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Yueming Jiang - One of the best experts on this subject based on the ideXlab platform.
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short term anaerobic Pure Oxygen and refrigerated storage conditions affect the energy status and selective gene expression in litchi fruit
Lwt - Food Science and Technology, 2015Co-Authors: Ting Liu, Xuewu Duan, Hui Wang, Jianfei Kuang, Chongde Sun, John Shi, Yueming JiangAbstract:Abstract Harvested litchi fruit were stored under cold temperature, short-term anaerobic and Pure Oxygen conditions to explore the energy characteristics and the genes that are related to pericarp browning. Fruits in short-term anaerobic and Pure Oxygen environments were stored at 25 °C. Additionally, fruits were stored at 1 °C for 1, 2 or 3 weeks and were then subjected to a post cold storage at 25 °C for up to 48 h. Short-term anaerobic and Pure Oxygen storage decreased the browning index and relative abundance of the ATP synthase β subunit ( LcAtpB ) and increased respiration intensity, ATP content, the contribution of an alternate oxidation pathway to the total respiration (ρV AP /Vt) and the transcription of plant uncoupling mitochondria protein 1 ( LcUCP1 ), with short-term anaerobic treatment being more significant than Pure Oxygen. Cold storage decreased the ATP levels but increased the browning index, respiration intensity, ρV AP /Vt and the transcription of alternative oxidase 1 ( LcAOX1 ), LcUCP1 , ADP/ATP carrier 1 ( LcAAC1 ) and sucrose non-fermenting-1-related kinase 2 ( LcSnRK2 ) during the post storage shelf-life at 25 °C. The data suggest that the energy level is closely related to the respiratory activity and is involved in the browning control of harvested litchi fruit. Transcripts of the 5 genes were found to be involved in the energy regulation and quality control of postharvest litchi fruit.
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energy status of kiwifruit stored under different temperatures or exposed to long term anaerobic conditions or Pure Oxygen
Postharvest Biology and Technology, 2014Co-Authors: Zihui Huang, Hui Wang, Lifang Guo, Yifei Liu, Hongwen Huang, Yueming JiangAbstract:Abstract Energy status is a key factor switching on ripening and senescence of fruit. In this study, kiwifruit was stored at 15 °C or 25 °C or exposed to long-term N 2 and O 2 . Energy characteristics and transcript abundance of energy-related genes cloned from kiwifruit in relation to fruit quality, respiration rate and ethylene production rate were investigated. The concentrations of adenylate triphosphate (ATP), adenylate diphosphate (ADP) and adenylate monophosphate (AMP) peaked during storage in the following order: AMP, ADP and ATP. The transcript abundances of ADP/ATP carrier 1 ( AdAAC1 ), ATP synthase β subunit ( AdAtpB ) and sucrose non-fermenting-1-related kinase 1 ( AdSnRK1 ) fluctuated during storage. Transcript abundance peaks of alternative oxidase 2 ( AdAOX2 ) and uncoupling protein ( AdUCP ) appeared after 2 days of storage, consistent with the peak in respiratory rate. Low temperature (15 °C) and long-term N 2 treatment maintained higher firmness, blocked respiration and energy production, and lowered the total soluble solids (TSS) content, ATP level, and ATP/AMP ratio, whilst these treatments increased the transcript abundance of AdAAC1 and AdSnRK1 . Furthermore, low temperature storage increased the transcript abundance of AdAtpB , AdAOX2 and AdAUCP . Long-term O 2 application dramatically elevated the transcript abundance of AdAOX2 and AdUCP , especially at the beginning of storage. It was suggested that ripening and senescence of kiwifruit was closely related to the energy level, which in turn was positively correlated with respiration activity and regulated in coordination with AdAAC1 , AdAtpB , AdAOX2 , AdAUCP and AdSnRK1 .
