Faculty Publications
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Item Green synthesis of iron nanoparticles using different leaf extracts for treatment of domestic waste water(Elsevier Ltd, 2016) Devatha, C.P.; Thalla, A.K.; Katte, S.Y.Green synthesis of iron nanoparticles being cost effective and ecofriendly treatment technique, is gaining importance nowadays. The aim of the present study is to prepare leaf extracts, precursor, and synthesis of iron nanoparticles and to evaluate its efficacy in treating domestic waste water. Synthesis of iron nanoparticles is done using various leaf extracts viz. Mangifera indica, Murraya Koenigii, Azadiracta indica, Magnolia champaca, and to check its potential for treating domestic waste water. Characterization of the synthesized iron nanoparticles is done by UV–Visible spectrophotometer, Scanning Electron Microscopy equipped with X-ray energy dispersive spectroscopy and Fourier Transform Infrared spectroscopy. The characterization results confirm the formation and presence of iron nanoparticles and biomolecules which could help in capping the nanoparticles. The effect of iron nanoparticles thus obtained is evaluated for simultaneous removal of total phosphates, ammonia nitrogen, and chemical oxygen demand. Among the different plant mediated synthesized iron nanoparticles, Azadiracta indica showed 98.08% of phosphate, 84.32% of ammonia nitrogen and 82.35% of chemical oxygen demand removal. Overall performance of Azadiracta indica synthesized iron nanoparticles showed satisfactory results compared to other leaf extracts for treating domestic waste water. © 2016 Elsevier LtdItem The combined effects of carbon/nitrogen ratio, suspended biomass, hydraulic retention time and dissolved oxygen on nutrient removal in a laboratory-scale anaerobic–anoxic–oxic activated sludge biofilm reactor(IWA Publishing, 2018) Manu, D.S.; Thalla, A.K.The current trend in sustainable development deals mainly with environmental management. There is a need for economically affordable, advanced treatment methods for the proper treatment and management of domestic wastewater containing excess nutrients (such as nitrogen and phosphorus) which can cause eutrophication. The reduction of the excess nutrient content of wastewater by appropriate technology is of much concern to the environmentalist. In the current study, a novel integrated anaerobic–anoxic–oxic activated sludge biofilm (A2O-AS-biofilm) reactor was designed and operated to improve the biological nutrient removal by varying reactor operating conditions such as carbon to nitrogen (C/N) ratio, suspended biomass, hydraulic retention time (HRT) and dissolved oxygen (DO). Based on various trials, it was seen that the A2O-AS-biofilm reactor achieved good removal efficiencies with regard to chemical oxygen demand (95.5%), total phosphorus (93.1%), ammonia nitrogen concentration (NH4þ-N) (98%) and total nitrogen (80%) when the reactor was maintained at C/N ratio of 4, suspended biomass of 3 to 3.5 g/L, HRT of 10 h, and DO of 1.5 to 2.5 mg/L. Scanning electron microscopy (SEM) of suspended and attached biofilm showed a dense structure of coccus and bacillus bacteria with the diameter ranging from 0.3 to 1.2 ?m. The Fourier transform infrared (FTIR) spectroscopy results indicated phosphorylated macromolecules and carbohydrates mix or bind with extracellular proteins in exopolysaccharides. © IWA Publishing 2018.Item Polymer-based immobilized Fe2O3–TiO2/PVP catalyst preparation method and the degradation of triclosan in treated greywater effluent by solar photocatalysis(Academic Press, 2021) Pragada, S.C.; Thalla, A.K.The present study involves a novel protocol to develop a ternary composite catalyst for an effective post-treatment technique for greywater. The ternary film of Fe2O3–TiO2/polyvinyl pyrrolidine (PVP) is coated on a glass tube using spray coating with annealing at 320 °C. The structure, thermal, microstructure, and surface properties of the coated film are characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and Thermo Gravimetric Analysis (TGA). The scratch hardness of photocatalysts at different Fe2O3/TiO2 compositions is investigated based on the width measurement of scratch using FESEM analysis. Results show that at an optimum coating of 5% of Fe2O3/TiO2 composition catalytic film, the maximum scratch hardness (7.984 GPa) is obtained. Also, the photocatalyst has the highest cohesive bond strength and wearing resistance. The degradation of triclosan (TCS) in treated greywater, discharged from the anaerobic-aerobic treatment system, is investigated at a lab-scale using a solar photocatalytic reactor. The response surface analysis has been performed from the different sets of experimental trials for various optimal parameters. It is observed that the TCS degradation efficiency of 83.27% has resulted under optimum conditions. © 2021 Elsevier LtdItem Biodegradation properties and