ULTRASOUND-ASSISTED MODIFICATION OF FLAX WASTES TO REMOVE METHYL VIOLET FROM AQUEOUS SOLUTION

Preparing an adsorbent to remove methyl violet (MV) from aqueous solution, flax wastes were used as raw material to synthesize new adsorbent via which modified with sodium hydroxide by ultrasound assisted technology. The optimum conditions were studied on the impact of factors such as sodium hydroxide concentration, modified time, modified temperature, modified power, adsorbent dosage, initial dye concentration, adsorption time and temperature. This shown that the adsorption properties of modified flax wastes (MFW) was better than the unmodified flax wastes (FW). The best adsorption capacity and removal rates were 24.80 mg/g and 99.22 %, respectively, which were improved 0.6 mg/g and 2.42%, respectively. Maximum adsorption capacity and removal rate under optimum condition of variables (modified time 60 min and temperature 50 degrees C, adsorption time 10 min, adsorbent dosage 0.04 g) by the orthogonal test were 23.83 mg/g and 98.03 %, respectively. Meanwhile, the equilibrium dates were found to fit the Langmuir model better than the Freundlich model (R-2=0.998). Kinetic date reveled that the adsorption process followed the pseudo-second-order equation. The thermodynamic parameters show that the adsorption process belong to spontaneous and endothermic adsorption.