Dissertations / Theses on the topic 'Aeration efficiency'
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SINGH, KANCHAN. "STUDY OF AERATION EFFICIENCY OVER THE PIANO KEY WEIRS." Thesis, DELHI TECHNOLOGICAL UNIVERSITY, 2021. http://dspace.dtu.ac.in:8080/jspui/handle/repository/18799.
Full textSundberg, Cecilia. "Improving compost process efficiency by controlling aeration, temperature and pH /." Uppsala : Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/2005103.pdf.
Full textOdize, Victory Oghenerabome. "Diffuser Fouling Mitigation, Wastewater Characteristics And Treatment Technology impact on Aeration Efficiency." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/82852.
Full textPh. D.
Fredericks, Dana Kathleen. "Optimization of intermittent aeration for increased nitrogen removal efficiency and improved settling." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/50427.
Full textMaster of Science
McCann, Brian Patrick. "The efficiency of aeration and COD removal of a modified rotating biological contractor." Thesis, Queen's University Belfast, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333844.
Full textKowsari, Assieh. "Analysis of design factors influencing the oxygen transfer efficiency of a Speece Cone hypolimnetic aerator." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/4168.
Full textAlsys, Aivaras. "Mechaninių ir pneumatinių aeratorių efektyvumo analizė." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2008. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20080930_090621-65016.
Full textThe following masters work consists of the analyse of the pneumatic and mechanical aeration systems, these problems and construction. Also explored factors who does influence for the efficiency of the aerators. When the constructions were explored, 3 aerators were selected, the experiments was made and valuated the efficiency. There are 8 chapters: introduction, the object of the analys and description of the problem, review of the explored aeration systems and analys of the constructions, efficiency analysis of mechanical and pneumatic aeration systems, methodology of the analysis and case of the experiment, results of the analysis, conclusions and suggestions, the list of the literature.
Khayi, Noureddine. "Deammonification efficiency in combined UASB and IFAS system for mainstream WWT." Thesis, KTH, Mark- och vattenteknik (flyttat 20130630), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210809.
Full textVatten är nödvändigt för existensen av allt liv på jorden och spelar en avgörande roll i alla mänskliga aktiviteter. Antropogena aktiviteter förorenar denna viktiga resurs och medför stor risk för människors och djurs hälsa samt växter. Kvävebelastning från jordbruket och avloppsvatten i mark- eller vattenmiljön har resulterat till övergödning, vilket är ett miljö- och ekonomiskt problem på grund av en obalans mellan ekosystemtillförseln och den naturliga näringsförbrukningen. I denna studie behandlades avloppsvatten i en pilotskala reaktor med en integrerad fastfilm aktiverat slam (IFAS) som drivs med ett enstegs partial nitritation/Anammox-process. Kväverening från den lågkoncentrerade huvudström avloppsvatten efter Uppflöde Anaerob Slam Blankett reaktor process (UASB) undersöktes. En blandning av olika koncentrationer av upplöst syre och olika luftningsmetoder har testats i pilotskala reaktorn i fem månader uppdelad i fem perioder där temperaturen sattes vid 15° C under hela studien. De bästa resultaten i kväve reningseffektivitet var 52 % i genomsnitt i period 4 varierande mellan 40 och 60 %, luftningsmetod med ett förhållande av R = 1/3 (R = 20 minuter med luftning till 40 minuter utan luftning) och ett upplöst syre Koncentration av 1,3 mg/l. Jämförelsen tog hänsyn till alla former av utsläpp av kväve- och energikostnader för luftning. Under de senaste decennierna har vattenbehandlingsprocesserna haft många positiva utvecklingar, vilket har lett till en kvalitetsförbättring av vatten samtidigt som kostnaden för kväveavlägsnande från avloppsvatten har minskat. För närvarande flyttar kvävereningsteknik från konventionell nitrifikations/denitrifikationsprocessen till partiell nitritation/Anammox (PN/A) -processen kallad deammonification. Det verkar som om den största svårigheten är att upprätthålla en stabil ackumulation av nitrit medan man försöker delvis med nitritation av ammonium. Partiell nitritation/Anammox (PN/A) anses vara mer kostnadseffektivt avlägsnande av kväve från avloppsvatten, mer miljövänligt än konventionella nitrifikations-denitrifikationsprocesser på grund av minskat energibehov för luftning och inget behov av en yttre källa av kol.
