• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.556-556
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• 2015

금호강 유역은 낙동강 유역에 위치한 22개 중권역에서도 본류에 유입되는 하천 규모가 크기 때문에 본류에 큰 영향을 미친다. 이로 인해 금호강에서 유출되는 유량과 비점오염원 부하량에 대한 정확한 분석이 반드시 필요한 상황이다. 더욱이, 기후변화로 인해 태풍이나 국지성 호우의 발생이 빈번해지고, 그 규모 역시 과거에 비하여 상당히 크기 때문에 각 유역에 대한 정확한 수문 및 수질 조사가 요구되고 있다. 점오염원에 의한 부하량은 강우량과 관계없이 발생되지만 비점오염원에 의한 부하량은 강우에 따른 유출 현상 때문에 매년 변동이 심하다. 도시지역의 경우 불투수 면적이 증가하고 있으며 지표면에 흡착된 오염물질들이 지표면을 통과하지 못하고 우수와 함께 하천으로 유입된다. 또한 도시화 산업화로 인해 교통량이 증가하면서 도로에 떨어진 기름, 타이어 분진 등이 강우 시 하천으로 유입된다. 특히 금호C지역의 공업단지의 경우 강우 유출수에 고농도의 오염물질이 혼입되어 있으며, 지표면에 퇴적되는 오염물질의 양도 주거지역보다 훨씬 높으며 강우 시 유독한 수질오염물질이 일시에 다량으로 하천에 유입된다. 시가지는 차지하는 면적이 각 소유역당 $20km^2$이내로 크지 않지만 BOD, T-N, T-P 모든 항목에서 영향이 큰 것으로 나타났고, 산림은 가장 큰 면적을 차지하고 있지만 BOD를 제외한 항목에서 영향을 미치지 않는 것으로 나타났다. 농경지의 경우 각 소유역당 $5{\sim}45km^2$의 면적을 차지하지만 전체적으로 영향을 많이 미치는 것으로 나타났으며 모두 T-N에 대한 영향이 큰 것으로 나타났다. 금호강 유역은 상류에서는 농경지의 비율이 높아 비료나 토양침식에 의한 비점오염에 의한 오염이 큰 것으로 나타났고, 하류에서는 영천시, 대구광역시가 위치하고 있어 생활하수와 공업용폐수 등에 의한 점오염과 불투수 지역이 많아 우수와 함께 하천으로 유입되는 비점오염원에 의한 오염 모두 큰 것으로 나타났다. 금호강유역의 효율적인 비점오염관리를 위해서는 금호강 유역 상류지역의 농업지역과 하류지역의 도시지역에서 필요한 비점오염 부하량 감소 방안에 대한 연구가 필요할 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.277-277
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• 2015

본 연구는 퍼클로레이트의 생물학적 환원 과정에 있어서 나이트레이트의 존재가 미생물에게 어떤 영향을 미치는지를 실험을 통해서 알아보고 적절한 모델링 접근을 통하여 나이트레이트의 퍼클로레이트 환원에 대한 저해의 정량적 분석을 위한 요소들을 도출하기 위해 수행되었다. 100mL 합성폐수를 포함하는 플라스크를 이용한 실험이 수행되었고, 유일 탄소원으로 아세트산나트륨이 사용되었고, 전자수용체로는 퍼클로레이트와 나이트레이트가 사용되었다. 먼저 퍼클로레이트와 나이트레이트 각각을 단일전자수용체로서 넣은 실험을 진행하였다. 퍼클로레이트의 동역학계수 qmax, Ks, Y, b값은 각각 0.9(mgClO4-/mgMLSSday), 42.28(mgClO4-/L), 0.382(mgClO4-/mgMLSS), 0.05(day-1)로 계산되었다. 그리고 나이트레이트의 동역학 계수 qmax, Ks, Y, b값은 각각 13.81(mgNO3-/mgMLSSday), 239.78(mgNO3-/L), 0.275(mgNO3-/mgMLSS), 0.05(day-1)로 계산되었다. 나이트레이트와 퍼클로레이트를 동시에 넣었을 경우에는 나이트레이트의 동역학 계수는 qmax, Ks, Y, b 값은 각각 13.72(mgClO4-/mgMLSSday), 235.64(mgClO4-/L), 0.263(mgClO4-/mgMLSS), 0.05(day-1)로 큰차이 없었으나, 퍼클로레이트의 경우에는 qmax, Ks, Y, b값은 각각 0.6(mgClO4-/ mgMLSSday), 42.24(mgClO4-/L), 0.393(mgClO4-/mgMLSS), 0.05(day-1)로 qmax값은 감소하였고, Y값은 증가하는 모습을 보임으로써, 나이트레이트의 존재가 퍼클로레이트의 환원을 저해시키는 것을 확인할 수 있었다.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.2
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• pp.51-58
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• 2009

