• Journal of Environmental Science International
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• v.11 no.1
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• pp.69-74
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• 2002

This study was performed to evaluate an applicability of the SMMCMAS system for reuse of the sewage from spa area and was operated to HLR(Hydraulic loading rate) of 211.3 to 126.8 $\ell$/㎥/d. The operating HRT(Hydraulic retention time) ranges were 2.5 to 1.5 hours. Conclusions are as follows; At the optimum HLR of 158.5 $\ell/\m^2$/d (HRT of 2.0 hours), the maximum BOD removal efficiency was 94% and the effluent BOD concentration was 1.1mg/$\ell$ in result. As the HLR was increased to 211.3 $\ell/\m^2$/d, BOD removal efficiency was decreased to 75% and BOD removal efficiency was also reduced to 74% at lower HLR of 126.8 $\ell/\m^2$/d. It shows that the maximum BOD removal efficiency occurs at an optimum HLR value and that the removal efficiency decreases when the HLR is either higher or lower than the optimum value. Sludge production rates were ranged 0.01 to 0.24gVSS/gBODrem/d and accomplished to 0.01gVSS/gBODrem/d at the optimum HLR of 158.5 $\ell/\m^2$/d.

• Resources Recycling
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• v.8 no.3
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• pp.26-30
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• 1999

The removal of phosphorus was investigated from sewage waste water (SWW) using the used foundry sand (UFS). The optimal pH occurred at pH 2 for adsorption of phosphorus species in batch test. Phosphorus could be recovered with 99.9% from SWW in two hours at pH 2 using 100 g of UFS per liler of SWW. The adsorption of phosphorus species on UFS obeyed Langmuir isotherm, whose equation could be expressed by 1= 0.00059/(1+2.49878). Continuous column test for adsorption showed that breakthrough point appeared In 25 hours on the condition of breakthrough concentration of 8 mg/l

• Journal of Korean Society on Water Environment
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• v.21 no.2
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• pp.190-195
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• 2005

The laboratory and pilot scale BAFs (biological aerated filters) were operated with 0.3 hr to 1.1 hr EBCT(empty bed contact time) at a maximum filtration rate of $472m^3/m^2/day$ as a treatment method for reuse of secondary effluent and by-pass flow in this study. The effluent BOD and SS were generally 3.5 to 5 mg/L and 2 to 3 mg/L, respectively with 2ndary effluent, but the SS concentrations increased to 4 to 8 mg/L with the increased flow rates of by-pass flow. Potential nitrification rates were very high, but the nitrogen removal efficiencies were low due to the limited carbon sources. Bypass of a part of primary effluent seemed to be desirable to increase the nitrogen removal. Disinfection must be furnished for the reuse of BAF effluent.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.501-501
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• 2022

2014년 개정된 물의 재이용 촉진 및 지원에 관한법률(이하, 물재이용법)에 따라서 빗물이용시설의 수는 꾸준히 증가하고 있는 추세이나 실제 연간사용량의 경우 연별 증가량은 미미하다. 또한 2016년도 환경부 하수도 통계에 따른 2,043개의 빗물이용시설 중 집수면적 미파악시설의 749개, 여과시설 유무 미파악시설 564개, 연간 운영비 산출 불가능 시설 1,843개, 연강 사용량 미집계 시설 905개로 관리실태가 부실함을 확인할 수 있다. 이에 빗물이용시설의 설치·운영 실태조사 및 문제점을 분석하고 빗물이용이 비교적 활성화 된 시설을 대상은 현장조사를 수행을 통해 빗물이용시설의 현황을 분석하고 현실적인 여건을 반영하여 빗물이용을 활성화할 수 있는 방안을 마련하고자 하였다. 물재이용법에 따른 빗물이용시설 법정의무대상시설의 빗물활용처는 전체의 약 92%가 조경요수로 활용하고 있으며, 다음으로 청소화장실용수(약 3%)로 활용하고 있다. 건축물 용도에 따라서 골프장, 공공기관청사/공공업무시설, 대규모점포, 실내체육관/종합운동장, 학교의 경우 건축물 용도별로 각 30% 정도가, 공동주택의 경우 약 60%가 빗물이용시설을 활용하고 있음에도 빗물을 사용하지 았는 것으로 파악되었다. 이는 빗물을 사용해야하는 시기에 저류조에 저류된 빗물의 양이 부족한 것과 운영비 부담 순으로 조사되었다. 따라서 빗물이용시설의 빗물이용활성화를 위해서는 물수요-공급에 대한 개념을 도입한 물수지 분석이 필요하며, 운영비 부담을 줄일 수 있는 다양한 방안을 탐색하는 것이 적절할 것이다. 현장조사 결과에서도 기술 등의 발달로 빗물이용시설은 잘 구축되고 있으나 활용처에서 필요한 필요수량에 따라 활용률이 상이한 것으로 조사되었다. 이러한 실태조사 및 현장조사를 바탕으로 빗물이용시설의 빗물이용 활성화를 위한 방안에 대하여 기술적 및 제도적 방안에 대해서 제안하였다.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2005.11a
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• pp.335-338
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• 2005

