Indian Journal of Science and Technology

Abstract

Objectives: To develop new and low cost hematite-coated quartz adsorbent for the removal of anionic dye from wastewater. Methods/Analysis: Hematite-coated quartz sand (HCQS), as adsorbent, was prepared from Natural Quartz Sand (NQS) and hematite particles. The morphologies, chemical compositions and the structures of the non-modified (NQS) and the modified (hematite-coated quartz sand, HCQS) adsorbents were determined by SEM-EDX methods. In addition, microelectrophoresis (Zeta-Sizer Nano series, Malvern Instrument) was used to evaluate the surface charges and the zeta potentials of HCQS and NQS adsorbents. Findings: The presence of Hematite particles on the Quartz Sand sample, (HCQS), enhances by several folds the removal from wastewater of the anionic dye, Eriochrome Black T (EBT). The removed EBT amount from wastewater by using HCQS adsorbent was found to depend on various parameters such as the pH, the ionic strength, the flow rate, and the anion nature. Thus, the pH decrease from pH = 9 to pH = 4, allowed the increase of the EBT adsorbed amount onto HCQS by about 70 folds. Further, a decrease of the flow rate Q from Q = 1.65 to Q = 0.55 cm.min-1, leads to an increase of EBT adsorbed amount onto HCQS by about 1.6 folds. The increase of the ionic strength I from I = 10-4 M to I = 10-1 M, gives an increase of the EBT adsorbed amount onto the solid adsorbent by about 2 folds. Furthermore, the overall data indicate an irreversible EBT adsorption process on the HCQS solid adsorbent. Application/Improvements: This work shows that the modification of natural quartz sand by hematite particles allows the obtention of new and more efficient adsorbent which can be applied for the wastewater treatment.

Keywords: Adsorption, Desorption, Hematite, Organic Pollutant, Quartz Sand