Department of Chemical Engineering

Permanent URI for this collectionhttp://localhost:4000/handle/123456789/1923

Browse

Author: search.filters.author.Chatterjee, SomakSubject: search.filters.subject.Chemical Engineering

Search Results

Now showing 1 - 10 of 22
  • No Thumbnail Available
    Item
    Aluminium terephthalate (Al-BDC) based metal organic framework decorated carboxymethylated filter cloth for defluoridation application
    (Elsevier, 2023-06) Chatterjee, Somak
    Current work adopts a novel approach for deposition of aluminium terephthalate-based metal organic framework (MOF) on carboxymethylated filter paper for defluoridation purpose. Aluminium terephthalate-based MOF was prepared using an optimized technique and showed a fluoride uptake capacity of 665 mg/g. However, due to its low yield, synthesized MOF was immobilized on carboxymethylated filter paper, using hydrothermal method. MOF immobilized filter paper (MOF cloth) showed a fluoride uptake capacity of 88 mg/g. Different surface-based characterization for MOF and MOF cloth were performed. Synthesized MOF was quasi-spherical in shape, forming flower like structures, when coalesced together and it showed crystalline property, having lattice fringes of 0.2 nm. Uniform and dense distribution was observed during its deposition process on filter paper. Both functional groups and mineralogical phases present in the MOF were also imparted to the immobilized filter paper. Uptake of fluoride by MOF cloth was governed by monolayer adsorption, as evident from Langmuir isotherm analysis. Uptake capacity increased with temperature and the highest one was recorded at 318 K. Prepared MOF cloth was subjected to dynamic studies via glass-funnel based filtration, where, effects of pH, coexisting ions including an organic pollutant and real-life feed were carried out. Regeneration of the MOF cloth was also studied for four cycles. Leaching study was performed at different time intervals. Finally, comparison was made with different conventional MOF based adsorbents and it was observed that this cloth can be an adaptable and pollution free medium for defluoridation applications.
  • No Thumbnail Available
    Item
    Polyaniline-doped sawdust as a promising adsorbent for defluoridation
    (Elsevier, 2023-11) Chatterjee, Somak
    Fluoride’s presence in groundwater is a growing concern, especially where access to safe drinking water is limited. Traditional water treatment methods have limitations in effectively removing fluoride. Thus, there is a need for an alternative, sustainable and cost-effective solution. This study develops an adsorbent where a conducting polymer (PAni) will be coated on agricultural byproduct (sawdust) for defluoridation application. Introduction of amino-tris-methylene-phosphonic acid (ATMPA) as a dopant into PAni enhances its exchange mechanism, thereby increasing its uptake capacity (58 mg/g). Potential application of this adsorbent lies in water treatment plants, which will cater needs of industry, mankind and agriculture
  • No Thumbnail Available
    Item
    Undoped polyaniline-modified sawdust as an adsorbent for lead removal
    (Elsevier, 2023-12) Chatterjee, Somak
    Heavy metal ion adsorption employing abundant natural and agricultural wastes appears to be promising. Biodegradable sawdust is promoted as a green and sustainable alternative. In this work, potential application of sawdust has been explored for uptake of lead ions from contaminated water. Specifically, undoped polyaniline, a highly conductive polymer, was added to sawdust to improve its uptake capacity. Highest lead uptake capacity of 218 mg/g was observed at 318 K. Different surface-based characterizations for this material were performed. Morphology of prepared sawdust revealed a one-dimensional flake-like structure having a porous nature. FTIR and XRD analysis inferred successful incorporation of polyaniline into sawdust. In addition, XPS analysis revealed the importance of polyaniline chains during electrostatic adsorption of lead ions. At an adsorbent dosage of 1 g/l, optimal equilibrium conditions were reached. In accordance with Langmuir isotherm analysis, lead ion uptake was mainly driven by monolayer adsorption. As-prepared adsorbent was subjected to batch studies, where, effects of pH and interfering ions were carried out. Regeneration was also studied for four cycles.