Silva, Henrique Joaquim Lopes da Silva e. "Optimization of air micro-bubble bioreactor for the winery wastewater treatment under oxygen-limited conditions." Master's thesis, ISA/UTL, 2012. http://hdl.handle.net/10400.5/5308.
Full textThe energy consumption of wastewater treatment processes had become an important tool parameter for designers and engineers in the wastewater treatment industry, and efforts to improve the energy efficiency of the equipments represent a great challenge. The present study proposes the use of the Air Micro-Bubble Bioreactor (AMBB), with a working volume of 14 dm3 and a hydraulic retention time of 14 days, operating in continuous mode to treat winery wastewater from second racking period, for seven different runs, during 167 days. The organic loads fluctuations, usual in the winemaking industry, and the aeration time rate (ATR), both related to energy costs, were the studied variables. The chemical oxygen demand (COD) was selected as a key parameter to monitor the AMBB performance. The total polyphenol compounds were also followed. The effect of the organic loading rate OLR was assessed by adjusting feed substrate concentration between 0.16-0.44 kg COD m-3 d-1. The ATR varied between 1, 5 and 15 min h-1. Each run was operated until steady state was reached with respect to COD concentration. All runs showed a positive answer for COD removal, having a minimum efficiency of 70%. Also the COD removal efficiency showed to be not dependent on the applied OLR and the decrease in the ATR to 5 min h-1 was accompanied by a nearly three-fold reduction in energy consumption without relevant changing on the final COD removal efficiency (93-96%). However, the total polyphenol compounds removal was highly affected by decreasing the ATR from 15 to 1 min h-1, leading to a decrease in the total polyphenols removal efficiency from 94% to 4%. In the present study, we report for the first time the impact of oxygen-limited conditions in the AMBB performance with emphasis on the efficiency energy use. The polyphenols as a performance indicator, the energy costs of treated wastewater and COD removal efficiency achieved in pilot scale show the technical feasibility of the process, giving a sustainable solution for this important sector of activity.
Niklasson, Isabell. "Energieffektivisering av aerob reningsprocess : Tillsats av biprodukter i skogsindustriellt avloppsvatten." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-28445.
Full textVid framställning av massa, papper och kartong används dagligen stora mängder vatten som måste renas vid det interna reningsverket innan det når recipienten. En av industrierna är Stora Enso, Skogshalls bruk. I det biologiska reningessteget vid Skoghalls bruk används en luftad damm där mikroorganismer med hjälp av syre oxiderar det organiska materialet till koldioxid. Luft pumpas in från botten av dammen och syret kan transporteras från luftbubblorna till vattnet genom diffusion. Problemet vid syresättning av skogsindustriellt avloppsvattnet är att vedrester som exempelvis fettsyror följer med avloppsvattnet och försvårar syretransporten. Tidigare studier visar att vid tillsats av salt förbättras syresättningen och att energianvändningen vid luftningsprocessen minskar. De salter som valts i den här undersökningen är natriumklorid samt mesa och elfilteraska. Varav det två sista är biprodukter från massaframställningen. I många av Sveriges skogsindustrier står elen till luftningsprocessen för mer än 50 % av den totala energianvändningen. Det här arbetet syftar till att undersöka syresättningen av ett skogsindustriellt avloppsvatten med avsikt att energieffektivisera luftningen i det biologiska reningssteget. Den experimentella delen omfattar syresättningsförsök samt mätning av ytspänning vid tillsats av salt i både rent vatten och obehandlat processvatten. Samtliga försök har utförts i labbskala vid Karlstads universitet. Det här arbetet har uppnått sitt mål med att jämföra och mäta hastigheten av syresättning vid tillsats av olika salter i skogsindustriellt avloppsvatten med avsikt att energieffektivisera reningsprocessen. Resultatet tyder på att tillsats av biprodukter kan öka hastigheten vid syresättning av skogsindustriellt avloppsvatten och därmed minska energianvändningen vid den aeroba reningsprocessen. Vid tillsats av elfilteraska i processvattnet ökar hastigheten av syresättningen med 60 %. Det verkliga syrebehovet i dammen, SOTR sjönk från 314 ton O2/dygn till 118 ton O2/dygn. Energibehovet vid luftningsprocessen minskade med 100 MWh/dygn.
