Browsing by Author "Srinikethan, G."

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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.
Bacterial Cellulose production by K. saccharivorans BC1 strain using crude distillery effluent as cheap and cost effective nutrient medium
(Elsevier B.V., 2019) Gopu, G.; Srinikethan, G.
Bacterial Cellulose (BC), a valuable biopolymer gaining importance over the past few decades due to its remarkable properties and applications. In this study, crude distillery effluent having a high COD value of 87,433 mg/L was used to produce Bacterial Cellulose under static fermentation by Komagataeibacter saccharivorans, a novel isolated bacterial strain. 1.24 g/L of cellulose production was noted after eight days along with 23.6% reduction in COD value. The BC pellicle was purified, lyophilized and stored. Further, the lyophilized BC pellicle was subjected to characterization techniques such as SEM, ATR-FTIR, XRD, NMR and TLC. Morphological analysis revealed that cellulose fibers were dense with higher porosity and an average fiber width of 60 nm. FTIR depicted similar functional groups as that of BC-HS medium. TLC of the biopolymer was performed to evaluate its purity. X-ray diffraction and 13C NMR studies gave more insights about the crystalline and the amorphous regions; the synthesized polymer exhibited 80.2% as crystallinity and crystallite size of 8.36. Hence, the present study demonstrates that distillery effluent waters could be effectively reused as production medium fulfilling two objectives namely one reducing COD and making the effluent safe for disposal and two to produce a value-added product. © 2019 Elsevier B.V.
Biocomposite composed of PVA reinforced with cellulose microfibers isolated from biofuel industrial dissipate: Jatropha Curcus L. seed shell
(Elsevier Ltd, 2017) Manjula, M.; Srinikethan, G.; Shetty K, V.K.
Biofuel production by Jatropha Curcas L. (JC) seeds result in large quantities of unused seed shells contributing as an extensive potential source for cellulose production. Present work consummates on isolation of cellulose microfibers (CMF) from JC seed shell by chlorination treatment and were characterized using Scanning Electron Microscope (SEM), Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and 13C NMR. Removal of hemicellulose and lignin were confirmed from FTIR results. Cellulose microfibers with diameter 0.23-1.04 ?m demonstrated considerable increase in crystallinity and thermal stability by chlorination treatment. Procured cellulose microfibers were reinforced in Poly-vinyl Alcohol (PVA) by solution casting in water to form biocomposites. Mechanical properties and thermal stability of these biocomposites increased on addition of cellulose microfiber, ensuring the potentiality of cellulose fibers as filler in biocomposites which can reinstate traditional plastics. © 2017 Published by Elsevier Ltd.
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.
Biofibres from biofuel industrial byproduct—Pongamia pinnata seed hull
(Springer Science and Business Media Deutschland GmbH, 2017) Manjula, P.; Srinikethan, G.; Shetty K, K.V.
Background: Biodiesel production using Pongamia pinnata (P. pinnata) seeds results in large amount of unused seed hull. These seed hulls serve as a potential source for cellulose fibres which can be exploited as reinforcement in composites. Methods: These seed hulls were processed using chlorination and alkaline extraction process in order to isolate cellulose fibres. Scanning electron microscopy (SEM), dynamic light scattering (DLS), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (NMR) analysis demonstrated the morphological changes in the fibre structure. Results: Cellulose microfibres of diameter 6–8 µm, hydrodynamic diameter of 58.4 nm and length of 535 nm were isolated. Thermal stability was enhanced by 70 °C and crystallinity index (CI) by 19.8% ensuring isolation of crystalline cellulose fibres. Conclusion: The sequential chlorination and alkaline treatment stemmed to the isolation of cellulose fibres from P. pinnata seed hull. The isolated cellulose fibres possessed enhanced morphological, thermal, and crystalline properties in comparison with P. pinnata seed hull. These cellulose microfibres may potentially find application as biofillers in biodegradable composites by augmenting their properties. © 2017, The Author(s).
Biological phenol removal using immobilized cells in a pulsed plate bioreactor: Effect of dilution rate and influent phenol concentration
(2007) Shetty K, K.V.; Ramanjaneyulu, R.; Srinikethan, G.
