Grass Waste: A Highly Biosorbent for the Removal of Malachite Green Dye From Aqueous Solution

Grass waste (GW), a low-cost agricultural waste, is a more effective adsorbent to remove malachite green MG dye. Treatments physical or chemical of GW by soaking in solution H۲O۲ (۱۰%) for ۴ hours at ۲۵ °C. The removal of MG from bio-sorption GW was studied at several weights of GW (۰.۰۱–۰.۱ g), equilibrium time (۲–۱۲۰ min), initial concentration (۱۰–۱۰۰ mg/L), and pH solution (۲–۱۰). The effect of the factors on the adsorption efficiency was studied using the batch process. Increasing MG dye concentration, the adsorption efficiency of GW increased, but the removal percentage decreased from ۱۰.۵۹۹ mg/g to ۱۱۰.۹۹ mg/g to ۹۴.۱۱% to ۸۳.۰۸%. The data evidently displayed a removal percentage of MG of about ۸۹.۸۹% at a weight of GW of ۰.۰۸ g/۱۰۰ mL. The adsorbent was characterized via SEM and TEM. Desorption of MG dye studies was performed with hydrochloric acid, sodium hydroxide, phosphoric acid, acidic acid, and H۲O. A high removal percentage of ۸۹.۰۸۸% in acid medium ۰.۱ N hydrochloric acid. With the addition of HCl, the solution pH decreases, and hence, at a pH of ۳, the GW surface becomes large and protonated, and the attachment among the molecules of dye and GW becomes weakened. The data revealed that bio-sorption GW adsorbent is potentially a very low-cost and eco-friendly adsorbent for the removal of MG dye.

Keywords:

Tetracycline , Drug , Advanced oxidation processes , ZnO NPs , TiO۲ NPs