회지
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• 제24권2호
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• pp.113-118
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• 1986

Optimum temperature and pH of glutamine synthetase activity (E.C. 3.6.1.2.) of R. sphaeroides D-230 was $35^{\circ}C$ and 6.8, respectively. The adenylated state of GS in R. sphaeroides D-230 was stabilized by addition of 0.2mg/ml of cethyltrimethylammoniumbromide. Valine, histidine, proline, isoleucine, and lysine were good nitrogen source for the growth of R. sphaeroides D-230. The growth of R. sphaeroides D-230 in $N_2,\;NaNO_3\;or\;NH_4Cl$ as sole nitrogen source was lower than in any otherculture conditions. GS activity was inhibited, more or less, by various amino acid. THe relative inhibition rate of the enzyme by added 7mM arginine, $NH_4Cl,\;N_2,\;and\;NaNO_3$ was 63.8%, 26.79%, 6.24%, and 10.64%, drespectively. THe hydrogen evolution of R. sphaeroides D-230 grown in N-limited media was inhibited by 0.1mM MSX, irreversible GS inhibitor. GS activity was completely inhibited by 1.0mM MSX but ammonia released maximally at the same concentration of MSX. Ammonia release by added MSX was increased up to 1.0mM MS, but decreased above 1.0mM MSX. It is probably due to inhibition of nitrogenase actixity by MSX. Nitrogenase activity was not inhibited at low concentration of MSX. These results suggests that the inhibition of nitrogenase activity by ammonia is mediated by products of ammonia assimilation rather than by ammonia itself.

• 대한기계학회논문집B
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• 제32권9호
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• pp.669-675
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• 2008

The objectives of this paper are to examine the effect of nano-particles on the pool type absorption heat transfer enhancement and to find the optimal conditions to design a highly effective compact absorber for ammonia/water absorption system. The effect of $Al_2O_3$ nano-particles and carbon nanotube(CNT) on the absorption performance is studied experimentally. The experimental ranges of the key parameters are 20% of ammonia concentration, $0{\sim}0.08\;vol%$ (volume fraction) of CNT particles, and $0{\sim}0.06 \;vol%$ of $Al_2O_3$ nano-particles. For the ammonia/water nanofluids, the heat transfer rate and absorption rate with 0.02 vol% $Al_2O_3$ nano-particles were found to be 29% and 18% higher than those without nano-particles, respectively. It is recommended that the concentration of 0.02 vol% of $Al_2O_3$ nano-particles be the best candidate for ammonia/water absorption performance enhancement.

• Environmental Engineering Research
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• 제19권4호
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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.

• 한국환경과학회지
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• 제30권12호
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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.

• 대한환경공학회지
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• 제29권1호
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• pp.106-112
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• 2007

Ammonia oxidizing bacteria(AOB)는 $NH_4^+-N$을 $NO_2^--N$으로 산화시키며, 생물학적 질산화 단계에서 율속 단계로 작용하기 때문에 중요한 미생물이다. AOB의 성장은 용존산소, 온도, pH 등의 환경 인자에 영향을 받는다. 본 연구에서는 DO 농도가 AOB에 미치는 영향을 조사하기 위해 세라믹 메디아가 충전된 4개의 호기성 생물막 반응기의 DO 농도를 각각 1, 3, 5, 7 mg/L로 운전하였다. 운전결과, 5 mg/L 이상에서 안정적인 질산화 효율을 얻을 수 있었다. AOB의 특성을 조사하기 위해 AOB의 16S rRNA와 amoA gene을 target으로 PCR을 이용한 DGGE와 cloning을 실시하였으며, 이들의 활성을 조사하기 위해 INT-DHA를 측정하였다. DO 농도 변화에 따른 각 반응기별 질산화 효율에 차이가 있었음에도 불구하고, DGGE 및 cloning 결과, AOB 군집 및 Nitrosomonas sp.의 비율의 변화는 거의 없었다. DO 농도가 감소함에 따라 AOB의 활성도가 감소한다는 것을 INT-DHA 측정으로 확인할 수 있었다. 따라서 DO 농도는 AOB 군집의 변화 보다는 활성에 영향을 미치는 것으로 판단되었다.