Faculty Publications
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Item A simple, rapid and accurate complexometric method for the determination of palladium(II) is proposed, based on the selective masking property of thioacetamide towards palladium(II). In the presence of diverse metal ions, palladium(II) is complexed with excess of EDTA and the surplus EDTA is back titrated at pH 5-5.5(acetic acid-sodium acetate buffer) with standard lead nitrate solution using xylenol orange as indicator. An excess of a 0.5% aqueous solution of thioacetamide is then added to displace EDTA from Pd(II)-EDTA complex. The released EDTA is titrated with the same standard lead nitrate solution as before. Reproducible and accurate results are obtained in the concentration range 0.5mg-17.80mg of palladium with relative error of ±0.16% and coefficient of variation not exceeding 0.26%. The effect of diverse ions is studied. The method is used for the determination of palladium in its complexes, catalysts and synthetic alloy mixtures.(Complexometric determination of palladium(II) using thioacetamide as a selective masking agent) Parameshwara, P.; Karthikeyan, J.; Nityananda Shetty, A.N.; Shetty, P.2006Item Studies on the removal of Pb(II) from wastewater by activated carbon developed from Tamarind wood activated with sulphuric acid(2008) Singh, C.K.; Sahu, J.N.; Mahalik, K.K.; Mohanty, C.R.; Mohan, B.R.; Meikap, B.C.The low-cost activated carbon were prepared from Tamarind wood material by chemical activation with sulphuric acid for the adsorption of Pb(II) from dilute aqueous solution. The activated carbon developed shows substantial capacity to adsorb Pb(II) from dilute aqueous solutions. The parameters studied include physical and chemical properties of adsorbent, pH, adsorbent dose, contact time and initial concentrations. The kinetic data were best fitted to the Lagergren pseudo-first-order and pseudo-second order models. The isotherm equilibrium data were well fitted by the Langmuir and Freundlich models. The maximum removal of lead(II) was obtained 97.95% (experimental) and 134.22 mg/g (from Langmuir isotherm model) at initial concentration 40 mg/l, adsorbent dose 3 g/l and pH 6.5. This high uptake showed Tamarind wood activated carbon as among the best adsorbents for Pb(II). © 2007 Elsevier B.V. All rights reserved.Item Characteristics of a novel Acinetobacter sp. and its kinetics in hexavalent chromium bioreduction(2012) Narayani, M.; Shetty K, K.V.Cr-B2, a Gram-uegadve hexavalent chromium [Cr(VI)] reducing bacteria, was isolated from the aerator water of an activated sludge process in the wastewater treatment facility of a dye and pigment based chemical industry. Cr-B2 exhibited a resistance for 1,100mg/l Cr(VI) and, similarly, resistance against other heavy metal ions such as Ni2+ (800 mg/l), Cu2+ (600 mg/l), Pb2+ (1,100 mg/l), Cd2+ (350 mg/l), Zn2+ (700 mg/l), and Fe3+ (1,000 mg/l), and against selected antibiotics. Cr-B2 was observed to efficiently reduce 200mg/l Cr(VI) completely in both nutrient and LB media, and could convert Cr(VI) to Cr(III) aerobically. Cr(VI) reduction kinetics followed allosteric enzyme kinetics. The Km values were found to be 43.11 mg/l for nutrient media and 38.05 mg/l for LB media. Vmax values of 13.17 mg/l/h and 12.53 mg/l/h were obtained for nutrient media and LB media, respectively, and the cooperativity coefficients (n) were found to be 8.47 and 3.49, respectively, indicating positive cooperativity in both cases. SEM analysis showed the formation of wrinkles and depressions in the cells when exposed to 800 mg/l Cr(VI) concentration. The organism was seen to exhibit pleomorphic behavior. Cr-B2 was identified on the basis of morphological, biochemical, and partial 16S rRNA gene sequencing chracterizations and found to be Acinetobacter sp. © The Korean Society for Microbiology and Biotechnology.Item The uptake mechanism of Cd(II), Cr(VI), Cu(II), Pb(II), and Zn(II) by mycelia and fruiting bodies of Galerina vittiformis(Hindawi Publishing Corporation 410 Park Avenue, 15th Floor, 287 pmb New York NY 10022, 2013) Damodaran, D.; Mohan Balakrishnan, R.M.; Shetty K, K.Optimum concentrations of heavy metals like copper, cadmium, lead, chromium, and zinc in soil are essential in carrying out various cellular activities in minimum concentrations and hence help in sustaining all life forms, although higher concentration of these metals is lethal to most of the life forms. Galerina