호흡률법에 의한 하수의 생분해 특성 평가 : Ⅰ. 호흡률법 Ⅰ. Respirometry

김동한,김희준,정태학 대한상하수도학회 2004 상하수도학회지 Vol.18 No.1

Organics may be divided into biodegradable and nonbiodegradable fractions on the basis of biodegradability. Biodegradable organics may be subdivided into readily and slowly biodegradable fractions. As this biodegradability of organics in municipal wastewater has a great influence on the efficiency of a biological nutrient removal process, it has been assessed by respirometry. The respirometer, which consisted of a respiration chamber and a respiration cell, was used to measure the respiration rate of biomass utilizing the readily biodegradable organics. The readily biodegradable organics are about 10% of the COD in municipal wastewater. The adequate ratio of wastewater to sludge volume and the concentration of sludge are required in measuring the respiration rate due to the readily biodegradable organics. By using a biochemical oxygen demand test, the slowly biodegradable organics including biomass are estimated about 66% of COD. The soluble inert organics are about 11% of COD. On the basis of mass balance, the particulate inert organics are estimated about 13% of COD.

호흡률법에 의한 하수의 생분해 특성 평가 : Ⅱ. 활성미생물 및 NUR Ⅱ. Active Biomass and NUR

김동한,김규동,정태학 대한상하수도학회 2004 상하수도학회지 Vol.18 No.2

The biodegradability of organics has become essential for the design and modeling of a biological nutrient removal process. Respirometry for the batch test just with wastewater has been conducted to estimate active biomass and readily biodegradable organics in municipal wastewater simultaneously. Municipal wastewater contains significant active biomass, which is estimated about 17% of COD. Compared to the batch test seeded with sludge, the batch test just with wastewater represents a little higher readily biodegradable organics. This might be due to the different environment of the logarithmic growth of active biomass. The nitrate uptake rate test has been also performed for the estimation of the readily biodegradable organics. The nitrate uptake rate test results in a little higher readily biodegradable organics compared to the batch test seeded with sludge and similar organics compared to the batch test just with wastewater. This might be caused by the different sludge of a sequencing batch reector process. Taking the result of the previous research into account, the readily biodegradable, slowly biodegradable, active biomass, soluble inert, and particulate inert organics are estimated about 11%, 49%, 17%, 11%, and 12% of COD, respectively.

Photostimulation of sequential degradation and assimilation of recalcitrant carbonaceous organics in <i>Scenedesmus quadricauda</i>

Elsevier 2018 PROCESS BIOCHEMISTRY Vol.65 No.-

<P><B>Abstract</B></P> <P>This study investigated the photostimulation of organic degradation with <I>Scenedesmus quadricauda</I> microalga, which is capable of assimilating organic carbon as a carbon source under mixo– and hetero–trophic growth conditions. The assimilability of carbonaceous organics in the microalga was significantly inhibited for polymeric organic compounds (a mixture of humic substances and polysaccharides) due to their recalcitrant characteristics when compared to using glucose. However, continuous illumination (150μmol photons m<SUP>−2</SUP> s<SUP>−1</SUP>) under non-aerated conditions stimulated the microalga to increase the degradability of the organic mixture. The subsequent algal cultivation in the light using aeration with 10% (v/v) CO<SUB>2</SUB> achieved a significant assimilation of the carbonaceous organics along with nitrate, which was comparable to that observed when using glucose as a carbon source. This is the first time that the photostimulation of <I>S. quadricauda</I> has been shown to induce the degradation of humic-like substances that are typically resistant to microbial decomposition.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>S. quadricauda</I> is capable of utilizing carbonaceous organics under oxic conditions. </LI> <LI> The recalcitrance of polymeric organic matter toward <I>S. quadricauda</I> was identified. </LI> <LI> Continuous light stimulated the microalga to improve the degradability of organics. </LI> <LI> Aeration was essential to subsequently utilize the transformed organics in the light. </LI> <LI> A remarkable photostimulation of nitrate uptake in <I>S. quadricauda</I> was also identified. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

계면활성제를 사용한 유기물 혼합토의 다짐 특성

권호진,박판영 한국지반공학회 2011 한국지반공학회논문집 Vol.27 No.3

Compaction tests have been performed to investigate the compaction characteristics of sands and clays with organic mixture. Weathered granite soil, kaolinite, and granulated carbon were used as the alternatives of sand, clay, and organics, respectively. The soapy water which is a kind of surfactant solutions was also used as water substitute to see the engineering properties changes of each soil. As seen when water was used, the optimum moisture contents increased and the maximum dry unit weight decreased for the soil with surfactants as the percentage of the organic contents increased. Surfactants slightly improved the compaction efficiency at low compactive energy level for the weathered granite soil with organics. As the organic contents increased for clays with surfactants, the optimum moisture contents decreased and the maximum dry unit weight increased. Surfactants slightly improved the compaction efficiency of clays with organics at all levels of compaction energy.

