Removal of Malachite Green (MG) From Aqueous Solutions by Adsorption, Precipitation, and Alkaline Fading Using Talc

Malachite green (MG), which is primarily used as a dye, is a chemical that is listed as a class II health hazard because of its toxicity to humans and the environment. Adsorption is frequently used to remove this cationic dye from aqueous solutions. Structural changes of the molecule should be considered during removal, because MG (or chromatic MG+ at neutral pH) turns into protonated MG (MGH+) at acidic pHs and a carbinol base at basic pHs. In this study, batch sorption experiments were conducted to remove MG from aqueous solutions using talc. We studied specific removal behaviors and mechanisms of the MG for different pH solutions, including adsorption, precipitation, and alkaline fading.