The continuous aerobic biodegradation of phenol in synthetic wastewater was carried out using Nocardia hydrocarbonoxydans immobilized over glass beads packed between the plates in a pulsed plate bioreactor at a frequency of pulsation of 0.5 s-1 and amplitude of 4.7 cm. The influence of dilution rate and influent phenol concentration on start up and steady state performance of the bioreactor was studied. The time taken to reach steady state has increased with increase in dilution rate and influent phenol concentration. It was found that, as the dilution rate is increased, the percentage degradation has decreased. Steady state percentage degradation was also reduced with increased influent phenol concentration. Almost 100% degradation of 300 and 500 ppm influent phenol could be achieved at a dilution rate of 0.4094 h-1 and more than 99% degradation could be achieved with higher dilution rates. At a higher dilution rate of 1.0235 h-1 and at concentrations of 800 and 900 ppm the percentage degradation has reduced to around 94% and 93%, respectively. The attached biomass dry weight, biofilm thickness and biofilm density at steady state were influenced by influent phenol concentration and dilution rate. © 2007 Elsevier B.V. All rights reserved.
Biosorption study on Ni(II) and Cd(II) removal in a packed bed column using brewery sludge pellets
(Springer Science and Business Media Deutschland GmbH, 2024) Kulkarni, R.M.; Shetty K, V.; Srinikethan, G.
The study covers the results of investigations on performance of packed bed column as a continuous contactor for nickel [Ni(II)] and cadmium [Cd(II)] biosorption on pellets of brewery sludge. Experiments were conducted to assess influence of design variables such as bed height (2.5 to 10 cm) and flow rate (2.5 to 10 mL/min). By fitting the column data into the model equations, the parameters of the Thomas and bed depth service time (BDST) models, which are utilized in the design of packed column adsorbers, were determined. For Ni(II) biosorption, the computed values of N0 and KA obtained using the BDST model were 1833 mg/L and 0.022 L/mg.h, respectively, whereas for Cd(II) biosorption, the values were 5424 mg/L and 0.005 L/mg.h, respectively. Predicted Ni(II) and Cd(II) uptake using the Thomas model were 7.33 mg/g and 14.79 mg/g at 2.5 mL/min flow rate. Optimal biosorption conditions for Ni(II) and Cd(II) were observed at 2.5 mL/min flow rate and 10 cm bed height. Critical design factors such as length of the unused bed (LUB), stoichiometric time (t*), and mass transfer zone (Δt) needed for scaling up the biosorption process were also determined. The present study has demonstrated that the biosorption of Ni(II) and Cd(II) onto pellets of brewery sludge in packed bed column is intraparticle mass transfer controlled process. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2022.
Cadmium (II) and nickel (II) biosorption by Bacillus laterosporus (MTCC 1628)
(Taiwan Institute of Chemical Engineers, 2014) Kulkarni, R.; Shetty K, V.; Srinikethan, G.
Biosorption of heavy metals is a promising technology that involves removal of toxic metals from industrial waste streams and natural waters. The study describes the sorption of cadmium (II) [Cd (II)] and nickel (II) [Ni (II)] by dead biomass of Bacillus laterosporus, MTCC 1628. The biosorption conditions for the removal of Cd (II) and Ni (II) were examined by studying the effect of pH, contact time, biosorbent dosage and initial metal ion concentration. Shake flask studies yielded adsorption equilibrium in almost 120. min, for both the metals. It was found from Langmuir model that the maximum adsorption capacity for Cd (II) and Ni (II) ions was 85.47. mg/g and 44.44. mg/g respectively. Kinetic evaluation of the experimental data showed that the biosorption process followed pseudo-second order kinetics. Thermodynamic analysis showed that biosorption is an endothermic process with ?. H° of 5.45. kJ/mol for Cd (II) biosorption and 24.33. kJ/mol for Ni (II) biosorption. The surface characteristics of B. laterosporus biomass before and after metal biosorption were analyzed by using scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDAX) to study the changes in surface morphology and elemental constitution of the adsorbent. B. laterosporus exhibited a higher and better potential biosorbent for the removal of Cd (II) as compared to Ni (II) from aqueous solution. © 2013 Taiwan Institute of Chemical Engineers.
Combined effect of plate pulsation parameters and phenol concentrations on the phenol removal efficiency of a pulsed plate bioreactor with immobilized cells
(2008) Shetty K, K.V.; Kedargol, M.R.; Srinikethan, G.
