• Journal of Korean Society of Water and Wastewater
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• v.28 no.3
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• pp.305-314
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• 2014

A pilot plant (Q=5 $m^3/d$) study was implemented for small and medium sized personal wastewater treatment plant effluent to evaluate MBR and A/O processes utilizing self-sufficient energy composed of wind and solar energy. The removal efficiencies of BOD, SS, turbidity and color were sufficient for legal water quality standards for gray water. However, those of nitrogen and phosphorus could not meet legal regulations which suggested that further removal of those contaminants were needed for reuse of the treated water. Self-sufficient energy rate was 100 % for the pilot plant due to excessive design capacity. In this research, wind and solar energy system was applied considering geological characteristics, which significantly improved energy self-sufficiency. Substantial improvement on energy self-sufficiency can be obtained by optimized investment and operation at a full scale wastewater treatment plant.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.4
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• pp.411-417
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• 2014

The performance of the new aerobic digestion system combined with inorganic sludge separation unit and sludge solubilization unit, CaviTec II, is evaluated. Anaerobic digester effluent sludge is used for feed sludge of CaviTec II system. By addition of CaviTec II, the amount of cake generated is reduced by 27%, and the soluble nitrogen is reduced by 92%.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.5
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• pp.131-139
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• 2004

In this study, on-site sewage treatment tests were conducted using the Absorbent Biofilter System (ABS) under different hydraulic loading rates to examine its treatment characteristics and efficiencies and to determine its feasibility as a small on-site sewage treatment system in a rural area. Results showed that the removal rates of BOD and SS were satisfactory at hydraulic loading rates of 100~150 cm/day, meeting the Korean effluent water quality standards for the riparian zone (10 mg/L). In the case of nutrients (N, P), however, the system did not perform well, necessitating further improvement for nutrient removal. A comparative analysis indicated that as a small on-site sewage treatment system, the ABS would be more suitable than other treatment systems in terms of performance stability, maintenance requirement, and cost-effectiveness and could be applied as an alternative treatment system in Korean rural areas.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.510.2-511
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• 1986

The biotechnology including genetic engineering is expected to be applied to various fields of wastewater treatments in order to promote biological reaction rate, to grade up the effluent quality and to advance the stability of microorganisms against temperature, pH and toxic substances. The current topics in Japan on application of biotechnology to wastewater treatment will be reviewed at the beginning of the presentation. Next, the research of Biochemical Engineering Laboratory is to be presented, especially focused on the following subjects ; (1) Application of genetic engineering to the investiation of heavy metal uptake by the resistant bacteria of Hg Cd or Zn. (2) Relationship between sulfate reducing bacteria and wastewater treatment, offensive odor and corrosion of sewer tranks.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.3
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• pp.250-256
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• 2017

This study investigated the removal efficiency of organic matter and nitrogen from fish farm effluent by hydraulic retention time (HRT) using an upflow biological filter (ANR system) reactor. The recycling time and influent flow in the reactor were controlled to 14.8, 7.4, 5.5 and 3.2 h to evaluate HRT. In addition, each reactor was coupled to a fixed bed upflow filter charged with media. The results showed that removal efficiency was ${\geq}95%%$ with an HRT of 5.5 h, and nitrification efficiency was reduced to 81% with an HRT of 3.2 h, although nitrification efficiency temporarily decreased due to the shock load as HRT decreased. Total nitrogen removal rate was also reduced to about 65% with an HRT of 3.2 h, which was considered a washout effect of nitrifying and denitrifying microorganisms by increasing the shearing force to the filter media, which decreased organic matter and nitrogen removal efficiency.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.202-202
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• 2006

With a modern size exclusion chromatography (SEC) column, molecular weight analysis of a polymer sample takes about 10 min. However, it is desirable to reduce the analysis time further, in particular, for high throughput measurements required in combinatorial analyses or 2D-HPLC analyses. We implemented the high temperature SEC for the purpose. By inserting a narrow bore tubing between the column and the detector, a sufficient backpressure can be maintained to prevent the mobile phase from boiling and the effluent is cooled down enough when it reaches the detector. Therefore, a normal SEC detector can be used without any modification. The SEC resolution is greatly improved at the elevated temperature at high flow rate which allows high speed operation.