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effect of Pure Oxygen atmosphere on antioxidant enzyme and antioxidant activity of harvested litchi fruit during storage
Food Research International, 2011Co-Authors: Xuewu Duan, Dandan Zhang, Xinguo Su, Yueming JiangAbstract:Abstract The effects of Pure Oxygen on pericarp browning, reactive Oxygen species (ROS) metabolism, antioxidant enzyme and antioxidant activity of harvested litchi fruit were investigated. Application of Pure Oxygen significantly prevented pericarp browning and delayed the increase in membrane permeability of litchi fruit during storage. Litchi fruit exposed to Pure Oxygen showed a lower level of lipid peroxides, compared to control fruit, with the delay in the increases of both H 2 O 2 content and superoxide production rate. Furthermore, it was found that the treatment with Pure Oxygen induced the activities of superoxide dismutase (SOD), ascorbated peroxidase (APX) and catalase (CAT), which could be beneficial in scavenging of H 2 O 2 and superoxide and alleviating lipid peroxidation. In addition, antioxidant ability (reducing power and free-radical scavenging activity against DPPH radical, superoxide anions and hydroxyl radical) of methanol extracts from litchi fruit pericarp declined gradually, with decreasing contents of anthocyanins and phenolic compounds, as storage time of the fruit progressed. There was a linear relationship between the contents of either anthocyanins or phenolic compounds and antioxidant ability or free radical scavenging activity. Treatment with Pure Oxygen markedly increased antioxidant ability, which was related to higher levels of anthocyanins and phenolic compounds, compared with those of control fruit. It is suggested that enhanced antioxidant activity and antioxidant enzyme induced by Pure Oxygen may contribute to alleviating lipid peroxidation and maintenance of membrane integrity, which reduced decompartmentation of enzymes and substrates, resulting in enzymatic browning.
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effects of Pure Oxygen on the rate of skin browning and energy status in longan fruit
Food Technology and Biotechnology, 2005Co-Authors: Yueming Jiang, Xuewu Duan, Hai Liu, Wenbin Lin, Yonghua ZhengAbstract:Summary Postharvest pericarp browning is one of the main problems resulting in reduced shelf life of longan fruit. Experiments were conducted to examine the changes in concentrations of adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP), energy charge levels and activities of polyphenol oxidase (PPO) and peroxidase (POD) in relation to pericarp browning of longan fruit. Fruit kept for 6 days in Pure Oxygen atmosphere at 28 C showed lower browning indices and higher ATP concentrations but lower AMP concentrations and higher respiratory rates, compared to those kept in air. While energy charge decreased during storage, the decrease was delayed markedly by exposure to Pure Oxygen. There was a lower energy charge in the browned fruit, which was associated with rapid increase in malondialdehyde concentration. Enhanced respiration of longan fruit exposed to Pure Oxygen can result in the production of ATP. However, fruit exposed to Pure Oxygen exhibited higher activities of PPO and POD, which was not associated with reduced skin browning inhibition. These results supported the hypothesis that skin browning of postharvest longan fruit may be a consequence of membrane injury caused by the lack of maintenance energy.
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role of Pure Oxygen treatment in browning of litchi fruit after harvest
Plant Science, 2004Co-Authors: Xuewu Duan, Yueming Jiang, Hai Liu, Yonghua Zheng, Zhaoqi Zhang, Weibo JiangAbstract:Abstract Experiments were conducted to test the effect of Pure Oxygen treatment on energy charge of peel tissue which may affect membrane integrity during browning of litchi fruit after harvest. Fruit were kept in air or Pure O 2 for up to 6 days at 25 °C. Changes in browning index, membrane permeability, contents of ATP, ADP and AMP and energy charge were measured. As fruit browned, membrane permeability increased gradually, while ATP content and energy charge decreased rapidly. Exposure to Pure O 2 significantly prevented peel browning, maintained high levels of ATP, ADP and energy charge, and reduced increase in membrane permeability of peel tissue of litchi fruit after 4 days of storage. The inhibition of browning of litchi fruit peel suggested that high levels of ATP, ADP and energy charge of litchi fruit kept in Pure O 2 may contribute to maintenance of membrane integrity which reduced decompartmentation of enzymes and substrates resulting in enzymatic browning.
