• Fisheries and Aquatic Sciences
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• 제2권1호
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• pp.52-57
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• 1999

Air-drived rotating biological contactor (RBC) system, which is effective method in filtering performance, was tested for the nitrification capacity in a recirculating system. At ammonia concentrations between 0.029 and 0.528 mg/l, the effect of ammonia loading rate on ammonia removal rate at three different hydraulic loading rates could be defined by the following first­order regression models: Hydraulic loading rate of $14.8 m^3/m^3/day:\;y=39.2\times+3.4 (r^2=0.9137)$, Hydraulic loading rate of $26.5 m^3/m^3/day: y=53.3\times+4.0 (r^2=0.8686)$, Hydraulic loading rate of $37.3 m^3/m^3/day: y=58.4\times+4.2 (r^2=0.7755)$, where, $\times$ is ammonia loading rate (mg/l), y is ammonia removal rate $(g/m^3/day)$, The equations showed the optimal ammonia removal rate at the hydraulic loading rate of $26.5m^3/m^3/day$. Below the ammonia concentration of 2.72 mg/l, first-order regression models between ammonia loading rate and ammonia removal rate at three different rates of speed are defined as follows: Rotational speed of $0.75 rpm: y=28.5\times+4.7 (r^2=0.9143)$, Rotational speed of $1.0 rpm: y=33.6\times+8.4 (r^2=0.9534)$, Rotational speed of $2.0 rpm: y=28.9\times+3.6 (r^2=0.9488)$, where, x is ammonia loading rate (mg/l), y is ammonia removal rate $(g/m^3day)$. The equations show the ammonia removal rate at the rotational speed of 1.0 rpm is significantly higher than that at the rotational speed of either 0.75 rpm or 2.0 rpm (P<0.05).

• 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.

• 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.

• 한국물환경학회지
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• 제25권2호
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• pp.306-310
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• 2009

Packed-bed reactor for removing ammonia was tested at different loading rates. Nitrifiers for ammonia removing was encapsulated in gel media which consisted of polyethlene glycol, alginate and activated carbon. The removal efficiency was nearly 100% when ammonia loading was $12g/m^3/hr$, and the maximum elimination capacity (EC) achieved on this study was $18g/m^3/hr$. The initial microbial portion of nitrifiers in the media was about 82% and it was increased to more than 90% at the end of the operation. Short-term shock loading test was carried out to survey the stability of the media. The inlet loading rates were varied from 2 to $20g/m^3/hr$. The packed-bed reactor overcame the shock loading i.e. removal efficiency recovered rapidly from about 80% to almost 100% within 6 hrs. The results of Live/Dead cell test showed that nitrifiers maintained there activity in the encapsulated media during the test and also against ammonia shock load.

• 한국물환경학회지
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• 제26권5호
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• pp.732-739
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• 2010

Two combined autothermal thermophilic aerobic digestion (ATAD) and biofilter (BF) systems were operated to treat the piggery wastewater and the ammonia offgas. Experimental results indicated that the organic removal efficiency of ATAD-2, operated with oxygen, was higher than that of ATAD-1, operated with air. The concentration of ammonia in ATAD-2 offgas was higher compared to ATAD-1 offgas, but the total amount of ammonia produced from ATAD-2 was less than that from ATAD-1 due to the lower oxygen flowrate. The ammonia gas produced from both ATAD reactors was successfully removed by the BF. The BF-1, connected with ATAD-1, removed 93% of ammonia at the loading rate of $9.4g\;NH_3-N/m^3/hr$. The BF-2, connected with ATAD-2, removed 95% of ammonia gas at the loading rate of $8.1g\;NH_3-N/m^3/hr$. As the nitrification process continued, pH value of recirculating solution continuously decreased due to the accumulation of nitrate. When the ammonia loading rate was less than $22.7g\;NH_3-N/m^3/h$, the proper replacing cycle of recirculating solution was in the range of 10 to 11 days. Almost 90% of total mass of nitrogen fed into the each BF was confirmed from the mass balance on nitrogen.

• 환경위생공학
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• 제12권2호
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• pp.1-12
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• 1997

This research aims to develop biofilm process for the nutrient removal of piggery wastewater. The developed process is the four stage anoxic-oxic biofilm process with recirculation of the final effluent. In summery, the results are as follows: 1. Nitrification in the piggery wastewater built up nitrite because of the high strength ammonia nitrogen. The nitrification of nitrobacter by free ammonia was inhibited in the total ammonia nitrogen loading rate with more than 0.2 kgNH$_{3}$-N/m$^{3}$·d. 2. The maximal total ammonia nitrogen removal rate was obtained at 22$\circ $C and without being affected by the loading rate. But total oxidized nitrogen production rate was largely affected by loading rate. 3. Autooxidation by the organic limit was a cause of the phosphorus release in the aerobic biofilm process. But the phosphorus removal rate was 90 percent less than the influent phosphorus volumetric loading rate of above 0.1 kgP/m$^{3}$·d. Therefore, the phosphorus removal necessarily accompanied the influent loading rate. 4. On the anoxic-oxic BF process, the total average COD mass balance was approximately 67.6 percent. Under this condition, the COD mass removal showed that the cell synthesis and metabolism in aerobic reactor was 42.8 percent and that the denitrification in anoxic reactor was 10.7 percent, respectively.