Continuous aerobic biodegradation of phenol in synthetic wastewater with phenol at different concentrations (200, 300, 500, 800 and 900 ppm) was carried out in a pulsed plate column, which is used as a bioreactor with immobilised cells of Nocardia hydrocarbonoxydans (NCIM 2386) at a dilution rate of 0.4094 h-1 and amplitude of 4.7 cm at various frequencies of pulsation (0, 0.25, 0.5, 0.75 and 1 s-1). The effect of frequency of pulsation on the steady state performance of the bioreactor for phenol biodegradation at different influent concentrations was studied. Percentage degradations were observed to be a combined effect of volumetric phenol loading, reactor residence time, mass transfer limitations and phenol inhibition effect. At 500 ppm influent phenol concentration the effect of frequencies of pulsation on the steady state percentage degradation at different amplitudes was studied. The percentage degradation increased with increase in frequency and almost 100% degradation was achieved at 0.75s-1, 0.5s-1 or 0.25s -1, with 3.3, 4.7 or 6.0 cm amplitudes respectively and hence the vibrational velocity (amplitude * frequency) was found to influence the steady state performance of the reactor. It was found that optimum vibrational velocities need to be fixed for maximum removal efficiency of the bioreactor depending on the influent phenol concentration. © IWA publishing 2008.
Continuous fixed-bed adsorption of reactive azo dye on activated red mud for wastewater treatment-Evaluation of column dynamics and design parameters
(Springer Science and Business Media Deutschland GmbH, 2023) Mavinkattimath, R.G.; Shetty K, V.; Srinikethan, G.
Continuous adsorption of Remazol Brilliant Blue (RBB) dye in water onto sulfuric acid activated red mud (CATRM) in a fixed bed column was investigated. Breakthrough curves were obtained experimentally by varying the bed height (Z), influent flow rate (Q), and dye concentration(C0). The adsorption efficiency in the removal of RBB was favored at lower C0, higher Z, and lower Q. The maximum adsorption capacity of the activated red mud bed in the column was obtained at C0 = 70 mg/L, Z = 8 cm, and Q = 5 mL/min and found to be 106 mg/g. Important parameters of column dynamics and design such as mass transfer zone (MTZ) and length of unused bed (LUB) were evaluated from the breakthrough curves. The MTZ and LUB have varied with varying Z, which indicated the existence of nonideal conditions. Thomas model was found to be valid to predict the column dynamics and the model parameters were evaluated. Bed depth service time (BDST) model parameters were evaluated to facilitate the determination of packed bed height for the design of packed bed adsorption column. The bed could be regenerated with NaOH solution with desorption efficiency decreasing from 83.8 to 55.72% from the first to third cycle. A fixed bed of CATRM can be effectively used for continuous dye removal from industrial wastewater. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Crude glycerol as a cost-effective carbon source for the production of cellulose by K. saccharivorans
(Elsevier Ltd, 2018) Gopu, G.; Srinikethan, G.
Bacterial cellulose (BC) has been gaining attention due to its widespread applications in various domains such as food, medical, paper industries etc. The culture medium required for the production of cellulose by bacteria generally needs a high amount of carbon and nitrogen source. Hence using a cost-effective carbon source could be a feasible option so as to reduce the production cost and make the process economical overall. Crude glycerol is a by-product generated in large quantities from the biodiesel industry worldwide every year. This form of glycerol also has very low commercial value due to the huge amount of impurities present in it, making the purification and disposal process expensive. Therefore in the current study, we attempted to replace the carbon source in the production medium using crude glycerol and produced bacterial cellulose using novel strain K.saccharivorans. The BC pellicle synthesized was further characterized by FTIR, SEM, XRD, and TGA which proved that crude glycerol could be a viable alternative over other expensive carbon sources for the synthesis of BC. © 2018 Elsevier Ltd
Effect of media characteristics on performance of upflow aerobic biofilters
(2008) Srinikethan, G.; Shrihari, S.; Pradeepan, V.S.
Laboratory studies were conducted to assess the influence of media related factors such as porosity, pore size, particle size and specific surface area on the performance of upflow aerobic biofilters (ABFs). Three simple models of 8 litre capacity upflow submerged ABFs packed with support media of size 40 mm, 20 mm and 10 mm respectively were installed. The hydraulic retention time (HRT) was maintained as 12 hours. The study was carried out for a period of 90 days. The reactor performance indicated that the aerobic biofilter (ABF-3), associated with media of lowest porosity, pore size, particle size and highest specific surface area, demonstrating the highest BOD and COD removal efficiency of 93.32 % and 85.01 % respectively.
Extraction and characterisation of cellulose microfibrils from pongamia pinnata seed shell
(2015) Manjula, P.; Srinikethan, G.; Vidya, Shetty, K.