Oliveira, Pedro Henrique da Silva. "Influ?ncia da intensidade de aera??o na forma??o do floco de lodo ativado e na efici?ncia de remo??o de mat?ria org?nica." Universidade Federal do Rio Grande do Norte, 2014. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15858.
Full textCoordena??o de Aperfei?oamento de Pessoal de N?vel Superior
In wastewater treatment, activated sludge systems have been a technology widely applied as secondary treatment. During this step, which has a strong biological aspect, it is necessary to introduce oxygen supply for the maintenance of metabolic activity of the bacteria through the aerators. Aeration devices are responsible for most of the energy consumption in this stage. In this background, the influence of three aeration intensities (atmospheric air flow 3.5, 7.0 and 10.5 L.min-1) and the concentration of dissolved oxygen (DO) on the dimension of activated sludge flocs as well as on the efficiency of organic matter removal were assessed using a traditional activated sludge system which was fed with synthetic domestic wastewater. Samples were taken weekly from the three units that make up the system feed, aeration and storage tank in order to verify the Chemical Oxygen Demand (COD). It was established the process efficiency through a comparison between the initial and final COD. Besides the parameters already mentioned, this monitoring work on activated sludge batch system was also observed by Mixed Liquor Suspend Solids (MLSS), Volatile Suspend Solids (VSS), pH and temperature measures. The results have showed a maximum removal efficiency around 75% in the first aeration sequence and approximately 85% for the second and third one. For the first aeration, the DO concentration remained higher than 3.0 mg.L-1 and a diameter range from 10 to 60 μm was observed. In the second e third sequence, the DO concentration remained higher than 4.0 mg.L-1 with a diameter range of 10 until 200 μm. Although the sequence 1 and 2 have presented similar performances for organic matter removal, the sequence 2 promoted a regular floc size distribution and with lower values of Sludge Volumetric Index (SVI) meaning a better flocculating ability. In addition, the results reaffirmed what the literature has reported: higher DO concentrations produce flocs with greater dimensions
No tratamento de ?guas residu?rias, os sistemas de lodos ativados t?m sido uma tecnologia largamente aplicada como tratamento secund?rio. Durante essa etapa, a qual possui uma caracter?stica fortemente biol?gica, ? necess?rio o fornecimento de oxig?nio para a manuten??o da atividade metab?lica das bact?rias atrav?s de aeradores. Os dispositivos de aera??o s?o respons?veis pela maior parte do consumo de energia ao longo dessa fase. Nesse contexto, a influ?ncia de tr?s intensidades de aera??o (vaz?o de ar atmosf?rico de 3,5, 7,0 e 10, 5 L.min-1) e a concentra??o de oxig?nio dissolvido (OD) sobre a dimens?o de flocos de lodo ativado, e bem como sobre a efici?ncia de remo??o foram avaliadas utilizando um sistema tradicional de lodos ativados alimentado com efluente dom?stico sint?tico. Amostras foram retiradas semanalmente das tr?s unidades que compunham o sistema tanque de alimenta??o, de aera??o e de armazenamento para verificar a Demanda Qu?mica de Oxig?nio (DQO). A efici?ncia do processo foi estabelecida atrav?s da compara??o entre a DQO inicial e final. Al?m dos par?metros j? mencionados, este trabalho de monitoramento do sistema de lodos ativados de bancada foi observado tamb?m por meio de medi??es de S?lidos em Suspens?o Totais (SST) e Vol?teis (SSV), pH e temperatura. Os resultados mostraram uma efici?ncia m?xima de remo??o de quase 75% na primeira sequ?ncia de aera??o e aproximadamente 85% para a segunda e terceira sequ?ncias. Para a primeira aera??o, a concentra??o de OD manteve-se maior que 3,0 mg.L-1 e uma faixa de di?metro de 10 a 60 μm foi observada, enquanto que na segunda e terceira sequ?ncia, a concentra??o de OD permaneceu superior a 4,0 mg.L-1 com uma faixa de di?metro de 10 a 200 μm. Embora a sequ?ncia 2 e 3 tenham apresentado, ambas, desempenhos similares para remo??o de mat?ria org?nica, a sequ?ncia 3 promoveu uma distribui??o de tamanho de flocos mais regular e com baixos valores de ?ndices Volum?tricos do Lodo (IVL), configurando em uma melhor habilidade de sedimenta??o. Em adi??o, os resultados reafirmam o que literatura tem relatado, maiores concentra??es de OD produzem flocos com maiores dimens?es
Al, Qarni Hamed M. "Investigating human pharmaceutical compounds present in municipal and hospital wastewaters and options for their removal." Thesis, Abertay University, 2015. https://rke.abertay.ac.uk/en/studentTheses/3e005266-63c0-4b98-b154-b7693dc2e37e.
