Studies on Continuous Reactor Kinetics of L-Lysine by Immobilized Corynebacterium glutamicum Cells

-- B Sarva Rao, Ch V R Murthy and A V N Swamy

L-Lysine (C6H14N2O2) one of the essential and commercially important amino acids is found in naturally occurring proteins of all living organisms. The steadily increasing L-Lysine demand indispensably necessitates its fermentative production over synthetic processes. In practice, most of the amino acids were produced by batch fermentation. Continuous fermentation processes have certain advantages over the traditional discontinuous processes. L-Lysine production using immobilized cells in continuous mode seem to be very promising for future applications. The method employed for immobilization is calcium alginate cross linked with gluteraldehyde entrapment. We made an attempt to investigate the dependence of dilution rate on substrate utilization rate and cell productivity in continuous culture studies. L-Lysine concentration improved to a maximum level of 45.34 g/L and yield was 0.55 (g/g) obtained at an optimum dilution rate of 0.3 (1/h) under operating conditions of fermentation time – 72 h, pH – 7.5, Temperature – 30 °C and glucose concentration of 90 g/L.

© 2011 IUP. All Rights Reserved.

Solubility of Butanedioic Acid in Solutions of Water-Ethanol and Water-Propanol From 293.2 K to 333.2 K

-- Mauro L N Oliveira,Vanusa M F Oliveira, Leticia R Oliveira
and Moilton R Franco Junior

Using a gravimetric analytical method, the solubilities of butanedioic acid in some pure solvents and in binary mixtures of water-ethanol and water-1-propanol were determined by the static method at temperatures between 293.2 K and 333.2 K. Maximum acid solubility was observed in all systems tested. The results obtained for the dicarboxylic acid in pure solvents were in good agreement with the exponential curve when their dependence with the temperature was analyzed. The experimental data for the mixtures could be well correlated by a 3rd polynomial empirical equation.

© 2011 IUP. All Rights Reserved.

Kinetic Modeling of Biosorption of Cadmium by Syzygium cumini (L.) from Aqueous Solution

-- M Sujatha, P Kalpana, D A Naidu, P King and V S R K Prasad

In this study Syzygium cumini (L.) was used as a biosorbent to remove Cadmium (Cd)(II) from aqueous solution. A kinetic study for the residual concentration of metal ions was determined after contacting up to 60 min. Equilibrium was established in about 20 min for Cd(II). The maximum uptake of Cd(II) was 36.363 mg/g for Syzygium cumini (L.). In order to examine the control mechanism of biosorption processes, pseudo-first order and pseudo-second order kinetic models were used to test the experimental data and kinetics was found to be the best fit with the pseudosecond order kinetic model

© 2011 IUP. All Rights Reserved.

Effect of Various Parameters on Cell Temperature for Production of Aluminum

-- Vijay Singh Sikarwar, Sandeepan Ray, Vijay Agrawal and Parmesh Kumar Chaudhari

Current efficiency and thus economy of an electrolytic cell for the production of aluminium from alumina depends on the temperature inside the cell. Adequate care must be taken in order to maintain favorable temperature, and thus, efficiency of the cell. The paper presents an analysis of a set of 30 electrolytic cells. Temperature details of each cell and the various parameters like bath height, metal height, excess AlF3 and Al2O3 affecting the cell temperature were studied. Favorable temperature for safe functioning of the cell was 940-970 °C. Addition of AlF3 and increase in metal height were found to decrease the cell temperature, while increase in bath height resulted in an increase of cell temperature.

© 2011 IUP. All Rights Reserved.

