TITLE:
Modeling and Optimization of Two Clays Acidic Activation for Phosphate Ions Removal in Aqueous Solution by Response Surface Methodology
AUTHORS:
Yao Joseph Adjoumani, Pierre Jean Marie Richard Dablé, Konan Edmond Kouassi, Soumahoro Gueu, Alain Stéphane Assémian, Kouassi Benjamin Yao
KEYWORDS:
Clay Acidic Activation, Modeling, Optimization, Phosphate Removal, Response Surface Methodology
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.11 No.2,
February
22,
2019
ABSTRACT: This work deals with phosphate ions removal in aqueous solution by adsorption carried out using two clays, both in activated form. One, non-swelling clay, rich in kaolinite, is associated with illite and quartz. The other, swelling, richer in montmorillonite, is associated with kaolinite, illite and quartz. Seven factors including these two clays were taken into account in a series of experimental designs in order to model and optimize the acidic activation process favoring a better phosphate removal. In addition to the choice of clay nature, the study was also interested in the identification of the mineral acid, between hydrochloric acid and sulfuric acid, which would promote this acidic activation. Response Surface Methodology (RSM) was used for this purpose by sequentially applying Plackett and Burman Design and Full Factorial Design (FD) for screening. Then, a central composite design (CCD) was used for modeling the activation process. A mathematical surface model has been successfully established. Thus, the best acidic activation conditions were obtained by activating the montmorillonite clay with a 2N sulfuric acid solution, in an acid/clay mass ratio of 7.5 at 100°C for 16H. The phosphate removal maximum rate obtained was estimated at 89.32% ± 0.86%.