thermogravimetric analysis of 3D braided flax PLA textile composites(SAGE Publications Ltd, 2022) Kanakannavar, S.; Jeyaraj, J.; Thalla, A.K.; RAJESH, M.Recent advances in the development and application of bio-based (natural fiber and biopolymer) composites are gaining broad attention because the resulting polymer completely degrades and does not release harmful substances. In this study, natural fiber 3 D braided yarn textile PLA (Polylactic acid) bio-composites are developed by film sequencing followed by hot-press compression molding. Bio-deterioration and thermal stability of the composites are analysed for storage, machining, transportation, and in-service uses in different environmental conditions (compost and thermal). Composite samples with different fiber wt.% (0, 22, 44) are exposed to compost soil. Tensile testing is performed under different configurations to characterise the tensile properties. Prepared bio-composite specimens are evaluated for weight loss and reduction in tensile properties over soil burial time, to observe the rate of biodegradation of braided yarn textile bio-composites. Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) is employed to analyse the biodegradability of the composites. To study the thermal stability of the prepared bio-composites thermogravimetric (TG) analysis is carried out. Results showed that biodegradability, tensile properties and thermal stability of the composites are enhanced significantly with the reinforcement of 3 D braided yarn fabric. © The Author(s) 2021.Item Synthesis of silver nanoparticles using Myristica fragrans seed shell: Assessment of antibacterial, antioxidant properties and photocatalytic degradation of dyes(Elsevier Ltd, 2023) Thomas, T.; Thalla, A.K.In this era, the research on nanoparticles has gained higher demand and found its applications in fields like medicine, textile, waste management and industries. In this study Myristica fragrans seed shells (agricultural waste) aqueous extract is utilised for synthesis of silver nanoparticles from silver nitrate. The characterisation study of synthesised nanoparticles was carried out using Small-angle X-ray scattering, X-ray diffraction, thermogravimetric analysis, zeta potential, Fourier-transform infrared spectroscopy, BET surface area analyser and field emission scanning electron microscope. UV–vis spectrophotometer analysis shows surface plasmonic resonance at 470 nm, confirming the formation of nanoparticles. The nanoparticles were in the range of 10–60 nm with a surface area of 88.16 m2/g. The present study analysed antibacterial (gram-positive and gram-negative bacteria) and antioxidant properties (DPPH and hydroxyl radicals) to prove the practical application of synthesised nanoparticles in the field of food processing. Best radical scavenging activity was observed at 200 μg/mL of nanoparticles. Further synthesised silver nanoparticles were used to study its feasibility in dye removal, and the results showed a better photocatalytic degradation (>90%) of rhodamine B (zwitterionic), remazol brilliant blue reactive (anionic) and methyl violet 10B (cationic) under UV light. The degradation mechanism follows the pseudo-first-order kinetic model and Langmuir isotherm model, which implies the dye degradation is influenced by the affinity of nanoparticles towards dye and their radical action. The degradation products are analysed using UPLC-MS and identified the degradation mechanism. © 2023 Elsevier LtdItem Screening, identification, and characterisation of bacteria in landfill leachate for polypropylene microplastic biodegradation(Taylor and Francis Ltd., 2025) Dubey, A.P.; Thalla, A.K.Plastic contamination is a serious concern for the environment, especially when it comes to microplastics. The biodegradation capability of bacterial strains isolated from landfill leachate against polypropylene microplastics (PPMPs) is examined in this study. A bacterial strain identified as Staphylococcus hominis with 99.77% sequence identity via 16S rRNA gene sequencing showed promising degrading capabilities. Over a 30-day incubation period at 37°C and 150 rpm, S. hominis reduced the weight of PPMPs from 995.2 mg to 833.5 ± 13.85 mg, suggesting a 16.25% degradation. Detailed examinations using bacterial growth tests, Field emission scanning electron microscope (FESEM), and energy-dispersive X-ray spectroscopy (EDS) show significant surface and chemical alterations in the PPMPs, confirming the degradation capability of the bacteria. The bacteria utilised carbon as an energy source, as indicated by the decrease in the percentage weight of molecular carbon from 98% to 78.5%. These findings promote the development of sustainable biological approaches to tackling plastics pollution and show the potential role of bacteria found in landfills, such as S. hominis, in the sustainable bioremediation of microplastic contamination. © 2025 Indian Institute of Chemical Engineers.