TITLE:
Modeling and Optimizations of Phosphate Removal from Aqueous Solutions Using Synthetic Zeolite Na-A
AUTHORS:
E. A. Mohamed, A. Q. Selim, M. K. Seliem, Mostafa R. Abukhadra
KEYWORDS:
Zeolite Na-A, Hydrothermal, Phosphate, Optimization
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.3 No.9,
September
8,
2015
ABSTRACT: Synthetic zeolite Na-A was prepared from Egyptian kaolinite by hydrothermal treatment to be
used as an adsorbent for removal of phosphate from aqueous solutions. The present work deals
with the application of response surface methodology (RSM) and central composite rotatable design
(CCRD) for modeling and optimization of the effect of four operating variables on the removal
of phosphate from aqueous solution using zeolite Na-A. The parameters were contact time (0.5 - 6
h), phosphate anion concentrations (10 - 30 mg/L), adsorbent dosage (0.05 - 0.1 g), and solution
pH (2 - 7). A total of 26 tests were conducted using the synthetic zeolite Na-A according to the conditions
predicted by the statistical design. In order to optimize removal of phosphate by synthetic
zeolite Na-A, mathematical equations of quadratic polynomial model were derived from Design
Expert Software (Version 6.0.5). Such equations are second-order response functions which represent
the amount of phosphate adsorbed (mg/g) and the removal efficiency (%) and are expressed
as functions of the selected operating parameters. Predicted values were found to be in
good agreement and correlation with experimental results (R2 values of 0.918 and 0.905 for
amount of phosphate adsorbed and removal efficiency of it, respectively). To understand the effect
of the four variables for optimal removal of phosphate using zeolite Na-A, the models were presented
as cube and 3-D response surface graphs. RSM and CCRD could efficiently be applied for the
modeling of removing of phosphate from aqueous solution using zeolite Na-A and it is efficient
way for obtaining information in a short time and with the fewer number of experiments.