• 한국환경과학회지
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• 제13권7호
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• pp.675-680
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• 2004

This study was conducted to remove organics and nutrients using 2 stage intermittent aeration reactor. First reactor, using suspended microbial growth in intermittent aeration instead of anaerobic reactor in the typical BNR process, used minimum carbon source to release P, and it was possible to reduce ammonia loading going to second reactor. In the second reactor, using moving media intermittent aeration, it was effective to reduce nitrate in non-aeration time by attached microorganisms having long retention time. In aeration time, nitrification and P uptake were taken place simultaneously. From the experiment, two major results were as follows. First, the removal of organics was more than 90%, and optimum aeration/non-aeration time ratio for organic removal was corresponded with aeration/non-aeration time ratio for nitrogen removal. Second, in the first reactor, optimum aeration/non-aeration time ratio was 15/75 (min.) because it was necessary to maintain 75 min. of non-aeration time to suppress of impediment of return nitrate and to lead release of phosphate. In the second reactor, optimum aeration/non-aeration time ratio was 45/90 (min.).

• 한국농공학회지
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• 제44권2호
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• pp.161-173
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• 2002

Recently, absorbent biofilters, which are inexpensive and easy to manacle, have been supplied to the rural areas, but have limitations in removing the nutrients effectively. Accordingly, as an alternative plan. natural zeolites were arranged in front or at the rear of the absorbent biofilters, and their removal efficiency for nitrogen and, ultimately, their applicability to the on-site wastewater treatment system were studied. Furthermore, the same experiments were carried out on artificial zeolites, made from coal ashes at National Honam Agricultural Experiment Station, to compare natural zeolites with artificial ones. Treated wastewater through the Absorbent Biofilter showed 22.6% nitrogen removal efficiency, while 64.6% was attained when natural Zeolites were placed in front of the absorbent biofilters (Zeolite-Aerobic process). As an addition, phosphorus was also efficiently removed. On the other hand, Aerobic-Zeolite process, which arranged natural zeolites at the rear of the biofilters, did not have significantly higher nitrogen removal as compared to the treatment using only the absorbent biofilters. Furthermore, upon regeneration of the natural zeolite, the ion exchange rate was fecund to increase over 10% as compared to before regeneration. Our results show that natural zeolites, applied to the on-site wastewater treatment system through the Zeolite-Aerobic process, not only increase the removal efficiency of nutrients, but, by choosing the appropriate regeneration time, can also be cast-effective. Artificial zeolites, on the other hand, though more efficient in removing nutrients, cannot be regenerated and, therefore, are not cost-effective.

• 한국물환경학회지
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• 제20권2호
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• pp.104-109
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• 2004

Removal of nutrients from domestic sewage or industrial wastewater is needed to protect surface waters from eutrophication. This research was carried out to remove the nitrogen (N) and phosphorus (P) from the wastewater using the iron oxide obtained from the steel industry and the natural zeolite, respectively. This research was conducted in both batch and continuous systems. The removal efficiency of the nutrients was evaluated in the batch system using the varying concentrations of zeolite and iron oxide added. The removal efficiency of N was 60% at the 8g of zeolite added. In the same condition, the removal efficiencies of N were 76% and 82% at 12g and 16g of zeolite added, respectively. Removal efficiency of P was 80% as 8g of iron oxide was added. The removal efficiency of P was correspondingly increased as the concentration of iron oxide was increased. Continuous column system was also used to evaluate the removal efficiency of N and P by the addition of zeolite and ferric oxide, respectively. Removal efficiencies of N were compared in the mixed packing, two stage, and four stage columns, respectively. The removal efficiencies (80%) of N in the separate packed columns (two and four stages) were higher than the mixed packing column (400%) after 90 hr. Whereas, the removal efficiencies of P were similar to each other in the three columns.

• Membrane and Water Treatment
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• 제10권3호
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• pp.191-199
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• 2019

In this study, we investigated the cultivation possibility using Hydrodictyon reticulatum in a continuous raceway pond as a tertiary sewage treatment plant. The cultivation possibility was evaluated by varying the light quantity, wavelength, and hydraulic retention time (HRT). Experimental results showed that the growth rates of algae and the removal efficiencies of nutrients increased as the light quantity increased, and the maximum photosynthetic rate was maintained at $100{\mu}mol/m^2{\cdot}s$ or higher. When wavelength was varied, nutrient removal efficiency and growth rate increased in the following order: green light, red light, white light, and blue light. The nutrient removal efficiencies and algae productivity in HRT 4 d were better than in HRT 8 d. We conclude that if Hydrodictyon reticulatum is cultivated in a raceway pond and used as a tertiary treatment facility in a sewage treatment plant, nutrients can be effectively removed, and production costs can be reduced.