본 논문에서는 기존의 수질측정 방법인 검사자가 수질 오염 측정기를 가지고 오염된 곳이나 오염이 예상되는 곳의 수질을 현장에서 측정 및 조사하거나, 오염된 물을 채취하여 수질 검사소에서 검사를 하여 측정하였다. 즉 이러한 수질 측정 방법은 실시간 측정이 어려우며, 수질의 상태를 정확히 측정하는데 한계가 있다. 이러한 한계점을 해결하기 위해 본 논문에서는 수질오염 측정 장치와 RFID(Radio Frequency Identification)기술을 이용하여 기존의 수질 오염 측정 방법을 제안하였다. 즉 전체 시스템이 자동적으로 처리되고, 수질 측정이나 실시간 모니터링을 통해서 관리가 되므로, 관리자는 수집 데이터의 분석이나 관리, 감시를 효율적으로 처리할 수 있도록 하였다.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.4
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• pp.276-282
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• 2013

The reclaimed water has been highlighted as a representative alternative to solve the lacking water resources. This study examined the reduction of residual free chlorine by temperature (5, 15, $25^{\circ}C$) and initial injection concentration (1, 2, 4, 6 mg/L) in the reclaimed water and carried out propose on the calculating method of the optimal chlorine dosage. As the reclaimed water showed a very fast reaction with chlorine at the intial time comparing to that of drinking water, the existing general first-order decay model ($C_t=C_o(e^{-k_bt})$) was not suitable for use. Accordingly, the reduction of residual free chlorine could be estimated in a more accurate way as a result of applying the exponential first-order decay model ($C_t=a+b(e^{-k_bt})$). ($r^2$=0.872~0.988). As a result of calculating the bulk decay constant, it showed the highest result at 653 $day^{-1}$ under the condition of 1 mg/L, $25^{\circ}C$ for the initial injection whereas it showed the lowest result at 3.42 $day^{-1}$ under the condition of 6 mg/L, $5^{\circ}C$ for the initial injection. The bulk decay constant tends to increase as temperature increases, whereas the bulk decay constant tends to decrease as the initial injection concentration increases. More accurate calculation for optimal chlorine dosage could be done by using the experimental results for 30~5,040 min, after the entire response time is classified into 0~30 min and 30~5,040 min to calculate the optimal chlorine dosage. In addition, as a result of calculating the optimal chlorine dosage by temperature, the relationships of initial chlorine demand (y) by temperature (x) could be obtained such as y=1.409+0.450x to maintain 0.2 mg/L of residual free chlorine at the time after 4 hours from the chlorine injection.

• Journal of the Korean Geosynthetics Society
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• v.7 no.2
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• pp.49-52
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• 2008

Most of waste sludge has generally been disposed in landfill site or dumped in the ocean, which will be banned by the content of its heavy metals according to London Dumping Convention in Korea. Therefore, environmentally friend methods are urgently required for the treatment and disposal of the sewage sludge. Thermal hydrolysis is one of the good treatment methods to solve the sludge problems. In this study, the physical and environmental testing was conducted to evaluate the feasibility of by-product cake from the thermal hydrolysis as liner or cover materials in landfill.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.385-385
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• 2015

