• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 Proceedings of KSEH.Minamata Forum
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• pp.51-53
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• 2005

Disposal of waterwork sludge is important problem in WTP(water treatment plant). Purpose of this study is treated municipal waste water chemically using sludge that is produced in waterwork plant by link to reutilize waterwork sludge. Municipal waste water that use in an experiment used is produced at C university, and is SS 220 mg/L, BOD 145 mg/L, COD 160 mg/L, T-N 52 mg/L and T-P 2.6 mg/L. Used Alum, polymer coagulant and coagulant aid (diatomite, powered activated carbon) as CaO, coagulant as alkaline aid by chemical treatment medicine. In case of does slow speed agitation and stations after pours waterwork sludge in sewage and alkaline aid and coagulant at rapidly mixing the colloidal creation speed is fast and fine colloids concentration was high but settling time is shortened a little and removal rate of pollutant improved by $60{\sim}99%$.

• KSBB Journal
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• 제18권3호
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• pp.211-216
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• 2003

본 연구에서는 오존과 생물활성탄 연계공정의 효율성을 비교하고자 원수, 원수오존처리, 원수오존응집 침전 공정 처리수를 생물확성탄에 유입시켜 용존 유기물질의 제거효과를 비교ㆍ연구하였다. 또한 생물활성탄의 생물학적 처리능을 조사하기 위하여 총질소, 총인, 암모니아성 질소의 제거경향을 파악하였으며 그 결과 다음과 같은 결론을 얻었다. 오존 생물활성탄 처리시의 평균 제거율은 30.7%로 다른 처리 공정에 비하여 상대적으로 높은 용존 유기물질 제거율을 나타냈는데, 이것은 생물황성탄 컬럼 상에서 용존산소의 농도를 증가시킴과 오존의 산화로 인하여 유기물의 생분해도를 증가시킴으로서 활성탄 컬럼 내의 용존 유기물질 제거를 증가시킨 것으로 사료되며, 생물활성탄 컬럼의 DOC 저감율이 가장 높은 EBCT 10분을 최적의 EBCT로 판단하였다. 또한 각 공정별 유기물의 성상변화를 살펴보기 위하여 specific ultra violet adsorbance 성상 변화를 조사하였으며 오존처리에 의해 다량의 hydrophobic 성분이 hydrophilic 성분으로 전환되었으며 생물활성탄 처리에 의해 28%의 SUVA 값의 제거가 발생하였다. 이것은 오존 처리에 의해 다량의 hydrophobic 성분이 hydrophilic 성분으로 전환되었으며, 이러한 hydrophilic 성분이 생물활성탄 처리에 의해 제거된 것으로 사료된다. 원수를 유입시킨 생물 활성탄 처리수는 45.3%, 오존 처리수를 유입시킨 컬럼에서는 44.6%, 오존응집ㆍ침전처리수를 유입시킨 컬럼에서 58.4%의 UV$_{254}$ 제거율을 나타내었으며, 암모니아성 질소의 경우 66%, 81%, 29%의 제거율을 나타내어 생물학적 제거가 활발함을 관찰할 수 있었다. 따라서 본 연구를 통하여 오존산화처리와 황성탄의 연계처리는 용존 유기물질의 저감 뿐만 아니라 생물활성탄의 생물학적 처리능을 향상시키는 효율적인 공정임을 확인할 수 있었다.id의 효과와 거의 대등한 것을 나타났다. 이것으로 쇠비름 조추출물이 항산화효과 (in vitro)가 있음이 증명되었으며, 이 항산화활성은 극성이 비교적 큰 화합물들에 의한 것임을 추정할 수 있다. 현재 쇠비름 추출물로부터 항산화활성성분을 분리하기 위한 연구가 진행 중이다.는 exp-onential phase 동안 급격한 균체성장으로 용존산소가 부족하여 NADH balance에 의해 astaxanthin 생합성 경로 중 탈수소화 단계가 저해되기 때문으로 사료되었다. 최종 세포농도는 43.3 g/L, 단위부피당 carotenoids 함량은 149.4 mg/L, astaxanthin 함량은 110.6 mg/L로서 산업적인 생산성이 있는 것으로 나타났다. 이번 연구를 통하여 개발된 변이주 B76 및 이의 대량 발효를 위한 최종조건의 정립은 향후 astaxanthin의 산업적 생산공정에 필요한 기초자료로 이용될 것으로 기대된다.색총말내에 소형의 도형, 소형의 장형 연접소포 및 DENSE CORE VESICLE의 3가지 연접소포를 가지고 있었고 출현빈도수는 촉각엽에서 가장 큰 33%이었다. 제5형 신경연접은 축색종말내에 중등도크기의 원형, 대형의 원형연접소포 및 DENSE CORE VESICLE을 포함하였고 13%의 출현빈도수로 관찰되었다. 배추횐나비의 촉각에 있는 지각신경세포가 뇌의 촉각엽으로 뻗어 들어가 위의 5가지 신경연접중 어느 형을 형성하는지를 관찰하기 위하여 좌측 촉각의 기부를 제거하여 지각신경세포를 절단하였는데 그 결과, 좌측 촉각엽에서 제4형의 신경연접이 퇴행성 변화를 나타내었다. 그러므로 촉각의 지각신경세포는 뇌의 같은 족 촉각엽에 뻗어와 제4형 신경연접을 형성한다고 결론되었다.$/ 값이 210 $\mu\textrm{g}$/$m\ell$로서 효과적인 저해 활성을 나타내었다 따라서, 본 연구에서 빈랑으로부터 분리한 phenol 성 물질은 피부

