Nano-structured iron(III)–cerium(IV) mixed oxide: Synthesis, characterization and arsenic sorption kinetics in the presence of co-existing ions aiming to apply for high arsenic groundwater treatment

Abstract

Here, we aim to develop an efficient material by eco-friendly green synthetic route that was characterized to be nano-structured. The thermal stability of the sample was well established from the consistent particle size at different temperature and also, from differential thermal analysis. The bimetal mixed oxide contained agglomerated crystalline nano-particles of dimension 10-20nm, and its empirical composition as FeCe1.1O7.6. The surface area (m2g-1), pore volume (cm3 g-1) and maximum pore width (nm) obtained from BET analysis were found to be 104, 0.1316 and 5.68 respectively. Use of this material for estimating arsenic sorption kinetics in presence of some groundwater occurring ions revealed that the pseudo-second order kinetic model is unambiguously the best fit option to describe the nature of the reactions. Groundwater occurring ions exhibit a notable decrease of As(V)-sorption capacity (no other ion>chloride∼silicate>sulfate>bicarbonate>phosphate). However, As(III)-sorption capacity of the bimetal mixed oxide was nominally influenced by the presence of the above ions in the reaction system. Rate determining step of arsenic sorption reactions was confirmed to be a multistage process in the presence of the above ions at pH∼7.0 and 30°C.