In this paper checked up biomass which occurs in the Jeju as are classified as organic waste for integrated management system for review and circulation of resources. Biomass which occurs in the Jeju was the 10,818 tons of sludge, 61,284 tons of food-waste, 1,519,000 tons of livestock. Sludge is treated marine discharge, food-waste is treated regeneration and livestock is treated in the form of recycling. How to establish "System used by mechanism of recycling management on biomass resources" to introduce biomass town created by Hita-city, Oita-ken in Japan. Also there established a model system to building for recycling management of biomass and then checked up the economics. According to the report, it has the difference in facilities, but it will switch to a surplus in 4 years, therefore it was confirmed that the economy. To be considered priority most livestock in "System used by mechanism of recycling management on biomass resources" in Jeju. So it is introduced the urgent problem and the problem awaiting solution on treating livestock in this study.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.3
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• pp.117-125
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• 2002

This study experimented a possibility of advanced treatment through microorganism that converts $NH_3-N$ to organic nitrogen in wastewater contaminated by ammoniac nitrogen unlike conventional nitrogen removal process. After distributing three kinds of special bacteria that use $NH_3-N$ as a substrate, when those bacteria were cultured in no salt condition and salt condition (3% NaCl), M11 showed better growth in salt condition and M12 showed better growth in no salt condition. However M7l grew well in both no salt condition and salt condition. In the test of glucose effect, maximum growth and removal rate were observed in glucose concentration of 5g/L but in high concentration (1000mg/L as $NH_3-N$) of $NH_3-N$ growth and removal rate were low. Removal rate was the highest in 100mg/L $NH_3-N$ and the fact that concentration of $NO_2-N$ and $NO_3-N$ didn't increase assumed $NH_3-N$ was converted to organic nitrogen. Optimum concentration of $K_2HPO_4$ for phosphorous supply and buffer was 5g/L. Special bacteria distributed could use $NO_2-N$ and $NO_3-N$ as well as $NH_3-N$ as substrates. This study showed that when growth rate of bacteria was high removal rate also was high. It is possible to apply as a method to treat wastewater polluted by $NH_3-N$.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.2
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• pp.251-264
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• 2000

Organic removal from synthetic wastewater by electrochemical methods was investigated with various operating parameters, such as current density, retention time, electrode gap and $Cl^-/COD_{Cr}$ ratio. In electrolysis, dioxide iridium coated titanium ($IrO_2/Ti$) and stainless steel plate were used for anode and cathode respectively. The $COD_{Cr}$ removal efficiencies between plate type anode and net type anode were about same effect, but electrolytic power using net type anode is low than plate type anode. The $Cl^-/COD_{Cr}$ ratio was about $1.3kgCl^-/kgCOD_{Cr}$ when organic removal obtained 70 %, $Cl^-/COD_{Cr}$ ratio needs $2.2kgCl^-/kgCOD_{Cr}$ so as to organic completely remove. The removal efficiency of organics increased with current density, retention time and $Cl^-/COD_{Cr}$ ratio, but decreased with increasing electrode gap. The relationship of operating conditions and $COD_{Cr}$ removal efficiencies are as follows. $$COD_{Cr}(%)=80.0360(Current\;density)^{0.4451}{\times}(HRT)^{0.8102}{\times}(Gap)^{-0.4915}{\times}(Cl^-/COD_{Cr})^{0.5805}$$ There existed a competition between the removals for $COD_{Cr}$ and ammonium during electrolysis, the removal of ammonium was shown to be dominant and $COD_{Cr}$ removal was low. But $COD_{Cr}$ removal was raised as addition of alkalinity.

• Journal of the Korean Applied Science and Technology
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• v.34 no.2
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• pp.327-337
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• 2017

A continuous low temperature ($510^{\circ}C{\sim}530^{\circ}C$) pyrolysis experiment in a pilot-scale of 85.3 kg/hr was carried out by the mixed feedstock of half dried digested sewage sludge and waste plastics. As a result, the amount of pyrolysis gas generated was maximum 68.3% of input dry mass and scored $40.9MJ/Nm^3$ of lower heating value (LHV), and the percentage of air inflow caused by continuous pyrolysis was 19.6%. The oil was produced 4.2% of the input dry mass, and the LHV was 32.5 MJ/kg. The sulfur and chlorine contents, which could cause corrosion of the facility, were found to be 0.2% or more respectively. The carbide generated was 27.5% of the input dry mass which shows LHV of 10.2 MJ/kg, and did not fall under designated waste from the elution test. The concentration of carbon monoxide, sulfur oxides and hydrogen cyanide of emitted flu gas from pyrolysis gas combustion was especially high, and dioxin (PCDDs/DFs) was within the legal standards as $0.034ng-TEQ/Sm^3$. Among the 47 water pollutant contents of waste water generated from dry flue gas condensation, several contents such as total nitrogen, n-H extract and cyanide showed high concentration. Therefore, the merge treatment in the sewage treatment plants after pre-treatment could be considered.

