| dc.description.abstract |
The growing interest in chemical and green synthesis of metal oxide nanoparticles is
related to the environmental remediation. The promising materials may be in pure and
composite form. Various kinds of pollutants render the water unsuitable for
consumption, and complete restoration is often not feasible. The particular concerns
are hazardous dyes, which, even in small amounts, can cause significant environmental
damage due to their high toxicity. As a result, eliminating these dyes is studied by
various kinds of magnesium oxide nanomaterial.
The green-synthesized MgO nanostructures are commonly used as adsorbents and
effective photocatalysts for the degradation of organic dyes in wastewater. MgO
nanoparticles were produced through a sustainable neem leaf-assisted green method
and traditional chemical synthesis. XRD spectra confirmed the cubic phase of the
synthesized nanomaterial by both chemical and green methods. Material
characterization using FTIR, UV–Vis, and FESEM techniques was undertaken. The
maximum adsorption capacity of MgO@CM and MgO@GM for CR and BG dye
removal was revealed at an optimal pH range of 5 – 6. MgO@GM demonstrated
superior effectiveness, achieving over 98 % clearance efficiency for both dyes under
optimal conditions, emphasizing the enhanced performance of the environmentally
friendly synthesized material. The maximal adsorption capacities were determined as
427.73 mg/g (MgO@CM) and 420.34 mg/g (MgO@GM) for CR, and 294 mg/g
(MgO@CM) and 275.4 mg/g (MgO@GM) for BG, underscoring the superior capacity
of environmental synthesized magnesium oxide nanoparticles in decontaminating
wastewater, thereby highlighting their potential as eco-friendly adsorbents for water
purification. The other two green extracts are sweet lemon (Citrus Limetta)
(MgO@SL) peel extract and rosewood leaves (Dalbergia Sissoo) (MgO@DS) leaves
extract. The synthesized materials are verified by various characterizations. Both
magnesium oxide nanoparticles are then employed to evaluate their effectiveness in
removing the single and bicomponent solutions of CR and BG dye. Magnesium oxide
exhibits photocatalytic activity for CR and BG dye degradation in single and
binary-component systems due to the generation of electron-hole pairs after absorbing
the light, which subsequently produce hydroxyl and superoxide anion radicals. Also,
the degradation of a binary component solution of CR and BG dyes can occur through
photocatalysis, influenced by pH variations that impact the interaction of both dyes
with the catalyst surface. The optimal pH for degradation is different for each dye due
to their distinct chemical structures. As the conclusion, the removal of CR dye in the
pH range of 2 – 8 is increased in the binary component system of CR and BG dye as
compared to a single dye component. This photocatalytic activity is utilized in
environmental and making it a valuable tool in water purification and wastewater
v
treatment systems. For the synthesis of nanocomposites of magnesium oxide, various
carbon routes are studied individually for wastewater treatment. Bisphenol A (BPA) in
water is removed by employing activated carbon (AC), carbon nanotubes (CN), and
graphene oxide (GO) as effective adsorbents. Characterization of these materials
demonstrated their suitability, leading to successful BPA removal from contaminated
water, highlighting their potential for water treatment applications. The comparative
efficiency of adsorbents for BPA removal was analyzed by the different experiments
and confirmed that the AC and GO are more efficient in BPA removal, with the
average maximum removal percentages being 98% and 97%, respectively. The
maximum Langmuir adsorption capacity of AC, CN, and GO was 158.7 mg/g, 137
mg/g, and 63.3 mg/g, respectively. For removal of BPA, the adsorbents are reused
effectively up to 5 cycles run after desorbing BPA with ethanol. In conclusion, AC,
CN, and GO sheets exhibit significant potential for removing BPA from contaminated
water supplies, offering economic benefits through their effective reusability. These
findings have important implications for environmental remediation and sustainable
water treatment.
Nanocomposites of MgO and AC are successfully synthesized by chemical
methods (MgO@CM/AC) and green methods by using different green extracts
(MgO@NL/AC, MgO@DS/AC, MgO@SL/AC). The structural properties, chemical
composition, and surface properties of the synthesized material are successfully
observed by XRD, FTIR, and SEM, respectively. All materials exhibit good
photocatalytic activity for the removal of MB dye. The material shows good
photocatalytic performance for MB dye in a single - component system and removes in
a multicomponent system CR, BG, and MB dye. The large surface area of synthesized
nanocomposites provides additional reactive sites for catalysis, making it an effective
photocatalyst under UV light. The respective nanocomposite materials are also
successfully used to remove MB dye in the presence of external ions and at various pH
levels. The material is successfully used till the 5th cycle. The removal of MB dye is
MgO@DS/AC, MgO@DS/AC, 47 % to 9 % for MgO@SL/AC, and 56 % to 16 % for
MgO@DS/AC from the 1st to the 5th cycle. All the materials chemically or greenly
synthesized are successfully used to degrade the congo red, brilliant green dye, and
bisphenol A by carbon materials. The wastewater treatment is done successfully.
This study leads to the green synthesis and various characterizations of the
synthesized materials. These materials are used for the wastewater treatment. In this
study, MgO is successfully applicable for the removal of CR, BG, and MB dye. AC
shows good removal results as compared to the CN and GO. So, the nanocomposite of
MgO is synthesized by using activated carbon. The resulting nanocomposites of MgO
and AC is applicable for the removal of MB dye in single and multi-component
systems of dye. |
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