• 제목/요약/키워드: Ammonia-water

검색결과 948건 처리시간 0.021초

효소 고정화막의 응용에 대한 총설 (Zeolite Based Membrane for Removal of Ammonium: A Review)

  • 이주엽;라즈쿠마 파텔
    • 멤브레인
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    • 제32권3호
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    • pp.173-180
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    • 2022
  • 음용수 속 암모니아의 존재는 인간의 건강에 매우 해롭다. 농작물에서의 비료 사용, 산업 폐수, 화석 연료의 연소와 같은 활동으로 인해 가용성 암모니아는 지하수를 오염시킨다. 물에 존재하는 암모니아 농도가 낮더라도 해양생물 등의 수생환경을 훼손한다. 막 기술은 암모니아를 물로부터 효과적으로 제거하기 위한 매우 중요한 과정이다. 평평한 시트 막, 막 접촉기, 그리고 막 증류법은 암모니아를 제거하여 물을 정화하는 데 사용되는 방법들 중 하나이다. 막 접촉기는 막 증류법과는 달리 상변화 없이 액체와 가스 간의 또는 액체와 액체간의 질량 전달을 통해 암모니아를 제거하는 효율적인 공정이다. 다만 이 방법은 pH가 매우 높아 암모니아 제거에 비용이 많이 든다. 제올라이트는 우수한 이온 교환 능력을 가지고 있는데, 이는 암모니아와의 상호작용을 향상시켜 폐수로부터 흡착하는 능력을 향상시킨다. 제올라이트를 함유한 혼합 매트릭스 막은 암모니아 흡착 및 폐수로부터의 분리 효율을 향상시킨다. 이 리뷰에서는 위에서 소개된 내용이 자세히 논의될 것이다.

정수처리에서 암모니아성질소 제거를 위한 제올라이트 여과 (Zeolite Filtration for Ammonium Nitrogen Removal in Drinking Water Treatment)

  • 김우항;김충환
    • 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.

암모니아수/수산화나트륨에서 처리된 면의 미세구조와 물리적 성질(I) (Physical Properties and Fine Structure of Cotton Mercerized in Ammonia Water/Sodium Hydroxide(1))

  • 최철호;김미순;이찬민
    • 한국의류학회지
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    • 제12권2호
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    • pp.181-188
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    • 1988
  • Cotton fabrics were slack-mercerized in sodium hydroxide, ammonia water(min. $28{\%}\;NH_3$), and mixture of ammonia water/sodium hydroxide. The surface of treated cotton fabrics were observed through SEM, and the changes of fine structure were analyzed by X-ray diffractometer. In addition to that shrinkage was compared mutally, and tenacity-elongation compared, too. SEM photographs showed fibrls rearranged strightly toward fibre axis. X-ray diffraction represented increased amorphous fraction, and partial recrystallization into cellulose 2 lattic after treatment with sodium hydroxide and mixture of ammonia water/sodium hydroxide. The mercerization produced increased fibre tenacity-elongation with slark state. Lastly, the best condition of mercerization was $4\%/14\%$, $10^{\circ}C,\;5\~30$ min. in mixture of ammonia/sodium hydroxide.

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저온 열원 활용을 위한 암모니아-물 재생 랭킨 사이클의 성능 해석 (Performance Analysis of Ammonia-Water Regenerative Rankine Cycles for Use of Low-Temperature Energy Source)

  • 김경훈;한철호
    • 한국태양에너지학회 논문집
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    • 제31권1호
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    • pp.15-22
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    • 2011
  • It is a great interest to convert more energy in the heat source into the power and to improve the efficiency of power generating processes. Since the efficiency of power generating processes becomes poorer as the temperature of the source decreases, to use an ammonia-water mixture instead of water as working fluid is a possible way to improve the efficiency of the system. In this work performance of ammonia-water regenerative Rankine cycle is investigated for the purpose of extracting maximum power from low-temperature waste heat in the form of sensible energy. Special attention is paid to the effect of system parameters such as mass fraction of ammonia and turbine inlet pressure on the characteristics of system. Results show that the power output increases with the mass fraction of ammonia in the mixture, however workable range of the mass fraction becomes narrower as turbine inlet pressure increases and is able to reach 16.5kW per unit mass flow rate of source air at $180^{\circ}C$.

