Browsing by Author "Dissanayake, NSL"

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    item: Conference-Full-text
    Chitosan-graphene oxide composite membrane for methylene blue removal
    (IEEE, 2022-07) Dissanayake, NSL; Pathirana, MA; Wanasekara, ND; Nandasiri, GK; Rathnayake, M; Adhikariwatte, V; Hemachandra, K
    Textile wastewater accommodates many toxic organic contaminants which could potentially threaten the ecosystem if left untreated. Methylene blue is a toxic, nondegradable, cationic dye which is reportedly found in significant amounts in the textile effluent stream as it is widely used to dye silk and cotton fabrics. This study reports an investigation of methylene blue removal using a composite membrane fabricated using chitosan and graphene oxide. The fabricated composite membrane was characterized using Scanning Electron Microscopy, FTIR Spectroscopy, Raman Spectroscopy, UV vis spectroscopy, and X ray Diffraction. The isotherm modelling conducted confirmed a maximum adsorptive capacity of 179 mg/g which was well fitted with the Langmuir isotherm model indicating a homogenous monolayer adsorption.
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    item: Article-Full-text
    Chitosan-graphene oxide dip-coated polyacrylonitrile-ethylenediamine electro spun nanofiber membrane for removal of the dye stuffs methylene blue and congo red
    (Multidisciplinary Digital Publishing Institute, 2023) Pathirana, MA; Dissanayake, NSL; Wanasekara, ND; Mahltig, B; Nandasiri, GK
    Textile wastewater accommodates many toxic organic contaminants that could potentially threaten the ecosystem if left untreated. Methylene blue is a toxic, non-biodegradable, cationic dye that is reportedly observed in significant amounts in the textile effluent stream as it is widely used to dye silk and cotton fabrics. Congo red is a carcinogenic anionic dye commonly used in the textile industry. This study reports an investigation of methylene blue and Congo red removal using a chitosan-graphene oxide dip-coated electrospun nanofiber membrane. The fabricated nanocomposite was characterized using Scanning Electron Microscopy (SEM), FT-IR Spectroscopy, Raman Spectroscopy, UV-vis Spectroscopy, Drop Shape Analyzer, and X-ray Diffraction. The isotherm modeling confirmed a maximum adsorptive capacity of 201 mg/g for methylene blue and 152 mg/g for Congo red, which were well fitted with a Langmuir isotherm model indicating homogenous monolayer adsorption.
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    item: Conference-Extended-Abstract
    Development of a nanocomposite membrane for organic dye removal
    (Department of Textile and Apparel Engineering, 2023-08-31) Pathirana, MA; Dissanayake, NSL; Nandasiri, GK; Wanasekara, ND; Mahltig, B; Niles, SN; Nandasiri, GK; Pathirana, M; Madhurangi, C
    Contaminated wastewater poses a significant threat to both the ecosystem and human health. The annual production of commercial dyes exceeds 7x105 tonnes, with the textile industry being responsible for two-thirds of the consumption [1]. Moreover, an estimated 10-20% of the manufactured dye is annually released into the effluent stream [2]. Previous literature indicates that adsorption offers promising solutions to organic dye removal owing to its simplicity and cost-effectiveness. Adsorption is fundamentally defined as the process through which ions, atoms and molecules are retained on solid surfaces via physical or chemical bonding. The literature extensively covers adsorbents designed for individual removal of either anionic or cationic dyes. However, research on techniques for simultaneous removal of both types of dyes is limited. As anionic and cationic dye molecules contain charges, adsorption can initiate through the formation of electrostatic bonding.
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    item: Article-Full-text
    Removal of methylene blue and congo red using a chitosan–graphene oxide-electrosprayed functionalized polymeric nanofiber membrane
    (2023) Dissanayake, NSL; Pathirana, MA; Wanasekara, ND; Mahltig, B; Nandasiri, GK
    Untreated textile effluent may contain toxic organic pollutants that can have negative impacts on the ecosystem. Among the harmful chemicals present in dyeing wastewater, there are two frequently used organic dyes: methylene blue (cationic) and congo red (anionic). The current study presents investigations on a novel two-tier nanocomposite membrane, i.e., a top layer formed of electrosprayed chitosan–graphene oxide and a bottom layer consisting of an ethylene diamine functionalized polyacrylonitrile electrospun nanofiber for the simultaneous removal of the congo red and methylene blue dyes. The fabricated nanocomposite was characterized using FT-IR spectroscopy, scanning electron microscopy, UV-visible spectroscopy, and Drop Shape Analyzer. Isotherm modeling was used to determine the efficiency of dye adsorption for the electrosprayed nanocomposite membrane and the confirmed maximum adsorptive capacities of 182.5 mg/g for congo red and 219.3 mg/g for methylene blue, which fits with the Langmuir isotherm model, suggesting uniform single-layer adsorption. It was also discovered that the adsorbent preferred an acidic pH level for the removal of congo red and a basic pH level for the removal of methylene blue. The gained results can be a first step for the development of new wastewater cleaning techniques.