الفهرس 
CHAPTER ONEOnly 14 pages are availabe for public view
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Abstract
Conclusions
The present study shows that NiONPs prepared from a low-cost material are considerably efficient for removing dyes from wastewater. We succeed used the NiONPs as good adsorbent in the removal of TSP from wastewater. Scanning electron microscopy shows the irregular surface structure and many pores on the surface, which may act as adsorption sites. NiONPs absorbed TSP and formed a coating of TSP material on their surface. The XRD pattern of NiONPs shows crystal planes of Face-Centered Cubic (FCC) NiO. The average crystallite size of NiONPs was calculated as 15 nm. Again, the purity of NiONPs was confirmed by EDX spectroscopy, which accurately quantified the Ni and O contents by showing only NiO peak without any other impurity. Also, the specific surface area SBET was obtained as 8m2/g by applying the BET equation in its normal range of applicability (p/po = 0.05 – 0.30).
The adsorption depends on contact time, adsorbent dose, concentration, and pH. The ideal pH value for the adsorption of TSP dye on NiONPs is equal to 8. The kinetics of TSP dye adsorption on NiONPs follows the pseudo-second-order model. The equilibrium data fit well in the Langmuir and Freundlich adsorption models, showing monolayer coverage of dye molecules at the outer surface of NiONPs.
Again, the current investigation results demonstrate that [NiO-Inulin]C, which was synthesis by sol-gel method, is remarkably effective at removing colours from wastewater. SEM reveals the surface’s irregular surface structure and many pores, which might behave as adsorption sites. TSP was extensively absorbed by [NiO-Inulin]C, resulting in a TSP-material coating on their surface. The XRD pattern of [NiO-Inulin]C shows that all diffraction peaks correspond closely with their positions and order of intensity with the cubic crystal structure of pure inulin as found in the standard card (JCPDS 65 2908), indicating the pure crystal structure of the inulin structure. This confirms the deposition of NiONPs inulin thin layers of inulin on the surface of the inulin sheet. Besides, it can also be found that in comparison with the XRD pattern of the [NiO-Inulin]C nanocomposite is a typical pattern for both inulin and NiONPs. The sharpness of the diffraction peaks of NiONPs and [NiO-Inulin]C indicates the as-synthesized samples are highly crystalline. By calculating the average particle size of inulin and [NiO-Inulin]C nanocomposites, were found around 19.9 and 33.5 nm, respectively. Microparticles, due to crystal imperfection and distortion, surface diffusing atoms also contain unsaturated coordination. Since inulin has a high surface area, it can be used as nucleation sites and as a substrate for the precipitation of metal oxide nanoparticles. The TEM picture of the [NiO-Inulin]C reveals that the nanoparticles were narrowly distributed and had spherical shapes with particle sizes of 18nm. TEM images of NiONPs and [NiO-Inulin]C illustrate the highly polycrystalline nature of the nanocomposite material. These polygonal (mainly cubic) particles confirm the formation of NiONPs on the inulin sheets with a homogeneous distribution, and the appropriate interconnection is developed between the NiONPs and the inulin sheets. This interfacial contact of metal oxide particles and inulin sheets is suitable for efficient charge transfer between NiONPs and inulin sheets.
Contact time, adsorbent dosage, adsorbent concentration, and pH significantly impact the adsorption. The best pH for TSP dye to adhere to [NiO-Inulin]C is 10. The maximum removal efficiency values in comparison with [NiO-Inulin]C observed in the case of the influence of pH and [TSP] are 52.03 and 86.46 %, respectively. Still, in the case of NiONPs as adsorbent, the values are 17.6 and 12.35 %, respectively. Therefore, the removal efficiency percentage increases with the added inulin polymer. The pseudo-first-order and pseudo-second-order models are followed by the kinetics of TSP dye adsorption on [NiO-Inulin]C. The equilibrium findings, which demonstrate monolayer coverage of dye molecules at the outer surface of [NiO-Inulin]C, fit the Langmuir and Freundlich models of adsorption well.
Antibacterial activity, the most sensitive species against the biosynthesized NiONPs at (500 µg/ml) were detected against S. albus (16 mm), E. faecalis (15 mm), S. typhimurium (12 mm), and E. coli, (15 mm).While, the antibacterial of NiONPs at (100 µg/ml) were reordered as no activity at low concentration. The results indicate that the Gram-positive bacteria are more sensitive to NiONPs compared to Gram-negative bacteria.
Treatment of the HeLa, Caco-2 and K562 cells with NiONPs resulted in anti-cancer activity with IC50 of 35.3±1.47 µg/ml, 6.26±0.26 µg/ml and 2.87±0.12 µg/ml, respectively.
Recommendations and future work
The outcome of the current thesis is creating an environmentally friendly green approach to create biologically safe NiONPs coated with physiologically significant compounds. The NiONPs’ antibacterial prowess was additionally assessed. NiONPs were also researched for possible uses in the treatment of cancer. Our capacity to produce NiONPs in an eco-friendly, non-toxic manner represents a significant advancement in developing green chemistry methods for nanoparticle synthesis. These proposed synthesis processes, which include the generation of reactant solutions, take roughly 19 hours to complete. The information gained from the initial experiments for this project opens up new research directions for the design and development of novel processes to produce pure and stable metal oxide nanoparticles with the desired properties to successfully purify water, treat cancer, and fight microbes.
The following topics are recommended for the extension of this work:
1- Exploring more applications of the synthesized NiONPs, such as catalytic and antioxidant activities.
2- Investigating more useful physiochemical properties of the synthesized NiONPs, such as thermal, magnetic, and mechanical properties.
3- A desorption study of NSAIDs should be done to get the optimum cycle of adsorption usage.
4- As NiONPs are non-toxic to mammals, they may be utilized in drug delivery.
5- Antiviral activities of the bio-synthesized nanoparticles should be performed for HIV screening.
6- An advanced study should be carried out on the proper isolation of constituents act as the reducing agents in Ficus Nitida extract.