Performance assessment of carbon based on lignocellulosic material as an effective biosorbent for elimination of iron and manganese from monazite leachate

Abstract The purification of REEs from leaching liquor of monazite ore; which contains contaminated iron and manganese, are significant important for REEs applications. Herein, this work investigated the sorption and separation of Fe 3+ and Mn 2+ from both aquatic solution and REEs of monazite liquor using carbon-based on lignocellulosic cotton stalk material (CCS) as a green biosorbent at optimum conditions. The prepared CCS was characterized by different physicochemical and morphological techniques as FTIR, SEM, TEM, and specific surface area measurement, which was 831 m 2 g − 1 with total pore volume; 0.431 m 3 g − 1 , micro-pores percentage; 93.27%, and meso-pores percentage; 6.73%. The sorption investigations like pH, stirring time, initial metal-ions concentration, temperature, and adsorbent weight were carried out to identify the best reaction parameters. The obtained results were analyzed using different kinetic and isotherm patterns. The pseudo-second order kinetic model surpasses on the other kinetic models in the sorption process, indicating the chemisorption reaction. The sorption isotherm matched with Langmuir model, depending on the highest R 2 and lowest of error functions. The maximum monolayer sorption capacities of Fe 3+ and Mn 2+ ions onto CCS are 531.9 and 680.27 mg/g, respectively at optimum sorption conditions (pH 2.6 for Fe 3+ and pH 5.5 for Mn 2+ , stirring time 30 min. at 25 °C). The sorption approach was exothermic, randomness and spontaneous in nature. Lastly, CCS can be highly separated Fe 3+ and Mn 2+ from REEs of monazite leachate with separation factors reached 228.947 and 2.5735, respectively. Consequently, the low-cost CCS sorbent was utilized for purification of REEs from Fe 3+ and Mn 2+ pollutants of monazite ore liquor.