Effects of different aeration rate and oxygen concentrations on nitrogen removal of old waste in lab-scale simulated bioreactors landfill

• Autor(a) principal: Moreno, João Rodrigo Santos Graça Fernandes
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/55258
• topic: In situ aeration; Oxygen in the outlet gas; Nitrogen removal; Leachate; Municipal Solid Waste; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia do Ambiente

The application of in situ aeration in bioreactor landfill is a potential method to reduce the actual emissions and the emission potential from the waste material. This is achieved by accelerating the reduction of ammonia nitrogen concentration and biodegradable organic mass matter in the landfill body. In this study, lab-scale tests were carried out to investigate alternatives that can achieve better performances of waste stabilization and pollutants emissions, with particular focus on nitrogen compounds, regarding the current re-disposal conditions of municipal solid waste from the old Landfill of Legnago. In addition, the viability of using the oxygen concentration in the outlet gas as a dimensioning and operational parameter of in situ aeration technology was also studied. Different air flow rates were established and adjusted over time, with the aim of creating different oxygen concentrations in the outlet gas on five simulated landfill bioreactors. One control bioreactor was operated under anaerobic conditions in order to simulate the current conditions of the waste disposal. The anaerobic bioreactor landfill showed the highest level of leachate emissions, with the highest concentrations of COD, TOC and ammonium nitrogen. Better alternatives, in terms of nitrogen removal, were obtained by simulated aerobic bioreactors landfill. The results showed that oxygen concentration in the outlet gas is a more proper dimensioning and operational parameter than aeration flow rate itself in order to adjust the intensity of aeration required to reach the best performance of aerobic bioreactor landfills. The best performance of aeration efficiency, in terms of ammonium nitrogen removal in the leachate regarding the amount of oxygen supplied, was obtained by the bioreactor provided with the second lowest air flow rate and with an average value of 1.3% of oxygen in the outlet gas.