#aqueous solution

The removal of arsenic,a widely occurring natural poisonous metalloid, from water employing biological sorbents having low cost and higher sorption capacity has become an important field of research as arsenic is significantly endangering human health by contaminating drinking water. Filamentous fungi have gained important place as a bio-remedial due to their fine pores, large surface area and metal sorption capacity. In present study, arsenic (As-III) tolerance of 18 indigenous filamentous fungi was explored by exposing them to As concentrations of 50 to 5600 mg kg-1.Out of 18 isolates, 12 belonged to genus Aspergillus, 3 to Fusarium, 2 to Curvularea and one to Penicillium. The fungal isolates (G-2, M-4, I-5) identified as Aspergillus fumigatus and (G-5) as Fusarium oxysporum showed highest As (III) tolerance. The fungal biomasses of highly tolerant fungi, untreated and treated with NaOH and FeCl3, ware then assessed for their arsenic removal capacity from aqueous solutions. The fresh wet biomass of natural and treated fungus was equilibrated with aqueous solutions of varying As (III) concentrations (0-1000 mg L-1).. The maximum As (III) (3.2 mg g-1) was removed by FeCl3-treated Aspergillus fumigatus (G-2) biomass followed by NaOH-treated (2.83 mg g-1) and untreated biomass (2.66 mg g-1). Maximum increase in As (III) removal (33.65 % over untreated) was observed in FeCl3-treatmentedfungal biomass over untreated whereas NaOH treatment enhanced 22.27 %. Arsenic sorption parameters i.e. maximum sorption capacity and binding strength of fungal biomasses were calculated using Langmuir and Freundlic hsorption models. Langmuir regression coefficient (r2) (0.97-0.99) indicated its better fitness to adsorption data than Freundlich model with r2 values (0.85-0.93).The tested arsenic tolerant fungal strains removed significant amounts of arsenic from arsenic enriched media in laboratory conditions and may be used as an effective sorbent in arsenic removal technology from arsenic contaminated waters.