Full textJiun, Liou Yi, and 劉怡君. "Aeration Efficiency in Immobilized Nitrification Sludge Reactor." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/43897572644679091457.
Full textLin, Jyun-Sheng, and 林峻陞. "The efficiency of petrochemical wastewater treatment by deep aeration system." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/31760629638585672459.
Full text國立雲林科技大學
環境與安全工程系碩士班
95
This study was focus at the efficiency of petrochemical wastewater treatment by deep aeration system The treating process was carried out from August, 2004 to September, 2006. There are 7 parameters including pH, COD, BOD loading, MLSS, SV30, SS was monitored. From the result of experiment, control at pH = 7∼8, MLSS = 1000∼2000 mg/l, SV30 = 100ml/l, DO = 4∼6 mg/l, retention time = 30∼35 hrs, SVI = 80~200, BOD loading = 0.25∼0.35 kg COD/kg MLSS-day. The removal efficiency of COD is 94% and the effluent of COD is 59.5 mg/l. This effluent can meet the effluent standard.
Tsai, Kon-Jung, and 蔡高榮. "The Investigation on Oxygen Transfer Efficiency for Combination Aeration System." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/65157566592282857753.
Full text國立高雄第一科技大學
環境與安全衛生工程所
91
The oxygen transferring efficiencies for deep-shaft aeration processes was investigated in this study to develop energy-saving aerator systems. Both diffusers and jet aerators were tested in the study and their oxygen transferring efficiencies were compared, too. Several research objectives including to conduct aerator tests in a full-scale pilot aeration tank, to measure aeration efficiencies of both diffuser and jet aeration systems, to adopt computational fluid dynamics (CFD) software to simulate both fluid and oxygen concentration fields in the reaction tank and to elucidate their relationships, and, finally, to develop a energy-saving aerator system for deep-shaft aeration processes were interested in this study. Series of purging experiments were conducted in a deep-shaft aeration tank by using ambient air as an oxygen source. At least two water depths of 9 m and 11 m, respectively, were tested in this study. Before aeration testes, proper amount of Na2SO3 and CoCl2 was added to the tank to consume the residual D.O. in water and more than 4 D.O. meters with data logs were assembled in the deep-shaft aeration tank to measure dissolved oxygen concentrations during the experiments. Both oxygen transfer coefficients (KLa) and oxygen transfer rates (OTR) for the aeration systems were calculated for the tests. The experimental results showed the KLa value for traditional diffuser was 2.035 hr-1 and 1.870 hr-1 for the water depth of 9 m and 11m, respectively. But they were lower than those in the jet aeration system. 2.937 hr-1 and 2.537 hr-1 of KLa for water depth of 9 m and 11m, respectively, could be achieved in jet abreaction systems. The oxygen transfer rates for the jet aeration system were 0.378 kg-O2/KW-hr of water depth of 9 m and 0.429 kg-O2/KW-hr of water depth 11 m, respectively, and both of them were higher than diffuser aerator system. The jet aeration system can save 7.24-31.93 % energy consumption than the diffuser. There are several reasons that may cause jet aeration system achieving higher oxygen transfer efficiencies. The jet aeration system produces higher mixing conditions, which can enhance oxygen transfer rates, is one reason and less power consumption in the Ventric pipe also cause it save more energy. This research also indicates that the highest aeration efficiencies can be achieved as the flowrate ratio of the aeration air to circle water equal to 0.8.
Su, Yi-Feng, and 蘇一峰. "Study of the Efficiency and Capability of Aeration Cone in the Recirculating Culture System." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/21150039420578240555.