• Journal of Wetlands Research
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• v.17 no.1
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• pp.11-18
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• 2015

As the seriousness of water pollution resulted from nitrogen is being magnified, research has been conducted to reduce nitrogen in sewage as well as wastewater. Particularly research on innovative nitrogen removal methods that are based on the reaction of nitritation and are economically feasible and eco-friendly has been receiving attention. However, research on the applicability and efficiency of the methods based on the reaction of nitritation has not been completely done yet. Accordingly, the current study has analyzed the characteristics of sewage flowing into municipal wastewater treatment plants, primary clarifier supernatant, recycled water, and livestock wastewater and also operated a laboratory-level reactor. The result shows that recycled water and livestock wastewater contain higher-concentration nitrogen than other kinds of sewage, so they increase nitrogen loading in the water treatment line. And the result of operating a reactor shows that because of ammonium nitrogen low concentration, sewage and primary clarifier supernatant do not induce the reaction of nitritation. Also, there exist differences in the conditions of retention time inducing the reaction of nitritation by the types of sewage, and this seems to be attributed to organic compound and ammonium nitrogen concentration. Among the kinds of sewage inducing the reaction of nitritation, anaerobic digester supernatant indicates the highest efficiency.

• Korean Journal of Environmental Agriculture
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• v.4 no.1
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• pp.37-42
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• 1985

Recently the method using fixing biological contactor in treatment of sewage and wastewater has been propelling on the ground that it has advantages of reducing both motive and man power and applied treatment plants of this method are increasing gradually in Korea. After analysing the results from which real structure pilot plant had operated in the field with RBC sewage wastewater system-one of the fixing biological contact methods-for five months, this study was performed to investigate how to apply the standard of establishment that provided in article of sewage disposal facilities notified (act 8 of art 84) by the office of environment on May 16, 1984, to real treatment plant. The rotating velocity and the staying time of rotating disc have interrelation on removal efficiency of BOD. When circumferential velocity of rotating disc was ranged from 18 to 20 m per minute, economical price was the best. When the staying time was even about 120 minutes for that of home RBC facilities showed 90% or above of BOD removal efficiency of high concentration sewage also showed excellent efficiency ranged from about 85% to 90%.

• Korean Journal of Microbiology
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• v.37 no.3
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• pp.189-196
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• 2001

Eighty-seven microbial strains capable of growing on bisphenol A (BPA) as a sole carbon source were isolated from soils, waste waters and sludges. Among them, three bacterial strains were finally selected as potential decomposers through measuring BPA-degradation efficiency by HPLC analysis. Two of these bacterial strains were identified as Serratia marcescens 1901 and S. marcescens 1902, and another was Pseudomonas putida 1401 by 16S rDNA partial sequences and based on morphological and physiological properties. They showed higher cell growth and BPA degradation in PAV (PAS medium containing vitamin mixtures) than in PAS medium. The degradation efficiencies of these bacterial strains were within a range of 20-40% in the PAV containing 500 mg/1 or 100 mg/l of BPA fur 3 days. S. marcescens 1901 showed higher degradation efficiency at 100 mg/1 of BPA than those of other selected strains, while S. marcescens 1902 and P. putida 1401 degraded a high concentration of BPA (500 mg/l) with a degradation efficiency of 40% for 3 days. The BPA degradation using a mixed culture of three selected strains showed the similar level of dog-radation efficiency with that using a pure culture.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.5
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• pp.477-486
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• 2010

This study was performed with the object in which it improves the nitrification by using RBC, that is one of the biological waste water treatment process. By applying the Modified Dephanox process to RBC in this research in order to evaluate the improvement of the nitrification by RBC a research was conducted. There is the most conspicuous feature of the process of using RBC. it is that the nitrification can be smoothly performed even if the suspended solid of the high concentration as the interference factor in the nitrification tank is flowed in. Moreover, as a result of experiment, TCOD removal efficiency of the process showed up more than about 90%. when influent TCOD loading rate was 0.04~0.1 kg / $day{\cdot}m^3$. and T-N removal efficiency is high at about 75% in spite of the process operating of the laboratory scale was observed. Also, As increasing influent ${PO_4}^{3-}$-P, T-P loading rate, ${PO_4}^{3-}$-P, T-P removal efficiency was increased. Finally, it was elucidated that the utilization of RBC in external nitrification system resulted in not only high nitrification performance but also stable system operation by minimizing inhibitory effect of overflowed suspended solid (SS).