CFD Simulation of Heat Transfer Characteristics in Pilot Plant Scale Bubble Column

-- Lutukurthi D N V V Konda and P Sivashanmugam

Bubble columns are widely used as gas-liquid contactors and as reactors in chemical, petrochemical and biochemical industries. Effective mixing as well as high interfacial area between the phases lead to improved heat and mass transfer characteristics. Gas-liquid flow in bubble column reactors is characterized by a combination of inherently unsteady complex processes with widely varying spatial and temporal scales. Understanding the complexity of the fluid dynamics and heat transfer in bubble column is important due to their application in chemical and bioprocess industries. The potential of Computational Fluid Dynamics (CFD) for describing the hydrodynamics and heat and mass transfer of bubble columns has been established by several publications in the past. CFD predicts what happens quantitatively when fluids flow, often with the complications of simultaneous flow of heat, mass transfer, phase change, chemical reaction, mechanical movement, stresses and displacement of immersed or surrounding solids. This paper reports the heat transfer characteristics of a semi-batch gas (air)-liquid (water) up-flow bubble column by CFD analysis. The Euler-Euler approach has been used for modeling the multiphase flow and to find the time averaged radial profiles of heat transfer coefficient along the column height. The standard k – ? dispersed turbulence model has been used to account for the effect of turbulence. The simulated results have been compared with the experimental results found in literature.

© 2011 IUP. All Rights Reserved.

Assessing the Behavioral Aspects of Gas-Solid Fluidization

-- V K Singh, Surjit Parial, Ankit Kumar Singh, Amit Keshav and H Kumar

The importance of fluctuation ratio in the context of uniform gas-solid fluidization has been presented. Correlations in terms of system parameters have been developed for the prediction of fluctuation ratio and its experimental and calculated values have been compared. It has been observed that the fluctuation ratio for the same air mass velocity, decreases (i.e., quality of fluidization improves) with an increase in the bed height by keeping all distributor parameters unchanged. Similarly, an increase in the particle size leads to better fluidization quality. An increase in the free flow area for air through the distributor causes more and more non-uniformity in fluidization.

© 2011 IUP. All Rights Reserved.

Indigenous Water Filtration Technique in Rural Areas of Assam: A Study on Iron Removal by Bamboo Charcoals

-- Bhupen Kumar Baruah, Chitrani Medhi and Abani Kumar Misra

Deterioration of groundwater quality due to geogenic and anthropogenic activities is now a serious issue all over the world. Evidences of contamination of groundwater resources prevail in many areas of India, particularly Assam. More than 80% of the rural population of Assam depend on groundwater resources for drinking and irrigation. The iron quantity in the groundwater of Assam is found to be between the desirable to permissible limits almost throughout the state. Iron, the common household water contaminant, has no direct health effect at concentrations generally found in groundwater. But high concentration causes staining, offensive taste and odor. The rural population of Assam frequently use sand, pebbles, charcoal and lime in their common water filtration technique for water purification. A study was carried out on the common indigenous water filtration technique using four different bamboo charcoals (Bhaluka, Jati, Makal and Bijuli) separately for iron removal. The study reveals that all the four types of bamboo charcoal could effectively remove iron from water. However, charcoal from Bambusa balcooa (Bhaluka) is more capable of decreasing the iron levels to desirable limits.

© 2011 IUP. All Rights Reserved.

Research Note
Renal Failure in Uddanam Region of Srikakulam District, Andhra Pradesh: Areas Identifed for Further Investigations

-- K V Ramesh, B Sasibhushan, K Gouru Naidu and S Mohan Kumar

Uddanam is a lush green region in the Srikakulam district of the state of Andhra Pradesh, located on the eastern coast of India with rich coconut and cashew plantations. The survey conducted by the Harvard Medical School of USA under Screening and Early Evaluation of Kidney diseases (SEEK) project revealed that about 3,200 people died in the last eight years due to renal failure (Times of India, 2009). This is India’s highest at 20% against the national average of 6%. The cause is generally attributed to a claim made by the specialists on excessive usage of pain killers and less water consumption. Leading newspapers have published numerous articles on various studies taken up by several organizations in addition to a number of news articles frequently found in the local editions of vernacular newspapers (Times of India, 2009; The Hindu, 2008 and 2009; and Deccan Chronicle, 2009). Although many agencies and individuals are working to unearth the mystery behind this killer disease, the real cause seems to be elusive. This indicated the absence of serious attention towards systematic investigation that necessitated the present study (Sasibhushan et al., 2010; and Sasibhushan, 2010).

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