• Journal of Environmental Science International
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• v.14 no.2
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• pp.251-258
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• 2005

Statistical analysis between operating parameters and effluent quality on advanced wastewater treatment plant was performed. Through factor analysis four factors derived varimax rotation were selected each plant. Four components explained $80\%,\;82\%$ of the total variance of the process, respectively. The components on MLE plant were identified in the following order: 1) HRT increase and BOD load decrease by influent decrease, 2) Biomass, 3) SVI increase by internal return increase, 4) Microbial diversity by SRT increase. On $A_2O$ plant, we defined them as follows: factor 1, high MLSS by return rate increase, HRT increase by influent decrease; factor 2, biomass; factor 3, BOD of influent; factor 4 was relate to DO.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.683-690
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• 1998

국내의 원자력 관계법령은 1965년에 발표된 ICRP-9 권고안에 기초하고 있다. 그러나, 최근 국내 규제기관에서는 ICRP-60 권고안을 수용하는 새로운 방사선량 체계 및 한도등을 포괄한 원자력관계법령 개정 최종(안)을 마련하였고 이를 곧 시행할 예정임에 따라 현행 법령이 적용된 원자력시설의 설계 및 운영에 있어서는 적지않은 변경이 불가피하다. 본 논문에서는 이로인한 영향중의 하나로 ICRP-60 권고안을 적용하여 설계중인 신규원전의 기체유출물 방사선감시기에 대한 경보설정치를 산정하였으며, 비교를 위해 현행 법령이 적용된 기존원전에 대한 경보설정치 산정방법을 소개하였다. 이와함께 기존원전에 사용된 DRL (Dose Rate Limit, 선량률한도) 방식과 이를 보다 효과적으로 개선한 ECL (Effluent Concentration Limit, 방출농도한도) 방식을 소개하였으며, 각각의 방식에 의해 산정된 경보설정치를 상호 비교하여 ECL 방식의 효율성과 정확성을 입증코자 하였다. 마지막로는 국내 원전에 설치, 가동중인 기체유출물 방사선감시기에 대해 개정될 국내 법령의 적용과 보다 정확한 경보설정치 산정을 위한 작업이 수행되어야 할 것이며. 이러한 결과가 계통에 반영되어 운전되어야할 것임을 제안하였다.

• Journal of Korean Society of Water and Wastewater
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• v.13 no.2
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• pp.34-40
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• 1999

Aerobic night-soil treatment effluent containing high concentration of ammonia nitrogen was treated to remove nitrogen using Bardenpho process with Methanol addition. The objective of this study was to investigate the feasibility of complete nitrogen removal at three different HRTs such as 6.25d, 5d, and 3.75d, respectively. At each HRT, the nitrogen removal efficiencies are 92%, 99% and 97% and the required amount of methanol are 3.05gMeOH/gN, 2.75gMeOH/gN, and 3.38gMeOH/gN, respectively. Specific nitrification rates are decreased proportional to HRT and are $0.022gNH_4^+-N/g\;MLVSS{\cdot}day$, $0.0332gNH_4^+-N/g\;MLVSS{\cdot}day$ and $0.051gNH_4^+-N/g\;MLVSS{\cdot}day$ and specific denitification rate are decreased proportional to HRT and are $0.0210g\;N/gMLVSS{\cdot}day$, $0.0330g\;N/gMLVSS{\cdot}day$ and $0.0525g\;N/gMLVSS{\cdot}day$, respectively.

• Journal of Korean Society of Water and Wastewater
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• v.7 no.1
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• pp.5-12
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• 1993

The objectives of this paper are to present data to illustrate how an advanced digestion process, two-phase digestion, can provide superior performance in terms of waste stabilization efficiency and net energy recovery. As the result, it is possible to separate enrichment cultures of acidogenic and methanogenic organisms in isolated environments by kinetic control involving manipulation of dilution rates. In single-phase digestion process, HRT and COD loading for effective operation were 14.29 days and 2.33kg $COD/m^3$ day, but two-phase digestion may be conducted efficiently at 7 days of HRT and 5.71kg $COD/m^3$ day of loading. Data from this studies showed that the two-phase process is better than single-phase digestion under all test conditions when compared on the bases of gas yield and production rate, reductions of COD and VS, buffer capacity, and unconverted volatile acids in the effluent.