• 상하수도학회지
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• 제22권3호
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• pp.329-336
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• 2008

The pilot study was conducted to evaluate the applicability of air flotation(AF) processes combined with biological nutrient removal(BNR) for the retrofitting of conventional wastewater treatment facilities. The BNR system was operated in pre-denitrification and intermittent aeration; developed ceramic membrane diffusers were installed to separate the solid-liquid of activated sludge at the bottom of a flotation tank. Before performing a pilot scale study, the size distribution of microbubbles generated by silica or alumina-based ceramic membrane diffusers was tested to identify the ability of solid-liquid separation. According to the experimental results, the separation and thickening efficiency of the alumina-based ceramic membrane diffuser was higher than the silica-based ceramic membrane diffuser. In a $100m^3/d$ pilot plant, thickened and return sludge concentration was measured to be higher than 15,000mg SS/L, therefore, the MLSS in the bioreactor was maintained at over 3,000mg SS/L. The effluent quality of the AF-BNR process was 4.2mg/L, 3.7mg/L, 10.6mg/L and 1.6mg/L for $BOD_5$, SS, T-N and T-P, respectively. Lastly, it was revealed that the unit treatment cost by flotation process is lower than about $1won/m^3$ compared to a gravity sedimentation process.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권6호
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• pp.825-831
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• 2016

In this paper, a transimpedance amplifier based on a new DC offset cancellation (DCOC) method is proposed for WCDMA/LTE applications. The proposed method applies a sample and hold mechanism to the conventional DCOC method with a DC feedback loop. It prevents the removal of information around the DC, so it avoids signal-to-noise ratio degradation. It also reduces area and power consumption. It was designed in a $0.13{\mu}m$ deep n-well CMOS technology and drew a maximum current of 1.58 mA from a 1.2 V supply voltage. It showed a transimpedance gain of $80dB{\Omega}$, an input-referred noise current lower than 0.9 pA/${\surd}$Hz, an out-of-band input-referred 3rd-order intercept point more than 9.5 dBm, and an output DC offset lower than 10 mV. Its area is $0.46mm{\times}0.48mm$.

• 한국농공학회지
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• 제45권2호
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• pp.107-115
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• 2003

Dairy manure amended with crop and forest residues (moisture 69% wet basis, C/N 22) was composted in a 605 L pilot-scale vessel using continuous air flow (56 L/min) for 19 days. Three pilot-scale sawdust biofilters (moisture 63%, pH 5.0) were built to clean biological waste gas from the composting process. For each methods, two replicated experiments were monitored over a period of three weeks. The system was evaluated to determine the biofilter media depth that would be adequate for compost odour reduction. The compost air cleaning was measured based on ammonia gas concentration before and after passing through the biofilter. Ammonia gas removal efficiency over 3 weeks was 42, 75 and 87% at sawdust biofilter media depth levels of 202, 400 and 600 mm, respectively. Each sawdust biofilter was operated at a moisture content in the range of 60~62% (wb), a temperature from 15 to $25^{\circ}C$, an average pressure drop from 240 to 340 Pa and a detention time from 60 to 180 seconds during the biofiltration process.

• 한국항해항만학회지
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• 제34권5호
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• pp.375-381
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• 2010

본 연구에서는 선박오수 고도처리시스템 개발을 목적으로 SBR 공법을 도입하여 선박용 오수처리장치를 제작한 후 성능 평가를 수행하였다. Lab scale 과 Pilot Plant 규모의 기초 실험을 토대로 제작한 시제품은 시운전 결과 IMO의 Res.MEPC.159(55) 성능 기준을 충분히 만족시켰으며, 질소와 인의 동시처리도 가능하여 강화되어 가는 해양환경기준을 충분히 만족시킬 수 있을 것으로 평가되었다. 선박오수와 유사한 실 하폐수를 대상으로 한 제품 가동 결과 유기물의 경우 90% 이상, 질소와 인의 경우 50% 이상의 처리 효율을 나타내었으며, 운전 기간 내내 안정적인 처리 효율을 보이며 선박이라는 특수한 환경과의 접목성도 매우 우수한 시스템으로 확인되었다.

