Abstract

Reduction ofmethylene blue (MB) by ammonia in nanomordenite and mordenite zeolites:Method for the determination of ammonia concentration

Author(s): Sh.Sohrabnezhad, A.Pourahmad, B.Sadeghi.G

The increased encounter probability between ammonia and methylene blue dye(MB+) incorporated in nanomordenite and Na-MORzeolites demonstrated the reduction capacity of ammonia while present even at ppm level. The rate of reduction methylene blue dye by ammonia on the surface nanomordenite zeolite is faster than Na-MOR zeolite. Because nanomordenite zeolite with high silica(Si/Al=15) and surface area 400 (m2/ g) is referred to as hydrophobic support with respect to Na-MOR zeolite (Si/Al=6.5). On the other hand, the rate of color bleaching of MB+ by ammonia was found to be fastest in proton form of nanomordenite and mordenite zeolites. The results obtained with the zeolites were also compared with non-ionic micelle(TX-100). The calibration graph is valid for wide range of concentrations in nanomordenite zeolite. The limit of detection (LOD) is 0.12mg ml-1. This method is simple, sensitive and easy to carry out. By using only aUV-Visible spectroscopy, ammonia can be quantified.