  • No Thumbnail Available
    Item
    Polyacrylonitrile and polyethersulfone based co-axial electrospun nanofibers for fluoride removal from contaminated stream
    (Elsevier, 2024-02) Chatterjee, Somak
    Coaxial electrospun polyacrylonitrile (PAN) and polyethersulfone (PES) based nanofibers were prepared and was used for filtration of fluoride from drinking water for the first time. Well defined fiber geometry was obtained at 1 ml/h of core polymer, i.e., PES flow rate, 1.4 ml/h of shell polymer, i.e., PAN flow rate, voltage of 22 kV, while the distance between the needle tip and the collector was 15–17 cm. Increase in bead like structure in fiber strands was observed with higher PAN concentration, while it decreased for lower PES concentration, thereby giving an optimum composition (6 wt% PAN and 10 wt% PES) for uniform fiber morphology. This nanofiber, abbreviated as N2 acted as an ultrafiltration membrane having permeability in the lower range, i.e., 0.5 × 10−11 m/s Pa and its fluoride removal efficacy was 46%. Fibers were also hydrophilic with considerable porous nature. Uptake of fluoride by this N2 nanofibers were evident from binding energy of 685.2 eV during XPS analysis. It is probable that nitrile and sulfone groups present in the core and shell of the nanofibers played an active in fluoride uptake, which was estimated as 110 mg/g at 298 K. Isoelectric point was in alkaline range which promoted negative fluoride ion uptake on positive nanofiber surface. Lead played higher masking effect in the uptake of fluoride in comparison to arsenic as coexisting ion. Dynamic cross flow filtration was also studied with this nanofiber in both synthetic and real life feed solution.
  • No Thumbnail Available
    Item
    Carbonaceous catalysts (biochar and activated carbon) from agricultural residues and their application in production of biodiesel: A review
    (Elsevier, 2024-03) Chatterjee, Somak; Roy, Banasri
    Carbonaceous catalysts obtained from agricultural residue could have potential in the production of biofuels such as biodiesel. This review paper discusses the preparation conditions (temperature, heating rate, hold time, inert gas flow rate, etc play key roles in development of textural characteristics of the catalysts) and functionalization methods of biochar and activated carbon derived from agricultural residues and their application to produce biodiesel. Research works reported in achieving maximum yield of biodiesel in terms of variable precursors, alcohol-to-oil ratio, reaction time and temperatures have been profoundly tabulated. Effect of textural properties of the biochar and activated carbon (such as surface area, total pore volume, average pore size, and functional group attached with the catalyst) on the biodiesel yield are examined. Studies on Regeneration and reusing of the spent catalysts are carefully inspected. The economic evaluation studies for the biochar and activated carbon and the applications of these for biodiesel production are scrutinized. Finally, the strategies to increase biomass and catalyst productivity, future prospect and research directions to enhance biofuel/biodiesel production and for the development of biochar and activated carbon from agricultural residues for sustainable biodiesel production is suggested.
  • No Thumbnail Available
    Item
    Novel Fe-doped TiO2 metal-organic framework for electrocatalytic hydrogen evolution reaction
    (Elsevier, 2024-07) Chatterjee, Somak; Pande, Surojit; Garg, Mohit