Full text國立中興大學
農業機械工程學系
87
The aeration cone is the main equipment of pure oxygen absorption system for the recently domestic used water recirculating culture system. The operational control of the aeration cone which controls the Dissolved Oxygen (DO) value of water outlet and the oxygen transfer rate, is mainly by changing the inlet water flowrate and the regulatory valve setting pressure of pure oxygen. In this study, the temperature of water was maintained at about 30℃. When the inlet water flowrate of the aeration cone was controlled between 270-330L/min, the DO value of water outlet would demonstrate a decreasing tendency with the increasing of the inlet water flowrate. When the regulatory valve setting pressure was controlled between 0.35-0.40kg/cm2 (cm square), both of the DO value of water outlet and the oxygen transfer rate would increase as the regulatory valve setting pressure raised. The experimental results showed that the oxygen transfer rate was between 1.137-1.647g/min, the oxygen absorption efficiency was maintained between 72.4-81.5%, the oxygen transfer efficiency was between 0.0681-0.0941kg/kW-hr, the aeration effectiveness was 60.67-70.87%, and the utilization efficiency was maintained between 44.2-58.7%. Furthermore, the relative height between positions of the culture tank and the aeration cone can be designed and planned using Bernoulli's equation. The water lever inside the aeration cone would drop as the regulatory valve setting pressure increased and raise as the inlet water flowrate increased. The water level inside the aeration cone must be kept at least over 60 cm to avoid the water level being too low as the undissolved oxygen inside the aeration cone smuggled with the water flow to the culture tank resulting a waste of oxygen leaking to the atmosphere.
Chen, Chia-Jen, and 陳嘉仁. "Application of immobilized Cells to wastewater treatment Study the efficiency of Intermittent Aeration Process." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/37054616048981293949.
Full textHu, Jing. "Evaluation of parameters influencing oxygen transfer efficiency in a membrane bioreactor." Thesis, 2006. http://hdl.handle.net/10125/20477.
Full textVega, Floradelle Aboga, and Floradelle Aboga Vega. "IMPROVING WATER POLLUTION REMOVAL EFFICIENCY BY PARTIAL CIRCULATION AND AERATION IN SUBSURFACE FLOW CONSTRUCTED WETLANDS." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/63891250546773254573.
Full text嘉南藥理大學
環境資源管理系
105
This study aimed to improve the pollution removal efficiency of subsurface flow constructed wetlands by partial circulation and aeration. The experiment had been divided into two systems: the experimental system (HSSF-A) where partial circulation and aeration have been installed and the control system (HSSF-B) which was only a traditional a traditional subsurface flow constructed wetlands. Both models have the same design and operating conditions treating campus wastewater. Based on the experimental results, there is an increase from 43.7% on HSSF-B to 63.4% on HSSF-A under the condition of low concentration of biochemical oxygen demand (12.16mg / L). Moreover, the data have shown that the experimental system (HSSF-A) outperformed the control system (HSSF-B) with a recorded removal of ammoniacal nitrogen of 98% and 12%, respectively. Hence, there was no observed NO2- - N accumulation in both systems giving low effluent concentrations of 0.02 and 0.01 mg/L, respectively, as well as with the nitrate concentration. These results proved that aeration and partial circulation can effectively improve the organic pollution and nitrogen removal efficiency of the system.
Bellandi, Giacomo. "N2O emissions and aeration efficiency in wastewater treatment: improved monitoring, mechanistic modelling and data mining." Doctoral thesis, 2018. http://hdl.handle.net/2158/1127922.
Full textKuo, Nien-Tsu, and 郭念祖. "Artificial aeration to increase nitrogen removal efficiency of three-zone free water surface (FWS) constructed wetlands." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/17639669302106820469.
