A Comparison Study on Defluoridation Capabilities Using Syzygium cumini and Psidium guajava: Process Optimization, Isotherm, Kinetic, Reusability Studies

For the first time, this work conducted a comparison of two indigenous plants in Iran, namely, Syzygium cumini and Psidium guajava, which were prepared as low-cost adsorbents to remove fluoride contamination from aqueous solution. The results revealed nonlinearity interactive effects showed that pH adsorbent dosage most influential factors during adsorption. characterization exhibited mesoporous structure biosorbents; therefore, adsorption process may involve multiple functional groups, resulting electrostatic attraction hydrogen binding between ions biosorbents. In case cumini, maximum removal efficiency 72.5% was obtained under optimum experimental conditions (Co = 6 mg/L, 5, dose 8 g/L, contact time 75 min). 88.3% achieved at Co initial 5.1, 90 min. Moreover, four consecutive adsorption/desorption cycles with chemical agent NaOH solution (0.1 mol/L) excellent reusability isotherm fitted better Langmuir model kinetic data best accorded pseudo-second-order for both biosorbents, expressing monolayer chemisorption recorded capacities 1.14 1.50 mg/g respectively. Therefore, given their capacity potential utility, biomass could be effective reusable biosorbents treat water contaminated fluoride.