The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Hyung Jae Lee - One of the best experts on this subject based on the ideXlab platform.
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Vertical-cavity surface-emitting lasers fabricated using a sealing of AlAs against Wet Oxidation
Vertical-Cavity Surface-Emitting Lasers II, 1998Co-Authors: Dae-ho Lim, Gye Mo Yang, Jong-hee Kim, Kee Young Lim, Hyung Jae LeeAbstract:We have studied the process of sealing on exposed. AlAs and the Wet Oxidation behavior of AlAs to prevent further Wet Oxidation. A critical processing step consists of the formation of an oxide surface barrier by the first set Oxidation for a short time at 390-430 degrees C in the stream environment of previously room-ambient exposed AlAs surface. During this brief Wet Oxidation,a dense oxide barrier with a thickness of approximately 1 micrometers is formed, which further blocks diffusing oxygen species during the second Wet Oxidation. The oxide surface barriers of approximately 1 micrometers thickness formed at 408 degrees C and 410 degrees C have shown the best effectiveness of sealing against further Wet Oxidation. The effectiveness of the sealing is demonstrated through its use as a mask against Wet Oxidation in the fabrication of oxide-confirmed vertical-cavity surface-emitting lasers.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
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Sealing of AlAs against Wet Oxidation and its use in the fabrication of vertical-cavity surface-emitting lasers
Applied Physics Letters, 1997Co-Authors: Dae-ho Lim, Gye Mo Yang, Jong-hee Kim, Kee Young Lim, Hyung Jae LeeAbstract:We have studied the process of sealing an exposed AlAs to prevent further Wet Oxidation. A critical step in this sealing process consists of the first Wet Oxidation for a short time at 408 °C in a steam environment of a previously room-ambient exposed AlAs surface. During this brief Wet Oxidation, a dense oxide surface barrier with a thickness of 1.1 μm is formed, which further blocks diffusing oxygen species during the second Wet Oxidation. The effectiveness of the sealing is demonstrated through its use as a mask against Wet Oxidation in the fabrication of oxide-confined vertical-cavity surface-emitting lasers.
Saeid Baroutian - One of the best experts on this subject based on the ideXlab platform.
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Integrating Wet Oxidation and struvite precipitation for sewage sludge treatment and phosphorus recovery
Journal of Cleaner Production, 2019Co-Authors: Muhammad Munir, Brent R. Young, I Mardon, Saeid BaroutianAbstract:Abstract In this study, Wet Oxidation of sewage sludge and struvite-precipitation processes were integrated to safely manage sludge and to recover organic acids and phosphorus. To understand this process integration, the effects of temperature, treatment time, and sludge concentration during Wet Oxidation, and pH and magnesium dosage during struvite precipitation on total suspended solids (TSS), volatile suspended solids (VSS), organic acids production, and phosphorus recovery were investigated. The results showed that TSS and VSS destruction, organic acids production, and phosphorus recovery from sludge into the liquid phase are more sensitive to temperature and time than sludge concentration during Wet Oxidation. These are novel findings of this work. Furthermore, pH during struvite precipitation had a strong effect on phosphorus recovery. Wet-oxidised sludge was mainly converted to acetic acid, and its concentration increased with increasing temperature and time. These results may be used for optimised operation and revenue generation from wastewater treatment processes when integrated with Wet Oxidation and struvite precipitation.
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A kinetic model of municipal sludge degradation during non-catalytic Wet Oxidation
Water research, 2015Co-Authors: Arrian Prince-pike, Saeid Baroutian, David I. Wilson, John Andrews, Daniel J GapesAbstract:Wet Oxidation is a successful process for the treatment of municipal sludge. In addition, the resulting effluent from Wet Oxidation is a useful carbon source for subsequent biological nutrient removal processes in wastewater treatment. Owing to limitations with current kinetic models, this study produced a kinetic model which predicts the concentrations of key intermediate components during Wet Oxidation. The model was regressed from lab-scale experiments and then subsequently validated using data from a Wet Oxidation pilot plant. The model was shown to be accurate in predicting the concentrations of each component, and produced good results when applied to a plant 500 times larger in size. A statistical study was undertaken to investigate the validity of the regressed model parameters. Finally the usefulness of the model was demonstrated by suggesting optimum operating conditions such that volatile fatty acids were maximised.
