• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.177.2-177.2
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• 2011

세계적인 자원고갈과 지구온난화와 같은 환경문제가 발생됨에 따라 대체에너지 개발에 대한 연구가 활발히 이루어지고 있다. 섬유소 기질을 이용한 바이오에탄올 생산은 세계적으로 막대한 자원이 있으며 광합성에 의해 재생산되는 무한한 재원으로서 환경적으로도 대기오염물질을 적게 배출하여 유용한 에너지원으로 각광받고 있다. 하지만 섬유소 기질은 cellulose, hemicellulose, lignin과 같은 고분자 화합물이 유기적으로 결합된 단단한 결정구조로 이루어져 있어 이를 분해하여 원하는 물질을 얻기 위해서는 전처리 과정이 필요하다. 전처리 공정은 바이오에탄올을 생산하는 당화 및 발효공정의 효율 및 반응시간 단축에 기여하며, 특히 섬유소 기질일 경우에는 필수불가결한 공정이다. 전처리 공정은 물리적, 화학적, 생물학적 방법으로 나누어지며, 이러한 방법들 중 기질의 특성과 처리효율에 따라 기술들을 병합하여 사용하기도 한다. 이에 본 연구에서는 산 처리, 암모니아 처리, 과산화수소 처리 및 효소를 이용한 생물학적 처리를 단독 또는 병행하여, 전환된 당 성분 및 함량을 조사함으로서 섬유소계 기질인 채소 음식물류 쓰레기를 대상으로 바이오에탄올을 경제적으로 생산하기 위한 적합한 전처리법을 검토하였다. 전처리 방법별 당화율을 살펴보면, 산 처리와 암모니아-과산화수소-계면활성제 처리가 각각 65.3 % 및 65.7 %로 가장 높았으며, 과산화수소 처리는 16.2 %로 가장 낮았다. 반면 전처리 공정 없이 효소를 이용한 당화만을 실시한 경우에는 4.3 %의 낮은 당화율을 나타내었다. 섬유소계 기질의 전처리 효율을 향상시키기 위해 첨가하는 계면활성제의 효과는 암모니아-과산화수소 및 암모니아-과산화수소-계면활성제 처리의 당화율을 비교한 결과, 뚜렷한 효과를 확인할 수 없었다. 전처리 방법별 당의 성분 및 함량을 비교한 결과 육탄당은 암모니아-과산화수소-계면활성제 전처리에서 가장 많이 검출되었다. 오탄당은 산 처리 후 그 함량이 현저히 높았으며, 오탄당 중 xylose의 함량이 60.49 mg/g로 가장 많이 차지하고 있었다. 이 결과로부터 전처리 방법에 관계없이 당화율은 유사한 수준을 보이지만, 당화된 당의 성분 및 함량에는 큰 차이가 있음을 알 수 있었다. 이당류의 경우 과산화수소 및 암모니아-과산화수소 처리를 제외한 나머지 전처리 방법에서 유사한 수준을 나타내었다. 암모니아 처리 및 과산화수소 처리를 순차적으로 병행한 암모니아-과산화수소 처리에서는 각각의 처리시보다 육탄당의 함량은 증가하였으나 암모니아 처리시보다 이당류의 함량은 감소한 것으로 나타났다.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.1
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• pp.59-63
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• 2016

The objective of this study lies in identifying the applicability of zeolite for the removal of wastewater ammonium and nitrate nitrogens. To this end, the author tracked adsorption variations as seen with the adsorption removal of wastewater ammonium and nitrate nitrogens. As a result, it was indicated that the maximum adsorption of zeolite acting on the adsorption removal of ammonium nitrogen would reach 120mg/g (weight of ammonium nitrogen divided by that of zeolite), and that Langmuir adsorption isotherm explained the adsorption of ammonium and nitrate nitrogens better than Freundlich adsorption isotherm. This means that zeolite makes ion exchanges with adsorbate for unilayer adsorption. It was also indicated that the removal efficiency of ammonium nitrogen with varying pH would be higher in the order of pH7 > pH5 > pH9 > pH3.

• Applied Chemistry for Engineering
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• v.27 no.3
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• pp.265-269
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• 2016

Ammonia gas as a hydrogen source has received great attention since the importance of hydrogen gas as a clean energy source increased. However, ammonia is toxic and corrosive to metal such that the absorbent that can store and transport ammonia became an important issue. As an effort to solve this, a large pored covalent organic framework, COF-10 was proposed as an adsorbent for storage and safe transportation of ammonia. During the ammonia adsorption process, boron in COF-10 structure can act as a Lewis acid site and bind with ammonia. In this study, COF was synthesized and its structure was identified by BET, XRD and FT-IR. The adsorption characteristics of COF were investigated by TPD and adsorption isotherm. The COF-10 showed an excellent adsorption capacity for ammonia (9.79 mmol/g) which could be utilized as an ammonia adsorbent.

