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Present work described the synthesis of Al-Fe-Zn oxide nanocomposite and surface properties determinations by spectrophotometric method. Homogeneous mixing of metals, size range 9–13 nm, and rough surface determined from TEM and FESEM images are discussed. The specific surface area (121.3 m2/g), crystalline nature and elemental composition were deduced from XRD and EDAX analysis. The presence of surface hydroxyl group as identified by FTIR was found responsible for complex formation with chromate ion. The batch adsorption of chromium at different experimental variables revealed an optimised condition for chromium adsorption. Adsorption data followed second-order kinetics, Langmuir, and Freundlich isotherms. The pore diffusion and complex formation for chromium adsorption mechanism were predicted on the basis of kinetic and isotherm studies. The statistical data reveal that the double-layer model best explains the adsorption behaviour and mechanism. The unique surface properties, excellent reuse efficiency signify the application of nanocomposite. [ABSTRACT FROM AUTHOR]

An efficient co-precipitation followed by ultrasonication process is used for the synthesis of trimetallic MgZnFeO nanocomposites (MZFONCs) and further characterized by FE-SEM, FT-IR, XRD, EDX, etc. spectroscopic techniques. The adsorption process is applied for the removal of toxic cationic Basic Fuchsine (BF) dye using batch experiments. To enhance removal efficiency, the effect of deviation in parameters including shaking time; adsorbent dose; pH; etc. are studied. Qmax obtained by Langmuir is found to be 250 mg/g for BF on the MZFONCs surface, at pH = 6.5; 40 min of agitation time, and a small dose of nanoparticles. The best match for the adsorption of BF on MZFONCs is a double-layer method which also describes the adsorption mechanism. The 'n' parameter value (0.507–0.628) is obtained from the statistical physics model, which shows mixed-orientation type adsorption of BF molecules on MZFONCs adsorbents. The calculated energies for BF dye adsorption are found to be less than 30 KJ/mol, hence implying an endothermic and physical adsorption mechanism. [ABSTRACT FROM AUTHOR]

The latest developments in the adsorption of organic dyes by adsorbents (metal oxides, modified metal oxides) were addressed in this review study. The main goal of this paper is to sort out the dispersion information of adsorbent materials, which are often employed in organic dye adsorption. The review dedicated to the specific dyes adsorption using various adsorbent (metal oxides, modified metal oxides). The review covers the adsorption process including parameters, kinetics, and isotherms. The review gives the brief information of Congo red (CR) adsorption using metal oxide nano‐adsorbents which provide readers with massive dye specific collection. For the first time, several metal‐doped materials that absorb organic dyes are summarized and addressed. The review includes adsorption of organic dyes using single metal oxide, bimetallic oxide, trimetallic oxide, and modified metal oxide. This study also summarized the effects of critical factors such as pH, initial dye concentration, adsorbent dosage, contact time, and temperature on dye adsorption utilizing metal oxide nano‐adsorbents. In addition, the kinetic and applied isotherm models have been discussed. Finally, a few recommendations are made for further research on adsorbent materials. [ABSTRACT FROM AUTHOR]

Fe-Mn-Zn oxide trimetal alloy nanocomposite (FMZONC) fabricated and surface properties of the composite material revealed via several characterization methods. Porous nature and alloy type mixing of metals deduced from transmission electron microscopy analysis. Field emission scanning electron microscopy image revealed composite material is of size between 7 and 16 nm. The adsorption properties investigated through isotherm and kinetic experiments. In addition, pH effects and desorption properties were also studied. Maximum adsorption capacity (q max) 149 mg/g for phosphate removal observed at pH 6 and 0.20 g/L of adsorbent. Chemical interaction between metal hydroxide and phosphate elaborated from Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). [ABSTRACT FROM AUTHOR]

Recently composite metal oxides have gained significant attention to be used as adsorbent because of their synergetic effects. Particularly Manganese containing composite oxides are useful for removal of inorganic oxyacids such as phosphate or arsenate. In present study fabrication of Mn-Zn-Ti Oxide adsorbent for phosphate removal carried out via co precipitation method. Surface properties deduced by TEM, FESEM, EDAX and XRD, revealed nanosized composite material has a porous nature constitute of alloy type mixing of the metals. Size of the nanocomposite found to be as small as 6 nm. Adsorption capacity for phosphate estimated at different pH, time and adsorbent dose by batch mode. In addition desorption properties and thermodynamic study also carried out. Several isotherms and kinetic models applied to observe adsorption properties of the Mn-Zn-Ti Oxide nanocomposite. Adsorption capacity found to be 151 mg/g at pH 6, time 90 min, adsorbent dose 0.20 g/L and phosphate concentration of 200 mg/L. Adsorption data fitted to second order kinetics and Freundlich isotherm. Formation of complex between nanocomposite and phosphate predicted from FTIR and supported by pH kinetic and isotherm studies. Desorption and reusability found to be well maintained over five cycles. [ABSTRACT FROM AUTHOR]