Faculty Publications
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Item Insights on the advanced processes for treatment of inorganic water pollutants(Elsevier, 2020) Mohan Balakrishnan, R.M.; Uddandarao, P.; Manirethan, V.; Raval, K.A remarkable increase in the discharge of inorganic pollutants globally from various sources such as mines, industries, or agricultural lands is a major threat to the environment. Development of novel methodologies to mitigate the effects caused by inorganic pollutants in water is crucial in addressing environmental issues. In this regard, various biological sources as nanosorbents and biosensors are venerated as superior entities for the detection and removal of inorganic contaminants. This chapter summarizes the utility of marine bacterial melanin- and fungal-based selenium nanoparticles for the adsorption and further reports endophytic fungal–based ZnS and PbS nanoparticles for the detection of inorganic pollutants from the aqueous systems; moreover, it gives a perspective on current challenges for the removal of contaminants. © 2020 Elsevier Inc. All rights reserved.Item ZnS semiconductor quantum dots production by an endophytic fungus Aspergillus flavus(Elsevier Ltd, 2016) Uddandarao, P.; Mohan B, R.The development of reliable and eco-friendly processes for the synthesis of metal sulphide quantum dots has been considered as a major challenge in the field of nanotechnology. In the present study, polycrystalline ZnS quantum dots were synthesized from an endophytic fungus Aspergillus flavus. It is noteworthy that apart from being rich sources of bioactive compounds, endophytic fungus also has the ability to mediate the synthesis of nanoparticles. TEM and DLS revealed the formation of spherical particles with an average diameter of about 18 nm and 58.9 nm, respectively. The ZnS quantum dots were further characterized using SEM, EDAX, XRD, UV-visible spectroscopy and FTIR. The obtained results confirmed the synthesis of polycrystalline ZnS quantum dots and these quantum dots are used for studying ROS activity. In addition this paper explains kinetics of metal sorption to study the role of biosorption in synthesis of quantum dots by applying Morris-Weber kinetic model. Since Aspergillus flavus is isolated from a medicinal plant Nothapodytes foetida, quantum dots synthesized from this fungus may have great potential in broad environmental and medical applications. © 2016 Elsevier B.V. All rights reserved.Item Photocatalytic degradation of Irgalite violet dye using nickel ferrite nanoparticles(IWA Publishing 12 Caxton Street London SW1H 0QS, 2019) Vijay, S.; Mohan Balakrishnan, R.M.; Rene, E.R.; Uddandarao, P.Nanotechnologies have prominent applications in the field of science and technology owing to their size-tunable properties providing a promising approach for degradation of various pollutants. In this scenario, the present work aims to study the effect of nickel ferrite nanoparticles on the degradation of Irgalite violet dye by Fenton’s reaction using oxalic acid as an oxidizing agent in the presence of sunlight. The effect of pH and adsorbent dosage on the rate of dye degradation was monitored. Based on these studies it was observed that 99% dye degradation was achieved for catalyst dosage of 0.2 g, 400 ppm dye concentration and 2.0 mM oxalic acid at pH 3.0 within 60 min. The studies reveal that the degradation follows pseudo-first-order kinetics and the catalyst reusability remained constant almost for five cycles. Further, nickel ferrite nanoparticles are proven to be an efficient alternative for the removal of dyes from coloured solutions. © IWA Publishing 2019Item Bioinspired ZnS: Gd nanoparticles synthesized from an endophytic fungi Aspergillus flavus for fluorescence-based metal detection(MDPI AG, 2019) Uddandarao, P.; Mohan Balakrishnan, R.M.; Ashok, A.; Swarup, S.; Sinha, P.Recently, several nonconventional sources have emerged as strong hotspots for the biosynthesis of chalcogenide quantum dots. However, studies that have ascertained the biomimetic methodologies that initiate biosynthesis are rather limited. The present investigation portrays a few perspectives of rare-earth(Gd)-doped ZnS