• 한국물환경학회지
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• 제20권3호
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• pp.296-300
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• 2004

The rejection properties of 6 aromatic pesticides were evaluated by a continuous flow system equipped with a hollow fiber NF membrane. Different from the separation experiment of batch cell, the rejection and the removal could be calculated exactly because the concentration of feed, permeate and retentate was separately obtained. The lowest and the highest rejection were found in carbaryl(54.8%) and methoxychlor(99.2%), respectively, and the removals were always shown higher than rejections. This may be caused by some reasons such as the solute adsorption on the membrane, the variation of feed concentration. Although molecular weight, molecular width regarded as solute characteristics and log P(n-octanol/water partition coefficient) as hydrophobicity could be applied to explain the rejection property, these factors should be considered together for better analysis. According to the higher relationship between log B(solute permeability) and molecular weight, it was revealed that the solute separation with this membrane was influenced more by molecular weight.

• Environmental Engineering Research
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• 제23권1호
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• pp.1-9
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• 2018

The degradation of methylene blue (MB) in an aqueous solution by nano-metallic particles (NMPs) was studied to evaluate the possibility of applying NMPs to remove MB from the wastewater. Scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to characterize the synthesized NMPs before and after the reaction. The effects of the NMP dosage, the initial pH, the initial concentration of MB and the amount of $H_2O_2$ on the MB degradation outcomes were studied. The highest removal rate of MB was achieved to be 100% with an initial MB concentration of 5 mg/L, followed by 99.6% with an initial concentration of 10 mg/L under the following treatment conditions: dose of NMP of 0.15 g/L, concentration of $H_2O_2-100mM$ and a temperature of $25^{\circ}C$. The SEM analysis revealed that the nano particles were not spherical in shape. FTIR spectra shows occurrence of metal oxides on the surfaces of the NMPs. The XPS analyses results represent that Fe, Zn, N, Ca, C and O were occurred on the surfaces of the NMPs. The degradation of MB was suitable for the pseudo-first-order kinetics.

• Carbon letters
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• 제2권1호
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• pp.15-21
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• 2001

In this work, activated carbon fibers (ACFs) were plated with copper metal using electroless plating method and the effects of surface properties and pore structures on chromium adsorption properties were investigated. Surface properties of ACFs have been characterized using pH and acid/base values. BET data with $N_2$ adsorption were used to obtain the structural parameters of ACFs. The electroless copper plating did significantly lead to a decrease in the surface acidity or to an increase in the surface basicity of ACFs. However, all of the samples possessed a well-developed micropore. The adsorption capacity of Cr(III) for the electroless Cu-plated ACFs was higher than that of the as-received, whereas the adsorption capacity of Cr(VI) for the former was lower than that of the latter. The adsorption rate constants ($K_1$, $K_2$, and $K_3$) were also evaluated from chromium adsorption isotherms. It was found that $K_1$ constant for Cr(III) adsorption depended largely on surface basicity. The increase of Cr(III) adsorption and the decrease of Cr(VI) adsorption were attributed to the formation of metal oxides on ACFs, resulting in increasing the surface basicity.

• Carbon letters
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• 제8권4호
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• pp.299-306
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• 2007

Four stream- activated carbons were prepared by carbonizing apricot stones at $600^{\circ}C$ followed by gasification with steam at $950^{\circ}C$ to burn-off's=17, 32, 49 and 65%. The textural parameters of these activated carbons were determined from nitrogen adsorption results at 77 K. The total pore volume and the mean pore radius increased with the increase of % burn-off whereas the surface area increased with the increase of burn- off from 17 to 32 and further to 49%. Further increase of burn-off to 65% was associated with a considerable decrease in surface area as a result of pronounced pore widening due to pore erosion. The surface pH values of the carbons investigated range between 7.1 and 8.2. The adsorption of oxamyl onto the activated carbon followed pseudo-second order kinetics and the equilibrium adsorption isotherms fitted Langmuir adsorption model. The adsorption of oxamyl proved to be of the physical type and took place in non-micropores. The amount of oxamyl adsorbed expressed as $q_m$ depends to a large extent to the surface area located in non-micropores $S^{\propto}\;_n$, where a straight line relationship passing through the origin was obtained.