Successive columns of gravel, fine sand, and mixture of acidified cotton and zeolite clinoptilolite nanoparticles (ZNP) were found efficient in olive mill waste water (OMW) treatment and desalination. The treatment decreased OMW's salinity from 10.9 to 1.6 dSm(-1) due to K+ removal. Furthermore, most total phenol contents were removed. The adsorption of K+ (aqueous solution) onto normal zeolite particles (NSP) and ZNP indicated that the pseudo-second order kinetic model is best model for K+ adsorption. Langmuir model was best fit model for K+ adsorption equilibrium. K+ maximum adsorption capacities were 7.2 and 16.5 mgg(-1) for NSP and ZNP, respectively.