Removal of Cs+, Sr2+, and Co2+ Ions from the Mixture of Organics and Suspended Solids Aqueous Solutions by Zeolites

Xiang-Hong Fang,Fang Fang,Chun-Hai Lu,Lei Zheng 한국원자력학회 2017 Nuclear Engineering and Technology Vol.49 No.3

Serving as an excellent adsorbent and inorganic ion exchanger in the water purification field, zeolite 4A has in this work presented a strong capability for purifying radioactive waste, such as Sr2+, Csþ, and Co2+ in water. During the processes of decontamination and decommissioning of suspended solids and organics in low-level radioactive wastewater, the purification performance of zeolite 4A has been studied. Under ambient temperature and neutral condition, zeolite 4A absorbed simulated radionuclides such as Sr2+, Csþ, and Co2+ with an absorption rate of almost 90%. Additionally, in alkaline condition, the adsorption percentage even approached 98.7%. After conducting research on suspended solids and organics of zeolite 4A for the treatment of radionuclides, it was found that the suspended clay was conducive to absorption, whereas the absorption of organics in solution was determined by the species of radionuclides and organics. Therefore, zeolite 4A has considerable potential in the treatment of radioactive wastewater.

유기물로 수식된 몬트모릴로나이트 제조 및 특성조사

김재명,유중환,최의석,이성민,김형태,Kim, Jae-Myung,Yoo, Jung-Whan,Choi, Eui-Seok,Lee, Sung-Min,Kim, Hyung-Tae 한국세라믹학회 2004 한국세라믹학회지 Vol.41 No.1

층상구조를 갖는 점토광물은 층상의 이온교환자리에 친소수성 유기물을 화학적으로 치환할 수 있어 도자기 소지의 친소수성 정도를 조절할 수 있다. 본 연구에서는 Montmorillonite를 이온교환법으로 dodecylamine, hexadecylamine과 반응시켜 유기물이 점토광물에 복합화된 유기-점토 복합체를 조조하였다. 유기물이 점토광물 구조에 치환된 위치 및 층상구조의 간격변화는 FT-IR과 WAXD로, 수식된 유기물의 양은 TG-DSC, C/S 기기를 사용하여 조사하였다. 분석을 통하여 유기물은 층상에 선택적으로 치환하여 층간격을 증가 (12${\AA}{\leftrightarro}16{\AA}$) 시키는 역할을 하였고, 비교적 친수성을 보이는 MMT가 첨가된 가소제로 인하여 소수성으로 변하고 있음을 발견하였다. Hydrophilicity and hydrophobicity of pottery bodies can be controlled via chemical substitution of layered clay with hydrophilic and hydrophobic organics. In this study, organo-clay nanocomposites were prepared by ion-exchange of montmorillonite with dodecylamine and hexadecylamine, respectively. Substitution sites of organics and the interval changes of layered materials are characterized by FT-IR and WAXD and organics amounts loaded and water comtents contained by C/S analysis and TG-DSC. The organics were selectively intercalated so that increase layer interval from 12${\AA}\; to\;16{\AA}$. Organo-modified clay is changed to more hydrophobic comparing to clay itself.

Combination of ion exchange system and biological reactors for simultaneous removal of ammonia and organics

Park, Wooshin,Jang, Eunhee,Lee, Myun-Joo,Yu, Seungho,Kim, Tak-Hyun Elsevier 2011 Journal of environmental management Vol.92 No.4

<P><B>Abstract</B></P><P>A novel process for a simultaneous removal of ammonia and organics was developed on the basis of ion exchange and biological reactions. From batch experiments, it was found out that NH<SUB>4</SUB><SUP>+</SUP> could be removed effectively by combining cation exchange and biological nitrification showing 0.98 mg N/m<SUP>2</SUP>∙s of a maximum flux. On the other hand, the removal of NO<SUB>3</SUB><SUP>−</SUP> was 3.5 times faster than NH<SUB>4</SUB><SUP>+</SUP> and the maximum flux was calculated to be 3.4 mg N/m<SUP>2</SUP>∙s. The systems for NH<SUB>4</SUB><SUP>+</SUP> and NO<SUB>3</SUB><SUP>−</SUP> removal were combined for establishing the IEBR process. When the process was operated in a continuous mode, approximately 95.8% of NH<SUB>4</SUB><SUP>+</SUP> was removed showing an average flux of 0.22 mg N/m<SUP>2</SUP>·s. The removal efficiency of total nitrogen was calculated as 94.5% whereas that of organics was 99.5%. It was concluded that the IEBR process would be effectively used for a simultaneous removal of NH<SUB>4</SUB><SUP>+</SUP> and organics.</P>