J M Poyatos - One of the best experts on this subject based on the ideXlab platform.
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influence of sludge retention time and temperature on the sludge removal in a submerged membrane bioreactor comparative study between Pure Oxygen and air to supply aerobic conditions
Journal of Environmental Science and Health Part A-toxic\ hazardous Substances & Environmental Engineering, 2014Co-Authors: F A Rodriguez, Juan Carlos Leyvadiaz, Patricia Reboleirorivas, J Gonzalezlopez, E Hontoria, J M PoyatosAbstract:Performance of a bench-scale wastewater treatment plant, which consisted of a membrane bioreactor, was monitored daily using Pure Oxygen and air to supply aerobic conditions with the aim of studying the increases of the aeration and sludge removal efficiencies and the effect of the temperature. The results showed the capacity of membrane bioreactor systems for removing organic matter. The alpha-factors of the aeration were determined for six different MLSS concentrations in order to understand the system working when Pure Oxygen and air were used to supply aerobic conditions in the system. Aeration efficiency was increased between 30.7 and 45.9% when Pure Oxygen was used in the operation conditions (a hydraulic retention time of 12 h and MLSS concentrations between 4,018 and 11,192 mg/L). Sludge removal efficiency increased incrementally, from 0.2 to 1.5% when Pure Oxygen was used at low sludge retention time and from 1.5% to 15.4% at medium sludge retention time when temperature conditions were lower tha...
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influence of mixed liquid suspended solids and hydraulic retention time on Oxygen transfer efficiency and viscosity in a submerged membrane bioreactor using Pure Oxygen to supply aerobic conditions
Biochemical Engineering Journal, 2012Co-Authors: F A Rodriguez, Patricia Reboleirorivas, E Hontoria, Francisco Osorio, M V Martineztoledo, J M PoyatosAbstract:Abstract The performance of a wastewater bench-scale membrane bioreactor (MBR) treatment plant using Pure Oxygen conditions was monitored daily to provide aerobic conditions. The results showed the capacity of the MBR system to remove organic material over at hydraulic retention time (HRT) of 12 h and 18 h. The alpha-factors of aeration were determined at three different mixed liquid suspended solids (MLSS) concentrations, in order to understand the system performance when Pure Oxygen was used to provide the aerobic conditions of the MBR system. Under these working conditions, an alpha-factor in the range 0.90–0.12 was obtained when the HRT of 18 h was performed, and the MLSS concentration increased from 4300 to 10,275 mg/L. Additionally, an alpha-factor in the range of 0.28–0.02 was obtained at HRT of 12 h and the MLSS increased from 4071 to 11,192 mg/L. Our study suggested significant changes in the behaviour of the biological system (viscosity, aeration efficiency, organic matter removal) when the concentration of MLSS was increased and the HRT decreased in the bioreactor, decreasing the aeration efficiency in both cases. Furthermore, the efficiency of aeration seems to be more affected by MLSS concentration than by HRT under our operating conditions over the range studied.
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bacterial community structure and enzyme activities in a membrane bioreactor mbr using Pure Oxygen as an aeration source
Bioresource Technology, 2012Co-Authors: Kadiya Calderon, Patricia Reboleirorivas, J M Poyatos, M V Martineztoledo, Alejandro Gonzalezmartinez, Camino Monteropuente, Belen Juarezjimenez, B RodelasAbstract:Abstract A pilot-scale membrane bioreactor was used to treat urban wastewater using Pure Oxygen instead of air as a source of aeration, to study its influence on bacterial diversity and levels of enzyme activities (acid and alkaline phosphatases, glucosidase, protease, and esterase) in the sludge. The experimental work was developed in two stages influenced by seasonal temperature. Operational parameters (temperature, pH, BOD 5 , COD, total and volatile suspended solids) were daily monitored, and enzyme activities measured twice a week. Redundancy analysis (RDA) was used to reveal relationships between the level of enzyme activities and the variation of operational parameters, demonstrating a significant effect of temperature and volatile suspended solids. Bacterial diversity was analyzed by temperature-gradient gel electrophoresis of PCR-amplified partial 16S rRNA genes. Significant differences in community structure were observed between both stages. Sequence analysis revealed that the prevalent Bacteria populations were evolutively close to Alphaproteobacteria (44%), Betaproteobacteria (25%) and Firmicutes (17%).
