8. Operation and maintenance
41 / 54
– oxygen concentration (O
2
/l > 2 mg), if necessary adapt the compressor operating
times
– sludge as proportion of volume (< 400 ml/l)
if the sludge makes up more than 400 ml/l, the sludge should be removed more
frequently in agreement with the manufacturer;
Sampling from discharge and analysis of the following values:
– temperature of wastewater
– substances that can settle
– pH
– odour
– colour
– depth of visibility
– BOD
5
(every other maintenance)
– COD value
– NH
4
-N (if required)
– nanorg (if required)
– P (if required)
The maintenance work undertaken, any damage found, repairs undertaken and other infor-
mation should be summarised in a maintenance report by the maintenance company. A suitable
template is provided in the Annex. Anything established during the analyses should also be
documented in this report. The system operator should be given the maintenance report so that
it can be passed to the responsible authorities if demanded. The maintenance report should be
attached to the operating manual. Please keep the operating log in a place where it can be easi-
ly accessed.
