• Membrane and Water Treatment
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• 제9권2호
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• pp.123-128
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• 2018

Common aquaculture practices include the use of certain pharmaceuticals such as antibiotics in avoiding diseases and promoting a healthier growth of the culture. The aim of this study is to monitor and assess the influence of different low oxytetracycline concentrations on the transformation of nitrogen compounds under aeration condition in a lab-scale recirculating aquaculture system (RAS). Over $1mg\;L^{-1}$ dose of oxytetracycline to aquaculture had induced ammonia($NH_4-N$), nitrate($NO_3-N$), soluble COD accumulation in RAS. In addition, nitrous oxide ($N_2O$) emission from RAS was significantly reduced during the oxytetracycline dose periods. After ceasing the dose of oxytetracycline, ammonia oxidation and nitrous oxide re-emission were observed. This observation indicated that low concentrations of oxytetracycline could affect the nitrogen species in RAS. Also, the emission mechanisms of $N_2O$ may not be only dependent on nitrification process but also dependent on denitrification process in our RAS system.

• 한국환경과학회지
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• 제32권6호
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• pp.465-475
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• 2023

In this study, we evaluated the treatment efficiency of livestock wastewater by altering the current density using boron-doped diamond (BDD) electrodes. As the current density was adjusted from 10 to 35 mA/cm2, the removal efficiency of organic matter increased from 22.2 to 71.5%. Similar to that of organic matter, the removal efficiency of color increased with increasing current density up to 85.7%, indicating a higher removal efficiency for color than that of organic matter. The removal efficiency of ammonia nitrogen increased from 14.6 to 53.3% as the current density increased, but it was lower than that of organic matter. In addition, the removal of organic matter, color, and ammonia nitrogen followed first-order reactions, according to the reaction rate analysis. The energy consumption ranged from 4.87 to 8.33 kWh/kg COD, and it was found that the organic matter removal efficiency was more efficient at high current densities. Based on various analyses, the optimal current density was 20 mA/cm2, and the corresponding energy consumption was 6.824 kWh/kg COD.

• 한국환경과학회지
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• 제32권9호
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• pp.671-674
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• 2023

This study was conducted to evaluate the effects of using Hermetia illucens larvae as environmental purification insects on ammonia and Hanwoo manure for 15 days in the Hanwoo farms. H.illucens larvae were allocated into four treatment groups and three replicates using a randomized block design. The treatments were as follows: control, normal 1000 g of Hanwoo manure, T1, 1000 g of Hanwoo manure + 100 g of 2nd instar H.illucens L. larvae, T2, 1000 g of Hanwoo manure + 100 g of 3rd instar H.illucens L. larvae, and T3, 1000 g of Hanwoo manure + 100 g of 4th instar H.illucens L. larvae. After 0 days, ammonia fluxes did not occur in the 2nd, 3rd, and 4th instar H.illucens larvae treatments (p<0.05). Among the characteristics of Hanwoo manure, the pH and nitrogen content increased for each larvae instar of H.illucens, whereas ADF and NDF content decreased (p<0.05). In particular, nitrogen contents were found to be highest in the 3rd instar larvae of H.illucens owing to their greater ability to decompose Hanwoo manure than larvae at other growth stages.

• 한국환경농학회지
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• 제31권4호
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• pp.375-377
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• 2012

BACKGROUND: Hairy ventch (Vicia villosa) is a good green manure for supplying nitrogen in arable soil. Ammonia emission from rice fields can occur, and the degree of this emission can be great. However, quantitative information of ammonia emission from paddy soil using green manure is required to obtain emission factors for rice cropping in Korea. METHODS AND RESULTS: Ammonia emission from flooding soil with different application rate of hairy vetch was measured using the closed chamber method. For this study, hairy vetch was applied at rates of 0 (control), 500 (H500), 1000 (H1000), 2000 (H2000), and 3000 (H3000) kg/ha (fresh matter basis). This experiment was conducted for 54 days under flooding condition. The total NH3 emission throughout the experiment period was 0.32, 0.54, 1.20, 4.20, and 6.20 kg/ha for control, H500, H1000, H2000, and H3000, respectively. The ratio of NH3 emission to applied nitrogen by hairy vetch for each treatment was 0.7, 1.4, 3.2, and 3.2% for H500, H1000, H2000, and H3000, respectively. CONCLUSION(S): A very small amount of ammonia emission was recorded in the present study. Therefore, the use of hairy vetch in paddy field instead of chemical fertilizer can reduce ammonia emissions.

• 한국수산과학회지
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• 제33권4호
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• pp.367-372
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• 2000

