Performance and biofilm characteristics of a gas biofilter for n-hexane removal at various operational conditions

RSC Advances ◽  
2015 ◽  
Vol 5 (60) ◽  
pp. 48954-48960 ◽  
Author(s):  
Yan Cheng ◽  
Huijun He ◽  
Chunping Yang ◽  
Guangming Zeng ◽  
Zhou Yan ◽  
...  
Keyword(s):  
Residence Time ◽  
Nitrate Concentration ◽  
Inlet Concentration ◽  
Operational Parameters ◽  
Operational Conditions ◽  
Empty Bed Residence Time

The effects of operational parameters including nitrate concentration,n-hexane inlet concentration and gas empty bed residence time (EBRT) on long-term removal performance ofn-hexane were discussed.

Biofiltration of volatile organic compounds – application to air treatment

2000 ◽  
Vol 41 (12) ◽  
pp. 183-190 ◽  
Author(s):  
E. M. Ramirez-Lopez ◽  
A. Montillet ◽  
J. Comiti ◽  
P. Le Cloirec
Keyword(s):  
Pressure Drop ◽  
Residence Time ◽  
Structural Parameters ◽  
Packing Material ◽  
Aerobic Biodegradation ◽  
Operational Conditions ◽  
Hydrodynamic Study ◽  
Wood Bark ◽  
Qualitative Measure ◽  
Empty Bed Residence Time

A hydrodynamic study and an ethanol biodegradation were carried out in an experimental biofilter using wood bark as packing material. The Comiti and Renaud model was used in order to determine, from pressure drop measurements, the tortuosity and the dynamic specific surface area of the packing material, and its structural parameters, considering the wall effect corrections. The pressure drop was used as a qualitative measure of the growth of native wood bark microorganisms. The aerobic biodegradation with a concentration of 1 g of ethanol m–3 was studied. An air superficial velocity of 100 m h–1, an air flow rate of 20 m3 h–1 and an empty bed residence time of 37 seconds with a true residence time of 19.5 s were the operational conditions in the biofilter. The ethanol concentration, pH, temperature and the pressure drop at different heights of the biofilter were measured. Performances of this process were presented.

Removal of Hydrogen Sulfide Using a Compost-Based Biofilter

2011 ◽  
Vol 356-360 ◽  
pp. 1601-1604 ◽  
Author(s):  
Chanee Wongwutthi ◽  
Wongpun Limpaseni
Keyword(s):  
Hydrogen Sulfide ◽  
Residence Time ◽  
Municipal Wastewater ◽  
Organic Fertilizer ◽  
Wastewater Sludge ◽  
Wood Chips ◽  
Sulfide Concentration ◽  
Inlet Concentration ◽  
Hydrogen Sulfide Concentration ◽  
Empty Bed Residence Time

Hydrogen sulfide (H2S) is a malodorous gas which can cause nuisance and health effects to people who live and work in the contaminated air environment. Therefore, the main objective of this work was to study the removal of hydrogen sulfide (H2S) using a biofilter packed with mixture of compost, organic fertilizer, wood chips and municipal wastewater sludge at a ratio of 60:10:20:10 by weight. The experiment was carried out at hydrogen sulfide concentration of 5-200 ppmv and empty bed residence time (EBRT) of 60 seconds. The results indicated that completer H2S removal can be achieved at H2S inlet concentration of 200 ppmv. Elimination capacity of the biofilter reached as high as 24.38 gm−3 h−1.

scholarly journals Hydrogen Production by Fluidized Bed Reactors: A Quantitative Perspective Using the Supervised Machine Learning Approach

J ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 266-287
Author(s):  
Zheng Lian ◽  
Yixiao Wang ◽  
Xiyue Zhang ◽  
Abubakar Yusuf ◽  
Lord Famiyeh ◽  
...  
Keyword(s):  
Machine Learning ◽  
Hydrogen Production ◽  
Fluidized Bed ◽  
Biomass Gasification ◽  
Supervised Machine Learning ◽  
Fluidized Bed Reactors ◽  
Hydrogen Yield ◽  
Carbon Conversion ◽  
Operational Parameters ◽  
Operational Conditions