• 생태와환경
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• 제50권2호
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• pp.187-194
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• 2017

본 연구는 경상북도에 위치한 하천과 호소에서 채집한 미세조류의 배양실험을 통해 영양염류 제거에 유용한 미세조류를 탐색하고, 실제 배출되는 폐수, 개인하수 및 가축분뇨 방류수에 미세조류를 접종하여 질소와 인 제거효율을 평가하고자 하였다. 조류를 채집하여 예비 배양조에서 배양한 미세조류 군집의 우점종은 Monoraphidium contortum, Scenedesmus acutus, Coelastrum microporum, Chlorella sp.로 나타났으며, 4000 Lux와 8000 Lux 조도에서 인공폐수를 배양액으로 배양한 미세조류 군집의 우점종은 Chlorella sp., Scenedesmus obliquus로 나타났다. 8000 Lux 조도에서 $NO_3-N$ 제거율은 63.0%~83.6%로 나타났고, 4000 Lux 조도에서 $NO_3-N$ 제거율은 27.2%~88.1%로 나타났다. 4000 Lux와 8000 Lux 조도에서 $PO_4-P$의 제거율은 95.3% 이상으로 $NO_3-N$의 제거율보다 높게 나타났다. $NO_3-N$와 $PO_4-P$의 제거 효율은 $1.0{\times}10^6cells\;mL^{-1}$ 농도로 접종하였을 때 $1.0{\times}10^5cells\;mL^{-1}$와 $1.0{\times}10^7cells\;mL^{-1}$ 농도로 접종하였을 때 보다 높게 나타났다. 미세조류를 이용한 인공폐수에서의 TN과 TP 제거율은 각각 94.9%과 90.0%로 나타났으며, TN과 TP 제거속도는 $1.961mg\;L^{-1}\;day^{-1}$, $0.200mg\;L^{-1}\;day^{-1}$로 나타났다. 실험에 사용된 모든 폐수에서 미세조류를 이용하여 영양염류가 제거되었고, 그중 개인하수 방류수가 영양염류 제거율이 가장 높게 나타났다.

• 한국물환경학회지
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• 제20권3호
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• pp.231-235
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• 2004

To investigate removal effects of nutrients in stormwater runoff by soil of riparian protection zone, soil column experiment was conducted for 20 months. Artificial stormwater runoff containing phosphate and nitrate was applied on the surface of soil column twice a week, and phosphate and nitrate concentrations were measured from the leached water. Soil of riparian protection zone reduced the released amount of infiltrated water to the surrounding water. After infiltration of 1m depth of soil column, average removal rates of phosphate and nitrate were 97.7 % and 74.7 %, respectively. As main mechanisms of phosphate are adsorption to soil particle and utilization by plants, periodical replacement of soil and harvesting of plant at the end of growing season are required. For the removal of nutrients in stormwater runoff by the soil layer, soil of riparian protection zone has higher hydraulic conductivity to infiltrate stormwater. Sandy soil having hydraulic conductivity of about $1{\times}10^{-2}cm/s$ range might be appropriate for this purpose.

• 한국환경과학회지
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• 제6권6호
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• pp.697-709
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• 1997