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Hydrothermal degradation of organic matter in municipal sludge using non-catalytic Wet Oxidation
Chemical Engineering Journal, 2015Co-Authors: Saeid Baroutian, Brent R. Young, John Andrews, Anne-marie Smit, Daniel J GapesAbstract:Abstract Of the treatment and conversion technologies used for municipal sludge, Wet Oxidation has become an important process owing to the characteristics of water as a reaction medium at elevated temperature and pressure. This study aimed to investigate the non-catalytic Wet Oxidation of municipal sludge and degradation of solids, organic matter and other compounds. A digested sludge consisting of primary and secondary sludges was subjected to 60 min Wet Oxidation at temperatures ranging between 220 and 240 °C and oxygen to biomass ratios of 1:1–2:1. Wet Oxidation was effective at degrading the organic solids, with maximum degradation of 86% for total suspended solids and 96% for volatile suspended solids. The concentration of oxidisable organic matter was reduced by 98% of the untreated sludge. It was found that reaction temperature has the most significant impact on sludge Oxidation.
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Formation of organic acid intermediates during Wet Oxidation of biomass
2014Co-Authors: Saeid Baroutian, Daniel J Gapes, Ajit K. Sarmah, Mohammed M. Farid, Stuart Norris, Brent R. YoungAbstract:Wet Oxidation is a hydrothermal technology with the potential for the treatment of wastes, being particularly applicable for wastes having high concentrations of organic matter or toxic contaminants. This treatment method has become an important process owing to the characteristics of water as a reaction medium at elevated temperature and pressure. In Wet Oxidation, destruction of organic matter is based on the formation and destruction of intermediate compounds. Most of the available literature has dealt with reaction kinetics or has suggested new approaches and focused on inherent advantages in the handling of waste and the potential for resource recovery. There are only a few studies that have investigated formation and transformation of intermediate compounds. The current study investigated the formation of organic acids as major intermediate products of Wet Oxidation of municipal sludge. Sludge was subjected to 60 min Wet Oxidation at temperatures ranging between 220 and 240 C, with oxygen to biomass ratios of 1:1-2:1. Acetic acid was the main organic acid produced in this study followed by propionic, n-butyric and iso-butyric acids. It was found that reaction temperature has the most significant impact on the formation of these intermediates. The amounts of these products could be reduced if the Wet Oxidation treatment is conducted at higher temperature. It was also found that increasing oxygen content resulted in increased degradation of organic acids, due to the increased dissolved oxygen concentration. Production of organic acid intermediates during Wet Oxidation is highly desirable because these compounds consist of small, readily degradable carbon compounds that form a suitable substrate for many applications.
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Non-catalytic subcritical Wet Oxidation of a wastewater treatment sludge
2013Co-Authors: Saeid Baroutian, Daniel J GapesAbstract:Among the treatment and conversion technologies used for organic solid waste, Wet Oxidation has become an important process due to the fascinating characteristics of water as a reaction medium at elevated temperatures and pressure. Wet Oxidation is able to degrade and remove organic compounds and thus reduce the mass and volume of solid wastes. Recovering valuable compounds and enhancement of anaerobic fermentation are the other advantages. Wet Oxidation of soluble compounds such as phenol, aromatic alcohols and carboxylic acids has been well studied. However, behaviour of Wet Oxidation of wastewater treatment sludges has not been studied completely due to their complex structure. The current work was aimed at investigating non-catalytic Wet Oxidation of wastewater treatment sludge and studying degradation of solids, organic compounds and nutrients. A fermented mixed sludge which consisted of primary and secondary sludges was subjected to Wet Oxidation at temperature ranging 220-240 degreesC, oxygen to biomass ratio of 1:1-2:1 and stirring speed of 300-500 rpm. Wet Oxidation was effective at degrading the organic solids, with approximately 90 % degradation within 60 minutes. It was found that reaction temperature has the most significant impact on sludge Oxidation. The results also showed production of acetic acid under Wet Oxidation treatment.
Dae-ho Lim - One of the best experts on this subject based on the ideXlab platform.