vittiformis, a macrofungus, was found to accumulate these heavy metals into its fleshy fruiting body in the order Pb(II) > Cd(II) > Cu(II) > Zn(II) > Cr(VI) from 50 mg/kg soil. It possesses various ranges of potential cellular mechanisms that may be involved in detoxification of heavy metals and thus increases its tolerance to heavy metal stress, mainly by producing organic acids and phytochelatins (PCs). These components help in repairing stress damaged proteins and compartmentalisation of metals to vacuoles. The stress tolerance mechanism can be deduced by various analytical tools like SEM-EDX, FTIR, and LC-MS. Production of two kinds of phytochelatins was observed in the organism in response to metal stress. © 2013 Dilna Damodaran et al.Item Effect of chelaters on bioaccumulation of Cd (II), Cu (II), Cr (VI), Pb (II) and Zn (II) in Galerina vittiformis from soil(2013) Damodaran, D.; Shetty K, K.; Raj Mohan, B.Remediation of heavy metal contaminated soil and water streams are of great necessity as heavy metals are toxic and pose hazardous ecological impacts. Low cost mitigation measures like phytoremediation and mycoremediation are commonly employed. Mycoremediation using macro fungi (mushroom) have proven to provide effective tolerance using an efficient accumulation mechanism in removing heavy metals from soil. The current paper reports the heavy metal remediation potential of macro fungi on soil artificially contaminated with 50mgkg-1 of Cu (II), Cd (II), Cr (VI), Pb (II), and Zn (II) ions. Galerina vittiformis belonging to Strophariacea family was found to be effective in removing the heavy metal from the soil under study within 30 days. Both chemical and biological chelaters at 1, 5, and 10mmolkg-1 concentrations were found to increase the mycoremediation potential of the organism. This study showed that G. vittiformis are efficient in remediating heavy metal from contaminated soil and that their remediation potential can be enhanced by the addition of chelaters. © 2013 Elsevier Ltd.Item Uptake of certain heavy metals from contaminated soil by mushroom-Galerina vittiformis(Academic Press, 2014) Damodaran, D.; Shetty K, K.; Raj Mohan, B.Remediation of soil contaminated with heavy metals has received considerable attention in recent years. In this study, the heavy metal uptake potential of the mushroom, Galerina vittiformis, was studied in soil artificially contaminated with Cu (II), Cd (II), Cr (VI), Pb (II) and Zn (II) at concentrations of 50 and 100. mg/kg. G. vittiformis was found to be effective in removing the metals from soil within 30 days. The bioaccumulation factor (BAF) for both mycelia and fruiting bodies with respect to these heavy metals at 50. mg/kg concentrations were found to be greater than one, indicating hyper accumulating nature by the mushroom. The metal removal rates by G. vittiformis was analyzed using different kinetic rate constants and found to follow the second order kinetic rate equation except for Cd (II), which followed the first order rate kinetics. © 2013 Elsevier Inc.Item Source apportionment of lead and cadmium by chemical characterization of PM2.5(Enviro Media rktem@pn3.vsnl.net.in, 2016) Srinikethan, G.; Ayare, A.Particulate matter below 2.5 micron (PM2.5) and its existence in atmosphere is observed in most of major cities in India and abroad. Health impacts of such pollutant on human being leading asthma and chronic bronchitis in India in last decade. Pune city in Maharashtra state of India is rapidly emerging as mega city in India due to its urbanization and modernization. Particulate matter and trace elements in it are causing severe effects on people of Pune. In present study, trace elements like lead (Pb) and cadmium (Cd) in PM2.5 at Pune city in Maharashtra, India were measured with the help of PM2.5 sampler and chemical characterization of Pb and Cd was done to determine the concentrations in the ambient air. The source apportionment of Pb and Cd was done by applying US EPA positive matrix factorization model to identify the sources and quantitative distribution of these elements at receptor location of Katraj in Pune city. The main objective was to identify and determine health impacts of Pb and Cd as well as PM2.5. The results of the study shall help urban planners, air quality planners and people of medicine to initiate urban air pollution management in Pune city.Item Exploring the fungal protein cadre in the biosynthesis of PbSe quantum dots(Elsevier B.V., 