http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Khac-Uan (검색결과 7 건)
- 무료
- 기관 내 무료
- 유료
-
Khac-Uan Do,J. Rajesh Banu,S. Kaliappan,ICK-TAE YEOM 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.2
In the present study, a laboratory scale anoxic/oxic (A/O) reactor is used for the removal of nutrient and sludge reduction. Phosphorus removal was achieved through simultaneous precipitation, and sludge production was reduced through thermochemical pretreatment. The main objective of the study was to investigate the influence of sludge pretreatment on the nitrification rate. Total phosphorus in the effluent was maintained around 0.5 ~1.0 mg/L by simultaneous precipitation, using coagulant alum at 2.2 mole ratio. Before simultaneous precipitation,the nitrification rate of the A/O reactor was found to be 0.050 g N-NH4+/g MLVSS.d. The thermochemical sludge pretreatment began on the 120th day at pH 11 and 80oC. The initiation of sludge pretreatment brought about a significant reduction of the A/O reactor nitrification rate,which fell to 0.038 g N-NH4+/g MLVSS/day. The effect of sludge pretreatment was reflected in the reduction of the nitrogen removal efficiency from 85 to 74%. Recycling of the thermochemically pretreated sludge accounted for 57%sludge reduction, which had an adverse influence on the nitrification rate of the system.
-
Do, Khac-Uan,Banu, J. Rajesh,Chung, Ik-Jae,Yeom, Ick-Tae John Wiley Sons, Ltd. 2009 Journal of chemical technology and biotechnology Vol.84 No.9
<P>BACKGROUND: Reduction of excess sludge production has become an urgent issue. An investigation into the influence of thermochemical sludge pretreatment on sludge reduction in a bench-scale anoxic-aerobic membrane bioreactor was performed. Two systems were operated. In one system, part of the mixed liquid (1.5% of the influent flow rate) was pretreated thermochemically (at 80 °C, pH 11 and 3 h) and returned to the bioreactor. This study examined and evaluated the effect of thermochemical sludge pretreatment on the reduction of excess sludge and on the performance of the system.</P><P>RESULTS: The average solubilization efficiency of the pretreated sludge was found to be about 0.2. The sludge production rate of the experimental system (E-MBR) was less than that of the control (C-MBR) by about 33%. The total phosphorus was removed mainly by normal cell synthesis, with removal efficiencies of 38–40% and 40–42% for the E-MBR and C-MBR, respectively. The total nitrogen removal in the E-MBR was slightly higher than in the C-MBR due to supply of soluble chemical oxygen demand (SCOD) from the digested sludge solution as an external carbon source. The mixed liquor volatile suspended solids (MLVSS) and mixed liquor suspended solids (MLSS) ratios for the two systems were almost identical, in the range 74–77%, indicating that the inorganics from the disintegrated cells do not accumulate as particulates in the reactor. The TMP was maintained at less than 6 cmHg for 180 days without membrane cleaning.</P><P>CONCLUSION: Thermochemical sludge pretreatment can play an important role in reducing sludge production. The qualities of the effluent water were not significantly affected during 6 months of operation. Copyright © 2009 Society of Chemical Industry</P>
-
Effect of Alum on Nitrification during Simultaneous Phosphorous Removal in Anoxic/Oxic Reactor
J. Rajesh Banu,Khac-Uan Do,S. Kaliappan,염익태 한국생물공학회 2009 Biotechnology and Bioprocess Engineering Vol.14 No.4
Phosphorus and nitrogen are the important eutrophication nutrients. They are removed in the anoxic/oxic reactor through simultaneous precipitation and biological nitrogen removal. The effect of alum a commonly used simultaneous precipitant on biological nitrification and denitrification are investigated in the present study. Simultaneous removal of phosphorus was carried out using the coagulant alum Al₂(SO₄)₃∙14H₂O at 2.2 mol ratio. Before the start of simultaneous precipitation the nitrification rate of the A/O reactor was found to be 0.05 g N-NH4+/g VSS/d. It starts to decrease with increase in coagulant dosage. The nitrification rate for alum dosage 97.13 mg/L was 0.38 g N- NH₄+/g VSS/d. There was no accumulation of nitrate in anoxic tank. The nitrogen removal efficiency of the reactor was affected and it fell from 88 to 78%. There was a slight decrease in effluent COD from 16~20 mg/L to 8~12 mg/L after the introduction of simultaneous precipitation into the reactor. The usage of alum as a simultaneous precipitant in the anoxic/oxic reactor was limited due to its inhibition on nitrification. Alum did not have any affect over denitrification process.
-
A study on the performance of a pilot scale A2/0-MBR system in treating domestic wastewater.
