TEC-BNR공법 하수처리장에서 산발효액 투입효과 연구

학위논문(석사)--아주대학교 공학대학원 :환경안전공학과,2022. 22019년 국내 하수도 보급률은 94.3%이며, 이중 고도처리공법을 이용한 처리율은 96.8%로 대부분의 하수처리시설에서 고도처리공법을 이요하여 하수를 처리하고 있다. 하수 고도처리공법은 기존의 호기조로 구성된 생물반응조에 탈질을 위한 무산소조, 인 제거를 위한 혐기조를 추가하여 질소, 인의 제거율을 40~90%까지 높인 것이 특징이다. 이를 위해서는 혐기조, 무산소조에 유기탄소원의 공급이 필수적이나 2019년 국내 하수처리시설 유입수의 평균 COD/TN ratio 2.2, COD/TP ratio 22.0으로 낮은 유기물 부하를 나타내고 있다. 특히 집중강수가 발생하는 여름철에 발생된 강수가 하수관로로 유입됨에 따라 하수유입수의 유기물 농도는 더욱 감소하게 되는데, oo하수처리장의 경우 강수발생에 의한 수처리 효율은 최대 T-N 5.8%, T-P 10.2% 감소하는 것으로 나타났다. 이에 따라 oo하수처리시설 운영자료 분석을 통해 강수발생이 하수처리시설에 미치는 영향을 분석하고, 강수 발생시 가장 큰 특징인 저농도 유입수를 제조하여 실제 운용중인 산발효조의 산발효액 투입하여 Lab-scale실험을 통해 질소·인 제거 효과를 측정하였다. 산발효액 투입에의한 비탈질율(SDNR)은 169~215%증가 되었으며, 인 방출율(SPRR)은 46~33% 증가하는 것으로 나타났다. 시료의 COD/P ratio와 인 방출량간의 상관관계 분석결과 상관계수는 0.689로 나타났고 COD/P ratio 13~16범위 에서는 상관관계가 명확하지 않았으나 COD/P ratio 25이상에서는 COD/P ratio가 증가할수록 인 방출량도 증가하는 것으로 나타났다. 산발효액의 VFA분석을 통해 탈질에 이용된 VFA량은 12.6~32.3mgVFA/mgNO₃-N으로 나타났고, 인 방출에 이용된 VFA량은 1.7~2.4mgVFA/mgPO₄-P으로 나타났다.제1장 서론 1 1.1 연구의 배경 및 목적 1 1.2 연구 방법 3 제2장 문헌연구 4 2.1 생물학적 질소제거 4 2.2 하수중 인의 구성 11 2.3 생물학적 인 제거 12 제3장 하수처리시설 운영현황 19 3.1 하수처리시설 개요 19 3.2 유입하수량 분석 23 3.3 유입수질 분석 27 3.4 산발효 공정 35 3.5 산발효액 투입량 분석 38 3.6 월평균 항목별 제거율 40 제4장 실험방법 및 내용 42 4.1 실험개요 42 4.2 실험방법 43 4.3 분석방법 44 제5장 결과 및 고찰 45 5.1 산발효액의 VFA분석결과 45 5.2 실험결과 45 5.3 비탈질율 비교 53 5.4 인 방출율 비교 55 5.5 인 섭취율 비교 57 5.6 COD/P ratio와 P-release 상관관계 59 5.7 VFA이용량 계산 60 제6장 결 론 62Maste

A Study on Frequency Synthesizer PLL for Low-Power Sensor Platform

DoctorThis thesis presents a fast-lock 2.4GHz fractional-N phase-locked loop (PLL) for ultra-low-power applications. To minimize power consumed by all the other circuits except for the main oscillator, we propose a master-slave PLL structure where a low-frequency master PLL is followed by a slave injection-locked oscillator operating at high-frequency. A frequency-error compensation circuit is also implemented in the slave oscillator to eliminate possible drift in the free-running frequency. With a fractional-N coarse-lock unit in the master PLL and a fine frequency initialization unit in the slave oscillator, the PLL supports two fast-lock modes – 1) start-up locking from deep power down mode and 2) instantaneous relocking from standby mode. The implemented PLL in 65nm CMOS consumes 250μW from 0.8V supply, demonstrating a power efficiency of 0.102mW/GHz. The PLL performs the two fast-lock operations with lock times of less than 22μs from deep power down and 1μs from standby, respectively