2017) Jacob, J.M.; Sharma, S.; Mohan Balakrishnan, R.M.While a large number of microbial sources have recently emerged as potent sources for biosynthesis of chalcogenide quantum dots (QDs), studies regarding their biomimetic strategies that initiate QD biosynthesis are scarce. The present study describes several mechanistic aspects of PbSe QD biosynthesis using marine Aspergillus terreus. Scanning electron microscopic (SEM) studies indicated distinctive morphological features such as abrasion and agglomeration on the fungal biomass after the biosynthesis reaction. Further, the biomass subsequent to the heavy metal/metalloid precursor was characterized with spectral signatures typical to primary and secondary stress factors such as thiol compounds and oxalic acid using Fourier Transform Infra-Red Spectroscopic (FTIR) analysis. An increase in the total protein content in the reaction mixture after biosynthesis was another noteworthy observation. Further, metal-phytochelatins were identified as the prominent metal-ion trafficking components in the reaction mixture using Liquid Chromatography Mass Spectroscopic analysis (LCMS). Subsequent assays confirmed the involvement of metal binding peptides namely metallothioneins and other anti-oxidant enzymes that might have played a prominent role in the microbial metal detoxification system for the biosynthesis of PbSe QDs. Based on these findings a possible mechanism for the biosynthesis of PbSe QDs by marine A. terreus has been elucidated. © 2016 Elsevier B.V.Item Biologically synthesized PbS nanoparticles for the detection of arsenic in water(Elsevier Ltd, 2017) Uddandarao, U.; Gowda K M, A.; M G, E.; Teja B, S.; Nitish, N.; Mohan B, R.Semiconductor nanoparticles have gained importance because of their interesting optical properties. Among these, lead sulfide (PbS) has been extensively studied due to its potential technological applications in field effect transistors, solar cells, photo-voltaics, light emitting diodes, photocatalysis, photo-luminescence, infrared photodetectors, environmental and biological sensors. Hence there is a need to explore cost effective and eco-friendly biological routes for their synthesis. In this paper, biosynthesis of PbS nanoparticles were carried out using endophytic fungi, subsequently detailed characterization was also performed using UV–visible, fluorescence spectrometer, FTIR, SEM, TEM, EDX and XRD. TEM revealed the formation of PbS nanoparticles in typical size range of 35–100 nm. The application of these nanoparticles for detection of arsenic in aqueous solution through their absorbance properties was also dealt. Importantly, the results were demonstrated for detection of 50 ppb As (III) in water without any interference of other selected ions maintained upto 20 ppb under same conditions. Further, the correlation for the bio-sensitivity of PbS nanoparticles based on the quenching effect with arsenic concentrations ranging between 10 and 100 ppb in water samples was deduced. © 2016 Elsevier LtdItem Kinetic and thermodynamic studies on the adsorption of heavy metals from aqueous solution by melanin nanopigment obtained from marine source: Pseudomonas stutzeri(Academic Press, 2018) Manirethan, V.; Raval, K.; Rajan, R.; Thaira, H.; Mohan Balakrishnan, R.M.The difficulty in removal of heavy metals at concentrations below 10 mg/L has led to the exploration of efficient adsorbents for removal of heavy metals. The adsorption capacity of biosynthesized melanin for Mercury (Hg(II)), Chromium (Cr(VI)), Lead (Pb(II)) and Copper (Cu(II)) was investigated at different operating conditions like pH, time, initial concentration and temperature. The heavy metals adsorption process was well illustrated by the Lagergren's pseudo-second-order kinetic model and the equilibrium data fitted excellently to Langmuir isotherm. Maximum adsorption capacity obtained from Langmuir isotherm for Hg(II) was 82.4 mg/g, Cr(VI) was 126.9 mg/g, Pb(II) was 147.5 mg/g and Cu(II) was 167.8 mg/g. The thermodynamic parameters revealed that the adsorption of heavy metals on melanin is favorable, spontaneous and endothermic in nature. Binding of heavy metals on melanin surface was proved by Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray Photoelectron Spectroscopy (XPS). Contemplating the results, biosynthesized melanin can be a potential adsorbent for efficient removal of Hg(II), Cr(VI), Pb(II) and Cu(II) ions from aqueous solution. © 2018 Elsevier Ltd