Nitrite Removal from Water: New Support Materials for Pd-Based Catalysts Aiming for a Low Ammonium Production

TheWater concentrationConcentration of nitrogen oxyanionsNitrogen oxyanions in natural watersNatural water hasCatalyst steadilyAmmonium increased in recent decades, as a result of the intensification of agricultureAgriculture and populationPopulation growth. Reverse osmosisReverse osmosis, ion exchangeIon exchange, adsorptionAdsorption and electrodialysisElectrodialysis are currently used as separation technologiesSeparation technologies for water denitrificationWater denitrification. Also, nitrite reduction technologiesNitrite reduction technologies such as biological treatmentBiological treatment and catalytic reductionCatalytic reduction, are able to convert nitrite into inertInert nitrogen gasNitrogen gas. Several studies have proposed the catalytic reductionCatalytic reduction of nitrite to nitrogenNitrogen in waterWater over Pd supported on different materials as a promising alternative for water treatmentWater treatment. In this chapter, an overview of the currentCurrent state of the art of catalytic nitrite reductionReduction is presented. The use of catalystsCatalyst supported on CeO2, Nb2O5, ZrO2, TiO2, γ-Al2O3, SiO2, and ZSM-5 for the removal of high concentrationsConcentration of nitrite in waterWater is reported in this chapter. All synthesized materials were evaluated and they showed catalytic activityCatalytic activity in the reductionReduction of nitrites in the waterWater. The total conversionConversion was achieved by catalystsCatalyst supported in γAl2O3, ZSM-5 (Si: Al = 30), SiO2, and TiO2. Among this groupGroup, the most nitrogenNitrogen-selective under the evaluated conditions were supported on ZSM-5 (Si: Al = 30) and TiO2. These findings contribute to the existing data, providing insights into previously untested materials as supports for waterWater removal nitrite catalystsCatalyst.