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kinetic study and Oxygen transfer efficiency evaluation using respirometric methods in a submerged membrane bioreactor using Pure Oxygen to supply the aerobic conditions
Bioresource Technology, 2011Co-Authors: F A Rodriguez, Patricia Reboleirorivas, J Gonzalezlopez, J M Poyatos, Francisco Osorio, E HontoriaAbstract:Abstract The performance of a wastewater bench-scale ultrafiltration membrane bioreactor (MBR) treatment plant using Pure Oxygen to supply the aerobic conditions for 95 days was studied. The results showed the capacity of the MBR systems to remove organic material under a hydraulic retention time of 12 h and a sludge retention time of 39.91 days. Aeration represents its major power input; this is why the alpha-factor of the aeration and kinetic parameters (design parameters) were determined when the mixed liquid suspended solids (MLSS) was increased from 3420 to 12,600 mg/l in order to understand the system. An alpha-factor in the range 0.462–0.022 and the kinetic parameters measured with the respirometric method ( K M of 73.954–3.647 mg/l, k d of 0.0142–0.104 day −1 , k H of 0.1266–0.655 day −1 , and the yield mean coefficient of 0.941) were obtained. Our study suggested significant changes in the behaviour of the biological system when the concentration of MLSS was increased.
E Hontoria - One of the best experts on this subject based on the ideXlab platform.
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influence of sludge retention time and temperature on the sludge removal in a submerged membrane bioreactor comparative study between Pure Oxygen and air to supply aerobic conditions
Journal of Environmental Science and Health Part A-toxic\ hazardous Substances & Environmental Engineering, 2014Co-Authors: F A Rodriguez, Juan Carlos Leyvadiaz, Patricia Reboleirorivas, J Gonzalezlopez, E Hontoria, J M PoyatosAbstract:Performance of a bench-scale wastewater treatment plant, which consisted of a membrane bioreactor, was monitored daily using Pure Oxygen and air to supply aerobic conditions with the aim of studying the increases of the aeration and sludge removal efficiencies and the effect of the temperature. The results showed the capacity of membrane bioreactor systems for removing organic matter. The alpha-factors of the aeration were determined for six different MLSS concentrations in order to understand the system working when Pure Oxygen and air were used to supply aerobic conditions in the system. Aeration efficiency was increased between 30.7 and 45.9% when Pure Oxygen was used in the operation conditions (a hydraulic retention time of 12 h and MLSS concentrations between 4,018 and 11,192 mg/L). Sludge removal efficiency increased incrementally, from 0.2 to 1.5% when Pure Oxygen was used at low sludge retention time and from 1.5% to 15.4% at medium sludge retention time when temperature conditions were lower tha...
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influence of mixed liquid suspended solids and hydraulic retention time on Oxygen transfer efficiency and viscosity in a submerged membrane bioreactor using Pure Oxygen to supply aerobic conditions
Biochemical Engineering Journal, 2012Co-Authors: F A Rodriguez, Patricia Reboleirorivas, E Hontoria, Francisco Osorio, M V Martineztoledo, J M PoyatosAbstract:Abstract The performance of a wastewater bench-scale membrane bioreactor (MBR) treatment plant using Pure Oxygen conditions was monitored daily to provide aerobic conditions. The results showed the capacity of the MBR system to remove organic material over at hydraulic retention time (HRT) of 12 h and 18 h. The alpha-factors of aeration were determined at three different mixed liquid suspended solids (MLSS) concentrations, in order to understand the system performance when Pure Oxygen was used to provide the aerobic conditions of the MBR system. Under these working conditions, an alpha-factor in the range 0.90–0.12 was obtained when the HRT of 18 h was performed, and the MLSS concentration increased from 4300 to 10,275 mg/L. Additionally, an alpha-factor in the range of 0.28–0.02 was obtained at HRT of 12 h and the MLSS increased from 4071 to 11,192 mg/L. Our study suggested significant changes in the behaviour of the biological system (viscosity, aeration efficiency, organic matter removal) when the concentration of MLSS was increased and the HRT decreased in the bioreactor, decreasing the aeration efficiency in both cases. Furthermore, the efficiency of aeration seems to be more affected by MLSS concentration than by HRT under our operating conditions over the range studied.
