Investigation of factors affecting removal of arsenic from polluted water using iron-based particles: Taguchi optimization design

Intensive research efforts have been followed to remove arsenic (As) from contaminated water to provide potable water to millions living in different countries. Adsorption is a simple and efficient way for arsenic contamination purification in water, with a pressing challenge to find a cheap and efficient adsorbent. The present paper deals with optimizing various batch parameters for the adsorption of As from solution by synthesized iron-based particles (hematite, magnetite, and zero-valent iron (ZVI)) nano materials using Taguchi's optimization methodology. Taguchi's (L27) orthogonal design with six effective factors, namely: initial As concentration, ph, contact time, adsorbent type, size, and dose, was applied for the multivariate optimization in adsorption studies for As to maximize the adsorption capacity along with the signal-to-noise ratio. The equilibrium studies revealed that the data were well described by Freundlich isotherm. The results showed that initial As concentration was the most important parameter in the adsorption process. The morphological characteristics of iron-based particles were analyzed by field emission scanning electron microscopy (FESEM, Zeiss, Sigma VP) coupled with an energy dispersive X-ray (EDX). The Powder X-ray diffraction (XRD) data were collected on a Bruker D8 Advance X-ray diffractometer (Cu Ka X-radiation at 40 kV and 40 m A). (author)