Research - Results: Full scale installation
The MBR plant at Varsseveld has been in operation since the end of December 2004. The installation was inoculated using activated sludge from the existing Varsseveld wastewater treatment plant, which continued to operate during the start-up process of the new plant. The sludge content after inoculation amounted to approximately 2.5 g DS/l. In a period of about seven weeks, the sludge content increased to the desired level of 10 g DS/l.
The biological results are promising. Five weeks after start-up, the total nitrogen content in the effluent dropped below the required maximum level of 5 mg/l. Since then, the effluent content has varied between 2 and 4 mg Ntotal/l at a process temperature of around 12ºC. The phosphate content ranges between 2 and 5 mg Ptotal/l. The iron-salt dosage system will soon be put into operation in order to further decrease the effluent content to the desired level of 0.15 mg Ptotal/l.
The four membrane channels have been in operation since the beginning of
2005 and are functioning according to expectations. In the coming weeks,
the membranes
will undergo further capacity testing.