biosynthesis using the endophytic fungi Aspergillus flavus for sensing metals based on their fluorescence. Analysis of ZnS:Gd nanoparticles was performed by elemental analysis, energy-dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), photoluminescence (PL), and transmission electron microscopy (TEM). The results of TEM demonstrated that the particles were polycrystalline in nature, with a mean size of 10-18 nm. The fluorescence amenability of the biogenic ZnS nanoparticles was further used for the development of a simple and efficient sensing array. The results showed sensitive and detectable quenching/enhancement in the fluorescence of biogenic colloidal ZnS nanoparticles, in the presence of Pb (II), Cd (II), Hg (II), Cu (II) and Ni (II), respectively. The fluorescence intensity of the biogenic ZnS:Gd nanoparticles was found to increase compared to that of the ZnS nanoparticles that capacitate these systems as a reliable fluorescence sensing platform with selective environmental applications. © 2019 by the authors.Item Mycosensing of soil contaminants by Ganoderma lucidum and Omphalotus subilludens including the insights on growth media requirements(Elsevier Ltd, 2019) Gupta, C.; Mohan Balakrishnan, R.M.; Uddandarao, P.; Arivalagan, A.Heavy metals are regarded as one of the major threats to environmental biota due to prolonged soil residence time. In this scenario, mycoremediation emerged as an effective tool for the removal of heavy metal contaminants. The present study reports the responses of two wild mushroom species Ganoderma lucidum and Omphalotus subilludens under metal stress conditions and the nutritional requirements of the mushroom species. The media was screened wherein the media containing glucose and sucrose as carbon source showed better growth for Ganoderma lucidum and Omphalotus subilludens respectively. In addition, peptone as a nitrogen source is required for the growth of both Ganoderma lucidum and Omphalotus subilludens. Further, it is observed that macronutrients play a crucial role in the stimulation of enzymes and the micronutrients are mandatory for intermediary metabolism of the fungi in both the species. Tolerance studies are carried out in-vitro and the results reveal that the Ganoderma lucidum showed tolerance towards Cr (VI), Ni (II), Pb (II) and Cd (II) at maximum tolerant concentrations of 1000 mg/kg, 500 mg/kg, 100 mg/kg and 10 mg/kg, in case of, Omphalotus subilludens showed tolerance towards Cr (VI), Ni (II) and Pb (II) at maximum tolerant concentration of 700 mg/kg, 700 mg/kg and 500 mg/kg respectively. Moreover, FTIR spectral analysis indicated the presence of components like oxalic acid and thiol compounds during metal stress conditions. © 2019 Elsevier LtdItem Solar assisted photocatalytic degradation of organic pollutants in the presence of biogenic fluorescent ZnS nanocolloids(Elsevier Ltd, 2019) Uddandarao, P.; Hingnekar, T.A.; Mohan Balakrishnan, R.M.; Rene, E.R.The main aim of this study was to ascertain the photocatalytic degradation of organic pollutants present in aqueous phase using fluorescent biogenic ZnS nanocolloids produced from an endophytic fungus Aspergillus flavus. The degradation studies were carried out using different organic pollutants such as methyl violet (MV), 2,4-dichlorophenoxyacetic acid (2,4-D) and paracetamol (PARA) for 120 min, 270 min and 240 min, respectively, at pH varying from 3.0 to 11.0. The results from this study indicate that the degradation efficiency of ZnS nanocolloids for MV, 2,4-D and PARA were 87%, 33% and 51%, respectively, at the optimum concentration of 100 mg/L of the tested organic pollutants. At different time intervals, the samples were analyzed for their chemical oxygen demand (COD) and total organic carbon (TOC) contents. The reduction of COD and TOC were 78% and 74% for MV at 120 min; 55.5% and 57.2% for 2,4-D at 270 min and 47.6% and 44.5% for PARA at 240 min, respectively. The degradation pathway was determined based on the mass spectrum and the intermediates formed; in addition, the interaction between organic pollutants and nanocolloids was also elucidated based on atomic force microscopy (AFM) and fluorescence spectrum. © 2019 Elsevier Ltd