스코리아/활성탄의 혼합 충전탑에서의 중금속 및 유기물의 흡착 거동

김승건 ( Seung-geon Kim ),문수형 ( Soo-hyoung Moon ),이호원 ( Ho-won Lee ) 한국공업화학회 2021 공업화학 Vol.32 No.1

스코리아와 활성탄의 혼합 충전탑에서 중금속과 유기물의 흡착 특성, 스코리아의 물리화학적 특성과 관능기를 조사하였다. 스코리아의 혼합비율이 증가할수록 카드뮴, 니켈, 크롬, 납 이온의 평균제거율은 증가하였으나, 벤젠과 톨루엔의 평균 제거율은 감소하였다. 스코리아와 활성탄의 혼합 충전탑은 중금속과 유기물의 동시 제거에 효과적으로 사용될 수 있었다. 스코리아는 Si-H와 Si-O 작용기를 갖고 있으며, 이중 Si-O 관능기가 중금속의 흡착에 크게 기여함을 확인할 수 있었다. Adsorption properties of heavy metals and organics in the mixed packed column of scoria and activated carbon, as well as physicochemical properties and functional groups of scoria were investigated. As the mixing ratio of scoria increased, the average removal ratios of cadmium, nickel, chromium, and lead ions increased, but that of benzene and toluene decreased. The mixed packed column of scoria and activated carbon could be effectively used for the simultaneous removal of heavy metals and organics. Scoria has Si-H and Si-O functional groups, and it was confirmed that Si-O functional groups greatly contributed to the adsorption of heavy metals.

Microbial Evaluation for Biodegradability of Recalcitrant Organic in Textile Wastewater using an Immobilized-cell Activated Sludge Process

배우근,한덕규,Fenghao Cui,김문일 대한토목학회 2014 KSCE JOURNAL OF CIVIL ENGINEERING Vol.18 No.4

Textile wastewater is difficult to be treated because it contains recalcitrant matters. This study evaluated the performance of an immobilized-cell process using polyethylene glycol media and microbial properties of the immobilized-cells for biodegradation of recalcitrant organics. The immobilized-cell process could remove hardly-biodegradable soluble COD more than 50% at various Hydraulic Retention Times (HRTs) over 8~24 hours. Active microbial distribution was fluctuated at the start-up operation, but became stable at both lower and upper part of the reactor after 92 days of operation. Cell mass in the media at the bottom was higher than at the middle or top parts of the reactor. The microbial decay in the media was more dependent on oxygen than organics. Stentrophomonas sp. and Pseudomonas putida, known as aromatic and aliphatic compound degraders, were identified in the media, confirming spontaneous selection and growth of cells that could oxidize the hardly biodegradable contaminants in the textile wastewater.

테라헤르츠파 변조에 기여하는 유기물/반도체 경계면에서의 광여기 캐리어 주입 효과의 실험적 검증

이중욱 한국물리학회 2018 새물리 Vol.68 No.5

We investigated the injection effect of photo-excited carriers at organic/semiconductor interfaces on the transmission modulation of terahertz (THz) waves. To systematically verify the relationship between the injection effect and the THz wave modulation, we employed Si and GaAs with different carrier recombination lifetimes as a semiconductor substrate and a trilayer system (organic/SiO$_2$/Si) with silicon dioxide as a spacer layer, respectively, to confirm the effect of blocking photo-excited carrier injection on the THz wave modulation. The experimental results clarify that the transmission modulation of the THz wave in organic/semiconductor hybrid structures is associated with the injection of carriers optically excited on the semiconductor substrate into the organic thin film. 본 연구에서는 유기물/반도체 복합 구조에서 나타나는 테라헤르츠파 변조 현상의 기저 메커니즘으로 여겨지는 경계면에서의 광 여기된 캐리어 주입 효과를 체계적으로 분석하였다. 이를 위해 캐리어 재결합 수명(carrier recombination lifetime)이 다른 Si과 GaAs를 사용하였고, 반도체와 유기물 사이에 SiO$_2$층을 형성하여 변조 효율의 차이를 측정하였다. 이를 통하여 유기물/반도체 복합 구조에서 나타나는 테라헤르츠파 변조 현상은 반도체에서 광 여기된 캐리어들이 유기물 층으로 주입되면서 나타나는 현상임을 실험적으로 검증할 수 있었다.