Influence of the operational conditions during the start-up of an UASB and EGSB pilot plant

Proceedings su CD (senza ISBN) del Congresso \u201cVI International Congress: Valorization and Recycling of Industrial Waste\u201d, L\u2019Aquila (I), 27-29 giugno 2007. - This research focuses on examining the Start-Up procedure of an UASB reactor (Upflow Anaerobic Sludge Blanket). The experiment was carried out with a feed of 10000 mg/L of COD (Chemical Oxygen Demand), for about 25 days. The UASB reactor reached an average removal of 51% of COD, and never arrived to stationary state. It failed as a result of organic overload and excessive pH drop (4.3) inside the system by accumulation of acetate and fatty acids. Another attempt was carried out as an EGSB (Expanded Granular Sludge Bed) reactor (with recycle), feeding of 3000 mg/L COD and adding bicarbonate as a buffer solution. This new configuration achieved a stationary state without further problems