회전원판식 해수 여과시스템에서 암모니아성 질소 부하율과 수리학적 부하량이 암모니아 제거율에 미치는 영향을 조사하기 위하여 일련의 실험을 실시하였다. 이 실험에서 회전원판 시스템은 폴리비닐필름 원판으로 여과조를 제작하였는데, 여과조의 표면적은 $12m^2$으로 용적은 $0.075m^3$이다. 회전원판식 시스템에서 암모니아성 질소부하율에 따른 암모니아 제거율을 조사하기 위하여 암모니아원으로 염화암모늄을 $10{\~}150 g$ 첨가하였다. 회전원판식 순환여과 사육시스템의 사육수에 암모니아원으로 염화암모늄을 $10{\~}150 g$ 투입하여 사육수의 암모니아 농도 (x: NH_4-N mg/l)에 따라 회전원판 여과조에서의 암모니아 제거에 필요한 시간 (y: hr)을 조사하였으며, 그 관계식은 다음과 같았다. $y=3.51+7.76 lnx (r^2=0.936)$사육수의 암모니아 농도가 2mg/l일 때 회전원판 여과사육 시스템에서 암모니아 제거에 소요되는 시간은 10시간이었으나, 암모니아 농도가 5와 16.5mg/l에서는 각각 16과 27시간이 소요되었다. 따라서 사육수의 암모니아 농도가 높아질수록 암모니아 제거에 소요되는 시간이 감소하는 경향을 나타내었다. 결론적으로 회전원판 여과 사육시스템의 최대 암모니아 제거율은 사육수의 암모니아 농도가 16.5 mg/l까지 상승함에 따라 증가함을 알 수 있었다.

• 한국환경과학회지
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• 제28권8호
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• pp.713-717
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• 2019

The purpose of this study was to investigate the effects of dietary Hermetia illucens powder on duck litter quality. One hundred twenty Pekin ducks (0 day old) were assigned to 2 groups (0% and 0.5% Hermetia illucens powder) with 3 replicates (20 ducks per replicate) for 42 days. Duck litter quality included moisture, pH, VBN, total nitrogen, ammonia, and temperature. Litter pH and VBN values were significantly affected by Hermetia illucens powder (p<0.05). However, moisture and total nitrogen values were not greatly influenced by the addition of 0.5% Hermetia illucens powder (p>0.05). At 21, 28 and 35 days, both 0.5% Hermetia illucens powder and controls had a great effect (p<0.05) on ammonia contents, except at 7, 14 and 42 days. In comparison to control, ammonia contents in groups with 0.5% Hermetia illucens powder were reduced from 16.9 to 41.8% as the days increased. Duck litter showed lower temperature by 0.5% Hermetia illucens powder compare to control. In terms of environmental managements, these results suggest that using 0.5% Hermetia illucens powder as feed additives improved litter quality and decreased ammonia contents.

• 한국동물위생학회지
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• 제22권4호
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• pp.357-361
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• 1999

The most harmful nitrogenous compounds in fish-breeding place using are ammonia and nitrate. Excessively high total nitrogen concentration is the signal of unbalance for breeding fishes in seawater and may result overfeeding or overstocking without seawater treatment system. The failure of elimination for the organic ingredients or nitrogen compounds can also cause the consequence of inadequate oxygen concentration in seawater, either. The study shows the effect of biofilter and W disinfector of seawater in the fish- breeding place. In the results, these tools had ammonia, nitrite, nitrate and decreased 71.8%, 27.6% and 1%, respectively, and the total number of microorganisms decreased up to 81.9%.

• 환경위생공학
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• 제10권1호
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• pp.66-75
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• 1995

This survey is executed about the water quality and improvement measure of Imjin- river. The results are summarized as follows; 1 ) Ammonia nitrogen concentration in tap water was two times higher than drinking water standard. 2) The concentration of BOD in textile wastewater was 235ppm which is higher than wastewater distribution standard and leather wastewater showed high nitrogen concentration. 3) Water quality of the Imjin- river upstream was not in problem but that of Shin- stream showed somewhat high concentration in BOD, COD, and ammonia nitrogen. Especially the detected Cynide compound on the lower of Shin- stream implied seriously polluted condition. 4) The heavy metal in soil of the river bed was not detected but iron, zinc was detected to high concentration. 5) It Is urgently suggested to build more municipal sewage and sanitary treatment plants, and run dredging and river bed rearrangement project. 6) The Construction of the wastewater treatment complexes of relevant industries shall be propelled as soon as possible.

• Journal of Microbiology and Biotechnology
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• 제3권1호
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• pp.19-23
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• 1993

Spirulina platensis NIES 39 was grown in effluents from a wastewater treatment plant utilizing activated sludge process at a pig farm to reduce pollutants and to produce feed resources. The addition of 2 g/l NaCl was required for the growth of S. platensis in the effluents with about 100 mg/l ammonia nitrogen concentration. The growth was stimulated by the addition of 2 g/l sodium bicarbonate and 4 mg/l ferrous sulfate. The microorganism grew well at pH 8~11, and the optimum pH for the growth was 10. The algal concentration of 1.1 g/l was attained after 8 days of growth at the optimum condition with the removal of 95% ammonia nitrogen and 34% phosphorus.

• 한국초전도ㆍ저온공학회논문지
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• 제23권3호
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• pp.20-25
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• 2021

Milking parlor wastewater contains high concentration suspended solid (SS), nitrogen, and/or phosphate as well as organic compounds. A new biological wastewater process by magnetic separation, magnetic activated sludge (MAS) process, was applied to milking parlor wastewater treatment process. A three step wastewater treatment process of coagulation sedimentation / ammonia stripping (C/S), magnetic activated sludge process and contact oxidation (CO) was proposed for removal of these pollutants. First step, C/S process recovered 96% TN and 96% PO₄^3--P as resource for fertilizer from the wastewater. 81% biochemical oxygen demand (BOD) in wastewater was removed after MAS process. As a results, all pollutant concentrations satisfied Japanese effluent standards. Most of residual BOD and SS were removed by the CO process. It was estimated that the proposed process could reduce the process space to 1/7.