폭기식 잠수여상을 이용한 고밀도 양식장의 순환수 처리 -1. 해수중의 암모니아 제거 특성- (The Recycling Water Treatment of High Density Fish Culture System Using the Aerated Submerged Filter -1. Ammonia Removal Characteristics in Sea Water-)

  • 이헌모;이재관;정병곤;양병수
    • 한국수산과학회지
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    • 제26권5호
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    • pp.502-509
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    • 1993
  • Submerged filter process was used to evaluate the nitrifying efficiency of ammonia in the recycling water of marine aquatic culture system. The ammonia removal efficiency was achieved as high as $99\%$ at the hydraulic surface loading rate of up to $4.3{\ell}/m^2-day$. And the nitrite accumulation did not occur in the reactor even when the hydraulic surface loading rate of up to $36.8{\ell}/m^2day$ was applied. In the present study, the relationship between the effluent ammonia concentration and ammonia surface loading rate was formulated as an equation. The attachment rate of biofilm on the filter media at the ammonia surface loading rate of 62.3 and $311.7mg/m^2day$ was 15 and $55mg/m^2-day$, respectively, showing the linear relationship between the attachment rate and ammonia loading rates. Biofilm thickness and density of the filter media were found to be the function of the ammonia loading rate.

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Nitrification of low concentration ammonia nitrogen using zeolite biological aerated filter (ZBAF)

  • Kim, Jin-Su;Lee, Ji-Young;Choi, Seung-Kyu;Zhu, Qian;Lee, Sang-Ill
    • Environmental Engineering Research
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    • 제25권4호
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    • pp.554-560
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    • 2020
  • This study focuses on nitrification through a biological aerated filter (BAF) that is filled with a zeolite medium at low concentrations of ammonia. The zeolite medium consists of natural zeolite powder. The BAF is operated under two types of media, which are a ball-type zeolite medium and expanded poly propylene (EPP) medium. Nitrification occurred in the zeolite BAF (ZBAF) when the influent concentration of ammonia nitrogen was 3 mg L-1, but the BAF that was filled with an EPP medium did not experience nitrification. The ammonia nitrogen removal efficiency of ZBAF was 63.38% and the average nitrate nitrogen concentration was 1.746 mg/L. The ZBAF was tested again after a comparison experiment to treat pond water, and municipal wastewater mixed pond water. The ZBAF showed remarkable ammonia-nitrogen treatment at low concentration and low temperature. During this period, the average ammonia nitrogen removal efficiency was 64.56%. Especially, when water temperature decreased to 4.7℃, ammonia nitrogen removal efficiency remained 79%. On the other hand, the chemical-oxygen demand (COD) and phosphorus-removal trends were different. The COD and phosphorus did not show as efficient treatment as the ammonia-nitrogen treatment.

Ammonia as Extractant and Reactant for Ginsenosides

  • Cho In-Ho;Hohaus Eberhard;Lentz Harro
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 2002년도 학술대회지
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    • pp.486-490
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    • 2002
  • In different approaches ginsenosides were extracted from Korean ginseng roots by ammonia and for comparison with methanol-water and water. The extracts have been analyzed qualitatively and quantitatively to evaluate yield and selectivity of extractions of ginsenosides. Water supplied the lowest yield. The yields of extracts with liquid ammonia were higher than those with methanol-water. However, this is partly due to the conversion of malonyl ginsenoside to normal ginsenosides by ammonia. It was proved by HPLC that malonyl-ginsenosides $m-Rb_1,\;m-Rb_2,$ m-Rc and m-Rd were converted to the corresponding neutral ginsenosides. Furthermore, ginsenosides from ginseng roots were extracted by alkaline methanol-water $(60\%)$ solutions. Alternatively, the extracts of the methanol-water $(60\%)$ extraction were treated with sodium hydroxide solution. Both methods also convert the malonyl-ginsenosides to neutral ginsenosides.

