Nitrate Removal from Aqueous Solution Using Nanoporous MCM-41 Silica Adsorbent Functionalized with Diamine Group

Nitrate is one of the contaminants in the aquatic environment and causes health problems. In the present study، removal of nitrate from aqueous solution using the mesoporous MCM-41 silica functionalized with diamine group (NH2-NH-MCM-41) was investigated. The modification of mesoporous MCM-41 materials by grafting diamine functional groups directly to the surface of a solid adsorbent was studied. The structure of the synthesis materials was characterized by XRD، BET and FT-IR. Results revealed that nitrate adsorption in batch system show high adsorption capacity (15. 74 mg/g) and removal percentage (75%). The optimal pH، amount of adsorbent and initial concentration for removal of the nitrate anion on NH2-NH-MCM-41 were found at 7، 5 g/l and 110 mg/l، respectively. Maximum adsorption capacity was also attained at contact time 15 min for removal of nitrate anion. The experimental data were analyzed using the Langmuir and Freundlich isotherm models and the maximal equilibrium uptake capacity of 29. 8 mg/g was obtained. The results of the present study showed that NH2-NH-MCM-41 adsorbent can be used as an adequate adsorbent for removing anion nitrate from aquatic environments.