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kinetic study and Oxygen transfer efficiency evaluation using respirometric methods in a submerged membrane bioreactor using Pure Oxygen to supply the aerobic conditions
Bioresource Technology, 2011Co-Authors: F A Rodriguez, Patricia Reboleirorivas, J Gonzalezlopez, J M Poyatos, Francisco Osorio, E HontoriaAbstract:Abstract The performance of a wastewater bench-scale ultrafiltration membrane bioreactor (MBR) treatment plant using Pure Oxygen to supply the aerobic conditions for 95 days was studied. The results showed the capacity of the MBR systems to remove organic material under a hydraulic retention time of 12 h and a sludge retention time of 39.91 days. Aeration represents its major power input; this is why the alpha-factor of the aeration and kinetic parameters (design parameters) were determined when the mixed liquid suspended solids (MLSS) was increased from 3420 to 12,600 mg/l in order to understand the system. An alpha-factor in the range 0.462–0.022 and the kinetic parameters measured with the respirometric method ( K M of 73.954–3.647 mg/l, k d of 0.0142–0.104 day −1 , k H of 0.1266–0.655 day −1 , and the yield mean coefficient of 0.941) were obtained. Our study suggested significant changes in the behaviour of the biological system when the concentration of MLSS was increased.
Patricia Reboleirorivas - One of the best experts on this subject based on the ideXlab platform.
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influence of sludge retention time and temperature on the sludge removal in a submerged membrane bioreactor comparative study between Pure Oxygen and air to supply aerobic conditions
Journal of Environmental Science and Health Part A-toxic\ hazardous Substances & Environmental Engineering, 2014Co-Authors: F A Rodriguez, Juan Carlos Leyvadiaz, Patricia Reboleirorivas, J Gonzalezlopez, E Hontoria, J M PoyatosAbstract:Performance of a bench-scale wastewater treatment plant, which consisted of a membrane bioreactor, was monitored daily using Pure Oxygen and air to supply aerobic conditions with the aim of studying the increases of the aeration and sludge removal efficiencies and the effect of the temperature. The results showed the capacity of membrane bioreactor systems for removing organic matter. The alpha-factors of the aeration were determined for six different MLSS concentrations in order to understand the system working when Pure Oxygen and air were used to supply aerobic conditions in the system. Aeration efficiency was increased between 30.7 and 45.9% when Pure Oxygen was used in the operation conditions (a hydraulic retention time of 12 h and MLSS concentrations between 4,018 and 11,192 mg/L). Sludge removal efficiency increased incrementally, from 0.2 to 1.5% when Pure Oxygen was used at low sludge retention time and from 1.5% to 15.4% at medium sludge retention time when temperature conditions were lower tha...