Full text國立宜蘭大學
環境工程學系碩士班
99
Recently, not only economic is growing fast, but water pollution is getting serious day after day. Many countries develop constructed wetland as a new technique for water pollution treatment, due to the lower cost of operation and easier maintenance. In this study, experiments were carried out in a laboratory scale three-zone free water surface constructed wetlands (FWS) which is divided into three units including full vegetabled zone 1, open water area and full vegetabled zone 2. The experiments are designed to test aeration and no aeration environment to provide varied microbes and plants proceeding purification. Because the nitrification of the open water area is not obvious in three-zone free water surface constructed wetland, the overall nitrogen removal rate doesn’t reach high value as expected. Consequently, artificial aeration on open water area will promote both nitrification and nitrogen removal. The objective of this study is to investigate the nitrogen removal efficiency of different pollution loading in three-zone free water surface constructed system. The air-water ratio and aeration position were used as parameters. The experiments were conducted the nitrogen form change and the effect to water quality in three units. The study involved low and high nitrogen pollution loading which include two and five tests, respectively. Experiments of two pollution loading tests contained both no aeration and aeration. In addition, we also investigate the high pollution loading test efficiency in different air-water ratio (6:1 and 12:1) at bottom and middle layer. The experimental result showed that NH3-N removal of no aeration and aeration in low pollution loading test were 94.9 % and 97.7 %, respectively. TN (total nitrogen) removal were 77.3 % and 85.3 %, BOD removal were 93.8 % and 95.4 %, respectively. Additionally, NH3-N removal of air-water ratio (12:1) at middle layer in high pollution loading test was 89.7 %. However, NH3-N removal of no aeration in high pollution loading test, which was the lowest removal efficiency, declined to 29.3 %, and the others were between 51.9 % and 54.3 %. TN removal ranged from 48.5 % to 60.0 %. BOD had higher removal efficiency, the removal ranged between 89.4 % and 97.5 %. In summary, aerating in low pollution loading will improve the removal of NH3-N, TN and BOD. It illustrated that aerating in bottom layer could increase nitrogen removal. In contract, aerating for high pollution loading, despite the significant increasing removal of NH3-N and BOD, the removal of TN decrease. It showed that aeration can enhance nitrification availably, and let NH3-N transform into NOx-N. Futhermore, artificial aeration in air-water 12:1 at middle layer is the most effective. Consequently, if aerating appropriately in the open water area in three-zone free surface water constructed wetland, dissolved oxygen will increase. As a result, promote nitrification can improve the nitrogen transformation and removal efficiency for the constructed wetlands.
Wu, Guo Huei, and 吳國輝. "Improvement of Pollution Removal Efficiency of Subsurface Flow Constructed Wetland with Artificial Aeration and Elemental Iron." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/k3968u.
Full text嘉南藥理大學
環境資源管理系
106
To improve the low efficiencies of pollutant degradation induced by lacking of sufficient oxygen transportation, there were two modifications of the artificial aeration and nitrate-dependent anaerobic ferrous oxidation (NAFO) was installed in a horizontal subsurface flow (HSSF) constructed wetland (CW). In the campus of Chia-Nan University of pharmacy and science, there were 2 systems established in this study which included an experimental system and a control one with identical dimension. The former (HSSF-H) installed those modifications while the other (HSSF-F) was regarded as a control system which only possessed a gravel bed and the aquatic plant (Hydrocotyle verticillata Thunb.). In the stage I of the experimental program, there only installed an artificial aeration in HSSF-G and the NAFO device added to HSSF-G in the stage II. The water quality parameters; biochemical oxygen demand (BOD), ammonia-nitrogen (ammonia-nitrogen; NH3-N), nitrate-nitrogen, nitrite- nitrogen, total Kjeldahl nitrogen (TKN), total nitrogen (TN), total Phosphorus (TP), ferrous iron (Fe2+), and total iron (TFe) were used to evaluate the removal efficiencies of HSSF-H and HSSF-F. The conclusions obtained in this study was described in the following. According the experimental results, there was significant differences between the BOD removal ratios of HSSF-G and HSSF-F. In the stage I, the removal ratios of HSSF-G and HSSF-F were 91.3 % and 71.5 %, respectively. When the NAFO device activated in the stage II, the removal ratios of HSSF-G maintained at 93.6 % and that of HSSF-F was 63.7 %. It implied that the aeration could effectively improve the BOD removal performance and the NAFO device played no negative role in the BOD removal process. It also found a similarity between the removal tendencies of NH3-N and TKN in HSSF-F and HSSF-G. In the stage I, the removal ratio of NH3-N in HSSF-G, 77.7%, was not significantly different from that in HSSF-F, 86.1%. As for the stage II, the removal ratios of NH3-N were 87.1 % and 86.6 %, respectively. No significant difference existed between these removal ratios of NH3-N. Similar tendency also occurred in the removal of TKN. In the stage I, a lower removal ratio of TKN in HSSF-G, 72.1 %, still observed and a higher one, 83.1 %, without significant difference from that of HSSF-G resulted in in HSSF-F. When coming to stage II, the removal ratios of TKN in HSSF-G and HSSF-F, 81.0% and 80.6%, were quit close to each other. As for the removal of TN in the stage I, they were 63.7 % and 82.8 % for HSSF-G and HSSF-F, respectively. In the stage II, those removal ratios became 69.5 % and 78.2 %, respectively. A lower removal ratio of HSSF-G mainly resulted from the lower removal ratio of TKN and NO3─-N which might be induced by the competition of organic carbon source. There observed a significant difference between the TP removals of HSSF-G and HSSF-F. No effective improvement of TP removal was activated by NAFO process. It was because that the suitable pH for the sedimentation of ferric phosphate was about 8 while the pH in HSSF-G ranges from 6.58 to 7.06. It was not a proper pH for the sedimentation of ferric phosphate.
