Development of Hydrogenotrophic Denitritation Process for Municipal Wastewater

Shortcut biological nitrogen removal has drawn research attention due to efficient removal of harmful nitrogenous compounds from wastewater by reducing energy and carbon requirements. In this thesis, the main objective is to develop a novel hydrogenotrophic denitritation system, in which high nitrite loading rate is reduced into nitrogen gas released to the air using a mixed bacterial consortium. This was proved first using a fed batch system followed by a sequential batch reactor (SBR) system under nitrite loading rate of 0.4 kg/m3d. The nitrite removal efficiency reached up to 97% and a final nitrite concentration of 5 mgNO2-N/L and a specific denitritation rate of 45 4.5 mgNO2-N/gVSS/d. The current study aims to achieve high rate nitrite removal using hydrogen gas. The proposed model is an important step to facilitate the coupling of this process with partial nitrification processes in a single reactor for side stream wastewater. This would lead to efficient nitrogen removal, and reduction in energy and aeration requirements.