• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.2
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• pp.125-131
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• 2003

This study was carried out to develop INSUB(Indirected Aerated Submerged Biofilter) which can remove organics, nitrogen and phosphorus with an advanced treatment system. The results were as followed in laboratory model experiment. As for treatment of sewage, when economical efficiency was considered in practice, the highest removal efficiency was at 18hr of HRT, 1.017m/hr of superficial velocity and 40% of media packing ratio. Each removal efficiency for $COD_{cr}$, $COD_{Mn}$, $BOD_5$, T-N, and T-P was 90.6, 85.3, 95.0, 52.3 and 56.8%. To remove the nitrogen and phosphorus With high efficiency, first of all, denitrification have to be completed, then uptake of phosphorus have to completed. Therefor, mixture of anoxic and aerobic reactor was necessary for the high removal efficiency of nitrogen and phosphorus in INSUB.

• Journal of Korean Society of Water and Wastewater
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• v.16 no.6
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• pp.670-678
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• 2002

Since Korean government imposed a stricter regulation on effluent T-N and T-P concentrations from wastewater treatment plant, a new process has to be developed to meet these rules and this process should remove T-N and T-P, economically, from weak wastewater that is typical for Korea's combined sewer system sewage. In this study, a computer simulator, BioWin from EnviroSim, Inc. was used. Three processes - A2/O, Modified Johannesburg, UCT- had been simulated under same operational conditions and a new process - Parallel BNR Process - had been developed based on these simulation results. The Parallel BNR process consists of two rows of reactors: One row has anaerobic and aerobic reactors in series, and the other row has RAS anoxic1 and RAS anoxic2 reactors in series. In order to ensure anaerobic state in anaerobic tank, a part of influent is fed to RAS anoxic1 tank in second row. This process had been simulated under same conditions of other three processes and the simulation results were compared. The results showed that three existing processes could not perform biological phosphorus removal when the average influent was fed at any operation temperatures. However, the Parallel BNR process was found that biological phosphorus removal could be performed when both design and average influent were fed at any operation temperatures. This process showed the T-N concentration in effluent had a maximum value of 15mg/L when design influent was fed at $13^{\circ}C$ and a minimum value of 14mg/L when average influent was fed at $20^{\circ}C$. Also, T-P concentrations had a maximum value of 1.3mg/L when average influent was fed at $20^{\circ}C$ and a minimum value of 1.1mg/L when design influent was fed at $13^{\circ}C$. Based on these results, we found that this process can remove nitrogen and phosphorus biologically under any operational conditions.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.3
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• pp.33-41
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• 2015

An alternative was investigated to maximize the treatment efficiency of wastewater treatment plant without large scale expansion. 79% of detention time was required for enough nitrogen control. As aeration time was extended, nitrification was processed, but opposite trend was seen in phosphorus. High concentration of $NO_3-N$ interrupted PAOs activity not to absorb phosphorus. An alternative was devised for selective use of anaerobic or anoxic zone. Trisection was suggested for alternative use of center room. The result was relatively successful. The concentration of phosphorus was reduced with reduction of nitrogen. Extended anaerobic condition seemed to stimulate denitrification. Valve connection of internal return from aeration tank will make it possible to use middle room alternatively. This method will be a good alternative for seasonal variation of water temperature.

• Journal of Animal Environmental Science
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• v.11 no.2
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• pp.135-146
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• 2005

This study was carried out to investigate the effect of Synechocystis sp. KACC 91007 when added to a pig slurry or pig liquid fertilizer (PLF) on germination index (GI) of Chinese cabbage. The preliminary experiment involved the screening of inoculant levels which were; 0.05, 0.1, 0.2, and $0.3\%$, respectively. The $0.05\%$ level of inoculant was selected based on low phytotoxicity and high GI.. The PLF underwent a 107 day aerobic and anoxic processing conditions. The T-N, T-P, $NH_4$, and $NO_3-N$ concentrations of the untreated pig slurry were; 2,873, 753, 1,441.6, and 16.48 ppm, respectively. Using aerobic processing treatment, the fertilizer value of the PLF was 3,672, 164, 183.87, and 21.97 ppm, respectively. In contrast, the fertilizer value of the PLF processed under anoxic condition was reduced to 1,261, 68, 161, and 16.87 ppm. The GI value of the untreated PLF under aerobic and anoxic processing condition was 83 and $40.4^{*}\%$, respectively. With the addition of the $0.05\%$ microbial inoculant, the GI improved by more than 40 and $50\%$ respectively, when the PLF was processed under anoxic and aerobic conditions. The above findings proved that the aerobic processing of PLF for 107 days was better than anoxic and yielded higher T-N which is a macro-nutrient fertilizer material. Consequently, the addition of $0.05\%$ microbial inoculant resulted to a higher GI of the Chinese cabbage specifically under aerobic processing condition.

• Journal of Environmental Impact Assessment
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• v.24 no.4
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• pp.386-395
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• 2015

In order to assess sewage treatment technology necessary to achieve water quality criteria in the watershed and to ensure best treatment technology is applied in building and expanding PSTWs when establishing the Watershed Sewer System Maintenance Plan, it is necessary to develop assessment guidelines to determinate the best treatment technologies applicable to the public sewage treatment works(PSTWs). Sewage treatment technologies such as anaerobic-anoxic-aerobic treatment process are employed at PSTWs, and treatment efficiency varies due to many factors such as how the PSTWs are operated. Therefore, analyzing assessment guideline of best available technology(BAT) using currently in USA and EU, this study presents assessment parameters for the assessment guidelines to be used in determining the best treatment technologies applicable to PSTWs. We have a plan to implement pilot assessment in preparation for the final assessment guidelines based on the results of professionals survey and to determine weighted factors and assessment parameters using analytic hierarchy process (AHP).