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influence of mixed liquid suspended solids and hydraulic retention time on Oxygen transfer efficiency and viscosity in a submerged membrane bioreactor using Pure Oxygen to supply aerobic conditions
Biochemical Engineering Journal, 2012Co-Authors: F A Rodriguez, Patricia Reboleirorivas, E Hontoria, Francisco Osorio, M V Martineztoledo, J M PoyatosAbstract:Abstract The performance of a wastewater bench-scale membrane bioreactor (MBR) treatment plant using Pure Oxygen conditions was monitored daily to provide aerobic conditions. The results showed the capacity of the MBR system to remove organic material over at hydraulic retention time (HRT) of 12 h and 18 h. The alpha-factors of aeration were determined at three different mixed liquid suspended solids (MLSS) concentrations, in order to understand the system performance when Pure Oxygen was used to provide the aerobic conditions of the MBR system. Under these working conditions, an alpha-factor in the range 0.90–0.12 was obtained when the HRT of 18 h was performed, and the MLSS concentration increased from 4300 to 10,275 mg/L. Additionally, an alpha-factor in the range of 0.28–0.02 was obtained at HRT of 12 h and the MLSS increased from 4071 to 11,192 mg/L. Our study suggested significant changes in the behaviour of the biological system (viscosity, aeration efficiency, organic matter removal) when the concentration of MLSS was increased and the HRT decreased in the bioreactor, decreasing the aeration efficiency in both cases. Furthermore, the efficiency of aeration seems to be more affected by MLSS concentration than by HRT under our operating conditions over the range studied.
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bacterial community structure and enzyme activities in a membrane bioreactor mbr using Pure Oxygen as an aeration source
Bioresource Technology, 2012Co-Authors: Kadiya Calderon, Patricia Reboleirorivas, J M Poyatos, M V Martineztoledo, Alejandro Gonzalezmartinez, Camino Monteropuente, Belen Juarezjimenez, B RodelasAbstract:Abstract A pilot-scale membrane bioreactor was used to treat urban wastewater using Pure Oxygen instead of air as a source of aeration, to study its influence on bacterial diversity and levels of enzyme activities (acid and alkaline phosphatases, glucosidase, protease, and esterase) in the sludge. The experimental work was developed in two stages influenced by seasonal temperature. Operational parameters (temperature, pH, BOD 5 , COD, total and volatile suspended solids) were daily monitored, and enzyme activities measured twice a week. Redundancy analysis (RDA) was used to reveal relationships between the level of enzyme activities and the variation of operational parameters, demonstrating a significant effect of temperature and volatile suspended solids. Bacterial diversity was analyzed by temperature-gradient gel electrophoresis of PCR-amplified partial 16S rRNA genes. Significant differences in community structure were observed between both stages. Sequence analysis revealed that the prevalent Bacteria populations were evolutively close to Alphaproteobacteria (44%), Betaproteobacteria (25%) and Firmicutes (17%).
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kinetic study and Oxygen transfer efficiency evaluation using respirometric methods in a submerged membrane bioreactor using Pure Oxygen to supply the aerobic conditions
Bioresource Technology, 2011Co-Authors: F A Rodriguez, Patricia Reboleirorivas, J Gonzalezlopez, J M Poyatos, Francisco Osorio, E HontoriaAbstract:Abstract The performance of a wastewater bench-scale ultrafiltration membrane bioreactor (MBR) treatment plant using Pure Oxygen to supply the aerobic conditions for 95 days was studied. The results showed the capacity of the MBR systems to remove organic material under a hydraulic retention time of 12 h and a sludge retention time of 39.91 days. Aeration represents its major power input; this is why the alpha-factor of the aeration and kinetic parameters (design parameters) were determined when the mixed liquid suspended solids (MLSS) was increased from 3420 to 12,600 mg/l in order to understand the system. An alpha-factor in the range 0.462–0.022 and the kinetic parameters measured with the respirometric method ( K M of 73.954–3.647 mg/l, k d of 0.0142–0.104 day −1 , k H of 0.1266–0.655 day −1 , and the yield mean coefficient of 0.941) were obtained. Our study suggested significant changes in the behaviour of the biological system when the concentration of MLSS was increased.
F A Rodriguez - One of the best experts on this subject based on the ideXlab platform.
