BITS Faculty Publications
Permanent URI for this communityhttp://localhost:4000/handle/123456789/1867
Browse
5 results
Search Results
Item Magnesium oxide nanoparticles-cellulose acetate based composite beads for lead uptake from contaminated stream: Experimental and DFT based study(Elsevier, 2026-02) Garg, Mohit; Chatterjee, SomakGroundwater, a primary source of drinking water, is becoming increasingly contaminated with toxic heavy metals, particularly lead. The unregulated discharge of industrial effluents into water bodies further exacerbates the problem. Accordingly, an effective system is required to treat these pollutants. Although there are existing solutions with certain challenges, this study aims to develop efficient composite polymeric beads composed of cellulose acetate and magnesium oxide nanoparticles for effective removal of lead from contaminated water. Prepared beads were spherical, synthesized by the phase inversion of polymer solution with the help of a needle-syringe assembly. As-prepared beads were characterized based on its morphological and chemical characteristics, revealing porous texture with considerable crystallinity. Presence of Pbsingle bondO bond in FTIR spectra post lead adsorption highlighted synergy between lead ions and Mgsingle bondOH groups. Uptake mechanism involved the substitution of hydrogen ions by lead ions, resulting in the formation of stable Mgsingle bondOsingle bondPb complexes. This was facilitated by lead's lower electronegativity in contaminated water. Lead uptake by composite beads was governed by monolayer adsorption as evident from isotherm studies. A maximum uptake capacity of 500 mg/g was observed at 298 K, which increased to 600 mg/g at 318 K. Optimum dosage of 1 g/l was identified as ideal for achieving equilibrium conditions. Thermodynamic parameters confirmed that the adsorption process was spontaneous and endothermic in nature. Regeneration studies showed effective reusability up to two cycles, after which the removal capacity reached saturation. Isoelectric point was obtained at a pH value of 9.7. Presence of MgO helped in stabilising lead ions and prevented precipitate formation in alkaline medium, providing a minor reduction in lead removal, as compared to conventional adsorbents. Furthermore, Density functional theory (DFT) based simulation was performed suggesting collective indication of consistent trends, with both approaches converging towards the same adsorption behaviour and Pbsingle bondO interaction patterns.Item Rare shungite carbon, carbon nanotubes and magnesium oxide nanoparticle based composite paste electrode for electrochemical lead ion detection(Elsevier, 2026-02) Roy, Banasri; Chatterjee, SomakComposite paste was synthesized using magnesium oxide nanoparticles with shungite carbon and multi-walled carbon nanotubes, to formulate two-electrode sensor, facilitating lead detection in aqueous stream. A uniform and homogeneously dispersed composite paste was obtained using the powder with a binder, i.e., silicone oil. Working electrode only comprises magnesium oxide nanoparticles, which was paired with reference electrode to measure potential against various lead concentration. Various factors including concentration of MgO, electrolyte pH, temperature, electrode-separation, detection time and real water sample analysis were examined to optimize sensor's performance. Most effective sensor was then chosen for electrochemical characterizations, which include, cyclic voltammetry, electrochemical impedance spectroscopy, differential pulse voltammetry across different electrolyte concentrations, i.e., lead. Amperometric analysis evaluated influence of co-existing ions, whereas leachate solution studies quantified ion content from working electrode. Electrochemically active surface area and surface coverage areas were measured as 0.022 cm2 and 0.036 cm2, and 2.85 mM.cm−2 and 2.39 mM.cm−2 for unmodified and modified electrodes. Sensor exhibited quasi-reversible behavior with sensitivities of 2.75 mA.cm−2.mg.L−1 and 0.0275 mA.cm−2.mg.L−1, along with detection limits of 0.3 μg.L−1 and 57 μg.L−1 over dynamic ranges. This performance, combined with low fabrication cost (~31.6 US$.g−1), presents a competitive and economical alternative against different commercial lead sensors.Item Graphene oxide-iron oxide based thin film nanocomposite membrane for congo red dye removal and simultaneous salt recovery from aqueous stream(Springer Nature, 