An UASB reactor (7 L) was installed in the Institute of
Wastewater Management and Water Protection, Hamburg
University of Technology, Germany. Fig. 1 shows a schematic
diagram of the system. The system was installed
in a temperature-controlled room at 30 1C. The grey water
was collected from ‘Flintenbreite’ settlement in Luebeck,
Germany. A container of 1m3 storage capacity was installed
in the settlement to collect the grey water from the
inlet sewer pipe of the first septic tank. The collected grey
water represented a wastewater of one day and was
transported directly to the Institute, where it was stored at
4 1C until usage for reactor feeding. Table 1 shows the
characteristics of the grey water. The UASB reactor was
operated for a period of 272 days and started operation after
addition of seed-sludge from an anaerobic digester treating
primary and secondary sludge. The UASB reactor was
operated at HRT of 16, 10 and 6h for 95, 91 and 86 days,
respectively.
2.2. Batch experiments