• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.421-421
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• 2021

도시화, 산업화로 인해 하수처리장 유입하수 내 질소 농도가 증가하면서 그에 따른 부영양화 발생, 수생태계에 독성을 미치는 등의 악영향 또한 증가하게 되었다. 하수 내 고농도 질소를 처리하기 위해 1990년 초 연구가 시작되어 현재 보편적으로 사용되고 있는 생물학적 질소 제거 공정은 산소공급과 외부탄소원 보충 과정에서 상당한 비용이 소요된다. 이와 같은 문제점이 대두됨에 따라 고도의 질소 제거 공정이 요구되면서, 경제적으로 개선이 이루어져 기존의 질산화·탈질 공정보다 효율적인 혐기성 암모늄 산화 공정(ANaerobic AMMonium OXidation, ANAMMOX)이 제안되었다. ANAMMOX 공정은 혐기성 조건 아래 전자공여체와 전자수용체로써 암모니아성 질소와 아질산성 질소를 이용해 질소가스 형태로 질소를 제거하는 공정이다. 질산화·탈질 공정과 비교했을 때, 폭기과정에서의 산소요구량 감소, 외부탄소원 불필요, 질소 제거 과정 단축 등의 장점을 가진다. 본 연구는 수처리공정에서의 ANAMMOX 공정의 적용 가능성을 확인하고, 암모니아성 질소대비 아질산성 질소 비율에 따른 Mainstream ANAMMOX 공정의 효율 비교를 통해 공정의 안정성과 높은 제거효율을 확보할 수 있는 NH₄⁺ 대비 NO₂^- 비율을 도출하는데 목적이 있다. 실험실 규모의 Mainstream ANAMMOX 반응조에 적용한 비율은 선행연구를 비롯한 화학양론식에서 제시된 비율을 바탕으로 산정하였다. 1.00부터 1.30의 전체적인 비율을 Initial과 Advanced 2개의 구간으로 나누어 운전한 결과, 각 구간의 NH₄⁺ 제거효율은 각각 58~86%, 94~99%였다. NH₄⁺ 대비 NO₂^- 비율이 증가함에 따라 공정의 안정성이 확보되고, NH₄⁺ 및 총질소(TN) 제거효율이 증가하는 경향이 나타났다. 본 연구의 결과는 수처리공정에서의 안정적인 ANAMMOX 공정 적용을 유도하고, ANAMMOX 공정의 성능개선을 도모하는 연구의 기초로 활용될 수 있다.

• Analytical Science and Technology
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• v.23 no.5
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• pp.477-484
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• 2010

Personal care products are a diverse group of synthetic organic chemicals such as antimicrobial compounds, UV filters and organo-phosphate flame retardants and derived from individual usages of soaps, toothpaste and cosmetics. It has been detected in municipal sewage effluent and various environmental samples such as surface water, marine, soil, sediment and aquatic biota in many countries. The occurrence of personal care products in environmental samples could negatively impact the health of the ecosystem and humans, due to persistent, long-term chronic exposure of aquatic organisms. In this study, fifteen personal care products in aquatic environmental samples were determined by gas chromatography-mass spectrometry (GC-MS) with liquidliquid extraction (LLE). Method detection limits were in the range of $0.004\sim0.273\;{\mu}g/L$. Two compounds (TCEP, TCPP) were detected in surface waters and seven compounds (triclosan, 4-MBC, EHMC, BP-3, TCEP, TPP, TBEP) were detected in sewage treatment plants (STP) influents or effluents.

• Proceedings of the KSEG Conference
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• 2002.04a
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• pp.129-136
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• 2002