Sequencing Batch Reactor(SBR) experiments for organics and nutrients removal have been conducted to find an optimum anaerobic/anoxic/aerobic cycling time and evaluate the applicability of oxidation-reduction potential(ORP) as a process control parameter. In this study, a 61 bench-scale plant was used and fed with night-soil wastewater in K city which contained TCODcr : 10, 680 mg/l, TBm : 6, 893 mg/l, $NH_4^+-N$ : 1, 609 mg/l, $PO_4^{3-}-P$ : 602 mg/l on average. The cycling time In SBRs was adjusted at 12 hours and 24 hours, and then certainly included anaerobic, aerobic and inoxic conditions. Also, for each cycling time, we performed 3 series of experiment simultaneously which was set up 10 days, 20 days and 30 days as SRT From the experimental results, the optimum cycling time for biological nutrient removal with nlght-soil wastewater was respctively 3hrs, 5hrs, 3hrs(anaerobic-aerobic-anoxic), Nitrogen removal efficiency was 77.9%, 77.9%, 81.7% for each SRT, respectively. When external carbon source was fed in the anoxic phase, ORP-bending point indicating nitrate break point appeared clearly and nitrogen removal efficiency increased as 96.5%, 97.1%, 98.9%. Phosphate removal efficiency was 59.8%, 64.571, 68.6% for each SRT. Also, we finded the applicability of ORP as a process control parameter in SBRs.

• 환경위생공학
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• 제11권1호
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• pp.83-91
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• 1996

It is not too much to say that the territorial inhabitants' concerns are wholly c concentrated on the environmental preservation-problem and development-problem in Korea given effect to the local self-government system. At a time like this I was studied the effect on nutrients removal through lighting period in aerobic high rate pond and we know that waste stabilization pond method is the most economical and energy saving wastewater treatment technology than others. At the results which was studied through operating the reactor-l artifically main-tained at a temperature, $25^{\circ}C$, a light intensity, 3000lux, and a lighting period, 24hrs and the reactor-2 artifically maintained at a tern야rature, $25^{\circ}C$ and a light intensity 3000lux, and a lighting period period, 12hrs, It has appeared for 24hrs.-lighting period -reactor-1 to be prior to the reactor-2. The attained results are that 1. reactor-1 is prior to reactor-2 on oxygen-generation 2. reactor-1 is prior to reactor-2 on algal production 3. COD removal efficiency, 90.76%, T-N removal efficiency, 80%, T-P removal e efficiency, 74.47 % in reactor-2, in reactor-1 COD removal efficiency, 94.85 %, T-N removal efficiency, 98.07%, T-P removal efficiency, 72.13% are, so the treatment efficiency of reactor-1 is more excellent than things of reactor-2 4. it appeared that the detention time is 8, 9days.

• 공업화학
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• 제33권6호
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• pp.666-674
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• 2022

The removal efficiencies of nutrients (N and P) and heavy metals (Cu and Ni) by Rhodobacter blasticus and R. blasticus attached to polysulfone carriers, alginate carriers, PVA carriers, and PVA + zeolite carriers in synthetic wastewater were compared. In the comparison of the nutrient removal efficiency based on varying concentrations (100, 200, 500, and 1000 mg/L), R. blasticus + polysulfone carrier treatment showed removal efficiencies of 98.9~99.84% for N and 96.92~99.21% for P. The R. blasticus + alginate carrier treatment showed removal efficiencies of 88.04~97.1% for N and 90.33~97.13% for P. The R. blasticus + PVA carrier treatment showed removal efficiencies of 18.53~44.25% for N and 14.93~43.63% for P. The R. blasticus + PVA + zeolite carrier treatment showed removal efficiencies of 26.65~64.33% for N and 23.44~64.05% for P. In addition, at the minimum inhibitory concentration of heavy metals, R. blasticus (dead cells) + polysulfone carrier treatment showed removal efficiencies of 7.77% for Cu and 12.19% for Ni. Rhodobacter blasticus (dead cells) + alginate carrier treatment showed removal efficiencies of 25.83% for Cu and 31.12% for Ni.

• 상하수도학회지
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• 제23권6호
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• pp.727-733
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• 2009

This study was performed to investigate the physical characteristics like compressive strength, permeability, porosity and the water quality removal characteristics of permeable concrete pavement filled with microbial-soil sheet to remove SS, organic matter and nutrients in artificial rainfall. As a result, it can show the removal efficiency is SS 90~95%, COD 85~93%, BOD 80~83%, T-N 61~75%, T-P 71~78% on WAPS I(W1) and WAPS II(W2). Therefore, permeable concrete pavement filled with microbial-soil sheet shows higher removal efficiency(SS 10%, organic matter and nutrients 30%) than a conventional porous concrete(W3). By filling microbial-soil sheet to permeable concrete pavement, we confirm that the function and efficiency are improved significantly and that a naturally-friendly facility can be developed and applied to treat non-point sources.