Faculty Publications

Search Results

Now showing 1 - 4 of 4

Artificial neural networks model for the prediction of steady state phenol biodegradation in a pulsed plate bioreactor
(2008) Shetty K, K.V.; Nandennavar, S.; Srinikethan, G.
Background: A recent innovation in fixed film bioreactors is the pulsed plate bioreactor (PPBR) with immobilized cells. The successful development of a theoretical model for this reactor relies on the knowledge of several parameters, which may vary with the process conditions. It may also be a time-consuming and costly task because of their nonlinear nature. Artificial neural networks (ANN) offer the potential of a generic approach to the modeling of nonlinear systems. Results: A feedforward ANN based model for the prediction of steady state percentage degradation of phenol in a PPBR by immobilized cells of Nocardia hydrocarbonoxydans (NCIM 2386) during continuous biodegradation has been developed to correlate the steady state percentage degradation with the flow rate, influent phenol concentration and vibrational velocity (amplitude x frequency). The model used two hidden layers and 53 parameters (weights and biases). The network model was then compared with a Multiple Regression Analysis (MRA) model, derived from the same training data. Further these two models were used to predict the percentage degradation of phenol for blind test data. Conclusions: The performance of the ANN model was superior to that of the MRA model and was found to be an efficient data-driven tool to predict the performance of a PPBR for phenol biodegradation. © 2008 Society of Chemical Industry.
Modelling and simulation of steady-state phenol degradation in a pulsed plate bioreactor with immobilised cells of Nocardia hydrocarbonoxydans
(2011) Shetty K, V.S.; Verma, D.K.; Srinikethan, G.
A novel bioreactor called pulsed plate bioreactor (PPBR) with cell immobilised glass particles in the interplate spaces was used for continuous aerobic biodegradation of phenol present in wastewater. A mathematical model consisting of mass balance equations and accounting for simultaneous external film mass transfer, internal diffusion and reaction is presented to describe the steady-state degradation of phenol by Nocardia hydrocarbonoxydans (Nch.) in this bioreactor. The growth of Nch. on phenol was found to follow Haldane substrate inhibition model. The biokinetic parameters at a temperature of 30 ± 1 °C and pH at 7.0 ± 0.1 are ? m = 0.5397 h -1, K S = 6.445 mg/L and K I = 855.7 mg/L. The mathematical model was able to predict the reactor performance, with a maximum error of 2% between the predicted and experimental percentage degradations of phenol. The biofilm internal diffusion rate was found to be the slowest step in biodegradation of phenol in a PPBR. © 2010 Springer-Verlag.
Mixing and solid-liquid mass transfer characteristics in a three phase pulsed plate column with packed bed of solids in interplate spaces-a novel aerobic immobilized cell bioreactor
(2011) Shetty K, V.S.; Srinikethan, G.
Background: The pulsed plate column (PPC) with packed bed of solids in the interplate spaces finds use as a three phase aerobic bioreactor and is a potential heterogeneous catalytic reactor. Good knowledge of the extent of mixing in the liquid phase and solid-liquid mass transfer coefficient are essential for modeling, design and optimization of these columns. The present work aims at the study of liquid phase mixing and solid-liquid mass transfer characteristics in a three phase PPC. Results: Residence time distribution studies were performed. Dispersion number was found to increase with increase in liquid superficial velocities, frequency of pulsation, amplitude of pulsation and the vibrational velocities. Increase in frequency and amplitude of pulsation, and hence increase in vibrational velocity, resulted in increase of the solid-liquid mass transfer coefficient. Conclusions: The mixing behaviour in this contactor approximated a mixed flow behaviour. The three phase PPC was found to outperform many other kinds of three phase contactors in terms of solid liquid mass transfer characteristics. Empirical correlations developed can be used for the determination of solid-liquid mass transfer coefficients for three phase PPC and hence can facilitate the design, scale-up and modeling of these columns, when used as chemical or biochemical reactors. © 2011 Society of Chemical Industry.
Biodegradation of phenol using immobilized nocardia hydrocarbonoxydans in a pulsed plate bioreactor: Effect of packed stages, cell carrier loading, and cell acclimatization on startup and steady-state behavior
(2013) Shetty K, K.; Yarangali, S.B.; Srinikethan, G.
The effect of the number of stages and cell carrier loading on the steady-state and startup performance of a continuous pulsed plate bioreactor with glass beads as the cell carrier material for biodegradation of phenol in wastewater using immobilized Nocardia hydrocarbonoxydans has been studied. It was found that the performance of the pulsed plate bioreactor during startup and at steady state can be improved by an increase in cell carrier loading, number of stages, total plate stack height, and with a decrease in plate spacing. The startup time for the continuous bioreactor can be decreased by increasing the number of preacclimatization steps for the cells. The attainment of steady effluent phenol concentration can be considered as an indication of steady state of the continuous bioreactor, as when phenol concentration attained a steady value, biofilm thickness, and the attached biomass dry weight also attained a constant value. © 2013 Copyright Taylor and Francis Group, LLC.

Faculty Publications

Browse

Filters

Settings

Sort By

Results per page

Search Results