Contributo para a minimização do consumo energético numa ETAR: estudo do efeito de diferentes proporções de lamas primárias e ativadas no processo de digestão anaeróbia - o estudo de caso da ETAR do Seixal

Mestrado em Engenharia do Ambiente - Instituto Superior de AgronomiaHuman population exponential growth and the pressures associated with human activities have caused drastic changes in the biosphere, leading to irreversible transformation in the life quality of our planet. Over the years, concerns about the quality and quantity of potable water and water and wastewater treatment methodologies have increased, making it the main focus of research. The main goal of this thesis is to study the minimization of the WWTP energy consumption, using different ratios of primary sludge and waste activated sludge (PS:WAS) as input in anaerobic digestion (AD). The impact of each proportion - T0 = 100:00; T1 = 80:20; T2 = 60:40; T3 = 40:60 , v:v – was analyzed in terms of biogas production and correspondent energy potential generated, as well as the main physicochemical characteristics and operational parameters of the anaerobic digestion process. Results show that increasing the PS proportion in the feeding mixtures, leads to an increase in the potential energy produced (55% for T0; 42% for T1; 32% for T2). Considering that most WWTP work on T3, this study provides a tool to optimize the sludge streams management as AD feeding, increasing the production of energy and decreasing the energetic costs associated to the WWT