대전광역시의 도심하천인 갑천, 유등천, 대전천을 대상으로 하천수의 수리화학적 특성과 동위원소 특성을 분석하였다. 하천의 수리화학적 특성은 상류에서는 $Ca(Mg)-HCO_3$ 유형을 보이다가 도심권을 통과하면서 $Ca(Mg)-SO_4(Cl)$유형으로 전환되고 하류에서는 $Na(Ca)-HCO_3(Cl,{\;}SO_4)$ 유형으로 변화를 보였다. 이와 같은 화학적 유형의 변화는 자연적 영향보다는 인위적 오염물질의 유입에 의한 것으로 해석된다. 하천수의 전기전도도와 수리화학적 유형으로 보면 대전천보다는 유등천과 갑천이 비교적 좋은 수질특성을 보인다. 그러나 하수종말처리장에서 방류되는 방류가 합류되는 갑천하류부터는 수질이 급격하게 나빠진다. 하천수의 pH는 상류에서 중성을 보이다가 도심권을 지나면서 최고 pH 9.8정도의 알카리성을 보인다. 이는 아파트의 우수관을 통한세제 유입에 기인하는 것으로 보인다. 하천수의 ${\delta}^{13}l3C-HCO_3$ 관계에서 중탄산 함량의 증가에 따른 ${\delta}^{13}C$ 값의 증가는 하천수내 $CO_2$의 기원이 유기물에서 무기물의 영향이 커짐을 의미한다. ${\delta}^{34}S-SO_4$의 함량관계는 황산염의 농도가 증가함에 따라서 ${\delta}^{34}S$ 값은 낮아진다. 갑천, 유등천, 대전천의 순으로 황산염의 농도가 증가하고 ${\delta}^{34}S$ 값은 낮아지는 경향을 보인다. 이를 바탕으로 볼 때 갑천 중상류의 경우에는 황산염의 기원이 자연적 반응외 비료 등으로부터 유입된 것으로 보이며, 대전천의 경우에는 유기오염에 의한 황산염의 유입이 상당한 것으로 판단된다. 갑천하류는 하수종말처리장의 방류수의 영향이 큰 것으로 해석된다. 대전시 도심하천수의 수리화학적수질 개선을 위해서는 하수종말처리장의 방류수 기준의 강화, 아파트단지에서의 세제의 유입의 차단, 그리고 부분적인 오염물질의 유입을 차단하여야 할 것이다.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.3
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• pp.27-33
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• 2012

According to the statistics of the Ministry of Environment, the emission of sewage sludge is increased by 7~9% yearly. In the future, it will be increased continuously because of extension of sewage disposal plants, high class treatment for removing nitrogen and phosphorus. Until now, we have depended on reclamation for lots of quantity and some part has been treated by ocean emission. But, direct reclamation of organic waste will be prohibited and even ocean emission will be prohibited now, so the treatment of sludge is put on emergency alert. Bio-gas can be produced by applying anaerobic digestion method for the recycling or refuse derived fuel can be conducted by applying carbonization method. However, the process is difficult, causes bad smell and makes it the second waste, so it cannot be practical method in fact. This study applied a fluidized bed combustor for sewage sludge treatment technologies that can actually take advantage of key technologies in order to verify its purpose is to demonstrate selected. If applying the fluidized bed combustor, it can be easily utilized as the replaced resource of energy(fuel) in the countries whose energy resources are insufficient, like our country. Especially, if applying only original strengths of the fluidized bed combustor sufficiently, the sewage sludge can be treated simply, eco-friendly, sanitarily and economically. Particularly, it is verified as the energy technology suitable for government's green growth policy.

• Microbiology and Biotechnology Letters
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• v.23 no.3
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• pp.365-371
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• 1995

Filamentous bacteria and other large microorganisms, which are useful indicators of bulking and poeration, were identified by microscopic observation. Activated sludge samples were taken from the aeration basin of 5 municipal wasterwater plants and 6 industrial ones. Among the filamentous bacteria founds, Microthrix parvicella was most frequently present, followed by type 0041, type 1701 and Nocardia. This frequency of occurrence was similar to those reorted in USA and the Neterland. The morphology of filamentous bacteria observed were generally identical with those previously reported. except type 1701 which had slender filament diameter. Among protozoa, Vorticella was most frequently present, followed by Aspidisca, Opercularia and Difflugia. Philodina was the only metazoa observed. Both filamentous bacteria and protozoa would be useful indicator organisms. The potential for these organisms as indicators were discussed.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.3
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• pp.79-89
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• 2017

Changes in pH, EC and water soluble cation and anion of the bed material in the rearing box of earthworms were investigated while sewage sludges or night soil sludge were cumulatively supplied to the 15 grams of initial earthworm population in the rearing box. Initial biochemical properties of sludges such as pH, EC, V.S. and water content were at the edible levels for earthworm. However, as the cumulative amount of sludges supplied to the earthworms were increased, pH of bed material in the rearing box was lowered and EC was increased, which meant that salt contents of bed material in the rearing box had been accumulated. Water soluble cations and anions were also accumulated in the bed material of the rearing box. Accumulation rates of ${NO_3}^-$ were especially prominent. Consequently, feeding rates of earthworm populations were reduced to nearly zero and earthworm populations finally died.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.911-916
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• 2005

