A BIOLOGICAL TREATMENT OF INDUSTRIAL WASTEWATERS: CONTOIS KINETICS

2015 ◽  
Vol 56 (4) ◽  
pp. 397-415 ◽  
Author(s):  
RUBAYYI T. ALQAHTANI ◽  
MARK I. NELSON ◽  
ANNETTE L. WORTHY
Keyword(s):  
Steady State ◽  
Residence Time ◽  
Continuous Flow ◽  
Biological Treatment ◽  
Membrane Bioreactor ◽  
Industrial Wastewaters ◽  
Steady State Operation ◽  
Recycle Ratio ◽  
Steady State Solutions ◽  
Bioreactor Performance

This paper analyses the steady-state operation of a generalized bioreactor model that encompasses a continuous-flow bioreactor and an idealized continuous-flow membrane bioreactor as limiting cases. A biodegradation of organic materials is modelled using Contois growth kinetics. The bioreactor performance is analysed by finding the steady-state solutions of the model and determining their stability as a function of the dimensionless residence time. We show that an effective recycle parameter improves the performance of the bioreactor at moderate values of the dimensionless residence time. However, at sufficiently large values of the dimensionless residence time, the performance of the bioreactor is independent of the recycle ratio.

scholarly journals Non-Aqueous Continuous-Flow Electrophoresis (NACFE): Separation Complement for Continuous-Flow Organic Synthesis

2019 ◽  
Author(s):  
Nikita A. Ivanov ◽  
Yimo Liu ◽  
Sven Kochmann ◽  
Sergey N. Krylov
Keyword(s):  
Steady State ◽  
Organic Synthesis ◽  
Flow Separation ◽  
Continuous Flow ◽  
Organic Molecules ◽  
Water Electrolysis ◽  
Organic Salt ◽  
Aqueous Electrolytes ◽  
Differential Distribution ◽  
Steady State Operation

<div>Continuous-flow organic synthesis naturally requires continuous-flow separation of reaction components. The most common continuous-flow separation approach is liquid-liquid extraction based on differential distribution of molecules between organic and aqueous phases. This approach has limited selectivity; it can hardly separate different hydrophobic organic molecules from each other. Continuous-flow electrophoresis can facilitate much more selective separation in a single phase, but it is currently limited to aqueous electrolytes which are incompatible with many hydrophobic organic molecules. Further, water electrolysis in aqueous electrolytes results in generation of large volumes of gas making steady-state operation a major technical challenge. Here, we introduce non-aqueous continuous-flow electrophoresis (NACFE) in which the electrolyte is a solution of an organic salt in an aprotic organic solvent. We demonstrate that NACFE can maintain stable separation of multiple species during 10 hours. The non-aqueous nature of NACFE and its ability to support steady-state operation make it suitable for its incorporation into continuous-flow organic synthesis.</div>

Non-Aqueous Continuous-Flow Electrophoresis (NACFE): Separation Complement for Continuous-Flow Organic Synthesis

2019 ◽  
Author(s):  
Nikita A. Ivanov ◽  
Yimo Liu ◽  
Sven Kochmann ◽  
Sergey N. Krylov
Keyword(s):  
Steady State ◽  
Organic Synthesis ◽  
Flow Separation ◽  
Continuous Flow ◽  
Organic Molecules ◽  
Water Electrolysis ◽  
Organic Salt ◽  
Aqueous Electrolytes ◽  
Differential Distribution ◽  
Steady State Operation

<div>Continuous-flow organic synthesis naturally requires continuous-flow separation of reaction components. The most common continuous-flow separation approach is liquid-liquid extraction based on differential distribution of molecules between organic and aqueous phases. This approach has limited selectivity; it can hardly separate different hydrophobic organic molecules from each other. Continuous-flow electrophoresis can facilitate much more selective separation in a single phase, but it is currently limited to aqueous electrolytes which are incompatible with many hydrophobic organic molecules. Further, water electrolysis in aqueous electrolytes results in generation of large volumes of gas making steady-state operation a major technical challenge. Here, we introduce non-aqueous continuous-flow electrophoresis (NACFE) in which the electrolyte is a solution of an organic salt in an aprotic organic solvent. We demonstrate that NACFE can maintain stable separation of multiple species during 10 hours. The non-aqueous nature of NACFE and its ability to support steady-state operation make it suitable for its incorporation into continuous-flow organic synthesis.</div>

Non-Aqueous Continuous-Flow Electrophoresis (NACFE): Separation Complement for Continuous-Flow Organic Synthesis

