Assessment of various treatment methods and reagents for cleanup and conditioning of sphagnum peat moss as sorbents in removal of malachite green as a cationic organic dye probe from water

Twelve sphagnum peat moss samples were studied for removal of malachite green, as a cationic dye probe, in assessment of various pretreatment methods using three low-cost reagents, applying different approaches such as flow-through, shaking, stirring, and sonication.These sphagnum sorbents were categorized as non-treated (sorbent 1), water-treated (sorbents 2-4), hydrochloric-acid-treated (sorbents 5-8), and finally sodium-hydroxide-treated (sorbents 9-12). Foremost, the physicochemical features of these sorbents were assessed in terms of acidity, matrix emission, total dissolved salts, cation-exchange capacity, and particle morphology. As a matter of fact, different reagents and treatment methods showed dissimilar enhancement in dye removal tendency.Yet, the water and hydrochloric acid treatments by sonication (sorbents 4 and 8) and more remarkably the sodium hydroxide treatment by shaking (sorbent 10) afforded astonishing dye removal rates. Correlating the dye removal tendencies of these sorbents, with their physical properties and sorbent capacity, indicated a slight fall in their cation-exchange capacity plus a genuine change in the particle shape and substantial reduction in size. Finally, excellent reproducibility was demonstrated for the cation-exchange capacity, % removal, and the adsorption pseudo-second-order rate constant. [GRAPHICS] .