Yeh, Ming-Tsan, and 葉明燦. "The investigation on oxygen transfer efficiency for diffused aeration system-Taking membrane fine bubble diffuser as an example." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/79105934553988237412.
Full text國立中央大學
環境工程研究所碩士在職專班
99
Aeration is a key control activated sludge processes, which can be achieved by various methods. The performance of membrane fine bubble diffuser was studied here. A model system similar to real aeration tank, that is, depth of 3~4 m, was used to eliminate the size effects in studies of small scale. The effects of temperature, water depth, aeration velocity, and salt concentration on the overall oxygen transfer coefficient (KLa20) were examined. The temperature correction factor was confirmed to be similar to that suggested by ASCE. The KLa20 was also found to be decreased than increased before 200 mg/L of sodium chloride and remained similar after that. It was similar to the effects of suspended solids, for which the reason is still not clear. The oxygen transfer coefficient and correction factors of two different municipal wastewaters and a organic pigment wastewater were examined. It was found that although the municipal wastewater came from different places and the compositions of them were slightly different, the values of the correction factors are similar, which is 0.67 ~ 0.69. However, for the organic pigment wastewater, the correction factors varied significantly from batch to batch. The result suggested that due to the variation in wastewater quality, the aeration efficiency might be affected correspondingly and, therefore, the performance of activated sludge system was not stable.
CHEN, HSU-HUI, and 陳旭暉. "Effects of aeration models and bio-gravel wall on the pollution removal efficiency of free water surface constructed wetland." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/4se7mc.
Full text嘉南藥理大學
環境資源管理系
106
In order to enhance the removal efficiency of constructed wetland (CW) under high load conditions, this study set up three sets of small modular systems for surface flow constructed wetlands which includes FWS-A operated in a continuous aeration mode with a shorter bio-gravel wall, FWS-B operated in an intermittent aeration with a longer bio-gravel wall, and a control one (FWS-C). By these FWS CWs, this study investigated the effects of the bio-gravel wall length and aeration mode on the of pollutants removal efficiency. During the experimental period, it included 5 stages with different hydraulic retention times (HRT) and aeration modes.The performance of FWS CWs was evaluated by the water quality parameters which included biochemical oxygen demand (BOD), total ammonia-nitrogen (TAN), nitrite-nitrogen (NO2--N), nitrate-nitrogen (NO3--N), total Kjeldahl nitrogen (TKN), total nitrogen (TN), and total phosphorous (TP).. During the experimental period at Stage-III, FWS-A operated under a continuous aeration without control dissolved oxygen (DO). FWS-B aerated on an aeration ratio (AR=8 : 16; 8 hours aeration : 16 hours non-aeration). The HRT of FWS-A, FWS-B, and FWS-C were 3.24. d, 3.27 d, and 2.28 d, respectively. From the experimental results, the removal rates of BOD were 70.3 %, 64.2 %, and 9.2 %, respectively. The TAN removal rates were: 99.6 %, 95.9%, and 81.5 %, respectively. The TKN removal rates were 97.9 %, 97 %, and 77.7 % and TN removal rates were 81.5 %, 89.8 %, and 76.4 %, respectively. By an optimizing process of Stage-IV, FWS-A operated under a continuous aeration but controlled the DO, while FWS-B intermittently aerated for AR=6 : 6. The HRT of FWS-A, FWS-B, and FWS-C system were: 1.52 d, 1.54 d, and 1.48 d, respectively and the responding removal ratios of BOD were 76.9%, 67.2%, and 37.6%, respectively. The TAN removal rates were 93.7%, 95.0%, and 73.1%, respectively. The TKN removal rates were 79.5 %. 84%, and 61.4% and TN removal rates were 76.3 %, 83.9%, and 61.5%, respectively. These results showed that the longer the HRT in CW operation was, the better the removal efficiency would be, but the experimental group can also be used under the finer operation strategy. A half-time reduction in HRT created a quite good removal performance. According to the results of the experiments in Stage-I~V, the artificial aeration was quite helpful for the removal of nitrogenous pollutants and organic pollutants by CW and the bio-gravel wall in this research system could also improve the artificial aeration of FWS CW. The bio-gravel wall also improved the accumulation of NO3--N caused by the continuous aeration in FWS CW. For the removal of TP, the removal rate was not affected by the aeration mode and bio-gravel wall.
