Faculty Publications
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Item Ba-ZnO nanoparticles for photo-catalytic degradation of chloramphenicol(American Institute of Physics Inc. subs@aip.org, 2018) Kulkarni, R.M.; Malladi, R.S.; Hanagadakar, M.S.; Shetti, N.P.; Doddamani, M.Pristine ZnO (PZO) and 5% barium doped ZnO nanoparticles (BZONP) were prepared by in expensive chemical precipitation method. The techniques used to characterize prepared nanoparticles are X-ray powder diffraction (XRD), Energy Dispersive X-ray Spectroscopy (EDX), Scanning Electron Microscope (SEM), UV-visible absorption spectroscopy and Transmission Electron Microscope (TEM) analysis. The particle size of PZO and BZONP were calculated using Scherrer equation. The photo-catalytic efficiency of 5% BZONP was studied with photo-degradation of chloramphenicol (CLP) under UVC (254 nm) irradiation in aqueous suspension. Pseudo-first order rate constants (kobs) were found to increase with the decrease in pH. The effect of initial concentration, photo-catalyst loading, light intensity, the effect of pH on the photo-degradation rate was also examined and elaborately discussed. The results showed that BZONP is a better photo-catalyst compared PZO. The HPLC and LC/MS were used to identify photo-degradation products. © 2018 Author(s).Item Electro-oxidation of nimesulide at 5% barium-doped zinc oxide nanoparticle modified glassy carbon electrode(Elsevier B.V., 2016) Bukkitgar, S.D.; Shetti, N.P.; Kulkarni, R.M.; Doddamani, M.R.Development of methods for the detection of an analyte at low concentration with less time for analysis has become a prior point of interest to every analyst. In reflection of this fact, an effort has been made to synthesize 5% barium doped zinc oxide nanoparticles and was characterized by using XRD, EDX, SEM, and TEM. Further, 5% barium doped zinc oxide nanoparticle modified glassy carbon electrode was used for investigating the electro-chemical behavior of nimesulide. Voltammograms obtained in a range of 3.0-11.2 (I = 0.2 M) pH had a maximum peak current at pH 7.0. Various physio-chemical parameters such as, process on the surface of the electrode, which was found to be diffusion controlled, heterogeneous rate constant, number of electrons transferred and charge transfer coefficient were estimated. Further, a method for nimesulide determination in a linear range of 1.0 × 10- 5 to 1.0 × 10- 7 M with LOD 1.794 nM was proposed. This technique was later used for analytical application. © 2015 Elsevier Ltd. All rights reserved.Item Ag-TiO2 nanoparticles for photocatalytic degradation of lomefloxacin(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2016) Kulkarni, R.M.; Malladi, R.S.; Hanagadakar, M.S.; Doddamani, M.R.; Bhat, K.U.The photocatalytic activity of silver-doped TiO2 (Ag-TiO2) nanoparticles was studied by photocatalytic degradation of lomefloxacin (LMF) using a photoreactor with a mercury lamp (PHILIPS, TUV 8 W T5, Emax = 254 nm). The 1 and 2% silver-doped TiO2 nanoparticles were synthesized by liquid impregnation (LI) method. The resulting nanoparticles were characterized by surface analytical methods such as X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray analysis and transmission electron microscope (TEM). The study shows 2% Ag-TiO2 nanoparticles exhibited better results (95% degradation) in 1 h for the degradation of lomeofloxacin compared to 1% Ag-TiO2 and pure TiO2. XRD analysis indicated that the crystallite size of TiO2 was 17.00 nm, while the crystallite size of 1% Ag-TiO2 and 2% Ag-TiO2 was 13.07 to 14.17 nm. TEM images show the particle size of Ag-TiO2 nanoparticles were in the range 40–45 nm in length and 10–15 nm in breadth. Pseudo-first-order rate constants were found to decrease with increase in pH. The effect of UV intensity, catalyst dosage and initial concentration of LMF on the degradation rate were also studied and elaborately discussed. © 2015 Balaban Desalination Publications. All rights reserved.Item Ru–TiO2 semiconducting nanoparticles for the photo-catalytic degradation of bromothymol blue(Springer New York LLC barbara.b.bertram@gsk.com, 2016) Kulkarni, R.M.; Malladi, R.S.; Hanagadakar, M.S.; Doddamani, M.R.; Santhakumari, B.; Kulkarni, S.D.Photo-catalytic degradation of bromothymol blue (BTB) in an aqueous medium by Ru–TiO2 using UVC (254 nm) irradiation was investigated for a pH range of 4.0–8.0. The liquid impregnation method was used to synthesize 0.2, 0.4 and 0.8 % ruthenium doped TiO2 (Ru–TiO2) nanoparticles. The characterizations of resulting nanoparticles were done using X-ray diffraction, scanning electron microscopy, fourier transform infrared spectroscopy, transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy analysis. The crystallite sizes of doped and undoped nanoparticles were determined from X-ray diffraction spectra using Scherrer equation. The average crystallite size of undoped TiO2 was found to be 17.00 nm, whereas the crystallite sizes of 0.2, 0.4 and 0.8 % Ru–TiO2 were 16.67, 15.70 and 14.40 nm respectively. The TEM images confirm the particle sizes to be 10–40 nm. Pseudo-first order rate constants (kobs) determined were found to decrease with increase in pH. The effect of BTB Concentration, catalyst dosage, a percentage of doping of photo catalyst, pH and UV light intensity of BTB on the degradation rate were also examined. © 2016, Springer Science+Business Media New York.Item 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.Item 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.