Sorption of As(V)-anions from aqueous solutions by organo-modified natural zeolitic materials

Natural zeolitic materials (sedimentary zeoliferous rocks) were organo-modified using polyhexamethyleneguanidine-chloride in order to enhance their anionic sorptive properties. The sorption of As(V)-anions from aqueous solutions [As(V) concentration range from 10 to 1000 mg/l] was investigated using radiochemical techniques. The samples exhibited an elevated tendency to sorb As(V)-anions (up to 6.73 mg/g) and the relative uptake was found to be much higher for solutions of low initial concentrations (up to 99.8% removal). The different As(V) species (mainly HAsO42−) are principally sorbed through ion-exchange reactions by the net of the polymeric, compound covering the mineral aggregates of the samples. The investigated materials could be considered for the removal of As(V) anionic species present in industrial or municipal wastewaters.