• 상하수도학회지
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• 제24권1호
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• pp.5-14
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• 2010

A pilot-scale biological aerated filter (BAF) was operated with an anaerobic, anoxic and oxic zone at $23{\pm}1^{\circ}C$. The influent sCOD and total nitrogen concentrations in the feedwater were approximately 250 mg/L and 35 mg N/L, respectively. sCOD removal at optimum hydraulic retention time (HRT) of 3 hours with recirculation rates of 100, 200 and 300% in the column was more than 96%. Total nitrogen removal was consistently above 80% for 4 and 6 hours HRT at 300% recirculation. For 3 hours HRT and 300% recirculation, total nitrogen removal was approximately 79%. Based on fitting results, the kinetic parameter values on nitrification and denitrification show that as recirculation rates increased, the rate of ammonia and nitrate transformation increased. The ammonium loading rates for maximum ammonium removed were 0.15 and 0.19 kg $NH_3$-N/$m^3$-day for 100% and 200% recirculation, respectively. The experimental results demonstrated that the BAF can be operated at an HRT of 3 hours with 200 - 300% recirculation rates with more than 96 % removal of sCOD and ammonium, and at least 75% removal of total nitrogen.

• 한국산업융합학회 논문집
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• 제5권3호
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• pp.213-218
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• 2002

Total nitrogen is a major pollutant which mostly causes eutrophication and red tide. Wastewater effluent from printing of cotton-viscose rayon containing high concentrations of total nitrogen can not be effectively treated with a typical biological treatment process. This paper provides a new treatment process and experimental results for the removal of high strength nitrogen from dyeing wastewater. The optimum conditions of air stripping for the removal of total nitrogen include around pH 12, temperature $60^{\circ}C$ with 60 minutes of stripping time. In case of a filtration-air stripping process, an initial level ($500mg/{\ell}$) of total nitrogen was significantly reduced to below $60mg/{\ell}$. Deconite was synthesised for further decomposition of organic nitrogen. Thus, a filtration-decomposition-air stripping process was possibly achieved, by which a high level ($900mg/{\ell}$) of total nitrogen was effectively removed to below $60mg/{\ell}$ P. Finally, a continuous new process for the removal of total nitrogen is proposed and confirmed, based on batch experimental results, and its process validity is further discussed throughout.

• 한국환경보건학회지
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• 제27권3호
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• pp.99-106
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• 2001

A laboratory experiment was performed to investigate phosphorus and nitrogen removal from synthetic wastewater by intermittently activated sludge process packed with aluminium plate. Three continuous experimental systems, I. e. an intermittently activated sludge process(Run A), an intermittently activated sludge process with an aluminium plate packed into the reactor(Run B), and a reactor post stage(Run C) were compared. In the batch experiments, the phosphorus removal time in the reactor packed with copper and aluminium plate simultaneously was faster than that of the reactor packed with only an aluminium plates. However, the reactor packed with only an aluminium plate could be used for phosphorus removal. Move phosphorus was removed with an increase of surface area of aluminium plate and electrolysis(NaCl) concentration. The efficiency of COD and nitrogen removal was not affected in Run B. However, the phosphrus removal efficiency decreased because of reaction products and activated sludge which gradually covered gradually the surface of the aluminium plate. The efficiency of phosphorus removal in Run C was 86.3% at the HRT of 3.2 hours. Especially, the efficiency of phosphorus removal in Run C was higher than that in Run B.

• 한국환경과학회지
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• 제6권4호
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• pp.409-415
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• 1997

In order to Investigate the possibility as a simple technique of wastewater treatment for recirculating aquaculture system, the experiment by a biofilter unfit was carried out. The high and stable removal efficiency of nitrogen could be obtained by selecting the optimum recycle ratio and DO concentration. It was found that the proper combination of nitrifacation and denitrfication step in the reactor would be required for increasing the removal efficiency. The extent of nitrogen removal gradually decreased UO the rise of re- cycle ratio since the depression of denitrificatlon by the lack of hydrogen donor. The depression of nitrogen removal was overcome by increasing the CIN ratio In the wastewater. The extent of phosphorus removal was increased slightly with the increase of DO concentration and recycle ratio, but high removal efficiency was not observed. However, the extent of COD removal was not affected by recycle ratio and DO concentration and showed the stable removal of above 90%.

• 상하수도학회지
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• 제18권6호
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• pp.807-813
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• 2004

Wastewater was treated by two different treatment processes; activated sludge process and advanced wastewater treatment process (KNR process) using lab-scale experiment. Two treated wastewater showed good treatment efficiency of organic matter removal, up to 90% removal. Nitrogen and phosphorus were not effectively removed though activated sludge process, while KNR process showed good removal efficiency of nitrogen and phosphorus; 56% nitrogen removal and 95% phosphorus removal. KNR process showed better removal efficiency of organic matter, nitrogen, and phosphorus compared to activated sludge process. Organic matter characterization was tracked though measurement of UV scan, SUVA, and XAD fractionation. Treated wastewater showed higher SUVA value than wastewater influent, indicting less aromatic characteristic of organic matter. XAD fractionation showed hydrophilic fraction decreased though wastewater treatment, suggesting microbes preferentially digest hydrophilic and aliphatic molecules rather than hydrophobic and aromatic molecules of organic matter.

