preparation of an adsorbent from pumice stone and its adsorption potential for removal of toxic recalcitrant contaminants

background: in recent years, proficient treatment of wastewaters containing recalcitrant and toxic compounds such as phenol has been a challenge. this study introduced and evaluated an efficient option for treating such wastewater . methods: this experimental study was performed on phenol removal as a recalcitrant and toxic compound in aqueous solutions in 2011. the pumice stone was collected from a local mine. collected samples were crushed and granulated using standard sieves (mesh size of 20). cuso 4 was used to modify prepared samples. the chemical composition and the surface area of the modified pumice were evaluated using x-ray fluorescence and n 2 gas via brunauer-emmett-teller isotherm and belsorb software. different parameters including of ph (3-12), contact time (20-120 min), phenol concentration (25-400 mg/l) and adsorbent dosage (0.25-1 g/l) were examined in a batch reactor. results: 93.5% of the phenol was removed under optimum experimental conditions of ph 3 and a 0.5 g/l adsorbent dose after 60 min contact time. the experimental adsorption isotherm the best fit with freundlich equation model. t he maximum amount of phenol adsorption onto modified pumice (mp) was 15.8 mg/g . conclusion: modified pumice is effective adsorbent for the removal of phenol from aqueous solution. accordingly, it is feasible and promise adsorbent for treating polluted phenol streams.