Utilization of nano-alumina and activated charcoal for phosphate removal from wastewater

- Application of nano-alumina & activated charcoal to remove phosphate from wastewater.
- Nano-alumina was found more effective to reduce the eutrophication of water bodies.
- Langmuir isotherm model and pseudo-second order model founds best fits.
- Adsorption process is spontaneous and endothermic in nature.

Nano-alumina (NA) and activated charcoal (AC) were compared as adsorbents to remove phosphate from aqueous wastewater. Batch-mode adsorption experiments were carried out to investigate the use of two commercially available adsorbents for the removal of phosphate from synthetic wastewater/solution. Effect of time, adsorbent dosage, pH and temperature was evaluated. Results revealed that maximum phosphate removal of 90.2% was achieved in 120 min at pH 6 using 3.2 g/L of dosage with activated charcoal whereas 100% removal was observed at pH 6 with nano-alumina at 90 min using 1.6 g/L of adsorbent dose The equilibrium data was applied to Langmuir, Freundlich, Tempkin, Dubininin-rudkavich isotherm models. Results revealed that Langmuir isotherm model and pseudo-second order kinetic model were found best fitted for both the adsorbents, having good correlation R2 value (0.999 and 0.938). The value of enthalpy (ΔH) calculated from the thermodynamic parameters revealed that adsorption process is endothermic for both adsorbents. Characterization of both adsorbents done with XRD shows their amorphous and crystalline nature while FTIR of the adsorbents shows the interaction of adsorbent and adsorbate of solution. Morphology of both adsorbent shows the porous nature of adsorbents which indicates their efficiency in wastewater treatment. Study clearly indicates that the removal potential of nano-alumina is more as compared to the activated charcoal.

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