Water and energy are popular topics around the world, due to the difficult environmental situation, as well as growing concerns about global warming. One place where these two resources are inextricably linked is the wastewater treatment plant. Improving the quality of treated wastewater is usually achieved through increased energy consumption – e.g. for raising the oxygen concentration in the reactor, or capital expenditure – e.g. for an external organic carbon dosing installation. At the same time, it is routine at larger facilities to produce energy from the combustion of methane gas generated in the sludge digestion process. The SNIT project, addresses both issues and aims to improve the quality of treated wastewater and increase digester gas production with moderate investment. The key to this is the use of nitric acid to induce partial nitrification in the main-stream, as well as to disintegrate the sludge to increase the organic load, which is the substrate for the fermentation. By removing nitrogen via nitritation, the consumption of oxygen and organic carbon in the biological reactor will be significantly reduced, and the shortened denitrification will allow for deeper nitrogen removal.

Source: Forum Eksploatatora 2020. nr 5, s. 60-62, ISSN 1640-8624