• Clean Technology
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• v.13 no.1 s.36
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• pp.16-21
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• 2007

This study estimated the effect of hydraulic residence time(HRT), influent total ammonia nitrogen(TAN) concentration, temperature and pH in the packed-bed bioreactor using immobilized nitrifiers. Removal rate of ammonia nitrogen was increased with decreasing HRT and the optimum HRT was 0.2 hour when influent TAN was $2g/m^3$. At this point, removal rate was $226.1\;g/m^3{\cdot}day$ and removal efficiency was 88.8%. Removal rate of ammonia nitrogen was Increased with increasing TAN concentration. Removal rate and efficiency of ammonia nitrogen were kept constant at $20{\sim}35^{\circ}C$ and pH $8{\sim}9$ value.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.651-659
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• 2000

The characteristics of ammonia removal by natural neutralizer were studied by using a scrubber type equipment. As operation parameters, neutralizer dilution ratio, neutralizer inlet flowrate, air flowrate and initial ammonia concentration were selected and their effects on ammonia removal efficiency were investigated. The optimal removal effect was achieved at neutralizer dilution ratio of 1.0% and neutralizer inlet flowrate of $60m{\ell}/min$. On the other hand, with respect to air flowrate and initial ammonia concentration, there was no significant effect on removal efficiency, when loading rate was considered. In addition, ammonia removal reaction was investigated by analyzing the ammonia oxides, such as nitrites and nitrates, after reacting ammonium solution with natural neutralizer. The result shows a partial oxidation by natural neutralizer besides dominant absorption of ammonia.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.1-7
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• 2015

An ammonia fuel system is developed and applied to a 1 liter gasoline engine to use ammonia as primary fuel. Ammonia is injected separately into the intake manifold in liquid phase while gasoline is also injected as secondary fuel. As ammonia burns 1/6 time slower than gasoline, the spark ignition is needed to be advanced to have better combustion phasing. The test engine showed quite high variation in the power output to lead high increase in THC emission with large amount of ammonia, that is, higher than 0.7 ammonia-gasoline fuel ratios.

• Membrane Journal
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• v.32 no.3
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• pp.173-180
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• 2022

Presence of ammonia in drinking water is very toxic to human health. Soluble ammonia contaminates ground water due to activities such as the use of fertilizer in crop, industrial effluents and burning of fossil fuel. Even low concentration of ammonia present in water will damage aqua environment such as marine organism. Membrane technology is an important process to remove ammonia from effectively from water. Flat sheet membrane, membrane contactor and membrane distillation are some of the methods used for water purification from ammonia. Membrane contractor is an efficient process in which ammonia is removed through liquid-gas or liquid-liquid mass transfer without change of phase unlike membrane distillation. However, the cost of ammonia removal in this method is high due to maintenance of very high pH. Zeolite has excellent ion exchange ability that enhances its ability to interact with ammonia and adsorb from wastewater. Mixed matrix membranes containing zeolite enhance the efficiency of ammonia adsorption and separation from wastewater. In this review the above discussed issues are summarized in detail.

• Journal of Animal Environmental Science
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• v.8 no.1
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• pp.1-8
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• 2002

Real sized open type biofilter system was manufactured to control the odor generated from the agitated composting system which composted swine manure and sawdust mixtures. The aim of this research was to develop a biofilter system using matured compost and to evaluate the performance of the biofilter system. Average ammonia reduction rate through the biofilter was 84% during about two month period of composting. The maximum ammonia concentration after filtering was 45ppm lower than allowable value of 50ppm. It was concluded that compost can be used as a biofilter materials.

• KSBB Journal
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• v.19 no.3
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• pp.231-235
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• 2004

This paper was investigated to clarify the possibility of ammonia gas removal by essential oil. First of all, the chemical analysis was peformed to analyze the composition of an essential oil by GC-MS. The monoterpenes in an essential oil react with ammonia by neutralization and their reaction mechanism was elucidated. Based on their chemical neutralized reaction, the removal efficiencies of ammonia gas were studied to derive the optimal conditions in the scrubber tower such as optimal temperature and pH. The experimental result shows that the removal efficiency of ammonia gas was achieved over 98 % by the misty aerosol dispersion of scrubber tower.

• Korean Journal of Microbiology
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• v.45 no.2
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• pp.112-118
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• 2009

Ammonia-oxidizing bacteria (AOB) are chemolithoautotrophs that play a key role in nitrogen removal from advanced wastewater treatment processes. Various AOB species inhabit and their community compositions vary over time in the wastewater treatment bioreactors. In this study, a hypothesis that operational and environmental conditions affect both the community compositions and the diversity of AOB in the bioreactors was proposed. To verify the hypothesis, the clone libraries based on ammonia monooxygenase subunit A were constructed using activated sludge samples from aerobic bioreactors at the Pohang, the Palo Alto, the Nine Springs, and the Marshall wastewater treatment plants (WWTPs). In those bioreactors, AOB within the Nitrosomonas europaea, N. oligotropha, N.-like, and Nitrosospira lineages were commonly found, while AOB within the N. communis, N. marina, and N. cryotolerans lineages were rarely detected in the samples. The AOB community structures were different in the bioreactors: AOB within the N. oligotropha lineage were the major microorganisms in the Pohang, the Palo Alto, and the Marshall WWTPs, while AOB within the N. europaea lineage were dominant in the Nine Springs WWTP. The correlations between the AOB community compositions of the wastewater treatment bioreactors and their operational (HRT, SRT, and MLSS) and environmental conditions (temperature, pH, COD, $NH_3$, and $NO_3{^-}$) were evaluated using a multivariate statistical analysis called the Redundancy Analysis (RDA). As a result, COD and $NO_3{^-}$ concentrations in the bioreactors were the statistically significant variables influencing the AOB community structures in the wastewater treatment bioreactors.