Banu, J Rajesh,Uan, Do Khac,Chung, Ik-Jae,Kaliappan, S,Yeom, Ick-Tae The Academy 2009 Journal of environmental biology Vol.30 No.6
<P>Phosphorus and nitrogen are the important eutrophication nutrients. They were removed in the anaerobic/anoxic/oxic (A2/O) system through biologically. The use of pilot scale A2/O systems with immersed membranes in removing nutrients phosphorus and nitrogen were investigated over a period of 150 days. The A2/O membrane bio reactor (MBR) was operated at a flux of 17 LMH. The designed flux was increased stepwise over a period of one week. The reactor was operated with the mixed liquid suspended solids (MLSS) concentrations in the range of 7000-8000 mg l(-1). The phosphorus removal was found to be in the range of 74-84%. The ammonification was completed in the aerobic zone and the ammonia concentration was almost nil. Nitrate concentration in the anoxic zone was found to be in the range of 0.3-1.6 mg l(-1) indicating efficient denitrification. The nitrogen removal efficiency of the A2/O-MBR system was in the range of 68 to 75%. The chemical oxygen demand (COD) in the effluent was in the range of 8-5 mgl(-1) indicating the efficiency of membrane. During the period of reactor operation transmembrane pressure (TMP) of the reactor increased slowly from 0 to 6 -cmHg over a period of 150 days.</P>
-
Schmitt, Fé,lix,Banu, Rajesh,Yeom, Ick-Tae,Do, Khac-Uan Elsevier 2018 Biochemical engineering journal Vol.133 No.-
<P><B>Abstract</B></P> <P>An artificial neural network (ANN) was first developed to predict the transmembrane pressure in an anoxic-aerobic membrane bioreactor (AO-MBR) treating domestic wastewater. A few studies about prediction of membrane fouling in MBRs using ANNs have been published so far, even though our recent work indicates that ANNs show a great potential for this application. In this study, 10 parameters linked to wastewater treatment and measured in the different parts of the AO-MBR system were used as the input variables of the ANN. The goal was to select the most relevant input parameters to predict the evolution of the transmembrane pressure based on the performances of the ANN. An ANN model was selected for its satisfying performances (<I>R</I> <SUP>2</SUP> = 0.850). In conclusion, ANNs could be a valid method to predict membrane fouling in AO-MBR systems treating domestic wastewater.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A set of ANNs is first developed to predict membrane fouling in AO-MBR. </LI> <LI> An optimal set of parameters was identified to predict TMP using ANN efficiently. </LI> <LI> High performances were reached (R<SUP>2</SUP> = 0.850) for the developed ANN. </LI> <LI> ANN model have shown high potential to predict membrane fouling. </LI> </UL> </P>
-
Kavitha, S.,Banu, J. Rajesh,Priya, A. Arul,Uan, Do Khac,Yeom, Ick Tae Elsevier 2017 APPLIED ENERGY Vol.208 No.-
<P><B>Abstract</B></P> <P>In the present study, a new and novel attempt was made to investigate the effect of liquefaction (20–60%) on energy efficient gaseous biofuel recovery and cost during chemo thermo disperser liquefaction of food waste (CTDL). The outcome of the study revealed that rpm (10,000), specific energy input (174 kJ/kg TS), disintegration time (5 min) and energy efficiency of about 11.1 kg SCOD/KWh were considered as optimum in terms of energy and cost. The cost incurred to achieve 20–40% liquefaction was estimated to be 0.0132–0.0168 USD and found to be comparatively very low than the cost incurred (0.0367–0.0547) to achieve 50–60% liquefaction. The biodegradability results showed that a significant increment in biodegradability was achieved (from 0.26 gCOD/gCOD to 0.8 gCOD/gCOD) when the liquefaction was increased from 30 to 40% and an insignificant increment in biodegradability (from 0.8 gCOD/gCOD to 0.84 gCOD/gCOD) was achieved when the liquefaction was increased from 40 to 60%, respectively. The impact of liquefaction on energy balance and cost at tonnage level revealed that 40% liquefaction was considered to be profitable with energy ratio and net profit of about 1.12 and 93 USD/Ton, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel study to evaluate the effect of food waste liquefaction on biodegradability. </LI> <LI> Energy efficiency of 11.1 kg SCOD/kWh was optimum for combinative liquefaction. </LI> <LI> Cost spent to attain 20–40% liquefaction was very low compared to others. </LI> <LI> No significant difference in biodegradability for samples with 40–60% liquefaction. </LI> <LI> Achievement of 40% liquefaction was beneficial in terms of energy and cost. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
-
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
