• Title/Summary/Keyword: Retention ratio

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The Nitrogen Removal of Municipal Wastewater with HRT using CNR Process (CNR공법의 체류시간에 따른 도시하수의 질소제거)

  • 김영규;양익배;김인배
    • Journal of Environmental Health Sciences
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    • v.26 no.3
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    • pp.98-102
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    • 2000
  • The aim of this study was to evaluate on the removal effect of total nitrogen in municipal wastewater by decreasing hydraulic retention time(HRT) from 6 hour to 4 hour on CNR process. CNR-A(Cilia Nutrient Removal) is the process combining A2/O process with cilium media of H2L corporation. The removal efficiencies for T-N were 63.1% in A-1 reactor, and 73.5% in A-2 reactor and 77.0% in A-3 reactor. The specific nitrification(g-NH3-N/g-MLVSS.d) of Oxic in CNR-A process was 0.07-0.32. The specific denitrification in Anoxic and the specific nitrification inOxic was higher in HRT 4 hour because of optimum F/M ratio.

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Thermal and Electrochemical Studies of Tris(2,4,6-trimethoxyphenyl)Phosphine as a Flame Retardant Additive for Li-ion Battery (리튬이차전지 난연성 전해액 첨가제로서의 Tris(2,4,6-trimethoxyphenyl)Phosphine의 열적, 전기화학적 특성)

  • Ahn, Se-Young;Kim, Ke-Tack;Kim, Hyun-Soo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.12
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    • pp.1130-1134
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    • 2008
  • Thermal and electrochemical properties were discussed with tris(2,4,6-trimethoxyphenyl)Phosphine (TTMPP) as a flame retradant additive for Li-ion battery. TTMPP showed excellent thermal stability with charged cathodes. Addition of 1 wt.% of the additive to the electrolyte improved the thermal stability without damaging the performance of the battery. The oxygne evolution reaction delayed nearly by $60^{\circ}C$. The capacity retention ratio in cycle life tests of the battery with 1 wt.% TTMPP was slightly improved comparing to the no additive cells.

Morphological features of thermophilic activated sludge treating food industry wastewater in MBR

  • Ince, Mahir;Topaloglu, Alikemal;Ince, Elif
    • Membrane and Water Treatment
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    • v.9 no.1
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    • pp.33-42
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    • 2018
  • Microscopic examination of the activated sludge and morphological characterization of the flocs provides detailed information about the treatment process. The aim of this study is to investigate the morphological parameters of flocs obtained from a thermophilic jet loop membrane bioreactor (JLMBR) in different sludge retention times (SRTs), considering EPS and SMP concentration, hydrophobicity, zeta potential. The results showed that irregularity decreased with the increasing SRT. The compactness value was calculated to be less than 1 for all SRTs. However, the sludge had a more compact structure when the SRT increased. Zeta potential increased whereas hydrophobicity and floc size reduced, with increasing SRT. Furthermore, 2-D porosity calculated using the hole ratio was higher at greater SRTs. Hence, there was a significant correlation between the results obtained using the imaging technique and operation conditions of thermophilic JLMBR.

Effect of Dietary Supplementation with Yeast Cell Suspension (Saccharomyces cerevisiae) on Nutrient Utilisation and Growth Response in Crossbred Calves

  • Singh, Rameshwar;Chaudhary, L.C.;Kamra, D.N.;Pathak, N.N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.11 no.3
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    • pp.268-271
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    • 1998
  • Twenty crossbred calves of $88{\pm}5.5kg$ initial live weight and 3-4 month of age were divided into two groups and fed wheat straw and concentrate to support a 500 g daily gain in body weight. Calves in the experimental group (YC) were given a daily dose of 10 ml yeast cell suspension (YC) containing live cells $(5{\times}10^9 cells/ml)$ of Saccharomyces cerevisiae ITCCF 2094. After a growth study of 122 days metabolism trials were conducted. The calves in the YC group recorded a daily weigt gain of $492{\pm}27.8g$ as compared to $476{\pm}20.1g$ in control group. There were no significant differences in feed intake, nutrient digestibility, feed/gain ratio and nitrogen retention between the YC supplemented and control groups.

광합성세균에 의한 미생물막의 형성

  • Oh, Kwang-Keun;Lee, Cheol-Woo;Jeon, Yeong-Joong;Lee, Jae-Heung
    • Microbiology and Biotechnology Letters
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    • v.24 no.6
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    • pp.733-737
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    • 1996
  • The formation of microbial films(biofilm) by a non-sulfur phototrophic bacteria, Rhodopseudomonas capsulata, on inorganic media was studied. Porous ceramic beads(PCB) were superior to other immobilizing media for the biofilm formation in a packed-bed reactor. It was found that the formation of microbial films favored a lower hydraulic retention time, showing a higher ratio of cells attatched to the media to those suspended in the solution. The cell concentration in the biofilm reactor was as high as 11,400mg/l, which is 8-folds of the cell concentration in an ordinary suspended treatment. It was observed that the formation of micribial film by R. capsulata followed a general serial process of cell attachment, microcolony formation, and biofilm formation. The microbial films thus formed was very stable even for an extremely high volumetric BOD loading rate of 15gBOD/l day. The scanning electron micrographs of the microbial films showed that the cells were attached to both the surface and pores of the media.

