NITRITE REMOVAL IN SALINE AQUATIC WATER BY PHOTOCATALYTIC REDUCTION UNDER LED LIGHTS /SUN LIGHTS USING ILMENHITE AND Ag/TiO2 NANOPARTICLES AS PHOTOCATALYSTS

Abstract

This paper deals with the selective removal and conversion of NH3/NO2/NO3 forms in freshwater and saltwater by photocatalytic process on reconstituted
Vietnamese natural mineral material ilmenite FeTiO3, Ag/TiO2, TiO2 anatas (KA 100) with citric acid as reducing agent, environmentally friendly. Samples of
photocatalyst materials with nanoparticle structure were synthesized and characterized by XRD, UV-Vis, FTIR, EDX methods, etc. The results show that ilmenite
photocatalysts FeTiO3, Ag/TiO2, TiO2 has shown photoreduction activity under LED and sunlight in selectively converting nitrogen forms in freshwater and actual shrimp
pond water when illuminating different light wavelength regions. Nitrite NO2
reduction capacity reaches 22.5mg/g, NO3 nitrate is 550mg/g under sunlight (with UV
light, intensity 880µW/cm2
); and respectively nitrite reached 10mg/g, nitrate 220mg/g under LED light (no UV, intensity 9400 Lux) on Ag/TiO2 photocatalyst. At the
same time, the photocatalysis-reduction process also showed a high inhibition efficiency of Coli and coliforms (EC) of 90% at a dose of 0.1g/l for 24 hours. In general,
photocatalytic reduction of NH3/NO2/NO3 in water by photocatalysis is a very viable technology regardless of water salinity, while effectively treating E. Coli/coliforms
(EC), especially applied in water environment control for aquaculture.