Information Collection and Modification for Development of Technology & Start-Up Information System Ⅲ

funder : 과학기술부agency : 한국과학기술정보연구원agency : Korea Institute of Science and Technology Information본 과제의 내용은 크게 두 부분으로 나누어진다. 첫째, 벤처경영자들이 해외시장 진출 및 국외 동종업계 파악에 필요한 해외 하이테크 기업정보를 제공한다. 둘째, 벤처기업의 기술개발 및 시장진입시 해당분야의 기술개발동향 및 시장분석에 필요한 기술 및 시장동향 보고서를 제공한다.The contents of this Research are divided into two categories in large. The first section contains profile information of foreign company in america and europe on needed on the process of new invention and technology development to the entrepreneurs. The second section contains information of technology & market trend which entrepreneurs can review their technolgy

Generation of uniform photonic balls by electrohydrodynamic atomization

We prepared uniform-sized suspension droplets with polystyrene (PS) beads by electrohydrodynamic atomization (EHDA) and subsequently colloidal crystals by evaporation-induced self-assembly (EISA) in the droplets. Electrospray of the aqueous suspension under a carbon dioxide sheath flow was conducted to study the feasibility of monodisperse droplet generation. For optical applications, spherical PS colloidal crystals were prepared in the size range of 10~20㎛ with PS beads in size range 200~350nm, which was measured by dynamic light scattering. The colloidal crystal possessed closed packed hexagonal domains in spherical shape. The size and morphology of colloidal crystals were imaged by SEM. In the present study, the suspension droplets were dispersed in silicon oil or mineral oil that has appropriate density and viscosity to form stable spherical-shaped colloidal crystals

전기 수력학적 미립화를 이용한 단분산 콜로이드 결정구의 제조

학위논문(석사) - 한국과학기술원 : 생명화학공학과, 2004, [ vii, 69 p. ]Colloidal assembled structures have been of special interest due to their characteristics such as photonic band gaps, diffraction patterns, high catalytic throughput and high packing density. Colloidal assemblies have been patterned and mounted for useful objects as themselves or used as a sacrificial template to develop porous structures. Among the various kinds of mounted shapes, a sphere may represent the simplest form driven by the minimization of interfacial free energy, which can be realized by using droplets. In this experiment, we prepared suspension droplets with narrow size distribution that contain silica, hydrophobic silica, and polystyrene beads respectively in cone-jet mode by electrohydrodynamic atomization, and subsequently spherical colloidal crystals, called photonic balls, by evaporation-induced self-assembly inside the droplets. The size of the suspension droplets was easily controlled by the AC field strength and the flow rate. The silica photonic balls were prepared in the size range of 10 - 40 ㎛ with bimodal size distribution. The SEM images of a photonic ball fractured revealed the random arrangement at the center part. The photonic balls redispersed in deionized water showed the characteristic color, green, corresponding to the size of building block beads, 252 nm, due to the opaline structure in the vicinity of the surface of a ball. On the other hand, organic photonic balls had a broad size distribution and showed the hollow ball shape with a rough surface. They were tinged with milky color due to their irregular surface. AC field enabled the photonic balls to be mass-produced due to its charge-diminishing property, while DC field led to extremely low yield owing to deposit of suspension droplets into the electrode. The production rate of the silica photonic ball under AC field was estimated at 34.25 mg/hr. And it can be increased as one intends by adding capillaries in the electrospray system. Our photonic balls can be applicable to ...한국과학기술원 : 생명화학공학과

DEMETER plant DNA demethylase induces antiviral response by interferon signalling in animal cells

DNA methylation is a prominent epigenetic modification in plants and animals regulated by similar mechanisms but the process of DNA demethylation is profoundly different. Unlike vertebrates that require a series of enzymatic conversions of 5-methylcytosine (5mC) into other bases for DNA demethylation, plants utilize the DEMETER (DME) family of 5mC DNA glycosylases to catalyze a direct removal of 5mC from DNA. Here we introduced Arabidopsis DME into human HEK-293T cells to allow direct 5mC excision, and observed that direct DNA demethylation activity was successfully implemented by DME expression. In addition, DME induced diverse cellular responses such as cell proliferation inhibition, cell cycle dysregulation and S phase arrest. Microarray and methylome analyses revealed that DME upregulated a number of genes including cell cycle components, heat shock proteins, and notably, various interferon-stimulated genes. Moreover, DME-mediated DNA demethylation activated endogenous repeat elements, which are likely to form dsRNAs as viral mimics and eventually trigger interferon cascades to establish the antiviral state. This work demonstrates that plant DNA demethylase catalyzes DNA demethylation with a bypass of initial base conversion steps, and the interferon signaling plays a pivotal role to alleviate genotoxic stresses associated with DME-induced DNA demethylation in mammalian cells.OAIID:RECH_ACHV_DSTSH_NO:T201724306RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A005197CITE_RATE:4.122DEPT_NM:생명과학부EMAIL:[email protected]_YN:YY