    A novel approach has been adopted to synthesize titanium oxide-based metal organic framework (MOF), which was doped with iron to increase its efficiency in hydrogen evolution reaction. Scanning electron microscopic images reveal the structure of bare titanium dioxide-based MOF as smooth and aggregated, while doping with iron renders a rough and irregular structure. Mineral phases of ferro-pseudobrookite, anatase, rutile and brookite were prevalent in the doped powder. The presence of iron and titanium in its structure is further confirmed by the deconvoluted spectra from x-ray photoelectron spectroscopy. 0.1 (M) iron doped powder showed an excellent current density of 10 mA/cm2 at an onset potential of 0.345 V, in a three-electrode system. Additionally, its Tafel slope value is 129.6 mV/dec, when compared to the undoped form (168.8 mV/dec), indicating the faster kinetics. Hydrogen evolution reaction is guided by Volmer-Heyrovsky pathway. Electrochemical active surface area of bare MOF powder is 0.62 cm2 while that for 0.1 (M) doped MOF powder is 0.965 cm2. This powder shows extremely good stability and retains its structural integrity even after 1000 linear sweep voltammetry cycles. Density functional theory calculations revealed an increase in the adsorption energy of water molecules attachment in the presence of iron, suggesting an enhanced HER activity.
  • No Thumbnail Available
    Item
  • No Thumbnail Available
    Item
    Iron terephthalate MOF-MWCNTs based composite paste two-electrode system for selective detection of lead in contaminated stream
    (Elsevier, 2024-10) Chatterjee, Somak
    A composite paste combining iron terephthalate metal-organic framework (MOF-235) and multi-walled carbon nanotubes (MWCNTs) was synthesized for potentiometric lead detection in aqueous solutions. Synthesis yielded a homogeneous and well-dispersed composite by blending MOF/CNT with silicon oil as a binder. This novel material combination of materials has been explored for the first time focussing more into potentiometric and electrochemical lead detection with various control settings, including MOF concentration, electrolyte pH, temperature, electrode spacing and saturation time as well as real-life water analysis. Optimal sensor was selected for electrochemical studies, including, cyclic voltammetry, electrochemical impedance spectroscopy and differential pulse voltammetry for analysis of various electrode configuration and effect of scan rates on peak currents. Amperometric studies assessed the impact of interfering ions, while leachate solution analysis determined the content of different ions from modified electrodes. Linear behaviour of peak current with scan rates indicated adsorption-controlled kinetics. ECSA for unmodified and modified electrodes were 0.033 cm² and 0.053 cm², with surface coverage areas of 8.5 mM cm−2 and 2.3 mM cm−2. Sensor exhibited a quasi-reversible nature with a sensitivities of 3075.5 mA.cm⁻².mg/l⁻¹ and 226.5 mA.cm⁻².mg/l⁻¹ and detection limits of 0.2 µg/l and 39 µg/l over dynamic ranges. This cost-effective sensor, with a material cost of 1893 INR (22.8 US$) per gram of paste, offers an alternative for lead detection.
  • No Thumbnail Available
    Item
  • No Thumbnail Available
    Item
    Adsorptive removal of fluoride by activated alumina doped cellulose acetate phthalate (CAP) mixed matrix membrane
    (Elsiever, 2014-04) Chatterjee, Somak
    Flat sheet mixed matrix membranes were prepared using cellulose acetate phthalate (CAP) and activated granular alumina using phase inversion technique. The membranes were characterized using porosity, permeability, molecular weight cut off (MWCO) and contact angle. Compositional analysis of the membrane was carried out by X-ray diffraction and the morphology and surface roughness were investigated by scanning electron microscope and atomic force microscope, respectively. The permeability of the membrane was reduced from 3.0 × 10−11 to 1.4 × 10−11 m/Pa s as alumina concentration increased from 0 to 35 wt% for constant CAP concentration at 20 wt%. Decrease in porosity from 75% to 45% supported the above fact. Membrane hydrophilicity was improved and most importantly, fluoride rejection from contaminated water increased to 91% using 35 wt% of alumina. Maximum adsorption capacity for fluoride was 2.3 mg/g for the mixed matrix membrane at room temperature. Continuous cross flow experiments revealed that the virgin membrane (24 kDa), having a surface area of 0.01 m2, could produce water well within the safety limit for a time of 11 h. Regeneration study was conducted for five cycles. Effect of other co-existing anions on fluoride removal efficiency of the membrane was also studied.