3.3.3. Evaluation of practical applicability of FLFW
In China and maybe some other countries, a low COD/TN ratio
often becomes a problem to restrict denitrification efficiency for
WWTPs. Therefore, addition of external carbon source is usually
required to increase the COD/TN ratio to a level sufficiently high for
effective denitrification. According to this study, the denitrification
potential PDN of the FLFWis 0.174 g N/g COD and the productivity of
carbon source from the food waste is 0.096 g SCOD/g FW. In some
cases, the effluent TN concentration could be as high as 15e20mg/L
due to lowCOD/TN ratio (Czerwionka et al., 2012; Lee et al., 2013). If
a complete TN removal is supposed to be the target of external
carbon source addition, it can be calculated that 0.9e1.2 kg FW
would be needed for the production of FLFW for the treatment of
per m3
wastewater, which is equivalent to the food wastes gener-
ated by 2 or 3 persons (Zhang and Fu, 2010). In the case of domestic
wastewater treatment, the per capita sewage discharge is usually
about 0.2 m3
. Therefore, the food wastes generation from domestic
sources can be considered sufficient to meet the needs for FLFW
production to prepare external carbon source for enhancing ni-
trogen removal in domestic wastewater treatment.