• 한국환경보건학회지
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• 제30권2호
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• pp.84-91
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• 2004

Biological nutrient removal(BNR) from wastewater was performed by adopting various process configurations. The simultaneous biological organics, phosphorus and nitrogen removal of synthetic wastewater was investigated in a sequencing batch biofilm reactor (SBBR). The other reactor was operating as a reference, without biofilm being added. The cycling time in SBR and SBBR was adjusted at 12 hours and then certainly included anaerobic and aerobic conditions. Both systems has been operated with a stable total organic carbon(TOC), nitrogen and phosphorus removal performance for over 90 days. Average removal efficiencies of TOC and total nitrogen were 83% and 95%, respectively. The nitrification rate in SBR was higher than that in SBBR. On the contrary, the denitrification rate in SBBR was higher than that in SBR. The phosphorus release was occurred in SBBR, however, not in SBR because of the inhibition effect of NO$_3$$^{[-10]}$ .

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.175.1-175.1
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• 2011

A rotating activated bacillus contactor (RABC) process with a series of aerobic reactors was tested in pilot scale to treat digested liquid from an anaerobic digester treating swine wastewater and sewage sludge. The influent (digested liquid) for the RABC process showed C/N ratios less than 2 as a typical feature of effluent from anaerobic digesters. The pilot process, which consists of three 3 RABC reactors, four aerobic tanks and a sedimentation tank, was operated for 210 days with a hydraulic retention time of 20 days without pH and temperature control. Since the Bacillus-enriched aerobic reactors shows high efficiencies of nitrogen removal at low DO levels less than 1.0 mg/L, they were operated at reduced aeration intensities. With relatively low concentrations of organics in comparison with nitrogen concentrations, the RABC process tested in this study showed stable and high nitrogen and organics removal efficiencies over 80%. The nitrogen removal process tested in this study was proven to be an effective and operation-cost saving (lower aeration) method to remove nitrogen without adding external carbon sources to meet the optimum C/N ratio.

• 상하수도학회지
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• 제26권6호
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• pp.833-840
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• 2012

This study aimed to investigate growth rate and nutrient removal efficiency of Chlorella vulgaris according to nitrogen sources and frequency of pH adjustment. Nitrogen and phosphorus removal efficiencies were evaluated in the three different conditions using $NO_3{^-}$, $NH_4{^+}$ as a sole nitrogen source and mixed condition. Initial nutrient concentrations in artificial wastewater were 30 mg-N/L and 3 mg-P/L similar to secondary wastewater effluent. When nitrogen source was $NO_3{^-}$, there was no inhibition on the growth of C. vulgaris with adjusting pH every 24 hr while growth inhibition occurred with $NH_4{^+}$ caused by pH drop. N, P removal efficiencies were no significant depending on the nitrogen sources. As pH was adjusted to 7 by pH-stat, growth rate and nutrient removal efficiencies were increased compared to adjusting pH every 24 hr, however, growth rate and nutrient removal efficiencies were no significant depending on the nitrogen sources.

• 청정기술
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• 제17권4호
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• pp.363-369
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• 2011

고농도의 암모니아성질소를 함유하는 폐수의 처리에 전기투석공정의 적용성이 실험적으로 평가되었다. 처리 성능은 전기투석공정의 운전인자 중 유입농도, 운전전압, 그리고 유속이 암모니아성질소의 제거효율에 미치는 영향으로 측정되었다. 한계전류밀도는 유입농도와 유입유속이 증가함에 따라 선형적으로 증가하였고, 유입농도에 따라 목표농도에 도달하는 시간은 직선적인 비례관계를 보였다. 상대적으로 큰 암모니아성질소의 이온당량전도도와 이온이동도로 인하여 유입유속의 증가는 제거속도를 지속적으로 증가시켰다. 또한 운전전압의 증가에 따라 제거속도는 증가하였다. 본 연구에 사용된 전기투석모듈에서 고농도의 암모니아성질소를 제거하는 운전조건으로 유입유속은 3.2 L/min, 운전전압은 한계전류밀도에 해당하는 전압의 80~90%가 추천된다.

• Journal of Microbiology and Biotechnology
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• 제3권3호
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• pp.214-216
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• 1993

Cow's liquid manure (CLM), an animal waste, was treated by a batch algal culture to remove inorganic nutrients. CLM used in this study was especially high in concentrations of inorganic nitrogen and phosphorus. The optimum dilution ratio of the CLM for maximum algal growth was 1:25. Ninety five percent of inorganic nitrogen and 100％ of inorganic phosphorus were removed from the CLM with a dilution ratio of 1:25.