REMOVAL OF ARSENIC FROM AN AQUEOUS SOLUTION BY PRETREATED WASTE TEA FUNGAL BIOMASS

Arsenic contamination in water poses a serious threat on human health. The tea fungus known as Kombucha is a waste produced during black tea fermentation. The objective of this study was to examine the main aspect of a possible strategy for the removal of arsenates employing tea fungal biomass. The pretreatment of biomass with FeCl₃ was found to improve the biosorption efficiency. Arsenics uptake was found to be rapid for all concentrations and reached to 79% of equilibrium capacity of biosorption in 20 min and reached equilibrium in 90 min. The pseudo second-order and first-order models described the biosorption kinetics of As (V) with good correlation coefficient (R²>0.93) and better than the other equations. The data obtained from the experiment of biosorption isotherm were analyzed using the Freundlich and Langmuir isotherm models. The equation described the isotherm of As (V) biosorption with relatively high correlation coefficient (R²>0.93). According to the Langmuir model, the maximum uptake capacities (qm) of tea fungal biomass for As (V) were obtained 3.98×10^-3 mmol/gr. The effect of Na⁺, K⁺, Mg⁺² and Ca⁺² on equilibrium capacities of As was not significant. The variation of sorption efficiency with pH showed that optimum biosorption takes place in the pH ranges of 6 to 8. Promising results were obtained in laboratory experiments and effective As (V) removals were observed.

Keywords
Waste tea, fungal biomass, biosorption, arsenates isotherm, aqueous solution