Catalytic Oxidation of Nitrite to Nitrate in Aquas Solution by Carbonate-Activated Charcoal

Mopoung, Sumrit; Thanakulwaranon, Rinlaphat

doi:10.22068/ijmse.4430

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‎ 10.22068/ijmse.4430

Catalytic Oxidation of Nitrite to Nitrate in Aquas Solution by Carbonate-Activated Charcoal

Sumrit Mopoung

, Rinlaphat Thanakulwaranon

Abstract: (1 Views)

Activated charcoals were prepared by activation with 600 W microwave irradiation in combination with pretreatments of tamarind wood derived charcoal in boiling mixtures with NaOH (1 g : 0 g - 1 g: 0.12 g). The samples were characterized by FTIR, XRD, SEM-EDS, and BET, and used for catalytic nitrite c oxidation under air atmosphere in the absence of light at 30°C, pH 6.5, and 120 rpm shanking for improved efficiency. The results show that the percent yields of tamarind wood derived activated charcoals (ACCs) were 88.51% - 94.66 %. The main carbonate compounds of ACCs are present in the materials after activation. Na⁺ ions and water molecules could be inserted into the graphitic layers during pretreatment and efficiently effected surface cracking of ACCs by 600 W microwave irradiation. The surface cracklings and porosities of ACCs increased with increasing concentration of NaOH from 1 M to 3 M with optimum at 2 M NaOH. The final products are mesopore materials containing macro and meso hole channels. It was found that the nitrite conversions exhibit high reaction rates and are completed within 20 min. The reactions proceed via catalytic oxidations and their rates increase with increasing concentrations of NaOH activation, while nitrite conversions via the disproportionation reaction wereinhibited.

Keywords: Microwave irradiation, Sodium hydroxide, Activated charcoal, Catalytic oxidation, Nitrite