The effect of base leaching on pure silica ITQ-29 zeolite being the counterpart of LTA zeolite, was investigated. The extent of the desilication process over pure silica zeolite was controlled by partial detemplation followed by silicon extraction. The potential of hierarchically porous ITQ-29 zeolite in environmentally friendly applications concern selective adsorption of organic molecules in aqueous environments. The introduction of additional porosity by desilication process offers full usage of zeolite grains volume without diffusional limitations during the adsorption process.