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Vertical-cavity surface-emitting lasers fabricated using a sealing of AlAs against Wet Oxidation
Vertical-Cavity Surface-Emitting Lasers II, 1998Co-Authors: Dae-ho Lim, Gye Mo Yang, Jong-hee Kim, Kee Young Lim, Hyung Jae LeeAbstract:We have studied the process of sealing on exposed. AlAs and the Wet Oxidation behavior of AlAs to prevent further Wet Oxidation. A critical processing step consists of the formation of an oxide surface barrier by the first set Oxidation for a short time at 390-430 degrees C in the stream environment of previously room-ambient exposed AlAs surface. During this brief Wet Oxidation,a dense oxide barrier with a thickness of approximately 1 micrometers is formed, which further blocks diffusing oxygen species during the second Wet Oxidation. The oxide surface barriers of approximately 1 micrometers thickness formed at 408 degrees C and 410 degrees C have shown the best effectiveness of sealing against further Wet Oxidation. The effectiveness of the sealing is demonstrated through its use as a mask against Wet Oxidation in the fabrication of oxide-confirmed vertical-cavity surface-emitting lasers.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
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Sealing of AlAs against Wet Oxidation and its use in the fabrication of vertical-cavity surface-emitting lasers
Applied Physics Letters, 1997Co-Authors: Dae-ho Lim, Gye Mo Yang, Jong-hee Kim, Kee Young Lim, Hyung Jae LeeAbstract:We have studied the process of sealing an exposed AlAs to prevent further Wet Oxidation. A critical step in this sealing process consists of the first Wet Oxidation for a short time at 408 °C in a steam environment of a previously room-ambient exposed AlAs surface. During this brief Wet Oxidation, a dense oxide surface barrier with a thickness of 1.1 μm is formed, which further blocks diffusing oxygen species during the second Wet Oxidation. The effectiveness of the sealing is demonstrated through its use as a mask against Wet Oxidation in the fabrication of oxide-confined vertical-cavity surface-emitting lasers.
Daniel J Gapes - One of the best experts on this subject based on the ideXlab platform.
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A kinetic model of municipal sludge degradation during non-catalytic Wet Oxidation
Water research, 2015Co-Authors: Arrian Prince-pike, Saeid Baroutian, David I. Wilson, John Andrews, Daniel J GapesAbstract:Wet Oxidation is a successful process for the treatment of municipal sludge. In addition, the resulting effluent from Wet Oxidation is a useful carbon source for subsequent biological nutrient removal processes in wastewater treatment. Owing to limitations with current kinetic models, this study produced a kinetic model which predicts the concentrations of key intermediate components during Wet Oxidation. The model was regressed from lab-scale experiments and then subsequently validated using data from a Wet Oxidation pilot plant. The model was shown to be accurate in predicting the concentrations of each component, and produced good results when applied to a plant 500 times larger in size. A statistical study was undertaken to investigate the validity of the regressed model parameters. Finally the usefulness of the model was demonstrated by suggesting optimum operating conditions such that volatile fatty acids were maximised.
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Hydrothermal degradation of organic matter in municipal sludge using non-catalytic Wet Oxidation
Chemical Engineering Journal, 2015Co-Authors: Saeid Baroutian, Brent R. Young, John Andrews, Anne-marie Smit, Daniel J GapesAbstract:Abstract Of the treatment and conversion technologies used for municipal sludge, Wet Oxidation has become an important process owing to the characteristics of water as a reaction medium at elevated temperature and pressure. This study aimed to investigate the non-catalytic Wet Oxidation of municipal sludge and degradation of solids, organic matter and other compounds. A digested sludge consisting of primary and secondary sludges was subjected to 60 min Wet Oxidation at temperatures ranging between 220 and 240 °C and oxygen to biomass ratios of 1:1–2:1. Wet Oxidation was effective at degrading the organic solids, with maximum degradation of 86% for total suspended solids and 96% for volatile suspended solids. The concentration of oxidisable organic matter was reduced by 98% of the untreated sludge. It was found that reaction temperature has the most significant impact on sludge Oxidation.
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Formation of organic acid intermediates during Wet Oxidation of biomass
2014Co-Authors: Saeid Baroutian, Daniel J Gapes, Ajit K. Sarmah, Mohammed M. Farid, Stuart Norris, Brent R. YoungAbstract:Wet Oxidation is a hydrothermal technology with the potential for the treatment of wastes, being particularly applicable for wastes having high concentrations of organic matter or toxic contaminants. This treatment method has become an important process owing to the characteristics of water as a reaction medium at elevated temperature and pressure. In Wet Oxidation, destruction of organic matter is based on the formation and destruction of intermediate compounds. Most of the available literature has dealt with reaction kinetics or has suggested new approaches and focused on inherent advantages in the handling of waste and the potential for resource recovery. There are only a few studies that have investigated formation and transformation of intermediate compounds. The current study investigated the formation of organic acids as major intermediate products of Wet Oxidation of municipal sludge. Sludge was subjected to 60 min Wet Oxidation at temperatures ranging between 220 and 240 C, with oxygen to biomass ratios of 1:1-2:1. Acetic acid was the main organic acid produced in this study followed by propionic, n-butyric and iso-butyric acids. It was found that reaction temperature has the most significant impact on the formation of these intermediates. The amounts of these products could be reduced if the Wet Oxidation treatment is conducted at higher temperature. It was also found that increasing oxygen content resulted in increased degradation of organic acids, due to the increased dissolved oxygen concentration. Production of organic acid intermediates during Wet Oxidation is highly desirable because these compounds consist of small, readily degradable carbon compounds that form a suitable substrate for many applications.