Biodiesel is a renewable resource of energy and has gained its importance in India due to soaring oil price and largely enhanced environmental awareness. Biodiesel and other biofuels are produced from agricultural plant and plant products. Pongamia Pinnata seeds have been identified as a superior and more sustainable source of biodiesel. The process generates large amount of unused Pongamia Pinnata seed shell. The present paper reports isolation of cellulose microfibrils from Pongamia Pinnata seed shell using chlorination and alkaline extraction process. The morphology of the cellulose microfibrils was investigated by Scanning Electron Microscopy. The cellulose microfibrils had diameter in the range of 0.8-2.6 ?m. The crystallinity index obtained from X-ray diffraction and spectrums from Fourier transform infrared and Nuclear magnetic resonance spectroscopy for seed shell and extracted cellulose microfibrils, showed that the chemical treatments removed most of the hemicellulose and lignin from the seed shell fibers. The thermal stability of the fibers was analysed using thermogravimetric analysis, which demonstrated that thermal stability was enhanced noticeably for cellulose microfibrils. This work provides a new approach for more effective utilisation of Pongamia Pinnata seed shell to examine their potential use as reinforcement fibres in biocomposites. � 2015 International Committee on Composite Materials. All rights reserved.
Extraction and characterisation of cellulose microfibrils from pongamia pinnata seed shell
(International Committee on Composite Materials M.Wisnom@bristol.ac.uk, 2015) Manjula, P.; Srinikethan, G.; Shetty K, K.
Biodiesel is a renewable resource of energy and has gained its importance in India due to soaring oil price and largely enhanced environmental awareness. Biodiesel and other biofuels are produced from agricultural plant and plant products. Pongamia Pinnata seeds have been identified as a superior and more sustainable source of biodiesel. The process generates large amount of unused Pongamia Pinnata seed shell. The present paper reports isolation of cellulose microfibrils from Pongamia Pinnata seed shell using chlorination and alkaline extraction process. The morphology of the cellulose microfibrils was investigated by Scanning Electron Microscopy. The cellulose microfibrils had diameter in the range of 0.8-2.6 Î¼m. The crystallinity index obtained from X-ray diffraction and spectrums from Fourier transform infrared and Nuclear magnetic resonance spectroscopy for seed shell and extracted cellulose microfibrils, showed that the chemical treatments removed most of the hemicellulose and lignin from the seed shell fibers. The thermal stability of the fibers was analysed using thermogravimetric analysis, which demonstrated that thermal stability was enhanced noticeably for cellulose microfibrils. This work provides a new approach for more effective utilisation of Pongamia Pinnata seed shell to examine their potential use as reinforcement fibres in biocomposites. Â© 2015 International Committee on Composite Materials. All rights reserved.
Industrial estate planning for Mangalore Taluk in Karnataka, using remote sensing and GIS
(2006) Navalgund, L.; Shreedhara, V.; Srinikethan, G.
The present work presents a technique to prepare zoning atlas to classify the environment and risks involved in siting an industry. Based on risks involved in a classified zone, the best-suited industries are recommended. Mangalore city has been taken as the study area has for the present work. Sensitivity of study area has been checked in terms of air pollution, surface water pollution and groundwater pollution. The study relies upon the database procured for this purpose from Central Pollution Control Board (CPCB) and Karnataka State Remote Sensing Technology, Bang lore. The database mainly comprises of topographic maps, thematic maps and groundwater information. Buffering and over-laying of the thematic maps have been carried out as per the guidelines of CPCB. © Enviromedia Printed in India. All rights reserved.
Isolation of Novel Aerobic denitrifier and optimization of process parameters for biological denitrification using RSM
(Slovak University of Agriculture info@jmbfs.org, 2019) Joshi, K.; Navalgund, N.; Shet, V.B.; Srinikethan, G.; Ashwini; Sneha; Anusha; Aparna, A.
The study aimed to isolate and characterize a high efficiency novel bacterium for denitrification in waste water and also to optimize process parameters under aerobic condition. One of the bacteria chosen among four, displayed a maximum of 98% reduction of nitrate. The strain was identified as Enterobacter sp. NCCP-29 by biochemical tests and further identified based on similarity of PCR-16S rRNA using universal primers. The parameters (pH, temperature, agitation speed, C:N ratio) which effect the denitrification were screened using one factor at a time. The pH, temperature and C:N ratio exhibited significant effect on the denitrification using Enterobacter sp. NCCP-29. The levels of these parameters were optimized using a central composite design (CCD). A maximum of 98% denitrification was achieved at pH 6.5, temperature 30°C and C: N ratio of 3:1. The second order model was generated and found to have a good fit with R2 value of 0.93. Investigations revealed the ability of Enterobacter sp. NCCP-29 to remove nitrate under aerobic conditions. © 2019, Slovak University of Agriculture.