Chuang, Kai-Ming, and 莊凱名. "The Characteristics of Stratified Dissolved Oxygen and the Aeration Efficiency at the Midstream of Tanshui River and the Lover River." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/24801977141586238189.
Full text國立臺灣大學
生物環境系統工程學研究所
96
The dissolved oxygen(DO)is nearly none at the bottom of water at the midstream of Tanshui river. Therefore, this study is applying an air-lift column to deal with low DO condition of water and investigating hydraulic characteristic of Dadaocheng Basin as air-lift column design reference resources. In this study, the air-lift column is a low energy costing and intermittently operating device which can mix different water layers. Field experiments in summer and winter are operated to measure the oxygen consumption rate of the sediment. And the air-lift column efficiency of the increased oxygen rate、the water mixing ability and the oxygen spread of ability are fast. Standard experiment of air-lift column is carried out in static state water. And compare the efficiency of the two types of column design. In addition, this study measures the increased oxygen efficiency and diffusive ability of the aeration boat to build up the database for river renovation. Results show DO below 3ppm and without-delaminating during the period of flood tide and only about 1ppm in the ebb tide in the Dadaocheng watershed. The oxygen consumption rate of the sediment are 9±6 mg/m2/min in summer (water temp. 26℃) and 5±5 mg/m2/min in winter (water temp. 19℃). The standard aeration efficiency (SAE) of air-lift column is 1.50 kgO2/kw/hr, up-welled water volume is 621~629 ml. when it is applied to the low speed flow watershed, the agitated range is about 3 m、the increased oxygen rate at the outlet is 0.86mg/l and the electric cost is 0.38 NT dollar/mgO2/l/hour. The increased oxygen rate of the aeration boat in Kaohsiung is 1.8mg/l and electric cost is 6.99 NT dollar/mgO2/lhour. Comparing water quality improvement ability and the oxygen spread of ability between indirect oxygen increasing air-lift column and continuous aeration boat, indirect oxygen increasing method has better performance than continuous oxygen increasing method. To sum up, the air-lift column can be one of the physics methods to effect oxygen increasing.
-ChangTu, Yu, and 杜禹璋. "Design of a High Efficient Aerator." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/st26j9.
Full text國立成功大學
機械工程學系
107
The high-efficiency aerator is a pump with upper and lower blades. The upper layer is a air pump and lower layer is a water pump. The air and water pushed out by the blade and mixed at a pipe. It can increase the amount of dissolved oxygen. The power used in this design is a 750W (1HP) DC brushless motor that produces micron-sized bubbles and a jet of water up to 13 meters. In addition, the pump can be rotated 360 degrees. After the experimental measurement, it is proved that the aeration effect caused by it is more than 100 times that of the traditional waterwheel. Overall, this design has the effect of saving electricity and super high oxygen. It will greatly improve the breeding environment, reduce subsidence of the formation, and improve sewage treatment efficiency. Rate and improve the problem of water eutrophication. This design follows the guidance of Dr. Sen-Yung Lee and Dr. Shueei-Muh Lin and refer to the design derivation of Xu Shuzheng's master thesis of Kunshan University of Science and Technology. Then, We modified the size of the pump and designed a highly efficient aerator that met the requirements.