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A study on the SONOS EEPROM devices (SONOS EEPROM소자에 관한 연구)

  • 서광열
    • Electrical & Electronic Materials
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    • v.7 no.2
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    • pp.123-129
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    • 1994
  • SONOS EEPROM chips, containing several SONOSFET nonvolatile memories of various channel size, have been fabricated on the basis of the existing n-well CMOS processing technology for 1 Mbit DRAM ($1.2\mu\textrm{m}$.m design rule). All the SONOSFET memories have the triple insulated-gate consisting of 30.angs. tunneling oxide, 205.angs. nitride and 65.angs. blocking oxide. The miniaturization of the devices for the higher density EEPROM and their characteristics alterations accompanied with the scaling-down have been investigated. The stabler operating characteristics were attained by increasing the ratio of the channel width to length. Also, the transfer, switching, retention and degradation characteristics of the most favorable performance devices were presented and discussed.

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Synthesis of Shrinkage Reducing Superplasticizer(SRS), and Mechanical properties and Hydration Behavior (수축저감 특성이 부여된 고유동화제 합성 및 성능에 관한 연구)

  • Shin, Jin-Yong;Park, Hun-Il;Lee, Byung-Youn;Yun, Hee-Keun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.203-204
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    • 2010
  • In this study, We synthesized new generation of superplasticizer(SP) which show a shrinkage reducing effect as well as water reducing effect with adequate slump retention in a wide range of water cement ratio by introduction a shrinkage-reducing group into the molecular structure. To investigate effects of the SRS on the hydration of cement, DSC have been analysed. Also the general and shrinkage properties of the concrete were evaluated.

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Optimum Dietary Protein Level of Ayu (Plecoglossus altivelis) (은어 사료의 적정 단백질 함량)

  • 이상민;김경덕
    • Journal of Aquaculture
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    • v.12 no.2
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    • pp.145-153
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    • 1999
  • This study was conducted to determine the protein requirement of ayu (Plecoglossus altivelis). Two replicate groups of fish initially averaging 6.6 g were fed the five isocaloric diets containing different protein level from 29% to 57% in a flow-through freshwater system for 25 days. White fish meal was used as a sole protein source. Weight gain and feed efficiency of fish increased significantly with dietary protein level up to 43% (P<0.05) with no additional response above this level. Protein and lipid retention, moisture, protein and lipid contents of body were not affected by dietary protein levels (P>0.05). Daily protein intake increased significantly with dietary protein level, whereas protein efficiency ratio of fish fed the 57% dietary protein decreased (P<0.05). The data obtained in this study indicate that a 43% dietary protein level could be recommended for the optimum growth of ayu.

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Supercapacitive Properties of Composite Electrode Consisting of Activated Carbon and Di(1-aminopyrene)quinone

  • Kim, Kwang Man;Lee, Young-Gi;Park, Jeong Ho;Ko, Jang Myoun
    • ETRI Journal
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    • v.38 no.2
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    • pp.252-259
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    • 2016
  • Di(1-aminopyrene)quinone (DAQ) as a quinone-containing conducting additive is synthesized from a solution reaction of 1-aminopyrene and hydroquinone. To utilize the conductive property of DAQ and its compatibility with activated carbon, a composite electrode for a supercapacitor is also prepared by blending activated carbon and DAQ (3:1 w/w), and its supercapacitive properties are characterized based on the cyclic voltammetry and galvanostatic charge/discharge. As a result, the composite electrode adopting DAQ exhibits superior electrochemical properties, such as a higher specific capacitance of up to $160F{\cdot}g^{-1}$ at $100mV{\cdot}s^{-1}$, an excellent high-rate capability of up to $1,000mV{\cdot}s^{-1}$, and a higher cycling stability with a capacitance retention ratio of 82% for the 1,000th cycle.

A Study on the Treatment of Paper Mill Wastewater with the Addition of High Thermal Microbial Inoculants (고온성 종균제를 이용한 제지폐수 처리)

  • 이성호;임택준;조준형
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.34 no.2
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    • pp.54-60
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    • 2002
  • The Wastewater of toilet paper mill recycling recovered milk carton was used as a raw material for this study. According to the actual mill conditions, hydraulic retention time was adjusted to 12 hours and F/M (Food/Micro-organism) ratio was adjusted to 0.23. Temperature of aeration basin was varied from 2$0^{\circ}C$ to 5$0^{\circ}C$. The change of Micro-organisms and removal efficiency of pollutant were investigated at the varied temperature of basin. Aeration basin using high thermal microbial inoculants showed more removal efficiency of SS, COD than aeration basin using conventional microbial inoculants at high temperature. Floc consolidation of aeration basin using high thermal microbial inoculants added sludge was better than that of sludge from aeration basin using conventional microbial inoculants.