DISEÑO Y CÁLCULO DE UN TREN DE TRATAMIENTO BIOLÓGICO PARA AGUAS RESIDUALES URBANAS USANDO LA TECNOLOGÍA DE LECHO GRANULAR EXPANDIDO

Abstract

Anaerobic process is a well established technology for wastewater treatment that has been used to treat high strength industrial wastewaters mainly, specially in the brewery, dairy and food industries. However when treating low strength domestic wastewaters at psicrophilic temperatures (below 15°C), anaerobic process seemed not to be the best choice, since it had a poor development regarding COD removal efficiency. In recent years, this perception has dramatically changed, since high rate treatment technology came up, giving a new prospective to a domestic low strength wastewaters treatment, that allows to many small and medium size cities in México, to give a feasible and affordable treatment to their liquid waste. Expanded Granular Sludge Bed (EGSB) is one of those high rate anaerobic technologies, that performs a suitable and fast wastewater treatment, since it combines, a high organic load, with an up flow liquid velocities that comes in to a fast and efficient operation, ranging 85 – 92 % COD removal levels. Another important advantage of this novel technology is the simplicity of equipment needed to perform the process that carries out it, for instances, without mixing equipment inside the reactor, that becomes an important feature because represents a high cost reduction when compared to aerobic or anaerobic traditional processes. All those reasons gave the EGSB process technology, the recognition on year 2008 by magazine Water Science Technology, as BAT (best available technology), in the wastewater treatment industry. Technical and operational aspects, regarding EGSB technology and process, are the main subject of the present work.