Study effect of different parameters on the sulphate sorption onto nano alumina

The aim of this research work is to investigate sorption characteristic of modified nano alumina (n-Al) for the removal of SO₄^2? from aqueous solutions and wastewater. The sorption of SO₄^2? by batch method is carried out. The optimum conditions of sorption were found to be: a sorbent dose of 0.3 g in 100 ml of SO₄^2?, contact time of 35 min, pH = 5. In optimum condition, removal efficiency was 85.6% for the SO₄^2?. Three equations, i.e. Morris–Weber, Lagergren and pseudo second order have been tested to track the kinetics of removal process. The Langmuir, Freundlich and D–R are subjected to sorption data to estimate sorption capacity. It can be concluded that n-Al has potential to remove SO₄^2? ions from aqueous solutions at different concentrations. It was found that the temperature has positive effect on the process and negative ΔG values indicated thermodynamically feasible and spontaneous nature of the sorption. Positive value of ΔS reveals the increased randomness at the solid–solution interface during the fixation of the ion on the active sites of the sorbent. The effect of other anions was studied and it was found the existence of them in the solution has considerable effect on the sulphate removal.