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저온폐열 활용을 위한 암모니아-물 혼합물을 작업유체로 하는 랭킨사이클에 관한 연구 (Study on the Rankine Cycle using Ammonia-Water Mixture as Working Fluid for Use of Low-Temperature Waste Heat)

  • 김경훈;김세웅;고형종
    • 한국수소및신에너지학회논문집
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    • 제21권6호
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    • pp.570-579
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    • 2010
  • Since the temperature of waste heat source is relatively low, it is difficult to maintain high level of efficiency in power generation when the waste heat recovery is employed in the system. In an effort to improve the thermal efficiency and power output, use of ammonia-water mixture as a working fluid in the power cycle becomes a viable option. In this work, the performance of ammonia-water mixture based Rankine cycle is thoroughly investigated in order to maximize the power generation from the low temperature waste heat. In analyzing the power cycle, several key system parameters such as mass fraction of ammonia in the mixture and turbine inlet pressure are studied to examine their effects on the system performance. The results of the cycle analysis find a substantial increase both in power output and thermal efficiency if the fraction of ammonia increases in the working fluid.

저온 열원 활용을 위한 암모니아-물 혼합물을 작동유체로 하는 칼리나 사이클의 성능 해석 (Performance Analysis of Kalina Cycle using Ammonia-Water Mixture as Working Fluid for Use of Low-Temperature Energy Source)

  • 김경훈;고형종;김세웅
    • 한국수소및신에너지학회논문집
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    • 제22권1호
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    • pp.109-117
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    • 2011
  • Since the thermal performance of cycles for use of low-temperature source is low if a pure working fluid is used, the cycles using ammonia-water binary mixture as a working fluid has attracted much attention over past two decades. Recently, several commercial power plants using Kalina cycles have been built and being operated successfully. In this work thermodynamic performance of Kalina cycles using ammonia-water mixture as a working fluid is investigated for the purpose of extracting maximum power from low-temperature energy source. Special attention is paid to the effect of system parameters such as concentration of ammonia and turbine inlet pressure on the characteristics of the system. Results show that the system performance is influenced sensitively by the ammonia concentration, and the role of the performance of heat exchangers is crucial.

수직원관형 GAX 흡수기 내부의 열 및 물질전달과정에 대한 수치모델 (A Numerical Model for Heat and Mass Transfer Processes within a Vertical Tube GAX Absorber)

  • 천태식;정은수
    • 설비공학논문집
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    • 제12권1호
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    • pp.102-111
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    • 2000
  • A numerical model which simulates the simultaneous heat and mass transfer within a vertical tube GAX absorber was developed. The ammonia vapor and the solution liquid are in counter-current flow, and the hydronic fluid flows counter to the solution liquid. The film thickness and the velocity distribution of the liquid film were obtained by matching the shear stress at the liquid-vapor interface. Two-dimensional diffusion and energy equations were solved in the liquid film to give the temperature and concentration, and a modified Colburn-Drew analysis was used for the vapor phase to determine the heat and mass fluxes at the liquid-vapor interface. The model was applied to a GAX absorber to investigate the absorption rates, temperature and concentration profiles, and mass flow rates of liquid and vapor phases. It was shown that the mass flux of water was negligible compared with that of ammonia except the region near the liquid inlet. Ammonia absorption rate increases rapidly near the liquid inlet and decrease slowly. Both the absorption rate of ammonia vapor and the desorption rate of water near the liquid inlet increase as the vapor mass flow rate increases, but the mass fluxes of the ammonia and the water near the liquid outlet decrease as the mass flow rate of the vapor increases.

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