Winery effluent treatment at an anaerobic hybrid USBF pilot plant under normal and abnormal operation

A 1.1 m3 hybrid USBF fully instrumented pilot plant has been used for the treatment of diluted wine for four years. In this work, the performance of the wastewater treatment plant (WWTP) during start up and operation (normal operation and overload experiments) is shown. A complete description of the treatment process behaviour (gas and liquid phase composition and anaerobic sludge characteristics) is given by on-line and off-line monitoring of 28 process variables. The results presented here demonstrate the reliability of this technology for the treatment of wastewater from seasonal processes, such as winery wastewaters, during a long period of time (four years). Furthermore, the USBF reactor presented very short start up periods after short and long shut down of the WWTP and rapidly turned back to normal operation after suffering a complete destabilization due to organic overload. Both effluent and biogas were of good quality. Dissolved organic carbon concentration in the effluent was always lower than 100 mg DOC l(-1) under normal operation, while methane concentration in the biogas was in the range 70-74%, making it suitable for energy recovering.