Majid H amzehloo - School of Che mistry, Colleg e of Science, U niversity of Tehran, P.O. Box ۱۴۱۵۵-۶۴۵۵, Tehran, Iran.
Bahman Hasanzade - School of Che mistry, Colleg e of Science, U niversity of Tehran, P.O. Box ۱۴۱۵۵-۶۴۵۵, Tehran, Iran.
Afsaneh Shah bazi - School of Che mistry, Colleg e of Science, U niversity of Tehran, P.O. Box ۱۴۱۵۵-۶۴۵۵, Tehran, Iran.
Alireza Badiei - School of Che mistry, Colleg e of Science, U niversity of Tehran, P.O. Box ۱۴۱۵۵-۶۴۵۵, Tehran, Iran.

The preparation o f nano-structured silica s since ۱۹۹۲ until now has opened a wide fi eld of applications. In comparison with other nano-structured silica materials, SBA-۱۵ exhibits thicker pore wall, higher pore volumes, a nd wider pores. The silic a wall surface of nanoporous silica can be modified with organic gr oups to tailor their properties and achieve specific purposes. Among the main uses of na noporous silicas, it is well-know n the desi gn of adsorb ents for environmental cleanup and many reports can be found [۳, ۴, ۵]. Remo val of dyes from aqueou s solutions is one of th e major pr oblems on w astewater treatment because they are mostly to xic. Malach ite green, a triphenylmethane dye, has been wi dely used f or the dyein g of leather, wool and s ilk as well as used as a fungicide and antisept ic in aquaculture industry to control fish parasites and disease [۳]. But recently, M G has been found exhibiting carcinogenic, genotoxic, mut agenic and teratogenic properties. Among the technique s for removal of dyes from wastewater, adsorption has been proved to be an effective and attr active proces s because of its inexpen sive nature and ease of operation.