The Influence of Stereochemistry of the Active Compounds on Fluoride Adsorption Efficiency of the Plant Biomass

Abstract

Several studies have reported various defluoridation capabilities of plant biomasses. The resultant variations in fluoride removal capacities are associated with the presence of different types of active functional groups in the respective biomasses. This study reports of the fluoride removal efficiencies of sisal leaf biomass in comparison. Comparison with other plant biomasses were made and hence the fluoride removal efficiencies of maize leaf (ML), goose grass (GG), banana false stem (BFS), Aloe vera (AV), untreated sisal fibre (USF) and sisal pith (SP) with similar active functional groups but different stereochemistry and solubility of the active compounds are reported. A portion of 0.5 g of each biomass was mixed with a 10 mg/l fluoride solution in a 10 ml portions under the same experimental conditions. The maximum fluoride removal capacity of sisal fibre biomass was found to be 26.6 %. By comparison, the fluoride removal efficiencies of ML, GG, BFS, AV, USF and SP were found to be, 4.1, 4.6, 7.1, 26.6, 29.4 and 47.3 % respectively. This suggests that, stereochemistry and solubility of the active compounds have a significant role to play in water defluoridation by plant biomasses, and thus, knowledge of the stereochemistry and solubility of the active compounds in plant biomass is very important to fully unlock biomass' defluoridation potentials.

Green Synthesis of Hydroxyapatite Nanoparticles Using Monoon longifolium Leaf Extract for Removal of Fluoride from Aqueous Solution

“…To achieve optimum removal efciency and fuoride ion absorption capacity, neutral pH was chosen as the ideal one. Te results of this investigation are in accordance with the study by Mwakabona et al [41], who found that when pH increased, both removal efciency and adsorption capacity enhanced gradually until an equilibrium point was reached.…”

Oxidative Polymerization of Aniline on the Surface of Sisal Fibers (SFs) as Defluoridation Media for Groundwater

“…The hydroxyl functionalities of sisal fibers can interact with hydronium ions in the solution to form positively charged surfaces leading to fluoride uptake. Moreover, other weak van der Waals interactions may occur between fluoride and the sisal surface [ 36 ]. Different scholars have applied cellulose, chitin, and chitosan as adsorption media due to the availability of hydroxyl functionality through H-bonding and other van der Waals interactions.…”

Water Defluoridation Methods Applied in Rural Areas over the World

“…Biosorption utilizes animal and plant remains in the pulverized form "as is" without prior gasification or charring. A study realized in Tanzania, reported F removal efficiencies, which was 4.1-47.3%, for several biosorbents [134]. In a particular defluoridation study, which was conducted by Yadav et al [135] using three agricultural-based biomasses as adsorbents tested on groundwater containing 5 mg/L F, the authors reported F removal efficacies of 40-58%.…”

“…Similarly, Aspergillus and Calcium treated Aspergillus biosorbents revealed Fluoride F adsorption capacities of 8.09 mg/g [145]. Differences in the capacity of various biomasses to sequestrate F from water are related to, among other factors, differences in active functional groups in the biomasses [134].…”