-
Non-catalytic subcritical Wet Oxidation of a wastewater treatment sludge
2013Co-Authors: Saeid Baroutian, Daniel J GapesAbstract:Among the treatment and conversion technologies used for organic solid waste, Wet Oxidation has become an important process due to the fascinating characteristics of water as a reaction medium at elevated temperatures and pressure. Wet Oxidation is able to degrade and remove organic compounds and thus reduce the mass and volume of solid wastes. Recovering valuable compounds and enhancement of anaerobic fermentation are the other advantages. Wet Oxidation of soluble compounds such as phenol, aromatic alcohols and carboxylic acids has been well studied. However, behaviour of Wet Oxidation of wastewater treatment sludges has not been studied completely due to their complex structure. The current work was aimed at investigating non-catalytic Wet Oxidation of wastewater treatment sludge and studying degradation of solids, organic compounds and nutrients. A fermented mixed sludge which consisted of primary and secondary sludges was subjected to Wet Oxidation at temperature ranging 220-240 degreesC, oxygen to biomass ratio of 1:1-2:1 and stirring speed of 300-500 rpm. Wet Oxidation was effective at degrading the organic solids, with approximately 90 % degradation within 60 minutes. It was found that reaction temperature has the most significant impact on sludge Oxidation. The results also showed production of acetic acid under Wet Oxidation treatment.
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Transformation and removal of wood extractives from pulp mill sludge using Wet Oxidation and thermal hydrolysis
Bioresource Technology, 2013Co-Authors: Saeid Baroutian, Anne-marie Smit, Murray Robinson, Suren Wijeyekoon, Daniel J GapesAbstract:In order to remove wood extractive compounds from pulp mill sludge and thereby enhancing anaerobic digestibility, samples were subjected to either oxidative hydrothermal treatment (Wet Oxidation) or non-oxidative hydrothermal treatment (thermal hydrolysis). Treatments were carried out at 220 °C with initial pressure of 20 bar. More than 90% destruction of extractive compounds was observed after 20 min of Wet Oxidation. Wet Oxidation eliminated 95.7% of phenolics, 98.6% fatty acids, 99.8% resin acids and 100% of phytosterols in 120 min. Acetic acid concentration increased by approximately 2 g/l after 120 min of Wet Oxidation. This has potential for rendering sludge more amenable to anaerobic digestion. In contrast thermal hydrolysis was found to be ineffective in degrading extractive compounds. Wet Oxidation is considered to be an effective process for removal of recalcitrant and inhibitive compounds through hydrothermal pre-treatment of pulp mill sludge.
Kee Young Lim - One of the best experts on this subject based on the ideXlab platform.
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Vertical-cavity surface-emitting lasers fabricated using a sealing of AlAs against Wet Oxidation
Vertical-Cavity Surface-Emitting Lasers II, 1998Co-Authors: Dae-ho Lim, Gye Mo Yang, Jong-hee Kim, Kee Young Lim, Hyung Jae LeeAbstract:We have studied the process of sealing on exposed. AlAs and the Wet Oxidation behavior of AlAs to prevent further Wet Oxidation. A critical processing step consists of the formation of an oxide surface barrier by the first set Oxidation for a short time at 390-430 degrees C in the stream environment of previously room-ambient exposed AlAs surface. During this brief Wet Oxidation,a dense oxide barrier with a thickness of approximately 1 micrometers is formed, which further blocks diffusing oxygen species during the second Wet Oxidation. The oxide surface barriers of approximately 1 micrometers thickness formed at 408 degrees C and 410 degrees C have shown the best effectiveness of sealing against further Wet Oxidation. The effectiveness of the sealing is demonstrated through its use as a mask against Wet Oxidation in the fabrication of oxide-confirmed vertical-cavity surface-emitting lasers.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
-
Sealing of AlAs against Wet Oxidation and its use in the fabrication of vertical-cavity surface-emitting lasers
Applied Physics Letters, 1997Co-Authors: Dae-ho Lim, Gye Mo Yang, Jong-hee Kim, Kee Young Lim, Hyung Jae LeeAbstract:We have studied the process of sealing an exposed AlAs to prevent further Wet Oxidation. A critical step in this sealing process consists of the first Wet Oxidation for a short time at 408 °C in a steam environment of a previously room-ambient exposed AlAs surface. During this brief Wet Oxidation, a dense oxide surface barrier with a thickness of 1.1 μm is formed, which further blocks diffusing oxygen species during the second Wet Oxidation. The effectiveness of the sealing is demonstrated through its use as a mask against Wet Oxidation in the fabrication of oxide-confined vertical-cavity surface-emitting lasers.
