Arsenic contamination in water causes many diseases. Therefore, various biosorbent materials have been tested for their ability to remove the two inorganic arsenic species commonly found in water, namely, arsenite As(III) and arsenate As(V). The arsenic biosorption is influenced by the pH value of the aqueous phase, arsenic concentration, presence of competing ions, and arsenic speciation. The biosorption kinetics of As(III) and As(V) has been reported to be rapid, with more than 80% biosorption occurring during the first hour, followed by a second step which may take up to several hours. The pseudo-second-order model provided the best fit, which corresponds to a chemisorption process. The Langmuir model indicated that most arsenic ions are adsorbed in monolayer form and removal is better for As(III) than for As(V).