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.147-152
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• 2004

In Sequence Batch Reactor (SBR), the removal efficiencies if nutrient materials such as nitrogen and phosphate depend highly on quantity and quality of organic carbon source. Food waste thai contains abundant organic materials has been produced in ship. The applicability if anaerobically fermented if food waste (AFFW) as an external carbon source was examined in the lab-scale SBR process operated at $25^{\circ}C$. With the addition if AFFW increased, average removal efficiencies if $COD_cr$, T-N, T-P changed to $98.5\%,\;95\%,\;93\%$, respectively. Denitrification rate is 0.30g $NO_3-N/g\;VSS{\cdot}day$. In summary, it was suggested tint AFFW sould be used as an economical and effective carbon source for the biological nitrogen and phosphate removal.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.05a
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• pp.275-278
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• 2003

본 연구에서는 축산폐수공공처리장내에 설치된 Pilot-scale SBR(유효부피,20㎥)를 이용하여 sub-cycle의 폭기/무산소구간을 최적화하기 위하여 DO를 입력으로 하여 넓은 운전조건에서 적용될 수 있는 퍼지제어기를 개발하고, 또한 부하이상을 신속히 진단하여 유입부하량을 제어할 수 있는 퍼지 시스템 제어기를 개발하였다. DO값을 입력으로 한 퍼지제어기로서 안정성과 연속성에서 우수하였으나 시스템에 따라서 소속함수의 범위를 재조정해야 할 필요가 있다. DO미분값은 변화폭이 큰 지점을 검출함으로써 지연시간(lag time)의 DO값에 관계없이 적용할 수 있는 장점이 있다. 제어기의 적용성과 안정성을 높이기 위해서는 두 가지 제어인자를 동시에 고려할 필요가 있으며 퍼지 소속함수에 대한 입력으로서 DO값과 DO미분값을 적용하였다. 그 결과 폭기구간에서 매우 안정적이고 신속하게 폭기제어지점의 검출을 보여주고 있어 최적화된 제어가 가능함을 보여준다. 현장실험결과 지연시간에서의 DO가 높고 외란이 심한 경우에도 적용될 수 있음을 보여주었다.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.2
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• pp.231-239
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• 2000

This study was investigated to estimate optimal conditions and biological oxic denitrification to treat wastewater with low C/N ratio and high strength total inorganic nitrogen (TIN) concentration by using $A_2O$ fixed biofilm system. The lab-scale experimental system packed with media, which were composed of polyvinylidene chloride fiber (oxic basin) and ceramic ball (anaerobic and anoxic basin), was used. This system was operated with various influent alkalinities at the C/N(TOC/TIN) ratio of 0.5. The study results showed that TOC were removed over 96.0% at all operation conditions. The removal efficiencies over 93.5% for $NH_4{^+}-N$ and 81.8% for TIN were obtained at the alkalinity of about 1210mg/L(Run 5). Among the removal of TIN, 64.9% was occurred by biological denitrification at an oxic basin. It was confirmed through mass balance of alkalinity and nitrogen that the amount of alkalinity produced during biological denitrification at oxic basin was 2.49~3.46 mg Alkalinity/mg $NO_2{^-}-N$, ${\Delta}TOC/{\Delta}DEN$ of 0.34 (Run 5) was obtained at an oxic basin, which was less than the theoretical value of 1.22.

• Korean Chemical Engineering Research
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• v.46 no.3
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• pp.610-618
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• 2008

It is not easy to compare the treatment processes and find an optimum operating condition by the experiments due to influent conditions, treatment processes, various operational conditions and complex factors in real wastewater treatment system and also need a lot of time and costs. In this paper, the activated sludge models are applied to four principal biological wastewater treatment processes, $A_2O$(anaerobic/anoxic/oxic process), Bardenpho(4 steps), VIP(Virginia Initiative Plant) and UCT(University of Cape Town), and are used to compare their environmental and economic assessment for four key processes. In order to evaluate each processes, a new assessment index which can compare the efficiency of treatment performances in various processes is proposed, which considers both environmental and economic cost. It shows that the proposed index can be used to select the optimum processes among the candidate treatment processes as well as to find the optimum condition in each process. And it can find the change of economic and environmental index under the changes of influent flowrate and aerobic reaction size and predict the optimum index under various operation conditions.

• Journal of Wetlands Research
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• v.23 no.2
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• pp.183-188
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• 2021

In the case of small-scale sewage treatment plants, it is reported that the amount of inflow fluctuates and it is difficult to operate the sewage treatment due to the inflow of unknown water due to the aging of sewage pipes. In particular, there are many overall operational problems due to the decrease in water temperature in winter. In this study, the operation status of small-scale sewage treatment facilities located in mountainous areas and water quality changes according to temperature were analyzed. It was found that the concentration of BOD, COD, and SS in effluent water was greatly changed depending on the temperature, and it was found that COD was particularly affected. Accordingly, the water level of the bioreactor was raised by 0.4m in order to temporarily apply measures to lower the water temperature in winter. As a result of comparing and analyzing the results when the bioreactor was covered and operated, a significant improvement effect occurred. In addition, a plan to improve the treatment efficiency of the bioreactor in winter is to extend the residence time of the bioreactor, a plan to expand the bioreactor specification, a new flow control tank and transport it to the outside, and an oxygen-free air diffuser to be used as an aerobic tank in case of an emergency in winter. The improvement plan was suggested. The results of this study are expected to be used as basic data for the operation plan of small-scale sewage treatment facilities in winter.