정부는 1998년부터 4대강 물관리종합대책을 세워 하천의 수질보전을 위한 대책을 시행하고 있다. 그 중 대유역 중심의 수질개선대책은 전체적인 큰 목표를 제시하는 것이며, 이러한 대유역의 목표수질을 달성하기 위해서는 먼저 소유역의 수질개선이 이루어져야 한다. 현재 영산강유역에서는 도시하수종말처리장, 산업폐수처리장과 같은 점오염원 관리시설은 대폭 확충되었으나 하천과 호소의 수질은 크게 향상되지 못하고 있다. 이는 중 소유역에 대한 효율적인 수질개선대책이 없기 때문이며, 특히 중 소유역 내 비점오염원 물질이 대량으로 하천 및 호소에 유입되기 때문이다 따라서 효율적인 유역관리를 위해서는 소유역중심의 관리가 필요하며, 소유역 중심의 수질보전 대책을 수립하기 위해서는 대상 소유역에 대한 조사분석이 선행되어야 하는데, 여기에는 관거(우수관, 오수관) 시스템 조사와 하수의 차집조사가 관계되며, 또한 소유역내의 오염원(점오염원과 비점오염원) 및 잠재적인 오염원조사 등과 같은 광범위한 조사 작업이 필요하다. 한편 유역모형 중 HSPF모형은 모형의 적용에 필요한 방대한 자료와 노력을 최소화 되도록 개발되어 왔으며, HSPF는 광범위한 수문 수질과정을 장기 모의가 가능하도록 일련의 구조화된 모듈로 구성되어 있다. 복잡한 모형일수록 자료관리에 많은 노력이 요구되나 HSPF는 자료를 직접적으로 접근할 수 있는 Time Series Management System에 가깝도록 개발되었다. 또한, HSPF 모델은 유역내의 토지이용에 따른 특정 오염물질의 비점오염 부하를 계산하며, 강우에 따른 물의 흐름을 하천의 수질오염모의와 연결시키는데, 광범위한 유역조건에 적용이 가능하고, 각 소유역을 구분하여 비교가 가능하므로 소유역별 관리방안을 비교하는데 가장 적합한 모델이다. 따라서 본 연구는 유역모형(HSPF)을 이용하여 영산강 유역을 대표할 수 있는 중 소유역을 선정하고, 선정된 중 소유역에 대한 기초적인 자료를 조사 분석하여 종합적이고 구체적인 유역 관리계획을 수립해 봄으로써 중 소유역 수질관리에 지침서로서 역할을 하는데 목적이 있다.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.3
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• pp.285-291
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• 2016

There has been an accelerating increase in water reuse due to growing world population, rapid urbanization, and increasing scarcity of water resources. However, it is well recognized that water reuse practice is associated with many human health and ecological risks due to numerous chemicals and pathogenic microorganisms. Especially, the potential transmission of infectious disease by hundreds of pathogenic viruses in wastewater is one of the most serious human health risks associated with water reuse. In this study, we determined the response of different bacteriophages representing various bacteriophage groups to chlorination in real wastewater in order to identify a more reliable bacteriophage indicator system for chlorination in wastewater. Different bacteriophages were spiked into secondary effluents from wastewater plants from three different geographic areas, and then subjected to various doses of free chlorine and contact time at $5^{\circ}C$ in a bench-scale batch disinfection system. The inactivation of ${\phi}X174$ was relatively rapid and reached ~4 log10 with a CT value of 5 mg/L*min. On the other hand, the inactivation of bacteriophage PRD1 and MS2 were much slower than the one for ${\phi}X174$ and only ~1 log10 inactivation was achieved by a CT value of 10 mg/L*min. Overall, the results of this study suggest that bacteriophage both MS2 and PRD1 could be a reliable indicator for human pathogenic viruses for chlorination in wastewater treatment processes and water reuse practice.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.7
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• pp.697-703
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• 2006

Endocrine disruptors were measured with GC/MS in effluents discharged from sewage treatment processes in pilot scale for the purpose of water reuse. From that analysis, we compared the removal rate of them by treatment processes. Nonylphenol was mainly detected in effluents and high concentration from 0.36 to 0.94 ${\mu}g/L$. $17{\beta}$-estradiol(E2) and $17{\alpha}$-ethynylestradiol(EE2) were detected as below the limit of detection in effluent. Endocrine disruptors were removed effectively in the range from 50 to 100% by treatment process. EC50 value($9.0{\times}10^{-3}$ M) of $17{\beta}$-estradiol(E2) by dose response curve of E-screen assay has higher than that of bisphenol A($2.736{\times}10^{-5}M$) and p-octylphenol($9.760{\times}10^{-6}$ M). These results showed that alkylphenols have lower relative estrogen potency than other estrogens such as $17{\beta}$-estradiol(E2). Calculated estrogenic activity(ng-EEQ/L) was 2 times higher than measured total estrogenic activity which estimated by E-screen assay. Moreover estrogenic activity of effluent by treatment process showed very low as below 1 ng-EEQ/L.