الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 154 |  |  |
| | | from | 154 | | |
Abstract
Algal-based nanoparticles are a promising new technology with a wide range of potential applications. Algae are a sustainable resource that can be grown using simple and inexpensive methods. They produce a variety of biomolecules that can be used to synthesize nanoparticles with enhanced properties. Phyco-synthesized nanoparticles have demonstrated their effectiveness in various fields, including wastewater treatment. Heavy metals are regarded as a key component of wastewater effluent from aquaculture, which poses serious risks to both humans and the environment.This thesis investigated the phyco-synthesis of AgNPs, FeNPs, and Ag-FeBNPs using Laurencia papillosa and Galaxaura rugosa extracts which are used as stabilizing and reducing agents. Various characterization approaches, including UV-Vis spectroscopy and X-ray diffraction (XRD), demonstrate the formation of different NPs. In addition, fourier transform infrared (FTIR) spectroscopy was employed that confirm the role of biomolecules found in the algal extracts in the reduction, capping, and stabilization processes of the phyco-synthesized NPs. Furthermore, transmission electron microscopy (TEM) and SAED patterns were used to describe the size, shape, and crystalline nature of nanoparticles. TEM images revealed the crystalline nature of AgNPs and FeNPs with spherical structures for both L. papillosa and G. rugosa extracts. Ag-FeBNPs from L. papillosa displayed a spherical-shaped morphology with no aggregation or agglomeration whereas Ag-FeBNPs from G. rugosa showed an agglomeration of nano-spheres. Also, the scanning electron microscope (SEM) strongly confirms the phyco-synthesize of AgNPs, FeNPs, and Ag-FeBNPs. Furthermore, the EDAX and zeta potential give more details about NPs.The thesis also demonstrated the optimization of AgNPs, FeNPs, and Ag-FeBNPs phyco-synthesis by using central composite design (CCD) of response surface methodology (RSM) for better biosynthesis of NPs in a lucrative and time-effective mode. After performing the designed experiments, the experimental results confirmed that all the factors studied were significant for the variable responses.The optimized AgNPs, FeNPs, and Ag–FeBNPs were immobilized in alginate beads which were used for Pb, Zn, and Fe removal from actual fish aquaculture wastewater effluents. The results have indicated that the total removal efficiency of heavy metal using Ag-FeBNPs@Alg beads was more efficient (60.4%). SEM images and FTIR spectra of different beads before and after heavy metal removal were studied. The reuse potentiality of Ag-FeBNPs@Alg beads has been investigated which indicated that even after four runs of reuse of Ag-FeBNPs@Alg beads, the percentage of Pb removal remained above 85%, the percentage of Zn removal decreased from 86.5 to 57.2 %, and the percentage of Fe removal decreased from 38.7 to 16.9 %.Techno-economic and scaling-up studies were done using the manufactured prototype to test the ability of Ag-FeBNPs@Alg beads in heavy metal (Pb, Zn, and Fe) removal from fish aquaculture wastewater effluents at a large scale. The percentage of removal of Pb, Zn, and Fe were 90.0, 82.5, and 6.6 %, respectively which were removed within the first 90 min of contact with Ag-FeBNPs@Alg beads. The sustainability of Ag-FeBNPs@Alg beads was studied for the economic viability of the beads giving a clear indication that the Ag-FeBNPs@Alg beads could be reused for multiple runs.Overall, the work presented in this thesis suggests the utility of Ag-FeBNPs@Alg beads as an adsorbent for heavy metal (Pb, Zn, and Fe) removal from fish aquaculture wastewater effluents due to the simplicity of preparation, biodegradability, practical utility, and relatively low preparation cost reveal in both large- and small-scale treatment facilities, as well as infield operations.