Polyaniline Coated Ethyl Cellulose with Improved Hexavalent
Chromium Removal
- Publication date
- Publisher
Abstract
The ethyl celluloses (ECs) modified
with 5.0, 10.0, and 20.0 wt
% polyaniline (PANI) (PANI/ECs) prepared by homogeneously mixing the
EC and PANI formic acid solutions have demonstrated a superior hexavalent
chromium (Cr(VI)) removal performance to that of pure EC. Having an
increased Cr(VI) removal percentage with increased PANI loading, the
PANI/ECs with 20.0% PANI loading were noticed to remove 2.0 mg/L Cr(VI)
completely within 5 min, much faster than the pristine EC (>1 h).
A chemical redox of Cr(VI) to Cr(III) by the active functional groups
of PANI/ECs was revealed from the kinetic study. Meanwhile, isothermal
study demonstrated a monolayer adsorption behavior following the Langmuir
model with a calculated maximum absorption capacity of 19.49, 26.11,
and 38.76 mg/g for the 5.0, 10.0, and 20.0 wt % PANI/ECs, much higher
than that of EC (12.2 mg/g). The Cr(VI) removal mechanisms were interpreted
considering the functional groups of both PANI and EC, the valence
state fates of Cr(VI), and the variation of solution acidity