ABSTRACT
Nitrification rates of algal-bacterial biofilms in wastewater stabilization ponds under
Published as:
M.A. Babu., E.M.A. Hes., N.P. van der Steen., C.M. Hooijmans and H.J. Gijzen.
Nitrification rates of algal-bacterial biofilms in wastewater stabilization ponds under light
and dark conditions. Ecological Engineering 36 (2010) 1741-1746
Chapter 5
Nitrification rates of algal-bacterial biofilms in wastewater stabilization ponds under
light and dark conditions
Abstract
The objective of this study was to investigate nitrification rates in algal-bacterial biofilms
of wastewater stabilization ponds (WSP) under different conditions of light, oxygen and
pH. Biofilms were grown on wooden plates of 6.0 cm by 8.0 cm by 0.4cm in a PVC tray
continuously fed with synthetic wastewater with initial NH4-N and COD concentrations of
. Batch activity
tests were carried out by exposure of the plates to light conditions as above (to simulate day
(to simulate reduced light as in deeper locations in
WSP) and dark conditions (to simulate night time). Dissolved oxygen concentration and pH
were controlled. At some experiments both parameters were kept constant and at others left
and
,
the biofilm nitrification rates under light and dark conditions did not differ significantly at
, the
. It therefore
seems that under these experimental conditions, biofilm nitrification rates are significantly
. As long as bulk
water DO under dark is high, light was not important in influencing the process of
nitrification.
