DEVELOPMENT OF NANOMATERIALS IN COMBINATION WITH BIO-SORBENT FOR POTENTIAL APPLICATION IN WATER REMEDIATION

Abstract

The integration of polymers with biomaterials offers promising and effective nanomaterials with intrinsic and extrinsic properties that are utilized in several applications namely tissue engineering, drug delivery, energy storage, sensors, environmental remediation etc. The present thesis reported the development of such polymer supported bio-sorbent (Moringa oleifera, (MO)) which was utilized for the application in water remediation. Owing to the industrialization, the water bodies are severely contaminated due to the uncontrolled discharge of industrial effluents i.e. specifically the dye pollutants from textile and tanning industries which are highly toxic and carcinogenic. This dissertation work was carried out by taking the pragmatic approach by the unique fabrication methodologies and developed two different forms of adsorbents i.e. the first one is the MO encapsulated sodium alginate (Na Alg/MO) beads and the latter represents the MO loaded polyacrylonitrile (PAN/MO) nanofibers. The former Na Alg/MO beads was synthesized by cross linking method and the latter was prepared by solvent homogenization method followed by the deposition of nanofibers through electrospinning method. The developed bio-sorbents were characterized by several analytical and spectroscopic techniques in order to investigate the material properties along with their control counterparts. The techniques used for the investigation are FESEM, TEM, XRD, FTIR, XPS. Further the batch adsorption experiments were performed for each adsorbent. The studies include effect of contact time, percentage removal, adsorption capacity, effect of pH and finally the reusability studies. The adsorption data are validated using the empirical equations of the pseudo-kinetic first order and pseudo-second order models. Similarly, the mechanism involved in the adsorption phenomena was investigated by the isothermal studies namely Langmuir and Freundlich models, respectively. The obtained model results and its parameters were compared with the experimental data and discussed. It was ascertained from the results that both the forms of adsorbents are effective in adsorption of Congo red (CR) dye. But considering the practical implications, it was suggested to utilize the bio-sorbents in the nanofibers form which will be beneficial for the commercialization in future. In a nutshell, this work corroborated the importance of bio-based natural materials available in nature and how it can be effectively engineered with the recent polymeric materials for obtaining novel hybrid materials with excellent properties for various applications.