Preparation and Characterization of Al-Diatomite Composite for the Remedial of Pb(II) from Aqueous Solution

Abstract

Aluminum-diatomite (Al-D) composite adsorbent is synthesized in one pot by heating natural diatomite in NaOH and subsequently mixed with a solution of aluminum salt. The chemical, surface, textural and structural properties of the prepared material were characterized by XRF, XRD, SEM, FTIR, and Nitrogen adsorption methods. The adsorption efficiency of the composite sample was evaluated towards Pb(II) species in batch technique and compared with the raw diatomite. The impact of operational conditions, such as pH, adsorption time, temperature, an initial concentration of adsorbate, and the adsorbent dose was also evaluated. As confirmed by XRD and FTIR, the partial dissolution of silica in NaOH leads to the formation of an alumina-silicate compound at the addition of an aluminum salt. SEM image showed that aluminum is successfully loaded both on the surface of the diatomite and on the inner surface of the meso- and macropores, which leads to the advance of the specific surface area from 19.7 m²/g to 80.9 m²/g. It was observed that the Al-Diatomite adsorbent showed a noticeable higher Pb (II) sorption capacity (67.9 mg/g) than the natural diatomite (17.2 mg/g). This result can be explained by the higher surface area, mesoporous structure and uniform deposition of small-sized Alumina particles.

Keywords: Aluminum, Composite, Lead ion, Modification, Sorption

DOI: 10.7176/CPER/60-02

Publication date:March 31^st 2019