The current hydrogen generation technologies, especially biomass gasification using fluidized bed reactors (FBRs), were rigorously reviewed. There are involute operational parameters in a fluidized bed gasifier that determine the anticipated outcomes for hydrogen production purposes. However, limited reviews are present that link these parametric conditions with the corresponding performances based on experimental data collection. Using the constructed artificial neural networks (ANNs) as the supervised machine learning algorithm for data training, the operational parameters from 52 literature reports were utilized to perform both the qualitative and quantitative assessments of the performance, such as the hydrogen yield (HY), hydrogen content (HC) and carbon conversion efficiency (CCE). Seven types of operational parameters, including the steam-to-biomass ratio (SBR), equivalent ratio (ER), temperature, particle size of the feedstock, residence time, lower heating value (LHV) and carbon content (CC), were closely investigated. Six binary parameters have been identified to be statistically significant to the performance parameters (hydrogen yield (HY)), hydrogen content (HC) and carbon conversion efficiency (CCE)) by analysis of variance (ANOVA). The optimal operational conditions derived from the machine leaning were recommended according to the needs of the outcomes. This review may provide helpful insights for researchers to comprehensively consider the operational conditions in order to achieve high hydrogen production using fluidized bed reactors during biomass gasification.

scholarly journals Optimising the performance of a lab-scale tidal flow reed bed system treating agricultural wastewater

2004 ◽  
Vol 50 (8) ◽  
pp. 65-72 ◽  
Author(s):  
Y.Q. Zhao ◽  
G. Sun ◽  
C. Lafferty ◽  
S.J. Allen
Keyword(s):  
Tidal Flow ◽  
High Strength ◽  
Pollutant Removal ◽  
Inorganic Pollutants ◽  
Operational Conditions ◽  
Agricultural Wastewater ◽  
Major Route ◽  
Reed Bed ◽  
Ammoniacal Nitrogen Removal

A gravel-based tidal flow reed bed system was operated with three different strategies in order to investigate its optimal performance for the treatment of a high strength agricultural wastewater. According to the three strategies, individual reed beds were saturated and unsaturated with the wastewater for different periods while reasonably stable hydraulic and organic loadings were maintained. Experimental results demonstrated that the system produced the highest pollutant removal efficiencies with a relatively short saturated period and long unsaturated period, highlighting the importance of oxygen transfer into reed bed matrices during the treatment. Significant removals of some major organic and inorganic pollutants were achieved under all three operational conditions. Nitrification was not the major route of ammoniacal-nitrogen removal when the system was under high organic loading. Due to the filtration of suspended solids and the accumulation of biomass, gradual clogging of the reed bed matrices took place, which caused concerns over the long-term efficiency of the tidal flow system.

Enhanced photocatalytic activity of CeO2 using β-cyclodextrin on visible light assisted decoloration of methylene blue

2013 ◽  
Vol 69 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Sakthivel Pitchaimuthu ◽  
Ponnusamy Velusamy
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Inclusion Complexation ◽  
Processing Parameters ◽  
Operational Parameters ◽  
Illumination Time ◽  
Operational Conditions ◽  
Electron Microscopy Analysis ◽  
Initial Ph

An attempt has been made to enhance the photocatalytic activity of CeO2 for visible light assisted decoloration of methylene blue (MB) dye in aqueous solutions by β-cyclodextrin (β-CD). The inclusion complexation patterns between host and guest (i.e., β-CD and MB) have been confirmed with UV–visible spectral data. The interaction between CeO2 and β-CD has also been characterized by field emission scanning electron microscopy analysis. The photocatalytic activity of the catalyst under visible light was investigated by measuring the photodegradation of MB in aqueous solution. The effects of key operational parameters such as initial dye concentration, initial pH, CeO2 concentration as well as illumination time on the decolorization extents were investigated. Among the processing parameters, the pH of the reaction solution played an important role in tuning the photocatalytic activity of CeO2. The maximum photodecoloration rate was achieved at basic pH (pH 11). Under the optimum operational conditions, approximately 99.6% dye removal was achieved within 120 min. The observed results indicate that the decolorization of the MB followed a pseudo-first order kinetics.

Surveillance Models of Large-Scale ESP With High Viscosity Fluids and Gas

2012 ◽  
Author(s):  
Lissett Barrios ◽  
Stuart Scott ◽  
Charles Deuel
Keyword(s):  
Large Scale ◽  
Two Phase Flow ◽  
Electrical Current ◽  
High Viscosity ◽  
Viscous Fluids ◽  
Phase Flow ◽  
Centrifugal Pumps ◽  
Operational Parameters ◽  
Two Phase ◽  
Operational Conditions