In this study, variations of water quality, sediment size and contaminant substances are analyzed at upstream and downstream in sewer systems in order to evaluate the characteristics of wastewater transformation by physico-chemical and biological reactions. The differences of DOC concentration between up and down stream showed the range of $-5.8{\sim}18.6$ from the result of continuous measurement at up and down stream. About 8.4% of DOC concentration was reduced and reduction rate was 2.3 mg/L/km. SS reduction rate was measured by 5.5 mg/L/km, 0.22 mg/L/min from upstream to downstream, which was twice than DOC reduction rate. When pollution load reduction was evaluated considering infiltration/inflow effect, DOC load was eliminated from 1,230 ka/d to 1,167 kg/d by physi-chemical and biological reaction in a sewer and 7.8% of the SS in upstream station was reduced under dry weather condition. The results showed that the characteristics of transformation process of wastewater in sewer should be considered for design and operation of wastewater treatment plant.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.11
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• pp.1154-1161
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• 2006

Air drying equipment was built as a device for reduction of dewatered cake from wastewater and waterworks sludge and to reproduce it by reusable matter. Dewatered cake was supplied into the air drying equipment which operated by air velocity of 80 m/sec, air rate 30 $m^3/min$ and air temperature of $40^{\circ}C$, and dried to produce the dried powder. The air drying equipment was composed of the air ejector which made high-speed fluid field, and cyclone which made circling fluid field. Dewatered cake was crushed at the high-speed zone as first step, and formed into dried powder of sphere shape by the collision between particles at the circling fluid zone.. Wastewater sludge with water content of 82.5 wt% was supplied 1.0 kg/min into air drying equipment and produced the dried powder which had the water content of 62.3 wt% and mass median diameter of 2.4 mm after process. At that time, it was analyzed that water removal rate was 0.1 $H_2O{\Delta}kg/min{\cdot}DS$ kg and air consumption was 170 $m^3/DS$ kg. Under same experimental conditions, when waterworks sludge was dried, water content of dried powder decrease to 47.5 wt% and mass median diameter decrease 2.1 mm and water removal rate increase 0.13 $H_2O{\Delta}kg/min{\cdot}DS$ kg. Air consumption increase 180 $m^3/DS$ kg with comparison to the results of wastewater sludge. Therefore, this technology was evaluated that drying the dewatered cake of waterworks sludge was more efficient than wastewater sludge, and also economical sludge handling technology due to drying the cake by only air.

• Journal of Energy Engineering
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• v.28 no.2
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• pp.18-35
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• 2019

The Korea District Heating Corporation operates a gas engine generator with a capacity of $4500m^3 /day$ of biogas generated from the sewage treatment plant of the Nanji Water Recycling Center and 1,500 kW. However, the actual operation experience of the biogas power plant is insufficient, and due to lack of accumulated technology and know-how, frequent breakdown and stoppage of the gas engine causes a lot of economic loss. Therefore, it is necessary to prepare technical fundamental measures for stable operation of the power plant In this study, a series of process problems of the gas engine plant using the biogas generated in the sewage treatment plant of the Nanji Water Recovery Center were identified and the optimization of the actual operation was made by minimizing the problems in each step. In order to purify the gas, which is the main cause of the failure stop, the conditions for establishing the quality standard of the adsorption capacity of the activated carbon were established through the analysis of the components and the adsorption test for the active carbon being used at present. In addition, the system was applied to actual operation by applying standards for replacement cycle of activated carbon to minimize impurities, strengthening measurement period of hydrogen sulfide, localization of activated carbon, and strengthening and improving the operation standards of the plant. As a result, the operating performance of gas engine # 1 was increased by 530% and the operation of the second engine was increased by 250%. In addition, improvement of vent line equipment has reduced work process and increased normal operation time and operation rate. In terms of economic efficiency, it also showed a sales increase of KRW 77,000 / year. By applying the strengthening and improvement measures of operating standards, it is possible to reduce the stoppage of the biogas plant, increase the utilization rate, It is judged to be an operational plan.

• Animal Systematics, Evolution and Diversity
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• v.20 no.2
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• pp.171-178
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• 2004

Two oxytrichid ciliates collected from the two habitats (soil under pine forest near beach and sewage treatment plant) in Korea were identified as Oxytricha balladyna Song and Wilbert, 1989 and O. longa Gelei and Szabados, 1950. These species are reported in this paper for the first time from Korea. The description was based on the observation of living specimens and protargol impregnated specimens. Diagnostic characteristics for each species are as follows. O. balladyna: one micronucleus located between two macronuclei, five transverse cirri, three caudal cirri, five rows of dorsal kinety, no granule in cytoplasm. O. longa: each micronucleus closely located near two macronuclei, three postoral ventral cirri lying in a straight line and positioned far away from transverse cirri, four transverse cirri, two caudal cirri, four rows of dorsal kinety, yellow-green granules scattered on cytoplasm.