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influence of sludge retention time and temperature on the sludge removal in a submerged membrane bioreactor comparative study between Pure Oxygen and air to supply aerobic conditions
Journal of Environmental Science and Health Part A-toxic\ hazardous Substances & Environmental Engineering, 2014Co-Authors: F A Rodriguez, Juan Carlos Leyvadiaz, Patricia Reboleirorivas, J Gonzalezlopez, E Hontoria, J M PoyatosAbstract:Performance of a bench-scale wastewater treatment plant, which consisted of a membrane bioreactor, was monitored daily using Pure Oxygen and air to supply aerobic conditions with the aim of studying the increases of the aeration and sludge removal efficiencies and the effect of the temperature. The results showed the capacity of membrane bioreactor systems for removing organic matter. The alpha-factors of the aeration were determined for six different MLSS concentrations in order to understand the system working when Pure Oxygen and air were used to supply aerobic conditions in the system. Aeration efficiency was increased between 30.7 and 45.9% when Pure Oxygen was used in the operation conditions (a hydraulic retention time of 12 h and MLSS concentrations between 4,018 and 11,192 mg/L). Sludge removal efficiency increased incrementally, from 0.2 to 1.5% when Pure Oxygen was used at low sludge retention time and from 1.5% to 15.4% at medium sludge retention time when temperature conditions were lower tha...
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influence of mixed liquid suspended solids and hydraulic retention time on Oxygen transfer efficiency and viscosity in a submerged membrane bioreactor using Pure Oxygen to supply aerobic conditions
Biochemical Engineering Journal, 2012Co-Authors: F A Rodriguez, Patricia Reboleirorivas, E Hontoria, Francisco Osorio, M V Martineztoledo, J M PoyatosAbstract:Abstract The performance of a wastewater bench-scale membrane bioreactor (MBR) treatment plant using Pure Oxygen conditions was monitored daily to provide aerobic conditions. The results showed the capacity of the MBR system to remove organic material over at hydraulic retention time (HRT) of 12 h and 18 h. The alpha-factors of aeration were determined at three different mixed liquid suspended solids (MLSS) concentrations, in order to understand the system performance when Pure Oxygen was used to provide the aerobic conditions of the MBR system. Under these working conditions, an alpha-factor in the range 0.90–0.12 was obtained when the HRT of 18 h was performed, and the MLSS concentration increased from 4300 to 10,275 mg/L. Additionally, an alpha-factor in the range of 0.28–0.02 was obtained at HRT of 12 h and the MLSS increased from 4071 to 11,192 mg/L. Our study suggested significant changes in the behaviour of the biological system (viscosity, aeration efficiency, organic matter removal) when the concentration of MLSS was increased and the HRT decreased in the bioreactor, decreasing the aeration efficiency in both cases. Furthermore, the efficiency of aeration seems to be more affected by MLSS concentration than by HRT under our operating conditions over the range studied.
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kinetic study and Oxygen transfer efficiency evaluation using respirometric methods in a submerged membrane bioreactor using Pure Oxygen to supply the aerobic conditions
Bioresource Technology, 2011Co-Authors: F A Rodriguez, Patricia Reboleirorivas, J Gonzalezlopez, J M Poyatos, Francisco Osorio, E HontoriaAbstract:Abstract The performance of a wastewater bench-scale ultrafiltration membrane bioreactor (MBR) treatment plant using Pure Oxygen to supply the aerobic conditions for 95 days was studied. The results showed the capacity of the MBR systems to remove organic material under a hydraulic retention time of 12 h and a sludge retention time of 39.91 days. Aeration represents its major power input; this is why the alpha-factor of the aeration and kinetic parameters (design parameters) were determined when the mixed liquid suspended solids (MLSS) was increased from 3420 to 12,600 mg/l in order to understand the system. An alpha-factor in the range 0.462–0.022 and the kinetic parameters measured with the respirometric method ( K M of 73.954–3.647 mg/l, k d of 0.0142–0.104 day −1 , k H of 0.1266–0.655 day −1 , and the yield mean coefficient of 0.941) were obtained. Our study suggested significant changes in the behaviour of the biological system when the concentration of MLSS was increased.