• Fisheries and Aquatic Sciences
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• 제14권4호
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• pp.363-369
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• 2011

Total ammonia nitrogen (TAN) removal efficiencies of a sand filter (SF), polystyrene microbead filter (PF), and Kaldnes bead filter (KF) media were evaluated under ammonia loading rates of 5, 25, and 50 g $m^{-3}day^{-1}$. The volume of each filter media tested was 7 L, and the water flow rate for all filter media was 24 L/min. The specific surface areas of the SF, PF, and KF were 7,836, 3,287, and 500 $m^2/m^3$, respectively. Sand was fluidized and the other two media were trickle filtered. The volumetric TAN removal rate increased with increasing ammonia loading rate for all filter media. Mean volumetric TAN removal rates under the ammonia loading rates of 5, 25, and 50 g $m^{-3}day^{-1}$ in SF (39.3, 168.6, and 322.7 g $m^{-3}day^{-1}$, respectively) were higher than those in PF (35.0, 157.4, and 310.5 g $m^{-3}day^{-1}$, respectively) and KF (32.1, 142.5, and 288.1 g $m^{-3}day^{-1}$, respectively). These results were related to differences in the specific surface areas of the filter media. PF was the most economic media for efficiently removing TAN.

• 청정기술
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• 제29권4호
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• pp.297-304
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• 2023

첨단 전자 제품 산업의 비약적인 발전은 환경적 측면에서 고농도 암모니아 폐수의 증가를 초래했다. 고농도 암모니아 폐수를 안정적으로 처리하기 위해 다양한 방법의 기술이 시도되고 있으나, 지금까지 성공적인 기술이 개발되어 적용되지는 못하고 있다. 본 연구에서는 첨단 전자산업에서 발생하는 고농도 암모니아 함유 폐수에 대하여 밀폐(closed) 순환형 대향류 충전탑 형식의 실증설비를 이용하여 온도, 공기부하율 그리고 폐수부하율 변화에 따른 암모니아성 질소의 제거효율과 제거 특성을 평가하였다. 폐수량 20.8 m³ h^-1, 공기량 18,000 Nm³ h^-1의 운전 조건에서 온도를 45, 50, 55 그리고 60℃로 변경하여 운전한 결과, 암모니아성 질소(NH₃-N)의 제거율은 각각 87.5, 93.4, 96.8 및 98.7%로 온도가 제거율에 미치는 가장 큰 영향 인자임을 알 수 있었다. 공기부하율을 증가시키면 제거율도 증가하나, 흡수탑의 액적(droplet)이 탈기탑으로 유입되어 제거율 증가는 크지 않았다. 폐수 부하율이 변경되어도 제거율은 크게 변하지 않았는데, 이는 제거율에 영향이 없는 것이 아니라, 상대적으로 높은 공기부하율에 기인한 것으로 판단된다. 실증연구를 통해 암모니아 탈기법은 첨단 전자산업에서 발생하는 고농도 암모니아 폐수를 안정적으로 처리할 수 있는 적정한 공법임을 확인할 수 있었다.

• 대한환경공학회지
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• 제22권1호
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• pp.53-60
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• 2000

본 연구는 활성탄 유동상 반응조의 암모니아 부하를 $0.1{\sim}7.5kg\;NH_3-N/m^3{\cdot}day$의 범위에서 단계적으로 증가시키면서 암모니아 부하가 질산화 효율 및 아질산성 질소의 축적에 미치는 영향을 파악하기 위하여 수행되었다. 실험 결과, $1.8kg\;NH_3-N/m^3{\cdot}day$ 이상의 암모니아 부하에서는 처리수의 아질산성 질소 농도 및 질산화 효율이 변동하였지만 평균 90%의 질산화효율을 나타내었으며, 유리 암모니아성 질소의 농도가 1 mg/L 이상으로 측정되었던 $1.8kg\;NH_3-N/m^3{\cdot}day$의 암모니아 부하부터 아질산성 질소의 축적이 시작되었다. 아질산성 질소가 축적되었던 기간에는 유입수의 암모니아성 질소 농도와 반응조내의 용존산소 농도 간의 비가 100 이상이거나 처리수 $NH_3-N$ 농도와 반응조 DO 농도 간의 비가 2 이상이었다. 결론적으로, 활성탄 유동상 반응조는 고농도로 암모니아성 질소를 함유하는 폐수의 생물학적 질산화에 효과적이며, 아질산화-탈질에도 유려할 것으로 판단된다.

• 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.