2019 ◽  
Author(s):  
Nikita A. Ivanov ◽  
Yimo Liu ◽  
Sven Kochmann ◽  
Sergey N. Krylov
Keyword(s):  
Steady State ◽  
Organic Synthesis ◽  
Flow Separation ◽  
Continuous Flow ◽  
Organic Molecules ◽  
Water Electrolysis ◽  
Organic Salt ◽  
Aqueous Electrolytes ◽  
Differential Distribution ◽  
Steady State Operation

<div>Continuous-flow organic synthesis naturally requires continuous-flow separation of reaction components. The most common continuous-flow separation approach is liquid-liquid extraction based on differential distribution of molecules between organic and aqueous phases. This approach has limited selectivity; it can hardly separate different hydrophobic organic molecules from each other. Continuous-flow electrophoresis can facilitate much more selective separation in a single phase, but it is currently limited to aqueous electrolytes which are incompatible with many hydrophobic organic molecules. Further, water electrolysis in aqueous electrolytes results in generation of large volumes of gas making steady-state operation a major technical challenge. Here, we introduce non-aqueous continuous-flow electrophoresis (NACFE) in which the electrolyte is a solution of an organic salt in an aprotic organic solvent. We demonstrate that NACFE can maintain stable separation of multiple species during 10 hours. The non-aqueous nature of NACFE and its ability to support steady-state operation make it suitable for its incorporation into continuous-flow organic synthesis.</div>

scholarly journals Non-Aqueous Continuous-Flow Electrophoresis (NACFE): Separation Complement for Continuous-Flow Organic Synthesis

2019 ◽  
Author(s):  
Nikita A. Ivanov ◽  
Yimo Liu ◽  
Sven Kochmann ◽  
Sergey N. Krylov
Keyword(s):  
Steady State ◽  
Organic Synthesis ◽  
Flow Separation ◽  
Continuous Flow ◽  
Organic Molecules ◽  
Water Electrolysis ◽  
Organic Salt ◽  
Aqueous Electrolytes ◽  
Differential Distribution ◽  
Steady State Operation

<div>Continuous-flow organic synthesis naturally requires continuous-flow separation of reaction components. The most common continuous-flow separation approach is liquid-liquid extraction based on differential distribution of molecules between organic and aqueous phases. This approach has limited selectivity; it can hardly separate different hydrophobic organic molecules from each other. Continuous-flow electrophoresis can facilitate much more selective separation in a single phase, but it is currently limited to aqueous electrolytes which are incompatible with many hydrophobic organic molecules. Further, water electrolysis in aqueous electrolytes results in generation of large volumes of gas making steady-state operation a major technical challenge. Here, we introduce non-aqueous continuous-flow electrophoresis (NACFE) in which the electrolyte is a solution of an organic salt in an aprotic organic solvent. We demonstrate that NACFE can maintain stable separation of multiple species during 10 hours. The non-aqueous nature of NACFE and its ability to support steady-state operation make it suitable for its incorporation into continuous-flow organic synthesis.</div>

scholarly journals An Analysis of a Standard Reactor Cascade and a Step-Feed Reactor Cascade for Biological Processes Described by Monod Kinetics

2015 ◽  
Vol 10 (1) ◽  
pp. 27-37 ◽  
Author(s):  
Harvinder S. Sidhu ◽  
Mark Ian Nelson ◽  
Easwaran Balakrishnan
Keyword(s):  
Growth Rate ◽  
Steady State ◽  
Biological Treatment ◽  
Specific Growth ◽  
Biological Process ◽  
Equal Proportion ◽  
Biological Processes ◽  
Feed Stream ◽  
Monod Kinetics ◽  
Steady State Operation

Abstract We analyse the steady-state operation of two types of reactor cascade without recycle. The first is a standard reactor cascade in which the feed stream enters into the first reactor. The second is a step-feed reactor cascade in which an equal proportion of the feed stream enters each reactor in the cascade. The reaction is assumed to be a biological process governed by Monod growth kinetics with a decay coefficient for the microorganisms. The steady-states of both models are found for an arbitrary number of reactors and their stability determined as a function of the residence time. We show that in a step-feed reactor cascade the substrate and biomass concentrations leaving the reactor of the cascade are identical to those leaving the first reactor of the cascade. We further show that this result is true for a general specific growth rate of the form μ (S,X). Thus for such processes the non-standard cascade offers no advantage over that of a single reactor. This is surprising because the use of a non-standard cascade has been proposed as a mechanism to improve the biological treatment of wastewater.

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