Effect of annealing on the spectral and optical characteristics of nano ZnO: Evaluation of adsorption of toxic metal ions from industrial waste water

Radhakrishnan, Asha; Rejani, P.; Khan, Jamshid; Beena, B.

doi:10.1016/j.ecoenv.2016.08.001

Cited by 11 publications

(5 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A slight decrease in lattice parameter from 8.4437 to 8.4404 was also recorded with annealing temperature. From our XRD and TEM results, it is well established now that annealing temperature can greatly influence grain growth and crystallite size in ZFO which are well accord to literature (Radhakrishnan et al, 2016). The XRD peaks broadening, smaller crystal size, high microstrain and larger lattice parameters of ZFO-500 compared to its counter parts may also indicate the existence of crystal lattice defects related to oxygen vacancies (Afzal et al, 2020).…”

Section: Structural Properties Of Zfo Nanoparticlessupporting

confidence: 87%

Thermally induced oxygen related defects in eco-friendly ZnFe2O4 nanoparticles for enhanced wastewater treatment efficiencies

et al. 2022

View full text Add to dashboard Cite

Section: Structural Properties Of Zfo Nanoparticlessupporting

confidence: 87%

Thermally induced oxygen related defects in eco-friendly ZnFe2O4 nanoparticles for enhanced wastewater treatment efficiencies

et al. 2022

View full text Add to dashboard Cite

“…Another study reported that the dominant mechanism in the adsorption of Cu(II) ions onto ZnONPs was complexation and precipitation based on the pH study (Mahdavi et al 2012). An ion-exchange mechanism was observed in another work by a drop in pH of the solution following adsorption of Cd(II) and Pb(II) due to the release of hydrogen ions (Radhakrishnan et al 2016). Furthermore, electrostatic interaction was proposed in the adsorption of Cr(VI) as a result of the drop in the zeta potential of ZnONPs from 32.6 to 19.0 mV after adsorption at pH 4.0 due to the uptake of negatively charged chromium species (Zhao and Qi 2012).…”

Section: Mechanism Of Adsorption Onto Zno Nanoparticlementioning

confidence: 92%

“…Moreover, the Langmuir model was found to give the best fit to the adsorption of Pb(II), Hg(II), Co(II), As(III), Cr(III), Ba(II), Zn(II), Se(IV) and V(V) with coefficients of determination (R 2 ) in the range 0.988-1.000. However, in one of the studies, the Sips isotherm also provided the best fit alongside the Langmuir model in the adsorption of Pb(II) ions (Radhakrishnan et al 2016). The implication of the good fit of the Langmuir model to the adsorption of these metal ions on ZnONPs is that process is restricted to monolayer adsorption onto a homogenous surface.…”

Section: Adsorption Isotherm Modelingmentioning

confidence: 97%

Adsorption mechanism and modeling of radionuclides and heavy metals onto ZnO nanoparticles: a review

et al. 2022

View full text Add to dashboard Cite

The contamination of environmental waters with heavy metals and radionuclides is increasing because of rapid industrial and population growth. The removal of these contaminants from water via adsorption onto metal nanoparticles is an efficient and promising technique to abate the toxic effects associated with these pollutants. Among metal nanoparticle adsorbents, zinc oxide nanoparticles (ZnONPs) have received tremendous attention owing to their biocompatibility, affordability, long-term stability, surface characteristics, nontoxicity, and powerful antibacterial activity against microbes found in water. In this review, we considered the adsorption of heavy metals and radionuclides onto ZnONPs. We examined the isotherm, kinetic, and thermodynamic modeling of the process as well as the adsorption mechanism to provide significant insights into the interactions between the pollutants and the nanoparticles. The ZnONPs with surface areas (3.93 to 58.0 m2/g) synthesized by different methods exhibited different adsorption capacities (0.30 to 1500 mg/g) for the pollutants. The Langmuir and Freundlich isotherms were most suitable for the adsorption process. The Langmuir separation factor indicated favorable adsorption of all the pollutants on ZnONPs. The pseudo-second-order kinetics presented the best for the adsorption of the adsorbates with regression values in the range of 0.986–1.000. Spontaneous adsorption was obtained in most of the studies involving endothermic and exothermic processes. The complexation, precipitation, ion exchange, and electrostatic interactions are the probable mechanisms in the adsorption onto ZnONPs with a predominance of complexation. The desorption process, reusability of ZnONPs as well as direction for future investigations were also presented.

show abstract

“…The RL values obtained were 0 and 1, indicating the advantageous impact of Langmuir adsorption. The Freundlich adsorption exponent "n" which must be equal to or greater than 1, indicates the presence of more favourable surfaces for adsorption by higher values [41]. Table-2 shows the adsorption capacity data for all ions in a 100 ppm solution.…”

Section: Effect Of Phmentioning

confidence: 99%

Effective removal of selective heavy metal ions from aqueous solution through green synthesized zinc oxide nanoparticles

Kashyap,

Moharana,

Agrawal

et al. 2023

ajc

View full text Add to dashboard Cite

The presence of pollutants such as harmful heavy metals in aqueous system is currently one of the largest environmental problems. Due to unmanaged discharge from numerous industries, this system is a serious problem in the major cities of developing nations. Due to the adverse effects on the environment and potential to cause cancer in humans, these contaminants are anticipated to require special consideration. Pollution clearance is a difficult problem that needs to be tackled if adverse effects on people and the environment are to be avoided or minimized. The main objective of this present research is to synthesize zinc oxide nanoiparticles (ZnO-NPs) from Nyctanthus arbor-tristis flower in a safe, non-toxic, and ecologically friendly manner. The adsorption of U(VI), Pb(II), Cr(VI) and Cd(II) ions from aqueous solutions by Nyctanthus arbor-tristis flower extract was investigated under laboratory conditions to assess its potential in removing these metal ions. The impacts of the experimental factors, such as ZnO-NPs dosage, solution pH, and contact time, were investigated. The study shows that the majority of the toxic metal ions can be adsorbed from the solution in a relatively short duration of time under ambient conditions. The adsorption behavior of toxic metal ions onto the ZnO-NPs was analyzed with Freundlich as well as Langmuir rate equations and the results were supported by the pseudo-second-order kinetic models. The study provides a safe, non-toxic, and eco-friendly green synthesis method and also demonstrated excellent performance of the synthesized ZnO-NPs.

show abstract

Effect of annealing on the spectral and optical characteristics of nano ZnO: Evaluation of adsorption of toxic metal ions from industrial waste water

Cited by 11 publications

References 21 publications

Thermally induced oxygen related defects in eco-friendly ZnFe2O4 nanoparticles for enhanced wastewater treatment efficiencies

Thermally induced oxygen related defects in eco-friendly ZnFe2O4 nanoparticles for enhanced wastewater treatment efficiencies

Adsorption mechanism and modeling of radionuclides and heavy metals onto ZnO nanoparticles: a review

Effective removal of selective heavy metal ions from aqueous solution through green synthesized zinc oxide nanoparticles

Contact Info

Product

Resources

About