Isotherm, kinetics, and process optimization for removal of Remazol Brilliant Blue dye from contaminated water using adsorption on acid-treated red mud
(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2016) Ratnamala, G.M.; Shetty K, K.V.; Srinikethan, G.
Red mud, which is a waste product from alumina production, has been utilized after activation with concentrated sulphuric acid treatment for removal of Remazol Brilliant Blue (RBB) dye from dye-contaminated water to investigate its potential as a low-cost adsorbent. The activation has enhanced the surface area of red mud from 20.2 to 32.28 m2/g, thus enhancing its adsorption capacity. The effect of initial dye concentration, contact time, initial pH and adsorbent dosage on percentage removal of dye using concentrated sulphuric acid-treated red mud (CATRM) was investigated. The ranges of these variables for optimization were selected based on batch studies. Acidic pH favoured adsorption and 300 min contact time was found to be suitable for attainment of equilibrium under shaking conditions of 145 rpm. Langmuir isotherm model has been found to represent the equilibrium data for RBB-CATRM adsorption system better in comparison with Freundlich model. The adsorption capacity of CATRM was found to increase with the increase in temperature, and at 40°C, it was found to be 125 mg dye/g of CATRM. The adsorption kinetics was represented by second-order kinetic model, and the kinetic constant was estimated to be 0.0063 g/mg min. Factors affecting the adsorption process were optimized by response surface methodology based on experiments designed as per central composite design. The effects of individual variables and their interaction effects on dye removal were determined. The results of the study showed that dye removal efficiency of almost 100% can be obtained with optimal conditions of initial dye concentration at 105 mg/l, red mud dosage of 2.05 g/l, initial pH of 1 and temperature of 31.65°C. pH and temperature were found to have high interaction effect on adsorption. © 2015 Balaban Desalination Publications. All rights reserved.
Kinetic and equilibrium modeling of biosorption of nickel (II) and cadmium (II) on brewery sludge
(IWA Publishing 12 Caxton Street London SW1H 0QS, 2019) Kulkarni, R.M.; Shetty K, K.; Srinikethan, G.
In the current study, utilization of industrial waste brewery sludge for the biosorption of nickel (II) and cadmium (II) has been explored. The suitable conditions for the effective removal of Ni (II) and Cd (II) from aqueous solutions were examined. The kinetic evaluation showed that the biosorption process using the sludge followed pseudo-second order kinetics. In the presence of a metal co-ion, competitive and preferential biosorption was observed. The Langmuir model and Freundlich model were able to describe the sorption equilibrium for biosorption of Ni (II) and Cd (II) ions in single and dual metal systems. The effects of co-ion concentrations onto mono-component isotherm parameters (Langmuir and Freundlich) were studied and the inhibitory effect of co-ion concentration was observed. The effective reusability of biomass was assessed by three cycles of sorption-desorption. The sludge, owing to its high biosorption intensity and large availability from the local supply, is a better biosorbent for the treatment of Ni (II) and Cd (II) contaminated water. © IWA Publishing 2019 Water Science & Technology.
Laboratory studies were conducted to assess the influence of media related factors such as porosity and pore size and specific surface area on performance of up flow anaerobic biofilters (ABFs). Two simple model of 8 litres capacity up flow anaerobic biofilters (ABFs), one packed with support media granite of size 50 to 40 mm and the other packed with granite of size 25 to 20 mm were installed. The experimental anaerobic biofilters were made of PVC tubes. The hydraulic retention time (HRT) was maintained as 12 hours. The study was carried out for a period of 90 days. The waste treatment performance indicates that the biofilter associated with media of the lesser pore size and porosity with higher specific surface area demonstrated the highest BOD and COD removal 91.03% and 82.50% respectively. Copyright © Enviromedia.
(Treatment of domestic wastewater in up flow anaerobic biofilters (using granite as packing material)) Srinikethan, G.; Shrihari, S.; Pradeepan, V.S.
2005
Materials, Energy and Environment Engineering: Select Proceedings of ICACE 2015
(2017) Raj Mohan, B.; Srinikethan, G.; Meikap, Bhim Charan