2025-11) Roy, Banasri; Chatterjee, SomakCurrent work focusses on the synthesis of iron oxide impregnated-graphene oxide incorporated polyvinylidene fluoride based thin-film nanocomposite (TFN) membrane and its application in Congo Red dye removal. Interfacial polymerization with 0.02 wt% graphene oxide significantly improved performance of prepared TFN membranes, achieving over 94% rejection of dye with permeability of 3.6 l/m2·h·bar. Testing performance of the membrane was further validated in the presence of real-life feed wastewater, showing 72% dye rejection over 12 h, while an enhanced 94% rejection was achieved with synthetic dye solution. Superior performance was observed in removal of dissolved solids, conductivity, salinity, nitrate, sulfate and dyes compared to commercial nanofiltration membranes. Effect of different operating conditions on membrane performance were examined, confirming its robust nature. Comprehensive characterization of prepared membrane revealed its superiority in texture and chemical nature. Optimized TFN membrane demonstrated recovery efficiency of 70% for sodium chloride and magnesium sulfate solutions, indicating its potential for desalination approach. Thermal regeneration and long-term filtration studies were conducted to evaluate membrane’s lifespan, indicating long-term durability and effectiveness in industrial applications. Studies also indicated weight loss of 62% over two months, which corroborated biodegradable nature of the membrane samples after exhaustion.Item Layered double hydroxide based composite core–shell electrospun nanofibers for lead and fluoride filtration from contaminated streams(RSC, 2025-04) Chatterjee, SomakCoaxial electrospinning was used to synthesize polyacrylonitrile–polyethersulfone (PAN–PES) core–shell nanofibers with magnesium–aluminum layered double hydroxide (Mg–Al LDH) for filtration of lead and fluoride from contaminated streams. Fiber geometry was characterized at a 0.5 mL h−1 flow rate for the core polymer (PES/LDH) and 0.8 mL h−1 flow rate for the shell polymer (PAN), with a potential of 23 kV and a distance of 15–17 cm between the collector and the needle head. A homogeneous fiber shape was achieved using an optimal LDH concentration of 0.7%. The prepared nanofibers served as an ultrafiltration membrane with a permeability of 5 × 10−12 m s−1 Pa−1. The uptake capacity of the produced nanofibers for fluoride and lead was estimated to be 948 mg g−1 and 196 mg g−1, respectively at 298 K as per Langmuir's isotherm model. These fibers exhibited hydrophilic properties and possessed a significant level of porosity. XPS study revealed binding energies of 139.3 eV and 685.2 eV, indicating lead and fluoride uptake by the nanofibers. Ether, sulfone, hydroxyl and nitrile groups found in the nanofibers' shell and core most likely contributed to the lead and fluoride uptake. This facilitated the uptake of both ions on the surface of the nanofibers. In terms of the inhibition effect, fluoride had a stronger masking effect compared with lead in a multicomponent solution (consisting of lead and fluoride). Dynamic vacuum filtration was also investigated using the prepared nanofibers in artificial and real-life feed solutions.Item Application of composite membrane-based technology in treatment of textile industry effluents(Springer, 2025-02) Chatterjee, SomakTechnological innovations have repeatedly made our lives easier over the centuries. Supplies have increased manifold to compete with growing consumer demands. For example, textile industries serve untired to meet the expectations of their end-user by gradually increasing the production. It is mainly characterized by fabric, which essentially starts with fibers, that is processed into making yarns and finally combined. These intermediate steps in a textile plant require huge quantity of freshwater feed, which is eventually converted to an effluent, containing colouring dyes, toxic chemicals and insoluble wastes. Additionally, functional textiles require water-repellent, anti-fungal agents and non-crease fabrics, which are persistent contaminants, thereby adding to environmental degradation. Conventional treatment methods, such as, adsorption, coagulation, oxidation, etc., are employed for their removal. However, these methods have associated limitations. This chapter discusses about a novel approach, i.e., composite membrane-based removal technique, which can prove to be an economic and feasible option for treatment of textile effluents.