Response Surface Modeling for Malachite Green Removal Using the Box-Behnken Experimental Design

The purpose of this work is to study the effectiveness of date seed powder as coagulants in the treatment of malachite green (MG) in coloured waters. The seeds were characterized by Fourier Transform Infrared (FTIR) Spectroscopy and Scanning Electron Microscopy (SEM) before and after treatment by coagulation-flocculation. Determination of optimal process conditions was performed using the response surface methodology using the Box-Behnken design (BBD). Three independent variables were chosen and set at three levels, namely the initial pH of the solution (2, 6 and 10), the dose of coagulant (100, 300 and 500mg/l) and the settling time (10, 30 and 50min) while performing 15 experimental trials. The results found showed that the maximum dye removal efficiency is 84.12% for a coagulant dose of 493.8 mg/L, a settling time of 50 minutes and a pH of 8.7. This confirms that date seeds can be considered as an alternative coagulant comparable to chemical coagulants, biodegradable and eco-friendly.