Nitrite removal from water: New support materials for Pd-based catalysts aiming for a low ammonium production

F. M. ZOPPAS; SACCO, NICOLÁS; AGHEMO, VANINA S.; FAVARINI BELTRAME, THIAGO; BATTAUZ, FABIO; DEVARD, ALEJANDRA; EDURDO MIRÓ; MARCHESINI F. A.

Advances in Catalysts Research

Springer

Lugar: New York; Año: 2022;

The concentration of nitrogen oxyanions in natural waters has steadily increased in recent decades, as a result of the intensification of agriculture and population growth. Reverse osmosis, ion exchange, adsorption and electrodialysis are currently used as separation technologies for water denitrification. Also, nitrite reduction technologies such as the biological treatment and the catalytic reduction, are able to convert nitrite into inert nitrogen gas. Several studies have proposed the catalytic nitrite to nitrogen reduction in water over Pd supported on different materials as a promising alternative for water treatment. In this chapter, an overview of the current state-of-the-art of catalytic nitrite reduction is presented. The use of catalysts supported on CeO2, Nb2O5, ZrO2, TiO2, γ-Al2O3, SiO2, and ZSM-5 for the removal of high concentrations of nitrite in water is reported in this chapter. All synthesized materials were evaluated and they showed catalytic activity in the reduction of nitrites in the water. The total conversion was achieved by catalysts supported in γAl2O3, ZSM-5 (Si: Al=30), SiO2, and TiO2. Of this group, the most selective to nitrogen under the evaluated conditions were supported on ZSM-5 (Si: Al=30) and TiO2. These findings contribute to the existing data, providing insight into materials previously untested as supports for catalysts for nitrite removal from water.