The paper reports on developmental research on the effects of viscosity and two phases, liquid–gas fluids on ESPs which are multi stage centrifugal pumps for deep bore holes. Multiphase viscous performance in a full-scale Electrical Submersible Pump (ESP) system at Shell’s Gasmer facility has been studied experimentally and theoretically. The main objectives is to predict the operational conditions that cause degradations for high viscosity fluids when operating in high Gas Liquid Radio (GLR) wells to support operation in Shell major Projects. The system studied was a 1025 series tandem WJE 1000. The test was performed using this configuration with ten or more pump stages moving fluids with viscosity from 2 to 200 cP at various speed, intake pressure and Gas Void Fractions (GVF). For safety considerations the injected gas was restricted to nitrogen or air. The ESP system is a central artificial lift method commonly used for medium to high flow rate wells. Multiphase flow and viscous fluids causes problems in pump applications. Viscous fluids and free gas inside an ESP can cause head degradation and gas locking. Substantial attempts have been made to model centrifugal pump performance under gas-liquid viscous applications, however due to the complexity this is still a uncertain problem. The determination of the two-phase flow performance in these harmful conditions in the ESP is fundamental aspects in the surveillance operation. The testing at Shell’s Gasmer facility revealed that the ESP system performed as theoretical over the range of single flowrates and light viscosity oils up to Gas Volume Fractions (GVF) around 25%. The developed correlations predict GVF at the pump intake based on the operational parameters. ESP performance degrades at viscosity higher than 100cp as compared to light oil applications, gas lock condition is observed at gas fraction higher than 45%. Pump flowrate can be obtained from electrical current and boost for all range of GVF and speed. The main technical contributions are the analysis of pump head degradation under two important variables, high viscosity and two-phase flow inside the ESP.

Mathematical modeling of fluid movement inside the eyeball during intravitreal injection

2021 ◽  
pp. 106-109
Author(s):  
D.V. Lipatov ◽  
◽  
S.A. Skladchikov ◽  
N.P. Savenkova ◽  
V.V. Novoderezkin ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Residence Time ◽  
Complex Structure ◽  
Posterior Vitreous Detachment ◽  
Vitreous Body ◽  
Complete Removal ◽  
Intravitreal Injections ◽  
The World

Background. The avalanche-like growth of intravitreal injections in the world has significantly increased interest in the hemodynamics of the processes that occur in the eye when a drug is injected into the vitreous cavity. Every year, the number of intravitreally used drugs and promising areas in which they can be used is growing. This also applies to the creation of new combined medicines and the development of drugs with a long-term therapeutic effect. Aims. Create mathematical model of eyeball to evaluate the movement of the drug substance in it; to estimate the time of the drug's presence in the eye cavity before its complete removal, to characterize the ways of its removal from the eye cavity; to assess the significance of posterior vitreous detachment during the time when the drug is present in the eye cavity; to evaluate the effect on the hydrodynamics of the depth of drug administration. Results. When the drug is administered closer to the center of the eyeball, its residence time increases in comparison with the parietal administration. With a complete posterior detachment of the vitreous body, the time of finding the drug in the eye is prolonged compared to its absence. The obtained results of mathematical modeling of the movement of the drug administered intravitreally cannot be mechanically transferred to the human eye, due to the more complex structure of the latter. Key words: intravitreal injections, vitreous body, mathematic computing.

Detection and residence time of bisphosphonates in bone of horses

2021 ◽  
Vol 34 (1) ◽  
pp. 23-27
Author(s):  
Heather K. Knych ◽  
Jennifer Janes ◽  
Laura Kennedy ◽  
Daniel S. McKemie ◽  
Rick M. Arthur ◽  
...  
Keyword(s):  
Synovial Fluid ◽  
Residence Time ◽  
Bone Fractures ◽  
Limited Information ◽  
Long Term Effects ◽  
Normal Bone ◽  
Postmortem Blood ◽  
Affect Bone Healing ◽  
Postmortem Sample

Bisphosphonates are potent anti-resorptive agents that have the potential to adversely affect bone healing in equine athletes, and normal bone adaption in young racehorses. A concern exists that bisphosphonate inhibition of normal bone metabolism could lead to increased bone fractures during high-intensity exercise. We found only a single report describing concentrations of tiludronate in the bone of horses, and no studies describing clodronate. Knowledge of the residence time in bone could allow for a better understanding of the long-term effects of these compounds. Our objectives were to develop a method for detection of bisphosphonates in bone and add to the limited information available regarding the disposition of these drugs in the bone of horses. Two horses received clodronate and 2 tiludronate disodium. Postmortem collection of bones and teeth occurred either 4 or 30 d post drug administration. Additionally, postmortem blood, synovial fluid, aqueous humor, and bone samples from racehorses with various histories of bisphosphonate administration were collected, and concentrations determined using the developed LC-MS/MS method. Bisphosphonates were detected in bones and teeth tested at 4 and 30 d. In a postmortem sample, clodronate was detected in bone from a horse with reported administration 18 mo prior; clodronate was not detected in other sample types collected from this horse. Bisphosphonates reside in bone for extended periods of time, which could lead to potential long-term effects, increasing the potential for bone fractures in young and/or athletic horses.

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