RESUMO
The objective of this study, is the removal of arsenic [three] from contaminated water, by adsorption on activated carbon, prepared from a lignocellulosic natural waste in fact "the dates stones". The effectiveness of adsorption was evaluated for the carbonized raw material at 600[degree]C and after its activation at 900[degree]C. Results of the adsorption capacity tests were found to be 21mg/g for the activated carbon and barely 2mg/g before activation. The satisfactory operating conditions are carried out with pH bordering neutrality and an ambient temperature of 20[degree]C. This result is similar to that found in the litterature but for other biosorbents. The optimal adsorption of arsenic [three] follows the Langmuir and Freundlich models. The kinetics of adsorption is slow, of the second order, with a value of adsorption constant k[ads] equal to 1,16.10[-2] h[-1].